Merge remote-tracking branch 'compton-update/master'

Conflicts:
	twin/compton-tde/common.h
	twin/compton-tde/compton.c
	twin/compton-tde/opengl.c

8 files changed, 935 insertions, 353 deletions

diff --git a/twin/compton-tde/c2.c b/twin/compton-tde/c2.c
index de221c01d..6baf1337e 100644
--- a/twin/compton-tde/c2.c
+++ b/twin/compton-tde/c2.c
@@ -764,6 +764,7 @@ c2_l_postprocess(session_t *ps, c2_l_t *pleaf) {
   if (pleaf->predef) {
     switch (pleaf->predef) {
       case C2_L_PFOCUSED: ps->o.track_focus = true; break;
+      // case C2_L_PROUNDED: ps->o.detect_rounded_corners = true; break;
       case C2_L_PNAME:
       case C2_L_PCLASSG:
       case C2_L_PCLASSI:
@@ -1057,6 +1058,8 @@ c2_match_once_leaf(session_t *ps, win *w, const c2_l_t *pleaf,
             case C2_L_PARGB:    tgt = (WMODE_ARGB == w->mode);  break;
             case C2_L_PFOCUSED: tgt = win_is_focused_real(ps, w); break;
             case C2_L_PWMWIN:   tgt = w->wmwin;                 break;
+            case C2_L_PBSHAPED: tgt = w->bounding_shaped;       break;
+            case C2_L_PROUNDED: tgt = w->rounded_corners;       break;
             case C2_L_PCLIENT:  tgt = w->client_win;            break;
             case C2_L_PLEADER:  tgt = w->leader;                break;
             default:            *perr = true; assert(0);        break;
@@ -1292,6 +1295,8 @@ c2_match_once(session_t *ps, win *w, const c2_ptr_t cond) {
 bool
 c2_matchd(session_t *ps, win *w, const c2_lptr_t *condlst,
     const c2_lptr_t **cache, void **pdata) {
+  assert(IsViewable == w->a.map_state);
+
   // Check if the cached entry matches firstly
   if (cache && *cache && c2_match_once(ps, w, (*cache)->ptr)) {
     if (pdata)
diff --git a/twin/compton-tde/c2.h b/twin/compton-tde/c2.h
index 129a5e739..9e04c09a8 100644
--- a/twin/compton-tde/c2.h
+++ b/twin/compton-tde/c2.h
@@ -113,6 +113,8 @@ struct _c2_l {
     C2_L_PARGB,
     C2_L_PFOCUSED,
     C2_L_PWMWIN,
+    C2_L_PBSHAPED,
+    C2_L_PROUNDED,
     C2_L_PCLIENT,
     C2_L_PWINDOWTYPE,
     C2_L_PLEADER,
@@ -201,6 +203,8 @@ const static c2_predef_t C2_PREDEFS[] = {
   [C2_L_PARGB       ] = { "argb"              , C2_L_TCARDINAL  , 0  },
   [C2_L_PFOCUSED    ] = { "focused"           , C2_L_TCARDINAL  , 0  },
   [C2_L_PWMWIN      ] = { "wmwin"             , C2_L_TCARDINAL  , 0  },
+  [C2_L_PBSHAPED    ] = { "bounding_shaped"   , C2_L_TCARDINAL  , 0  },
+  [C2_L_PROUNDED    ] = { "rounded_corners"   , C2_L_TCARDINAL  , 0  },
   [C2_L_PCLIENT     ] = { "client"            , C2_L_TWINDOW    , 0  },
   [C2_L_PWINDOWTYPE ] = { "window_type"       , C2_L_TSTRING    , 0  },
   [C2_L_PLEADER     ] = { "leader"            , C2_L_TWINDOW    , 0  },
diff --git a/twin/compton-tde/common.h b/twin/compton-tde/common.h
index fbdf49a89..4d9f41090 100644
--- a/twin/compton-tde/common.h
+++ b/twin/compton-tde/common.h
@@ -17,6 +17,7 @@
 // === Options ===
 
 // Debug options, enable them using -D in CFLAGS
+// #define DEBUG_BACKTRACE  1
 // #define DEBUG_REPAINT    1
 // #define DEBUG_EVENTS     1
 // #define DEBUG_RESTACK    1
@@ -83,6 +84,10 @@
 #define COMPTON_VERSION "unknown"
 #endif
 
+#if defined(DEBUG_ALLOC_REG)
+#define DEBUG_BACKTRACE 1
+#endif
+
 // === Includes ===
 
 // For some special functions
@@ -154,8 +159,6 @@
 #define GLX_BACK_BUFFER_AGE_EXT 0x20F4
 #endif
 
-#endif
-
 // === Macros ===
 
 #define MSTR_(s)        #s
@@ -195,6 +198,11 @@
 /// Macro used for shortening some debugging code.
 #define CASESTRRET(s)   case s: return #s
 
+// X resource checker
+#ifdef DEBUG_XRC
+#include "xrescheck.h"
+#endif
+
 // === Constants ===
 #if !(COMPOSITE_MAJOR > 0 || COMPOSITE_MINOR >= 2)
 #error libXcomposite version unsupported
@@ -222,7 +230,7 @@
 #define MS_PER_SEC 1000
 
 #define XRFILTER_CONVOLUTION  "convolution"
-#define XRFILTER_GUASSIAN     "gaussian"
+#define XRFILTER_GAUSSIAN     "gaussian"
 #define XRFILTER_BINOMIAL     "binomial"
 
 /// @brief Maximum OpenGL FBConfig depth.
@@ -454,7 +462,6 @@ struct _glx_texture {
   unsigned depth;
   bool y_inverted;
 };
-#endif
 
 #ifdef CONFIG_VSYNC_OPENGL_GLSL
 typedef struct {
@@ -480,6 +487,26 @@ typedef struct {
   /// Height of the textures.
   int height;
 } glx_blur_cache_t;
+
+typedef struct {
+  /// GLSL program.
+  GLuint prog;
+  /// Location of uniform "opacity" in window GLSL program.
+  GLint unifm_opacity;
+  /// Location of uniform "invert_color" in blur GLSL program.
+  GLint unifm_invert_color;
+  /// Location of uniform "tex" in window GLSL program.
+  GLint unifm_tex;
+} glx_prog_main_t;
+
+#define GLX_PROG_MAIN_INIT { \
+  .prog = 0, \
+  .unifm_opacity = -1, \
+  .unifm_invert_color = -1, \
+  .unifm_tex = -1, \
+}
+
+#endif
 #endif
 
 typedef struct {
@@ -547,10 +574,12 @@ typedef struct _options_t {
   int glx_swap_method;
   /// Whether to use GL_EXT_gpu_shader4 to (hopefully) accelerates blurring.
   bool glx_use_gpushader4;
-  /// Whether to try to detect WM windows and mark them as focused.
-  bool mark_wmwin_focused;
-  /// Whether to mark override-redirect windows as focused.
-  bool mark_ovredir_focused;
+  /// Custom fragment shader for painting windows, as a string.
+  char *glx_fshader_win_str;
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  /// Custom GLX program used for painting window.
+  glx_prog_main_t glx_prog_win;
+#endif
   /// Whether to fork to background.
   bool fork_after_register;
   /// Whether to detect rounded corners.
@@ -558,6 +587,8 @@ typedef struct _options_t {
   /// Whether to paint on X Composite overlay window instead of root
   /// window.
   bool paint_on_overlay;
+  /// Force painting of window content with blending.
+  bool force_win_blend;
   /// Resize damage for a specific number of pixels.
   int resize_damage;
   /// Whether to unredirect all windows if a full-screen opaque window
@@ -572,6 +603,10 @@ typedef struct _options_t {
   switch_t redirected_force;
   /// Whether to stop painting. Controlled through D-Bus.
   switch_t stoppaint_force;
+  /// Whether to re-redirect screen on root size change.
+  bool reredir_on_root_change;
+  /// Whether to reinitialize GLX on root size change.
+  bool glx_reinit_on_root_change;
   /// Whether to enable D-Bus support.
   bool dbus;
   /// Path to log file.
@@ -582,8 +617,14 @@ typedef struct _options_t {
   Window benchmark_wid;
   /// A list of conditions of windows not to paint.
   c2_lptr_t *paint_blacklist;
+  /// Whether to avoid using XCompositeNameWindowPixmap(), for debugging.
+  bool no_name_pixmap;
   /// Whether to work under synchronized mode for debugging.
   bool synchronize;
+  /// Whether to show all X errors.
+  bool show_all_xerrors;
+  /// Whether to avoid acquiring X Selection.
+  bool no_x_selection;
 
   // === VSync & software optimization ===
   /// User-specified refresh rate.
@@ -631,6 +672,8 @@ typedef struct _options_t {
   time_ms_t fade_delta;
   /// Whether to disable fading on window open/close.
   bool no_fading_openclose;
+  /// Whether to disable fading on ARGB managed destroyed windows.
+  bool no_fading_destroyed_argb;
   /// Whether to disable fading on opacity change
   bool no_fading_opacitychange;
   /// Fading blacklist. A linked list of conditions.
@@ -683,6 +726,10 @@ typedef struct _options_t {
   // === Focus related ===
   /// Consider windows of specific types to be always focused.
   bool wintype_focus[NUM_WINTYPES];
+  /// Whether to try to detect WM windows and mark them as focused.
+  bool mark_wmwin_focused;
+  /// Whether to mark override-redirect windows as focused.
+  bool mark_ovredir_focused;
   /// Whether to use EWMH _NET_ACTIVE_WINDOW to find active window.
   bool use_ewmh_active_win;
   /// A list of windows always to be considered focused.
@@ -701,6 +748,65 @@ typedef struct _options_t {
   bool track_leader;
 } options_t;
 
+#ifdef CONFIG_VSYNC_OPENGL
+/// Structure containing GLX-dependent data for a compton session.
+typedef struct {
+  // === OpenGL related ===
+  /// GLX context.
+  GLXContext context;
+  /// Whether we have GL_ARB_texture_non_power_of_two.
+  bool has_texture_non_power_of_two;
+  /// Pointer to glXGetVideoSyncSGI function.
+  f_GetVideoSync glXGetVideoSyncSGI;
+  /// Pointer to glXWaitVideoSyncSGI function.
+  f_WaitVideoSync glXWaitVideoSyncSGI;
+   /// Pointer to glXGetSyncValuesOML function.
+  f_GetSyncValuesOML glXGetSyncValuesOML;
+  /// Pointer to glXWaitForMscOML function.
+  f_WaitForMscOML glXWaitForMscOML;
+  /// Pointer to glXSwapIntervalSGI function.
+  f_SwapIntervalSGI glXSwapIntervalProc;
+  /// Pointer to glXSwapIntervalMESA function.
+  f_SwapIntervalMESA glXSwapIntervalMESAProc;
+  /// Pointer to glXBindTexImageEXT function.
+  f_BindTexImageEXT glXBindTexImageProc;
+  /// Pointer to glXReleaseTexImageEXT function.
+  f_ReleaseTexImageEXT glXReleaseTexImageProc;
+  /// Pointer to glXCopySubBufferMESA function.
+  f_CopySubBuffer glXCopySubBufferProc;
+#ifdef CONFIG_GLX_SYNC
+  /// Pointer to the glFenceSync() function.
+  f_FenceSync glFenceSyncProc;
+  /// Pointer to the glIsSync() function.
+  f_IsSync glIsSyncProc;
+  /// Pointer to the glDeleteSync() function.
+  f_DeleteSync glDeleteSyncProc;
+  /// Pointer to the glClientWaitSync() function.
+  f_ClientWaitSync glClientWaitSyncProc;
+  /// Pointer to the glWaitSync() function.
+  f_WaitSync glWaitSyncProc;
+  /// Pointer to the glImportSyncEXT() function.
+  f_ImportSyncEXT glImportSyncEXT;
+#endif
+#ifdef DEBUG_GLX_MARK
+  /// Pointer to StringMarkerGREMEDY function.
+  f_StringMarkerGREMEDY glStringMarkerGREMEDY;
+  /// Pointer to FrameTerminatorGREMEDY function.
+  f_FrameTerminatorGREMEDY glFrameTerminatorGREMEDY;
+#endif
+  /// Current GLX Z value.
+  int z;
+  /// FBConfig-s for GLX pixmap of different depths.
+  glx_fbconfig_t *fbconfigs[OPENGL_MAX_DEPTH + 1];
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  glx_blur_pass_t blur_passes[MAX_BLUR_PASS];
+#endif
+} glx_session_t;
+
+#define CGLX_SESSION_INIT { .context = NULL }
+
+#endif
+
 /// Structure containing all necessary data for a compton session.
 typedef struct _session_t {
   // === Display related ===
@@ -742,6 +848,10 @@ typedef struct _session_t {
   XdbeBackBuffer root_dbe;
   /// Window ID of the window we register as a symbol.
   Window reg_win;
+#ifdef CONFIG_VSYNC_OPENGL
+  /// Pointer to GLX data.
+  glx_session_t *psglx;
+#endif
 
   // === Operation related ===
   /// Program options.
@@ -784,10 +894,6 @@ typedef struct _session_t {
   /// Pointer to the <code>next</code> member of tail element of the error
   /// ignore linked list.
   ignore_t **ignore_tail;
-#ifdef CONFIG_VSYNC_OPENGL
-  /// Current GLX Z value.
-  int glx_z;
-#endif
   // Cached blur convolution kernels.
   XFixed *blur_kerns_cache[MAX_BLUR_PASS];
   /// Reset program after next paint.
@@ -847,57 +953,6 @@ typedef struct _session_t {
   int drm_fd;
 #endif
 
-#ifdef CONFIG_VSYNC_OPENGL
-  // === OpenGL related ===
-  /// GLX context.
-  GLXContext glx_context;
-  /// Whether we have GL_ARB_texture_non_power_of_two.
-  bool glx_has_texture_non_power_of_two;
-  /// Pointer to glXGetVideoSyncSGI function.
-  f_GetVideoSync glXGetVideoSyncSGI;
-  /// Pointer to glXWaitVideoSyncSGI function.
-  f_WaitVideoSync glXWaitVideoSyncSGI;
-   /// Pointer to glXGetSyncValuesOML function.
-  f_GetSyncValuesOML glXGetSyncValuesOML;
-  /// Pointer to glXWaitForMscOML function.
-  f_WaitForMscOML glXWaitForMscOML;
-  /// Pointer to glXSwapIntervalSGI function.
-  f_SwapIntervalSGI glXSwapIntervalProc;
-  /// Pointer to glXSwapIntervalMESA function.
-  f_SwapIntervalMESA glXSwapIntervalMESAProc;
-  /// Pointer to glXBindTexImageEXT function.
-  f_BindTexImageEXT glXBindTexImageProc;
-  /// Pointer to glXReleaseTexImageEXT function.
-  f_ReleaseTexImageEXT glXReleaseTexImageProc;
-  /// Pointer to glXCopySubBufferMESA function.
-  f_CopySubBuffer glXCopySubBufferProc;
-#ifdef CONFIG_GLX_SYNC
-  /// Pointer to the glFenceSync() function.
-  f_FenceSync glFenceSyncProc;
-  /// Pointer to the glIsSync() function.
-  f_IsSync glIsSyncProc;
-  /// Pointer to the glDeleteSync() function.
-  f_DeleteSync glDeleteSyncProc;
-  /// Pointer to the glClientWaitSync() function.
-  f_ClientWaitSync glClientWaitSyncProc;
-  /// Pointer to the glWaitSync() function.
-  f_WaitSync glWaitSyncProc;
-  /// Pointer to the glImportSyncEXT() function.
-  f_ImportSyncEXT glImportSyncEXT;
-#endif
-#ifdef DEBUG_GLX_MARK
-  /// Pointer to StringMarkerGREMEDY function.
-  f_StringMarkerGREMEDY glStringMarkerGREMEDY;
-  /// Pointer to FrameTerminatorGREMEDY function.
-  f_FrameTerminatorGREMEDY glFrameTerminatorGREMEDY;
-#endif
-  /// FBConfig-s for GLX pixmap of different depths.
-  glx_fbconfig_t *glx_fbconfigs[OPENGL_MAX_DEPTH + 1];
-#ifdef CONFIG_VSYNC_OPENGL_GLSL
-  glx_blur_pass_t glx_blur_passes[MAX_BLUR_PASS];
-#endif
-#endif
-
   // === X extension related ===
   /// Event base number for X Fixes extension.
   int xfixes_event;
@@ -1130,6 +1185,8 @@ typedef struct _win {
   /// Do not fade if it's false. Change on window type change.
   /// Used by fading blacklist in the future.
   bool fade;
+  /// Fade state on last paint.
+  bool fade_last;
   /// Override value of window fade state. Set by D-Bus method calls.
   switch_t fade_force;
   /// Callback to be called after fading completed.
@@ -1144,6 +1201,8 @@ typedef struct _win {
   // Shadow-related members
   /// Whether a window has shadow. Calculated.
   bool shadow;
+  /// Shadow state on last paint.
+  bool shadow_last;
   /// Override value of window shadow state. Set by D-Bus method calls.
   switch_t shadow_force;
   /// Opacity of the shadow. Affected by window opacity and frame opacity.
@@ -1170,12 +1229,16 @@ typedef struct _win {
 
   /// Whether to invert window color.
   bool invert_color;
+  /// Color inversion state on last paint.
+  bool invert_color_last;
   /// Override value of window color inversion state. Set by D-Bus method
   /// calls.
   switch_t invert_color_force;
 
   /// Whether to blur window background.
   bool blur_background;
+  /// Background state on last paint.
+  bool blur_background_last;
 
   /// Whether to show black background
   bool show_black_background;
@@ -1224,13 +1287,13 @@ extern session_t *ps_g;
 static inline void
 print_timestamp(session_t *ps);
 
-#ifdef DEBUG_ALLOC_REG
+#ifdef DEBUG_BACKTRACE
 
 #include <execinfo.h>
-#define BACKTRACE_SIZE  5
+#define BACKTRACE_SIZE  25
 
 /**
- * Print current backtrace, excluding the first two items.
+ * Print current backtrace.
  *
  * Stolen from glibc manual.
  */
@@ -1243,12 +1306,14 @@ print_backtrace(void) {
   size = backtrace(array, BACKTRACE_SIZE);
   strings = backtrace_symbols(array, size);
 
-  for (size_t i = 2; i < size; i++)
+  for (size_t i = 0; i < size; i++)
      printf ("%s\n", strings[i]);
 
   free(strings);
 }
 
+#ifdef DEBUG_ALLOC_REG
+
 /**
  * Wrapper of <code>XFixesCreateRegion</code>, for debugging.
  */
@@ -1279,6 +1344,8 @@ XFixesDestroyRegion_(Display *dpy, XserverRegion reg,
 #define XFixesDestroyRegion(dpy, reg) XFixesDestroyRegion_(dpy, reg, __func__, __LINE__)
 #endif
 
+#endif
+
 // === Functions ===
 
 /**
@@ -1874,6 +1941,18 @@ bkend_use_glx(session_t *ps) {
 }
 
 /**
+ * Check if there's a GLX context.
+ */
+static inline bool
+glx_has_context(session_t *ps) {
+#ifdef CONFIG_VSYNC_OPENGL
+  return ps->psglx && ps->psglx->context;
+#else
+  return false;
+#endif
+}
+
+/**
  * Check if a window is really focused.
  */
 static inline bool
@@ -1975,7 +2054,15 @@ rect_is_fullscreen(session_t *ps, int x, int y, unsigned wid, unsigned hei) {
 static inline bool
 win_is_fullscreen(session_t *ps, const win *w) {
   return rect_is_fullscreen(ps, w->a.x, w->a.y, w->widthb, w->heightb)
-      && !w->bounding_shaped;
+      && (!w->bounding_shaped || w->rounded_corners);
+}
+
+/**
+ * Check if a window will be painted solid.
+ */
+static inline bool
+win_is_solid(session_t *ps, const win *w) {
+  return WMODE_SOLID == w->mode && !ps->o.force_win_blend;
 }
 
 /**
@@ -2080,12 +2167,22 @@ glx_init(session_t *ps, bool need_render);
 void
 glx_destroy(session_t *ps);
 
+bool
+glx_reinit(session_t *ps, bool need_render);
+
 void
 glx_on_root_change(session_t *ps);
 
 bool
 glx_init_blur(session_t *ps);
 
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+bool
+glx_load_prog_main(session_t *ps,
+    const char *vshader_str, const char *fshader_str,
+    glx_prog_main_t *pprogram);
+#endif
+
 bool
 glx_bind_pixmap(session_t *ps, glx_texture_t **pptex, Pixmap pixmap,
     unsigned width, unsigned height, unsigned depth);
@@ -2121,10 +2218,24 @@ glx_dim_dst(session_t *ps, int dx, int dy, int width, int height, float z,
     GLfloat factor, XserverRegion reg_tgt, const reg_data_t *pcache_reg);
 
 bool
-glx_render(session_t *ps, const glx_texture_t *ptex,
+glx_render_(session_t *ps, const glx_texture_t *ptex,
     int x, int y, int dx, int dy, int width, int height, int z,
-    double opacity, bool neg,
-    XserverRegion reg_tgt, const reg_data_t *pcache_reg);
+    double opacity, bool argb, bool neg,
+    XserverRegion reg_tgt, const reg_data_t *pcache_reg
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    , const glx_prog_main_t *pprogram
+#endif
+    );
+
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+#define \
+   glx_render(ps, ptex, x, y, dx, dy, width, height, z, opacity, argb, neg, reg_tgt, pcache_reg, pprogram) \
+  glx_render_(ps, ptex, x, y, dx, dy, width, height, z, opacity, argb, neg, reg_tgt, pcache_reg, pprogram)
+#else
+#define \
+   glx_render(ps, ptex, x, y, dx, dy, width, height, z, opacity, argb, neg, reg_tgt, pcache_reg, pprogram) \
+  glx_render_(ps, ptex, x, y, dx, dy, width, height, z, opacity, argb, neg, reg_tgt, pcache_reg)
+#endif
 
 bool
 glx_render_specified_color(session_t *ps, int color, int dx, int dy, int width, int height, int z,
@@ -2133,12 +2244,19 @@ glx_render_specified_color(session_t *ps, int color, int dx, int dy, int width,
 void
 glx_swap_copysubbuffermesa(session_t *ps, XserverRegion reg);
 
+unsigned char *
+glx_take_screenshot(session_t *ps, int *out_length);
+
 #ifdef CONFIG_VSYNC_OPENGL_GLSL
 GLuint
 glx_create_shader(GLenum shader_type, const char *shader_str);
 
 GLuint
 glx_create_program(const GLuint * const shaders, int nshaders);
+
+GLuint
+glx_create_program_from_str(const char *vert_shader_str,
+    const char *frag_shader_str);
 #endif
 
 /**
@@ -2147,7 +2265,7 @@ glx_create_program(const GLuint * const shaders, int nshaders);
 static inline void
 free_texture_r(session_t *ps, GLuint *ptexture) {
   if (*ptexture) {
-    assert(ps->glx_context);
+    assert(glx_has_context(ps));
     glDeleteTextures(1, ptexture);
     *ptexture = 0;
   }
@@ -2214,19 +2332,39 @@ free_texture(session_t *ps, glx_texture_t **pptex) {
 }
 
 /**
+ * Free GLX part of paint_t.
+ */
+static inline void
+free_paint_glx(session_t *ps, paint_t *ppaint) {
+  free_texture(ps, &ppaint->ptex);
+}
+
+/**
+ * Free GLX part of win.
+ */
+static inline void
+free_win_res_glx(session_t *ps, win *w) {
+  free_paint_glx(ps, &w->paint);
+  free_paint_glx(ps, &w->shadow_paint);
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  free_glx_bc(ps, &w->glx_blur_cache);
+#endif
+}
+
+/**
  * Add a OpenGL debugging marker.
  */
 static inline void
 glx_mark_(session_t *ps, const char *func, XID xid, bool start) {
 #ifdef DEBUG_GLX_MARK
-  if (bkend_use_glx(ps) && ps->glStringMarkerGREMEDY) {
+  if (glx_has_context(ps) && ps->psglx->glStringMarkerGREMEDY) {
     if (!func) func = "(unknown)";
     const char *postfix = (start ? " (start)": " (end)");
     char *str = malloc((strlen(func) + 12 + 2
           + strlen(postfix) + 5) * sizeof(char));
     strcpy(str, func);
     sprintf(str + strlen(str), "(%#010lx)%s", xid, postfix);
-    ps->glStringMarkerGREMEDY(strlen(str), str);
+    ps->psglx->glStringMarkerGREMEDY(strlen(str), str);
     free(str);
   }
 #endif
@@ -2240,8 +2378,8 @@ glx_mark_(session_t *ps, const char *func, XID xid, bool start) {
 static inline void
 glx_mark_frame(session_t *ps) {
 #ifdef DEBUG_GLX_MARK
-  if (bkend_use_glx(ps) && ps->glFrameTerminatorGREMEDY)
-    ps->glFrameTerminatorGREMEDY();
+  if (glx_has_context(ps) && ps->psglx->glFrameTerminatorGREMEDY)
+    ps->psglx->glFrameTerminatorGREMEDY();
 #endif
 }
 
@@ -2389,6 +2527,28 @@ c2_matchd(session_t *ps, win *w, const c2_lptr_t *condlst,
 #endif
 
 /**
+ * @brief Dump the given data to a file.
+ */
+static inline bool
+write_binary_data(const char *path, const unsigned char *data, int length) {
+  if (!data)
+    return false;
+  FILE *f = fopen(path, "wb");
+  if (!f) {
+    printf_errf("(\"%s\"): Failed to open file for writing.", path);
+    return false;
+  }
+  int wrote_len = fwrite(data, sizeof(unsigned char), length, f);
+  fclose(f);
+  if (wrote_len != length) {
+    printf_errf("(\"%s\"): Failed to write all blocks: %d / %d", path,
+        wrote_len, length);
+    return false;
+  }
+  return true;
+}
+
+/**
  * @brief Dump raw bytes in HEX format.
  *
  * @param data pointer to raw data
@@ -2423,3 +2583,4 @@ hexdump(const char *data, int len) {
   fflush(stdout);
 }
 
+#endif
diff --git a/twin/compton-tde/compton.c b/twin/compton-tde/compton.c
index 2c467e2c4..f49518b7b 100644
--- a/twin/compton-tde/compton.c
+++ b/twin/compton-tde/compton.c
@@ -621,20 +621,20 @@ win_build_shadow(session_t *ps, win *w, double opacity) {
       shadow_picture_argb, 0, 0, 0, 0, 0, 0,
       shadow_image->width, shadow_image->height);
 
+  assert(!w->shadow_paint.pixmap);
   w->shadow_paint.pixmap = shadow_pixmap_argb;
+  assert(!w->shadow_paint.pict);
   w->shadow_paint.pict = shadow_picture_argb;
 
   // Sync it once and only once
   xr_sync(ps, w->shadow_paint.pixmap, NULL);
 
-  bool success = paint_bind_tex(ps, &w->shadow_paint, shadow_image->width, shadow_image->height, 32, true);
-
   XFreeGC(ps->dpy, gc);
   XDestroyImage(shadow_image);
   XFreePixmap(ps->dpy, shadow_pixmap);
   XRenderFreePicture(ps->dpy, shadow_picture);
 
-  return success;
+  return true;
 
 shadow_picture_err:
   if (shadow_image)
@@ -711,6 +711,9 @@ discard_ignore(session_t *ps, unsigned long sequence) {
 
 static void
 set_ignore(session_t *ps, unsigned long sequence) {
+  if (ps->o.show_all_xerrors)
+    return;
+
   ignore_t *i = malloc(sizeof(ignore_t));
   if (!i) return;
 
@@ -779,6 +782,8 @@ wid_get_prop_adv(const session_t *ps, Window w, Atom atom, long offset,
  */
 static void
 win_rounded_corners(session_t *ps, win *w) {
+  w->rounded_corners = false;
+
   if (!w->bounding_shaped)
     return;
 
@@ -808,11 +813,9 @@ win_rounded_corners(session_t *ps, win *w) {
   for (i = 0; i < nrects; ++i)
     if (rects[i].width >= minwidth && rects[i].height >= minheight) {
       w->rounded_corners = true;
-      cxfree(rects);
-      return;
+      break;
     }
 
-  w->rounded_corners = false;
   cxfree(rects);
 }
 
@@ -1257,6 +1260,14 @@ paint_preprocess(session_t *ps, win *list) {
         free_region(ps, &w->reg_ignore);
     }
 
+    // Restore flags from last paint if the window is being faded out
+    if (IsUnmapped == w->a.map_state) {
+      win_set_shadow(ps, w, w->shadow_last);
+      w->fade = w->fade_last;
+      win_set_invert_color(ps, w, w->invert_color_last);
+      win_set_blur_background(ps, w, w->blur_background_last);
+    }
+
     // Update window opacity target and dim state if asked
     if (WFLAG_OPCT_CHANGE & w->flags) {
       calc_opacity(ps, w);
@@ -1336,7 +1347,7 @@ paint_preprocess(session_t *ps, win *list) {
 
         // If the window is solid, we add the window region to the
         // ignored region
-        if (WMODE_SOLID == w->mode) {
+        if (win_is_solid(ps, w)) {
           if (!w->frame_opacity) {
             if (w->border_size)
               w->reg_ignore = copy_region(ps, w->border_size);
@@ -1370,7 +1381,7 @@ paint_preprocess(session_t *ps, win *list) {
       // is not correctly set.
       if (ps->o.unredir_if_possible && is_highest && to_paint) {
         is_highest = false;
-        if (WMODE_SOLID == w->mode
+        if (win_is_solid(ps, w)
             && (!w->frame_opacity || !win_has_frame(w))
             && win_is_fullscreen(ps, w)
             && !w->unredir_if_possible_excluded)
@@ -1393,8 +1404,17 @@ paint_preprocess(session_t *ps, win *list) {
       check_fade_fin(ps, w);
     }
 
-    if (!destroyed)
+    if (!destroyed) {
       w->to_paint = to_paint;
+
+      if (w->to_paint) {
+        // Save flags
+        w->shadow_last = w->shadow;
+        w->fade_last = w->fade;
+        w->invert_color_last = w->invert_color;
+        w->blur_background_last = w->blur_background;
+      }
+    }
   }
 
 
@@ -1430,6 +1450,9 @@ paint_preprocess(session_t *ps, win *list) {
 static inline void
 win_paint_shadow(session_t *ps, win *w,
     XserverRegion reg_paint, const reg_data_t *pcache_reg) {
+  // Bind shadow pixmap to GLX texture if needed
+  paint_bind_tex(ps, &w->shadow_paint, 0, 0, 32, false);
+
   if (!paint_isvalid(ps, &w->shadow_paint)) {
     printf_errf("(%#010lx): Missing painting data. This is a bad sign.", w->id);
     return;
@@ -1437,7 +1460,7 @@ win_paint_shadow(session_t *ps, win *w,
 
   render(ps, 0, 0, w->a.x + w->shadow_dx, w->a.y + w->shadow_dy,
       w->shadow_width, w->shadow_height, w->shadow_opacity, true, false,
-      w->shadow_paint.pict, w->shadow_paint.ptex, reg_paint, pcache_reg);
+      w->shadow_paint.pict, w->shadow_paint.ptex, reg_paint, pcache_reg, NULL);
 }
 
 /**
@@ -1529,6 +1552,20 @@ xr_blur_dst(session_t *ps, Picture tgt_buffer,
   return true;
 }
 
+/*
+ * WORK-IN-PROGRESS!
+static void
+xr_take_screenshot(session_t *ps) {
+  XImage *img = XGetImage(ps->dpy, get_tgt_window(ps), 0, 0,
+      ps->root_width, ps->root_height, AllPlanes, XYPixmap);
+  if (!img) {
+    printf_errf("(): Failed to get XImage.");
+    return NULL;
+  }
+  assert(0 == img->xoffset);
+}
+*/
+
 /**
  * Blur the background of a window.
  */
@@ -1593,7 +1630,7 @@ win_blur_background(session_t *ps, win *w, Picture tgt_buffer,
         // Minimize the region we try to blur, if the window itself is not
         // opaque, only the frame is.
         XserverRegion reg_noframe = None;
-        if (WMODE_SOLID == w->mode) {
+        if (win_is_solid(ps, w)) {
           XserverRegion reg_all = border_size(ps, w, false);
           reg_noframe = win_get_region_noframe(ps, w, false);
           XFixesSubtractRegion(ps->dpy, reg_noframe, reg_all, reg_noframe);
@@ -1607,7 +1644,7 @@ win_blur_background(session_t *ps, win *w, Picture tgt_buffer,
 #ifdef CONFIG_VSYNC_OPENGL_GLSL
     case BKEND_GLX:
       // TODO: Handle frame opacity
-      glx_blur_dst(ps, x, y, wid, hei, ps->glx_z - 0.5, factor_center,
+      glx_blur_dst(ps, x, y, wid, hei, ps->psglx->z - 0.5, factor_center,
           reg_paint, pcache_reg, &w->glx_blur_cache);
       break;
 #endif
@@ -1617,10 +1654,14 @@ win_blur_background(session_t *ps, win *w, Picture tgt_buffer,
 }
 
 static void
-render(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
+render_(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
     double opacity, bool argb, bool neg,
     Picture pict, glx_texture_t *ptex,
-    XserverRegion reg_paint, const reg_data_t *pcache_reg) {
+    XserverRegion reg_paint, const reg_data_t *pcache_reg
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    , const glx_prog_main_t *pprogram
+#endif
+    ) {
   switch (ps->o.backend) {
     case BKEND_XRENDER:
     case BKEND_XR_GLX_HYBRID:
@@ -1636,8 +1677,8 @@ render(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
 #ifdef CONFIG_VSYNC_OPENGL
     case BKEND_GLX:
       glx_render(ps, ptex, x, y, dx, dy, wid, hei,
-          ps->glx_z, opacity, neg, reg_paint, pcache_reg);
-      ps->glx_z += 1;
+          ps->psglx->z, opacity, argb, neg, reg_paint, pcache_reg, pprogram);
+      ps->psglx->z += 1;
       break;
 #endif
     default:
@@ -1818,7 +1859,7 @@ win_paint_win(session_t *ps, win *w, XserverRegion reg_paint,
         break;
 #ifdef CONFIG_VSYNC_OPENGL
       case BKEND_GLX:
-        glx_dim_dst(ps, x, y, wid, hei, ps->glx_z - 0.7, dim_opacity,
+        glx_dim_dst(ps, x, y, wid, hei, ps->psglx->z - 0.7, dim_opacity,
             reg_paint, pcache_reg);
         break;
 #endif
@@ -1942,7 +1983,7 @@ paint_all(session_t *ps, XserverRegion region, XserverRegion region_real, win *t
     // Painting shadow
     if (w->shadow) {
       // Lazy shadow building
-      if (!paint_isvalid(ps, &w->shadow_paint))
+      if (!w->shadow_paint.pixmap)
         win_build_shadow(ps, w, 1);
 
       // Shadow is to be painted based on the ignore region of current
@@ -2071,7 +2112,7 @@ paint_all(session_t *ps, XserverRegion region, XserverRegion region_real, win *t
         }
 
         // Blur window background
-        if (w->blur_background && (WMODE_SOLID != w->mode
+        if (w->blur_background && (!win_is_solid(ps, w)
               || (ps->o.blur_background_frame && w->frame_opacity))) {
           win_blur_background(ps, w, ps->tgt_buffer.pict, reg_paint, &cache_reg);
         }
@@ -2096,7 +2137,7 @@ paint_all(session_t *ps, XserverRegion region, XserverRegion region_real, win *t
     // effect
     XSync(ps->dpy, False);
 #ifdef CONFIG_VSYNC_OPENGL
-    if (ps->glx_context) {
+    if (glx_has_context(ps)) {
       if (ps->o.vsync_use_glfinish)
         glFinish();
       else
@@ -2152,7 +2193,8 @@ paint_all(session_t *ps, XserverRegion region, XserverRegion region_real, win *t
         glFlush();
       glXWaitX();
       glx_render(ps, ps->tgt_buffer.ptex, 0, 0, 0, 0,
-          ps->root_width, ps->root_height, 0, 1.0, false, region_real, NULL);
+          ps->root_width, ps->root_height, 0, 1.0, false, false,
+          region_real, NULL, NULL);
       // No break here!
     case BKEND_GLX:
       if (ps->o.glx_use_copysubbuffermesa)
@@ -2172,7 +2214,7 @@ paint_all(session_t *ps, XserverRegion region, XserverRegion region_real, win *t
   XFlush(ps->dpy);
 
 #ifdef CONFIG_VSYNC_OPENGL
-  if (ps->glx_context) {
+  if (glx_has_context(ps)) {
     glFlush();
     glXWaitX();
   }
@@ -2678,9 +2720,21 @@ static void
 win_determine_fade(session_t *ps, win *w) {
   if (UNSET != w->fade_force)
     w->fade = w->fade_force;
-  else if ((ps->o.no_fading_openclose && w->in_openclose)
-      || win_match(ps, w, ps->o.fade_blacklist, &w->cache_fblst)
-      || (ps->o.no_fading_opacitychange && (!w->in_openclose)))
+  else if (ps->o.no_fading_opacitychange && (!w->in_openclose))
+    w->fade = false;
+  else if (ps->o.no_fading_openclose && w->in_openclose)
+    w->fade = false;
+  else if (ps->o.no_fading_destroyed_argb && w->destroyed
+      && WMODE_ARGB == w->mode && w->client_win && w->client_win != w->id) {
+    w->fade = false;
+    // Prevent it from being overwritten by last-paint value
+    w->fade_last = false;
+  }
+  // Ignore other possible causes of fading state changes after window
+  // gets unmapped
+  else if (IsViewable != w->a.map_state) {
+  }
+  else if (win_match(ps, w, ps->o.fade_blacklist, &w->cache_fblst))
     w->fade = false;
   else
     w->fade = ps->o.wintype_fade[w->window_type];
@@ -2708,8 +2762,7 @@ win_update_shape(session_t *ps, win *w) {
 
     win_update_shape_raw(ps, w);
 
-    // Shadow state could be changed
-    win_determine_shadow(ps, w);
+    win_on_factor_change(ps, w);
 
     /*
     // If clear_shadow state on the window possibly changed, destroy the old
@@ -2754,38 +2807,55 @@ win_update_prop_shadow(session_t *ps, win *w) {
     win_determine_shadow(ps, w);
 }
 
+static void
+win_set_shadow(session_t *ps, win *w, bool shadow_new) {
+  if (w->shadow == shadow_new) return;
+
+  w->shadow = shadow_new;
+
+  // Window extents need update on shadow state change
+  // Shadow geometry currently doesn't change on shadow state change
+  // calc_shadow_geometry(ps, w);
+  if (w->extents) {
+    // Mark the old extents as damaged if the shadow is removed
+    if (!w->shadow)
+      add_damage(ps, w->extents);
+    else
+      free_region(ps, &w->extents);
+    w->extents = win_extents(ps, w);
+    // Mark the new extents as damaged if the shadow is added
+    if (w->shadow)
+      add_damage_win(ps, w);
+  }
+}
+
 /**
  * Determine if a window should have shadow, and update things depending
  * on shadow state.
  */
 static void
 win_determine_shadow(session_t *ps, win *w) {
-  bool shadow_old = w->shadow;
+  bool shadow_new = w->shadow;
 
-  w->shadow = (UNSET == w->shadow_force ?
-      (ps->o.wintype_shadow[w->window_type]
-       && !win_match(ps, w, ps->o.shadow_blacklist, &w->cache_sblst)
-       && !(ps->o.shadow_ignore_shaped && w->bounding_shaped
-         && !w->rounded_corners)
-       && !(ps->o.respect_prop_shadow && 0 == w->prop_shadow))
-       : w->shadow_force);
+  if (UNSET != w->shadow_force)
+    shadow_new = w->shadow_force;
+  else if (IsViewable == w->a.map_state)
+    shadow_new = (ps->o.wintype_shadow[w->window_type]
+        && !win_match(ps, w, ps->o.shadow_blacklist, &w->cache_sblst)
+        && !(ps->o.shadow_ignore_shaped && w->bounding_shaped
+          && !w->rounded_corners)
+        && !(ps->o.respect_prop_shadow && 0 == w->prop_shadow));
 
-  // Window extents need update on shadow state change
-  if (w->shadow != shadow_old) {
-    // Shadow geometry currently doesn't change on shadow state change
-    // calc_shadow_geometry(ps, w);
-    if (w->extents) {
-      // Mark the old extents as damaged if the shadow is removed
-      if (!w->shadow)
-        add_damage(ps, w->extents);
-      else
-        free_region(ps, &w->extents);
-      w->extents = win_extents(ps, w);
-      // Mark the new extents as damaged if the shadow is added
-      if (w->shadow)
-        add_damage_win(ps, w);
-    }
-  }
+  win_set_shadow(ps, w, shadow_new);
+}
+
+static void
+win_set_invert_color(session_t *ps, win *w, bool invert_color_new) {
+  if (w->invert_color == invert_color_new) return;
+
+  w->invert_color = invert_color_new;
+
+  add_damage_win(ps, w);
 }
 
 /**
@@ -2793,19 +2863,27 @@ win_determine_shadow(session_t *ps, win *w) {
  */
 static void
 win_determine_invert_color(session_t *ps, win *w) {
-  // Do not change window invert color state when the window is unmapped,
-  // unless it comes from w->invert_color_force.
-  if (UNSET == w->invert_color_force && IsViewable != w->a.map_state)
-    return;
-
-  bool invert_color_old = w->invert_color;
+  bool invert_color_new = w->invert_color;
 
   if (UNSET != w->invert_color_force)
-    w->invert_color = w->invert_color_force;
-  else
-    w->invert_color = win_match(ps, w, ps->o.invert_color_list, &w->cache_ivclst);
+    invert_color_new = w->invert_color_force;
+  else if (IsViewable == w->a.map_state)
+    invert_color_new = win_match(ps, w, ps->o.invert_color_list,
+        &w->cache_ivclst);
+
+  win_set_invert_color(ps, w, invert_color_new);
+}
 
-  if (w->invert_color != invert_color_old)
+static void
+win_set_blur_background(session_t *ps, win *w, bool blur_background_new) {
+  if (w->blur_background == blur_background_new) return;
+
+  w->blur_background = blur_background_new;
+
+  // Only consider window damaged if it's previously painted with background
+  // blurred
+  if (!win_is_solid(ps, w)
+        || (ps->o.blur_background_frame && w->frame_opacity))
     add_damage_win(ps, w);
 }
 
@@ -2814,16 +2892,13 @@ win_determine_invert_color(session_t *ps, win *w) {
  */
 static void
 win_determine_blur_background(session_t *ps, win *w) {
-  bool blur_background_old = w->blur_background;
+  if (IsViewable != w->a.map_state)
+    return;
 
-  w->blur_background = ps->o.blur_background
+  bool blur_background_new = ps->o.blur_background
     && !win_match(ps, w, ps->o.blur_background_blacklist, &w->cache_bbblst);
 
-  // Only consider window damaged if it's previously painted with background
-  // blurred
-  if (w->blur_background != blur_background_old && (WMODE_SOLID != w->mode
-        || (ps->o.blur_background_frame && w->frame_opacity)))
-    add_damage_win(ps, w);
+  win_set_blur_background(ps, w, blur_background_new);
 }
 
 /**
@@ -2831,6 +2906,10 @@ win_determine_blur_background(session_t *ps, win *w) {
  */
 static void
 win_update_opacity_rule(session_t *ps, win *w) {
+  if (IsViewable != w->a.map_state)
+    return;
+
+#ifdef CONFIG_C2
   // If long is 32-bit, unfortunately there's no way could we express "unset",
   // so we just entirely don't distinguish "unset" and OPAQUE
   opacity_t opacity = OPAQUE;
@@ -2846,6 +2925,7 @@ win_update_opacity_rule(session_t *ps, win *w) {
   else if (OPAQUE != w->opacity_set)
     wid_rm_opacity_prop(ps, w->id);
   w->opacity_set = opacity;
+#endif
 }
 
 /**
@@ -2879,10 +2959,10 @@ win_on_factor_change(session_t *ps, win *w) {
     win_determine_blur_background(ps, w);
   if (ps->o.opacity_rules)
     win_update_opacity_rule(ps, w);
-  if (ps->o.paint_blacklist)
+  if (IsViewable == w->a.map_state && ps->o.paint_blacklist)
     w->paint_excluded = win_match(ps, w, ps->o.paint_blacklist,
         &w->cache_pblst);
-  if (ps->o.unredir_if_possible_blacklist)
+  if (IsViewable == w->a.map_state && ps->o.unredir_if_possible_blacklist)
     w->unredir_if_possible_excluded = win_match(ps, w,
         ps->o.unredir_if_possible_blacklist, &w->cache_uipblst);
 }
@@ -3299,6 +3379,9 @@ restack_win(session_t *ps, win *w, Window new_above) {
   }
 }
 
+static bool
+init_filters(session_t *ps);
+
 static void
 configure_win(session_t *ps, XConfigureEvent *ce) {
   // On root window changes
@@ -3312,11 +3395,28 @@ configure_win(session_t *ps, XConfigureEvent *ce) {
     rebuild_shadow_exclude_reg(ps);
     free_all_damage_last(ps);
 
+    // Re-redirect screen if required
+    if (ps->o.reredir_on_root_change && ps->redirected) {
+      redir_stop(ps);
+      redir_start(ps);
+    }
+
 #ifdef CONFIG_VSYNC_OPENGL
+    // Reinitialize GLX on root change
+    if (ps->o.glx_reinit_on_root_change && ps->psglx) {
+      if (!glx_reinit(ps, bkend_use_glx(ps)))
+        printf_errf("(): Failed to reinitialize GLX, troubles ahead.");
+      if (BKEND_GLX == ps->o.backend && !init_filters(ps))
+        printf_errf("(): Failed to initialize filters.");
+    }
+
+    // GLX root change callback
     if (BKEND_GLX == ps->o.backend)
       glx_on_root_change(ps);
 #endif
 
+    force_repaint(ps);
+
     return;
   }
 
@@ -3466,6 +3566,9 @@ destroy_win(session_t *ps, Window id) {
 
     w->destroyed = true;
 
+    if (ps->o.no_fading_destroyed_argb)
+      win_determine_fade(ps, w);
+
     // Set fading callback
     set_fade_callback(ps, w, destroy_callback, false);
 
@@ -3604,11 +3707,13 @@ xerror(Display __attribute__((unused)) *dpy, XErrorEvent *ev) {
   {
     char buf[BUF_LEN] = "";
     XGetErrorText(ps->dpy, ev->error_code, buf, BUF_LEN);
-    printf("error %d (%s) request %d minor %d serial %lu (\"%s\")\n",
+    printf("error %4d %-12s request %4d minor %4d serial %6lu: \"%s\"\n",
         ev->error_code, name, ev->request_code,
         ev->minor_code, ev->serial, buf);
   }
 
+  // print_backtrace();
+
   return 0;
 }
 
@@ -3659,7 +3764,7 @@ win_update_focused(session_t *ps, win *w) {
         || (ps->o.mark_wmwin_focused && w->wmwin)
         || (ps->o.mark_ovredir_focused
           && w->id == w->client_win && !w->wmwin)
-        || win_match(ps, w, ps->o.focus_blacklist, &w->cache_fcblst))
+        || (IsViewable == w->a.map_state && win_match(ps, w, ps->o.focus_blacklist, &w->cache_fcblst)))
       w->focused = true;
 
     // If window grouping detection is enabled, mark the window active if
@@ -4226,10 +4331,12 @@ ev_focus_report(XFocusChangeEvent* ev) {
  * Determine whether we should respond to a <code>FocusIn/Out</code>
  * event.
  */
+/*
 inline static bool
 ev_focus_accept(XFocusChangeEvent *ev) {
   return NotifyNormal == ev->mode || NotifyUngrab == ev->mode;
 }
+*/
 
 static inline void
 ev_focus_in(session_t *ps, XFocusChangeEvent *ev) {
@@ -4727,6 +4834,8 @@ usage(int ret) {
     "  Daemonize process.\n"
     "-S\n"
     "  Enable synchronous operation (for debugging).\n"
+    "--show-all-xerrors\n"
+    "  Show all X errors (for debugging).\n"
     "-v\n"
     "  Print version Number and exit\\n"
     "--config path\n"
@@ -4755,13 +4864,21 @@ usage(int ret) {
     "  Mark windows that have no WM frame as active.\n"
     "--no-fading-openclose\n"
     "  Do not fade on window open/close.\n"
+    "--no-fading-destroyed-argb\n"
+    "  Do not fade destroyed ARGB windows with WM frame. Workaround of bugs\n"
+    "  in Openbox, Fluxbox, etc.\n"
     "--no-fading-opacitychange\n"
     "  Do not fade on window opacity change.\n"
     "--shadow-ignore-shaped\n"
-    "  Do not paint shadows on shaped windows.\n"
+    "  Do not paint shadows on shaped windows. (Deprecated, use\n"
+    "  --shadow-exclude \'bounding_shaped\' or\n"
+    "  --shadow-exclude \'bounding_shaped && !rounded_corners\' instead.)\n"
     "--detect-rounded-corners\n"
     "  Try to detect windows with rounded corners and don't consider\n"
-    "  them shaped windows.\n"
+    "  them shaped windows. Affects --shadow-ignore-shaped,\n"
+    "  --unredir-if-possible, and possibly others. You need to turn this\n"
+    "  on manually if you want to match against rounded_corners in\n"
+    "  conditions.\n"
     "--detect-client-opacity\n"
     "  Detect _NET_WM_OPACITY on client windows, useful for window\n"
     "  managers not passing _NET_WM_OPACITY of client windows to frame\n"
@@ -4861,7 +4978,7 @@ usage(int ret) {
     "  The element in the center must not be included, it will be forever\n"
     "  1.0 or changing based on opacity, depending on whether you have\n"
     "  --blur-background-fixed.\n"
-    "  A 7x7 Guassian blur kernel looks like:\n"
+    "  A 7x7 Gaussian blur kernel looks like:\n"
     "    --blur-kern '7,7,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.001723,0.059106,0.493069,0.493069,0.059106,0.001723,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003'\n"
     "  Up to 4 blur kernels may be specified, separated with semicolon, for\n"
     "  multi-pass blur.\n"
@@ -4919,7 +5036,8 @@ usage(int ret) {
     "--glx-no-rebind-pixmap\n"
     "  GLX backend: Avoid rebinding pixmap on window damage. Probably\n"
     "  could improve performance on rapid window content changes, but is\n"
-    "  known to break things on some drivers.\n"
+    "  known to break things on some drivers (LLVMpipe, xf86-video-intel,\n"
+    "  etc.).\n"
     "--glx-swap-method undefined/copy/exchange/3/4/5/6/buffer-age\n"
     "  GLX backend: GLX buffer swap method we assume. Could be\n"
     "  undefined (0), copy (1), exchange (2), 3-6, or buffer-age (-1).\n"
@@ -4949,6 +5067,12 @@ usage(int ret) {
 #else
 #define WARNING
 #endif
+    "--glx-fshader-win shader\n"
+    "  GLX backend: Use specified GLSL fragment shader for rendering window\n"
+    "  contents.\n"
+    "--force-win-blend\n"
+    "  Force all windows to be painted with blending. Useful if you have a\n"
+    "  --glx-fshader-win that could turn opaque pixels transparent.\n"
     "--dbus\n"
     "  Enable remote control via D-Bus. See the D-BUS API section in the\n"
     "  man page for more details." WARNING "\n"
@@ -5011,7 +5135,8 @@ register_cm(session_t *ps) {
     printf_errf("(): Failed to set COMPTON_VERSION.");
   }
 
-  {
+  // Acquire X Selection _NET_WM_CM_S?
+  if (!ps->o.no_x_selection) {
     unsigned len = strlen(REGISTER_PROP) + 2;
     int s = ps->scr;
 
@@ -5066,7 +5191,7 @@ fork_after(session_t *ps) {
 
 #ifdef CONFIG_VSYNC_OPENGL
   // GLX context must be released and reattached on fork
-  if (ps->glx_context && !glXMakeCurrent(ps->dpy, None, NULL)) {
+  if (glx_has_context(ps) && !glXMakeCurrent(ps->dpy, None, NULL)) {
     printf_errf("(): Failed to detach GLx context.");
     return false;
   }
@@ -5084,8 +5209,8 @@ fork_after(session_t *ps) {
   setsid();
 
 #ifdef CONFIG_VSYNC_OPENGL
-  if (ps->glx_context
-      && !glXMakeCurrent(ps->dpy, get_tgt_window(ps), ps->glx_context)) {
+  if (glx_has_context(ps)
+      && !glXMakeCurrent(ps->dpy, get_tgt_window(ps), ps->psglx->context)) {
     printf_errf("(): Failed to make GLX context current.");
     return false;
   }
@@ -5399,6 +5524,7 @@ parse_geometry_end:
  */
 static inline bool
 parse_rule_opacity(session_t *ps, const char *src) {
+#ifdef CONFIG_C2
   // Find opacity value
   char *endptr = NULL;
   long val = strtol(src, &endptr, 0);
@@ -5423,6 +5549,10 @@ parse_rule_opacity(session_t *ps, const char *src) {
   // Parse pattern
   // I hope 1-100 is acceptable for (void *)
   return c2_parsed(ps, &ps->o.opacity_rules, endptr, (void *) val);
+#else
+  printf_errf("(\"%s\"): Condition support not compiled in.", src);
+  return false;
+#endif
 }
 
 #ifdef CONFIG_LIBCONFIG
@@ -5650,6 +5780,9 @@ parse_config(session_t *ps, struct options_tmp *pcfgtmp) {
     wintype_arr_enable(ps->o.wintype_fade);
   // --no-fading-open-close
   lcfg_lookup_bool(&cfg, "no-fading-openclose", &ps->o.no_fading_openclose);
+  // --no-fading-destroyed-argb
+  lcfg_lookup_bool(&cfg, "no-fading-destroyed-argb",
+      &ps->o.no_fading_destroyed_argb);
   // --no-fading-opacitychange
   lcfg_lookup_bool(&cfg, "no-fading-opacitychange", &ps->o.no_fading_opacitychange);
   // --shadow-red
@@ -5743,7 +5876,7 @@ parse_config(session_t *ps, struct options_tmp *pcfgtmp) {
       && !parse_conv_kern_lst(ps, sval, ps->o.blur_kerns, MAX_BLUR_PASS))
     exit(1);
   // --resize-damage
-  config_lookup_int(&cfg, "resize-damage", &ps->o.resize_damage);
+  lcfg_lookup_int(&cfg, "resize-damage", &ps->o.resize_damage);
   // --glx-no-stencil
   lcfg_lookup_bool(&cfg, "glx-no-stencil", &ps->o.glx_no_stencil);
   // --glx-copy-from-front
@@ -5806,6 +5939,7 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
     { "shadow-offset-y", required_argument, NULL, 't' },
     { "fade-in-step", required_argument, NULL, 'I' },
     { "fade-out-step", required_argument, NULL, 'O' },
+    { "fade-delta", required_argument, NULL, 'D' },
     { "menu-opacity", required_argument, NULL, 'm' },
     { "shadow", no_argument, NULL, 'c' },
     { "no-dock-shadow", no_argument, NULL, 'C' },
@@ -5813,6 +5947,7 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
     { "fading", no_argument, NULL, 'f' },
     { "inactive-opacity", required_argument, NULL, 'i' },
     { "frame-opacity", required_argument, NULL, 'e' },
+    { "daemon", no_argument, NULL, 'b' },
     { "no-dnd-shadow", no_argument, NULL, 'G' },
     { "shadow-red", required_argument, NULL, 257 },
     { "shadow-green", required_argument, NULL, 258 },
@@ -5871,7 +6006,16 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
     { "vsync-use-glfinish", no_argument, NULL, 311 },
     { "xrender-sync", no_argument, NULL, 312 },
     { "xrender-sync-fence", no_argument, NULL, 313 },
-    { "no-fading-opacitychange", no_argument, NULL, 314 },
+    { "show-all-xerrors", no_argument, NULL, 314 },
+    { "no-fading-destroyed-argb", no_argument, NULL, 315 },
+    { "force-win-blend", no_argument, NULL, 316 },
+    { "glx-fshader-win", required_argument, NULL, 317 },
+    { "version", no_argument, NULL, 318 },
+    { "no-x-selection", no_argument, NULL, 319 },
+    { "no-name-pixmap", no_argument, NULL, 320 },
+    { "no-fading-opacitychange", no_argument, NULL, 321 },
+    { "reredir-on-root-change", no_argument, NULL, 731 },
+    { "glx-reinit-on-root-change", no_argument, NULL, 732 },
     // Must terminate with a NULL entry
     { NULL, 0, NULL, 0 },
   };
@@ -5892,6 +6036,14 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
         ps->o.display = mstrcpy(optarg);
       else if ('S' == o)
         ps->o.synchronize = true;
+      else if (314 == o)
+        ps->o.show_all_xerrors = true;
+      else if (318 == o) {
+        printf("%s\n", COMPTON_VERSION);
+        exit(0);
+      }
+      else if (320 == o)
+        ps->o.no_name_pixmap = true;
       else if ('?' == o || ':' == o)
         usage(1);
     }
@@ -5946,6 +6098,9 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
       case 'v': fprintf (stderr, "%s v%-3.2f\n", argv[0], _TDE_COMP_MGR_VERSION_); my_exit_code=0; exit (0);
       case 'd':
       case 'S':
+      case 314:
+      case 318:
+      case 320:
         break;
       P_CASELONG('D', fade_delta);
       case 'I':
@@ -6125,7 +6280,15 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
       P_CASEBOOL(311, vsync_use_glfinish);
       P_CASEBOOL(312, xrender_sync);
       P_CASEBOOL(313, xrender_sync_fence);
-      P_CASEBOOL(314, no_fading_opacitychange);
+      P_CASEBOOL(315, no_fading_destroyed_argb);
+      P_CASEBOOL(316, force_win_blend);
+      case 317:
+        ps->o.glx_fshader_win_str = mstrcpy(optarg);
+        break;
+      P_CASEBOOL(319, no_x_selection);
+      P_CASEBOOL(321, no_fading_opacitychange);
+      P_CASEBOOL(731, reredir_on_root_change);
+      P_CASEBOOL(732, glx_reinit_on_root_change);
       default:
         usage(1);
         break;
@@ -6416,13 +6579,13 @@ vsync_opengl_init(session_t *ps) {
     return false;
 
   // Get video sync functions
-  if (!ps->glXGetVideoSyncSGI)
-    ps->glXGetVideoSyncSGI = (f_GetVideoSync)
+  if (!ps->psglx->glXGetVideoSyncSGI)
+    ps->psglx->glXGetVideoSyncSGI = (f_GetVideoSync)
       glXGetProcAddress((const GLubyte *) "glXGetVideoSyncSGI");
-  if (!ps->glXWaitVideoSyncSGI)
-    ps->glXWaitVideoSyncSGI = (f_WaitVideoSync)
+  if (!ps->psglx->glXWaitVideoSyncSGI)
+    ps->psglx->glXWaitVideoSyncSGI = (f_WaitVideoSync)
       glXGetProcAddress((const GLubyte *) "glXWaitVideoSyncSGI");
-  if (!ps->glXWaitVideoSyncSGI || !ps->glXGetVideoSyncSGI) {
+  if (!ps->psglx->glXWaitVideoSyncSGI || !ps->psglx->glXGetVideoSyncSGI) {
     printf_errf("(): Failed to get glXWait/GetVideoSyncSGI function.");
     return false;
   }
@@ -6441,13 +6604,13 @@ vsync_opengl_oml_init(session_t *ps) {
     return false;
 
   // Get video sync functions
-  if (!ps->glXGetSyncValuesOML)
-    ps->glXGetSyncValuesOML = (f_GetSyncValuesOML)
+  if (!ps->psglx->glXGetSyncValuesOML)
+    ps->psglx->glXGetSyncValuesOML = (f_GetSyncValuesOML)
       glXGetProcAddress ((const GLubyte *) "glXGetSyncValuesOML");
-  if (!ps->glXWaitForMscOML)
-    ps->glXWaitForMscOML = (f_WaitForMscOML)
+  if (!ps->psglx->glXWaitForMscOML)
+    ps->psglx->glXWaitForMscOML = (f_WaitForMscOML)
       glXGetProcAddress ((const GLubyte *) "glXWaitForMscOML");
-  if (!ps->glXGetSyncValuesOML || !ps->glXWaitForMscOML) {
+  if (!ps->psglx->glXGetSyncValuesOML || !ps->psglx->glXWaitForMscOML) {
     printf_errf("(): Failed to get OML_sync_control functions.");
     return false;
   }
@@ -6471,14 +6634,14 @@ vsync_opengl_swc_init(session_t *ps) {
   }
 
   // Get video sync functions
-  if (!ps->glXSwapIntervalProc)
-    ps->glXSwapIntervalProc = (f_SwapIntervalSGI)
+  if (!ps->psglx->glXSwapIntervalProc)
+    ps->psglx->glXSwapIntervalProc = (f_SwapIntervalSGI)
       glXGetProcAddress ((const GLubyte *) "glXSwapIntervalSGI");
-  if (!ps->glXSwapIntervalProc) {
+  if (!ps->psglx->glXSwapIntervalProc) {
     printf_errf("(): Failed to get SGI_swap_control function.");
     return false;
   }
-  ps->glXSwapIntervalProc(1);
+  ps->psglx->glXSwapIntervalProc(1);
 
   return true;
 #else
@@ -6499,14 +6662,14 @@ vsync_opengl_mswc_init(session_t *ps) {
   }
 
   // Get video sync functions
-  if (!ps->glXSwapIntervalMESAProc)
-    ps->glXSwapIntervalMESAProc = (f_SwapIntervalMESA)
+  if (!ps->psglx->glXSwapIntervalMESAProc)
+    ps->psglx->glXSwapIntervalMESAProc = (f_SwapIntervalMESA)
       glXGetProcAddress ((const GLubyte *) "glXSwapIntervalMESA");
-  if (!ps->glXSwapIntervalMESAProc) {
+  if (!ps->psglx->glXSwapIntervalMESAProc) {
     printf_errf("(): Failed to get MESA_swap_control function.");
     return false;
   }
-  ps->glXSwapIntervalMESAProc(1);
+  ps->psglx->glXSwapIntervalMESAProc(1);
 
   return true;
 #else
@@ -6523,8 +6686,8 @@ static int
 vsync_opengl_wait(session_t *ps) {
   unsigned vblank_count = 0;
 
-  ps->glXGetVideoSyncSGI(&vblank_count);
-  ps->glXWaitVideoSyncSGI(2, (vblank_count + 1) % 2, &vblank_count);
+  ps->psglx->glXGetVideoSyncSGI(&vblank_count);
+  ps->psglx->glXWaitVideoSyncSGI(2, (vblank_count + 1) % 2, &vblank_count);
   // I see some code calling glXSwapIntervalSGI(1) afterwards, is it required?
 
   return 0;
@@ -6539,8 +6702,8 @@ static int
 vsync_opengl_oml_wait(session_t *ps) {
   int64_t ust = 0, msc = 0, sbc = 0;
 
-  ps->glXGetSyncValuesOML(ps->dpy, ps->reg_win, &ust, &msc, &sbc);
-  ps->glXWaitForMscOML(ps->dpy, ps->reg_win, 0, 2, (msc + 1) % 2,
+  ps->psglx->glXGetSyncValuesOML(ps->dpy, ps->reg_win, &ust, &msc, &sbc);
+  ps->psglx->glXWaitForMscOML(ps->dpy, ps->reg_win, 0, 2, (msc + 1) % 2,
       &ust, &msc, &sbc);
 
   return 0;
@@ -6549,14 +6712,14 @@ vsync_opengl_oml_wait(session_t *ps) {
 static void
 vsync_opengl_swc_deinit(session_t *ps) {
   // The standard says it doesn't accept 0, but in fact it probably does
-  if (ps->glx_context && ps->glXSwapIntervalProc)
-    ps->glXSwapIntervalProc(0);
+  if (glx_has_context(ps) && ps->psglx->glXSwapIntervalProc)
+    ps->psglx->glXSwapIntervalProc(0);
 }
 
 static void
 vsync_opengl_mswc_deinit(session_t *ps) {
-  if (ps->glx_context && ps->glXSwapIntervalMESAProc)
-    ps->glXSwapIntervalMESAProc(0);
+  if (glx_has_context(ps) && ps->psglx->glXSwapIntervalMESAProc)
+    ps->psglx->glXSwapIntervalMESAProc(0);
 }
 #endif
 
@@ -6593,7 +6756,6 @@ void
 vsync_deinit(session_t *ps) {
   if (ps->o.vsync && VSYNC_FUNCS_DEINIT[ps->o.vsync])
     VSYNC_FUNCS_DEINIT[ps->o.vsync](ps);
-  ps->o.vsync = VSYNC_NONE;
 }
 
 /**
@@ -6633,7 +6795,7 @@ init_dbe(session_t *ps) {
 /**
  * Initialize X composite overlay window.
  */
-static void
+static bool
 init_overlay(session_t *ps) {
   ps->overlay = XCompositeGetOverlayWindow(ps->dpy, ps->root);
   if (ps->overlay) {
@@ -6661,6 +6823,11 @@ init_overlay(session_t *ps) {
         "back to painting on root window.\n");
     ps->o.paint_on_overlay = false;
   }
+#ifdef DEBUG_REDIR
+  printf_dbgf("(): overlay = %#010lx\n", ps->overlay);
+#endif
+
+  return ps->overlay;
 }
 
 /**
@@ -7071,6 +7238,9 @@ session_init(session_t *ps_old, int argc, char **argv) {
       .backend = BKEND_XRENDER,
       .glx_no_stencil = false,
       .glx_copy_from_front = false,
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+      .glx_prog_win = GLX_PROG_MAIN_INIT,
+#endif
       .mark_wmwin_focused = false,
       .mark_ovredir_focused = false,
       .fork_after_register = false,
@@ -7113,6 +7283,7 @@ session_init(session_t *ps_old, int argc, char **argv) {
       .fade_out_step = 0.03 * OPAQUE,
       .fade_delta = 10,
       .no_fading_openclose = false,
+      .no_fading_destroyed_argb = false,
       .no_fading_opacitychange = false,
       .fade_blacklist = NULL,
 
@@ -7187,15 +7358,6 @@ session_init(session_t *ps_old, int argc, char **argv) {
     .drm_fd = -1,
 #endif
 
-#ifdef CONFIG_VSYNC_OPENGL
-    .glx_context = None,
-    .glx_has_texture_non_power_of_two = false,
-    .glXGetVideoSyncSGI = NULL,
-    .glXWaitVideoSyncSGI = NULL,
-    .glXGetSyncValuesOML = NULL,
-    .glXWaitForMscOML = NULL,
-#endif
-
     .xfixes_event = 0,
     .xfixes_error = 0,
     .damage_event = 0,
@@ -7247,14 +7409,6 @@ session_init(session_t *ps_old, int argc, char **argv) {
   // Allocate a session and copy default values into it
   session_t *ps = malloc(sizeof(session_t));
   memcpy(ps, &s_def, sizeof(session_t));
-#ifdef CONFIG_VSYNC_OPENGL_GLSL
-  for (int i = 0; i < MAX_BLUR_PASS; ++i) {
-    glx_blur_pass_t *ppass = &ps->glx_blur_passes[i];
-    ppass->unifm_factor_center = -1;
-    ppass->unifm_offset_x = -1;
-    ppass->unifm_offset_y = -1;
-  }
-#endif
   ps_g = ps;
   ps->ignore_tail = &ps->ignore_head;
   gettimeofday(&ps->time_start, NULL);
@@ -7319,7 +7473,8 @@ session_init(session_t *ps_old, int argc, char **argv) {
 
     XCompositeQueryVersion(ps->dpy, &composite_major, &composite_minor);
 
-    if (composite_major > 0 || composite_minor >= 2) {
+    if (!ps->o.no_name_pixmap
+        && (composite_major > 0 || composite_minor >= 2)) {
       ps->has_name_pixmap = true;
     }
   }
@@ -7450,6 +7605,17 @@ session_init(session_t *ps_old, int argc, char **argv) {
 #endif
   }
 
+  // Initialize window GL shader
+  if (BKEND_GLX == ps->o.backend && ps->o.glx_fshader_win_str) {
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    if (!glx_load_prog_main(ps, NULL, ps->o.glx_fshader_win_str, &ps->o.glx_prog_win))
+      exit(1);
+#else
+    printf_errf("(): GLSL supported not compiled in, can't load shader.");
+    exit(1);
+#endif
+  }
+
   // Initialize software optimization
   if (ps->o.sw_opti)
     ps->o.sw_opti = swopti_init(ps);
@@ -7543,12 +7709,13 @@ session_init(session_t *ps_old, int argc, char **argv) {
     cxfree(children);
   }
 
-
   if (ps->o.track_focus) {
     recheck_focus(ps);
   }
 
   XUngrabServer(ps->dpy);
+  // ALWAYS flush after XUngrabServer()!
+  XFlush(ps->dpy);
 
   // Initialize DBus
   if (ps->o.dbus) {
@@ -7711,6 +7878,7 @@ session_destroy(session_t *ps) {
   free(ps->pfds_read);
   free(ps->pfds_write);
   free(ps->pfds_except);
+  free(ps->o.glx_fshader_win_str);
   free_xinerama_info(ps);
 
 #ifdef CONFIG_VSYNC_OPENGL
@@ -7746,6 +7914,11 @@ session_destroy(session_t *ps) {
   // Flush all events
   XSync(ps->dpy, True);
 
+#ifdef DEBUG_XRC
+  // Report about resource leakage
+  xrc_report_xid();
+#endif
+
   // Free timeouts
   ps->tmout_unredir = NULL;
   timeout_clear(ps);
@@ -7754,6 +7927,16 @@ session_destroy(session_t *ps) {
     ps_g = NULL;
 }
 
+/*
+static inline void
+dump_img(session_t *ps) {
+  int len = 0;
+  unsigned char *d = glx_take_screenshot(ps, &len);
+  write_binary_data("/tmp/dump.raw", d, len);
+  free(d);
+}
+*/
+
 /**
  * Do the actual work.
  *
diff --git a/twin/compton-tde/compton.h b/twin/compton-tde/compton.h
index dfdbe53d3..c1c877056 100644
--- a/twin/compton-tde/compton.h
+++ b/twin/compton-tde/compton.h
@@ -273,7 +273,7 @@ free_reg_data(reg_data_t *pregd) {
  */
 static inline void
 free_paint(session_t *ps, paint_t *ppaint) {
-  free_texture(ps, &ppaint->ptex);
+  free_paint_glx(ps, ppaint);
   free_picture(ps, &ppaint->pict);
   free_pixmap(ps, &ppaint->pixmap);
 }
@@ -292,6 +292,7 @@ free_wpaint(session_t *ps, win *w) {
  */
 static inline void
 free_win_res(session_t *ps, win *w) {
+  free_win_res_glx(ps, w);
   free_region(ps, &w->extents);
   free_paint(ps, &w->paint);
   free_region(ps, &w->border_size);
@@ -302,9 +303,6 @@ free_win_res(session_t *ps, win *w) {
   free(w->class_instance);
   free(w->class_general);
   free(w->role);
-#ifdef CONFIG_VSYNC_OPENGL_GLSL
-  free_glx_bc(ps, &w->glx_blur_cache);
-#endif
 }
 
 /**
@@ -356,7 +354,7 @@ isdamagenotify(session_t *ps, const XEvent *ev) {
  */
 static inline XTextProperty *
 make_text_prop(session_t *ps, char *str) {
-  XTextProperty *pprop = cmalloc(1, XTextProperty);
+  XTextProperty *pprop = ccalloc(1, XTextProperty);
 
   if (XmbTextListToTextProperty(ps->dpy, &str, 1,  XStringStyle, pprop)) {
     cxfree(pprop->value);
@@ -678,20 +676,37 @@ static win *
 paint_preprocess(session_t *ps, win *list);
 
 static void
-render(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
+render_(session_t *ps, int x, int y, int dx, int dy, int wid, int hei,
     double opacity, bool argb, bool neg,
     Picture pict, glx_texture_t *ptex,
-    XserverRegion reg_paint, const reg_data_t *pcache_reg);
+    XserverRegion reg_paint, const reg_data_t *pcache_reg
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    , const glx_prog_main_t *pprogram
+#endif
+    );
+
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+#define \
+   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram) \
+  render_(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram)
+#else
+#define \
+   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg, pprogram) \
+  render_(ps, x, y, dx, dy, wid, hei, opacity, argb, neg, pict, ptex, reg_paint, pcache_reg)
+#endif
 
 static inline void
-win_render(session_t *ps, win *w, int x, int y, int wid, int hei, double opacity, XserverRegion reg_paint, const reg_data_t *pcache_reg, Picture pict) {
+win_render(session_t *ps, win *w, int x, int y, int wid, int hei,
+    double opacity, XserverRegion reg_paint, const reg_data_t *pcache_reg,
+    Picture pict) {
   const int dx = (w ? w->a.x: 0) + x;
   const int dy = (w ? w->a.y: 0) + y;
-  const bool argb = (w && w->mode == WMODE_ARGB);
+  const bool argb = (w && (WMODE_ARGB == w->mode || ps->o.force_win_blend));
   const bool neg = (w && w->invert_color);
 
   render(ps, x, y, dx, dy, wid, hei, opacity, argb, neg,
-      pict, (w ? w->paint.ptex: ps->root_tile_paint.ptex), reg_paint, pcache_reg);
+      pict, (w ? w->paint.ptex: ps->root_tile_paint.ptex),
+      reg_paint, pcache_reg, (w ? &ps->o.glx_prog_win: NULL));
 }
 
 static inline void
@@ -838,12 +853,21 @@ static void
 win_update_prop_shadow(session_t *ps, win *w);
 
 static void
+win_set_shadow(session_t *ps, win *w, bool shadow_new);
+
+static void
 win_determine_shadow(session_t *ps, win *w);
 
 static void
+win_set_invert_color(session_t *ps, win *w, bool invert_color_new);
+
+static void
 win_determine_invert_color(session_t *ps, win *w);
 
 static void
+win_set_blur_background(session_t *ps, win *w, bool blur_background_new);
+
+static void
 win_determine_blur_background(session_t *ps, win *w);
 
 static void
@@ -1204,10 +1228,10 @@ swopti_handle_timeout(session_t *ps, struct timeval *ptv);
 static inline bool
 ensure_glx_context(session_t *ps) {
   // Create GLX context
-  if (!ps->glx_context)
+  if (!glx_has_context(ps))
     glx_init(ps, false);
 
-  return ps->glx_context;
+  return ps->psglx->context;
 }
 #endif
 
@@ -1254,7 +1278,7 @@ init_alpha_picts(session_t *ps);
 static bool
 init_dbe(session_t *ps);
 
-static void
+static bool
 init_overlay(session_t *ps);
 
 static void
diff --git a/twin/compton-tde/dbus.c b/twin/compton-tde/dbus.c
index 8aec9ea82..874f565ca 100644
--- a/twin/compton-tde/dbus.c
+++ b/twin/compton-tde/dbus.c
@@ -901,6 +901,11 @@ cdbus_process_opts_get(session_t *ps, DBusMessage *msg) {
   cdbus_m_opts_get_do(fork_after_register, cdbus_reply_bool);
   cdbus_m_opts_get_do(detect_rounded_corners, cdbus_reply_bool);
   cdbus_m_opts_get_do(paint_on_overlay, cdbus_reply_bool);
+  // paint_on_overlay_id: Get ID of the X composite overlay window
+  if (!strcmp("paint_on_overlay_id", target)) {
+    cdbus_reply_uint32(ps, msg, ps->overlay);
+    return true;
+  }
   cdbus_m_opts_get_do(unredir_if_possible, cdbus_reply_bool);
   cdbus_m_opts_get_do(unredir_if_possible_delay, cdbus_reply_int32);
   cdbus_m_opts_get_do(redirected_force, cdbus_reply_enum);
diff --git a/twin/compton-tde/opengl.c b/twin/compton-tde/opengl.c
index bbef9bf16..2b9ff6286 100644
--- a/twin/compton-tde/opengl.c
+++ b/twin/compton-tde/opengl.c
@@ -15,15 +15,15 @@
 void
 xr_glx_sync(session_t *ps, Drawable d, XSyncFence *pfence) {
   if (*pfence) {
-    // GLsync sync = ps->glFenceSyncProc(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
-    GLsync sync = ps->glImportSyncEXT(GL_SYNC_X11_FENCE_EXT, *pfence, 0);
-    /* GLenum ret = ps->glClientWaitSyncProc(sync, GL_SYNC_FLUSH_COMMANDS_BIT,
+    // GLsync sync = ps->psglx->glFenceSyncProc(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+    GLsync sync = ps->psglx->glImportSyncEXT(GL_SYNC_X11_FENCE_EXT, *pfence, 0);
+    /* GLenum ret = ps->psglx->glClientWaitSyncProc(sync, GL_SYNC_FLUSH_COMMANDS_BIT,
         1000);
     assert(GL_CONDITION_SATISFIED == ret); */
     XSyncTriggerFence(ps->dpy, *pfence);
     XFlush(ps->dpy);
-    ps->glWaitSyncProc(sync, 0, GL_TIMEOUT_IGNORED);
-    // ps->glDeleteSyncProc(sync);
+    ps->psglx->glWaitSyncProc(sync, 0, GL_TIMEOUT_IGNORED);
+    // ps->psglx->glDeleteSyncProc(sync);
     // XSyncResetFence(ps->dpy, *pfence);
   }
   glx_check_err(ps);
@@ -99,10 +99,28 @@ glx_init(session_t *ps, bool need_render) {
   if (need_render && !glx_hasglxext(ps, "GLX_EXT_texture_from_pixmap"))
     goto glx_init_end;
 
-  if (!ps->glx_context) {
+  // Initialize GLX data structure
+  if (!ps->psglx) {
+    static const glx_session_t CGLX_SESSION_DEF = CGLX_SESSION_INIT;
+    ps->psglx = cmalloc(1, glx_session_t);
+    memcpy(ps->psglx, &CGLX_SESSION_DEF, sizeof(glx_session_t));
+
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    for (int i = 0; i < MAX_BLUR_PASS; ++i) {
+      glx_blur_pass_t *ppass = &ps->psglx->blur_passes[i];
+      ppass->unifm_factor_center = -1;
+      ppass->unifm_offset_x = -1;
+      ppass->unifm_offset_y = -1;
+    }
+#endif
+  }
+
+  glx_session_t *psglx = ps->psglx;
+
+  if (!psglx->context) {
     // Get GLX context
 #ifndef DEBUG_GLX_DEBUG_CONTEXT
-    ps->glx_context = glXCreateContext(ps->dpy, pvis, None, GL_TRUE);
+    psglx->context = glXCreateContext(ps->dpy, pvis, None, GL_TRUE);
 #else
     {
       GLXFBConfig fbconfig = get_fbconfig_from_visualinfo(ps, pvis);
@@ -124,18 +142,18 @@ glx_init(session_t *ps, bool need_render) {
         GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
         None
       };
-      ps->glx_context = p_glXCreateContextAttribsARB(ps->dpy, fbconfig, NULL,
+      psglx->context = p_glXCreateContextAttribsARB(ps->dpy, fbconfig, NULL,
           GL_TRUE, attrib_list);
     }
 #endif
 
-    if (!ps->glx_context) {
+    if (!psglx->context) {
       printf_errf("(): Failed to get GLX context.");
       goto glx_init_end;
     }
 
     // Attach GLX context
-    if (!glXMakeCurrent(ps->dpy, get_tgt_window(ps), ps->glx_context)) {
+    if (!glXMakeCurrent(ps->dpy, get_tgt_window(ps), psglx->context)) {
       printf_errf("(): Failed to attach GLX context.");
       goto glx_init_end;
     }
@@ -170,52 +188,52 @@ glx_init(session_t *ps, bool need_render) {
   // Check GL_ARB_texture_non_power_of_two, requires a GLX context and
   // must precede FBConfig fetching
   if (need_render)
-    ps->glx_has_texture_non_power_of_two = glx_hasglext(ps,
+    psglx->has_texture_non_power_of_two = glx_hasglext(ps,
         "GL_ARB_texture_non_power_of_two");
 
   // Acquire function addresses
   if (need_render) {
 #ifdef DEBUG_GLX_MARK
-    ps->glStringMarkerGREMEDY = (f_StringMarkerGREMEDY)
+    psglx->glStringMarkerGREMEDY = (f_StringMarkerGREMEDY)
       glXGetProcAddress((const GLubyte *) "glStringMarkerGREMEDY");
-    ps->glFrameTerminatorGREMEDY = (f_FrameTerminatorGREMEDY)
+    psglx->glFrameTerminatorGREMEDY = (f_FrameTerminatorGREMEDY)
       glXGetProcAddress((const GLubyte *) "glFrameTerminatorGREMEDY");
 #endif
 
-    ps->glXBindTexImageProc = (f_BindTexImageEXT)
+    psglx->glXBindTexImageProc = (f_BindTexImageEXT)
       glXGetProcAddress((const GLubyte *) "glXBindTexImageEXT");
-    ps->glXReleaseTexImageProc = (f_ReleaseTexImageEXT)
+    psglx->glXReleaseTexImageProc = (f_ReleaseTexImageEXT)
       glXGetProcAddress((const GLubyte *) "glXReleaseTexImageEXT");
-    if (!ps->glXBindTexImageProc || !ps->glXReleaseTexImageProc) {
+    if (!psglx->glXBindTexImageProc || !psglx->glXReleaseTexImageProc) {
       printf_errf("(): Failed to acquire glXBindTexImageEXT() / glXReleaseTexImageEXT().");
       goto glx_init_end;
     }
 
     if (ps->o.glx_use_copysubbuffermesa) {
-      ps->glXCopySubBufferProc = (f_CopySubBuffer)
+      psglx->glXCopySubBufferProc = (f_CopySubBuffer)
         glXGetProcAddress((const GLubyte *) "glXCopySubBufferMESA");
-      if (!ps->glXCopySubBufferProc) {
+      if (!psglx->glXCopySubBufferProc) {
         printf_errf("(): Failed to acquire glXCopySubBufferMESA().");
         goto glx_init_end;
       }
     }
 
 #ifdef CONFIG_GLX_SYNC
-    ps->glFenceSyncProc = (f_FenceSync)
+    psglx->glFenceSyncProc = (f_FenceSync)
       glXGetProcAddress((const GLubyte *) "glFenceSync");
-    ps->glIsSyncProc = (f_IsSync)
+    psglx->glIsSyncProc = (f_IsSync)
       glXGetProcAddress((const GLubyte *) "glIsSync");
-    ps->glDeleteSyncProc = (f_DeleteSync)
+    psglx->glDeleteSyncProc = (f_DeleteSync)
       glXGetProcAddress((const GLubyte *) "glDeleteSync");
-    ps->glClientWaitSyncProc = (f_ClientWaitSync)
+    psglx->glClientWaitSyncProc = (f_ClientWaitSync)
       glXGetProcAddress((const GLubyte *) "glClientWaitSync");
-    ps->glWaitSyncProc = (f_WaitSync)
+    psglx->glWaitSyncProc = (f_WaitSync)
       glXGetProcAddress((const GLubyte *) "glWaitSync");
-    ps->glImportSyncEXT = (f_ImportSyncEXT)
+    psglx->glImportSyncEXT = (f_ImportSyncEXT)
       glXGetProcAddress((const GLubyte *) "glImportSyncEXT");
-    if (!ps->glFenceSyncProc || !ps->glIsSyncProc || !ps->glDeleteSyncProc
-        || !ps->glClientWaitSyncProc || !ps->glWaitSyncProc
-        || !ps->glImportSyncEXT) {
+    if (!psglx->glFenceSyncProc || !psglx->glIsSyncProc || !psglx->glDeleteSyncProc
+        || !psglx->glClientWaitSyncProc || !psglx->glWaitSyncProc
+        || !psglx->glImportSyncEXT) {
       printf_errf("(): Failed to acquire GLX sync functions.");
       goto glx_init_end;
     }
@@ -260,33 +278,86 @@ glx_init_end:
   return success;
 }
 
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+
+static void
+glx_free_prog_main(session_t *ps, glx_prog_main_t *pprogram) {
+  if (!pprogram)
+    return;
+  if (pprogram->prog) {
+    glDeleteProgram(pprogram->prog);
+    pprogram->prog = 0;
+  }
+  pprogram->unifm_opacity = -1;
+  pprogram->unifm_invert_color = -1;
+  pprogram->unifm_tex = -1;
+}
+
+#endif
+
 /**
  * Destroy GLX related resources.
  */
 void
 glx_destroy(session_t *ps) {
+  if (!ps->psglx)
+    return;
+
+  // Free all GLX resources of windows
+  for (win *w = ps->list; w; w = w->next)
+    free_win_res_glx(ps, w);
+
 #ifdef CONFIG_VSYNC_OPENGL_GLSL
   // Free GLSL shaders/programs
   for (int i = 0; i < MAX_BLUR_PASS; ++i) {
-    glx_blur_pass_t *ppass = &ps->glx_blur_passes[i];
+    glx_blur_pass_t *ppass = &ps->psglx->blur_passes[i];
     if (ppass->frag_shader)
       glDeleteShader(ppass->frag_shader);
     if (ppass->prog)
       glDeleteProgram(ppass->prog);
   }
+
+  glx_free_prog_main(ps, &ps->o.glx_prog_win);
+
+  glx_check_err(ps);
 #endif
 
   // Free FBConfigs
   for (int i = 0; i <= OPENGL_MAX_DEPTH; ++i) {
-    free(ps->glx_fbconfigs[i]);
-    ps->glx_fbconfigs[i] = NULL;
+    free(ps->psglx->fbconfigs[i]);
+    ps->psglx->fbconfigs[i] = NULL;
   }
 
   // Destroy GLX context
-  if (ps->glx_context) {
-    glXDestroyContext(ps->dpy, ps->glx_context);
-    ps->glx_context = NULL;
+  if (ps->psglx->context) {
+    glXDestroyContext(ps->dpy, ps->psglx->context);
+    ps->psglx->context = NULL;
   }
+
+  free(ps->psglx);
+  ps->psglx = NULL;
+}
+
+/**
+ * Reinitialize GLX.
+ */
+bool
+glx_reinit(session_t *ps, bool need_render) {
+  // Reinitialize VSync as well
+  vsync_deinit(ps);
+
+  glx_destroy(ps);
+  if (!glx_init(ps, need_render)) {
+    printf_errf("(): Failed to initialize GLX.");
+    return false;
+  }
+
+  if (!vsync_init(ps)) {
+    printf_errf("(): Failed to initialize VSync.");
+    return false;
+  }
+
+  return true;
 }
 
 /**
@@ -356,7 +427,7 @@ glx_init_blur(session_t *ps) {
       "  gl_FragColor = sum / (factor_center + float(%.7g));\n"
       "}\n";
 
-    const bool use_texture_rect = !ps->glx_has_texture_non_power_of_two;
+    const bool use_texture_rect = !ps->psglx->has_texture_non_power_of_two;
     const char *sampler_type = (use_texture_rect ?
         "sampler2DRect": "sampler2D");
     const char *texture_func = (use_texture_rect ?
@@ -375,7 +446,7 @@ glx_init_blur(session_t *ps) {
       if (!kern)
         break;
 
-      glx_blur_pass_t *ppass = &ps->glx_blur_passes[i];
+      glx_blur_pass_t *ppass = &ps->psglx->blur_passes[i];
 
       // Build shader
       {
@@ -440,6 +511,7 @@ glx_init_blur(session_t *ps) {
         P_GET_UNIFM_LOC("offset_x", unifm_offset_x);
         P_GET_UNIFM_LOC("offset_y", unifm_offset_y);
       }
+
 #undef P_GET_UNIFM_LOC
     }
     free(extension);
@@ -459,6 +531,43 @@ glx_init_blur(session_t *ps) {
 #endif
 }
 
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+
+/**
+ * Load a GLSL main program from shader strings.
+ */
+bool
+glx_load_prog_main(session_t *ps,
+    const char *vshader_str, const char *fshader_str,
+    glx_prog_main_t *pprogram) {
+  assert(pprogram);
+
+  // Build program
+  pprogram->prog = glx_create_program_from_str(vshader_str, fshader_str);
+  if (!pprogram->prog) {
+    printf_errf("(): Failed to create GLSL program.");
+    return false;
+  }
+
+  // Get uniform addresses
+#define P_GET_UNIFM_LOC(name, target) { \
+      pprogram->target = glGetUniformLocation(pprogram->prog, name); \
+      if (pprogram->target < 0) { \
+        printf_errf("(): Failed to get location of uniform '" name "'. Might be troublesome."); \
+      } \
+    }
+  P_GET_UNIFM_LOC("opacity", unifm_opacity);
+  P_GET_UNIFM_LOC("invert_color", unifm_invert_color);
+  P_GET_UNIFM_LOC("tex", unifm_tex);
+#undef P_GET_UNIFM_LOC
+
+  glx_check_err(ps);
+
+  return true;
+}
+
+#endif
+
 /**
  * @brief Update the FBConfig of given depth.
  */
@@ -469,15 +578,15 @@ glx_update_fbconfig_bydepth(session_t *ps, int depth, glx_fbconfig_t *pfbcfg) {
     return;
 
   // Compare new FBConfig with current one
-  if (glx_cmp_fbconfig(ps, ps->glx_fbconfigs[depth], pfbcfg) < 0) {
+  if (glx_cmp_fbconfig(ps, ps->psglx->fbconfigs[depth], pfbcfg) < 0) {
 #ifdef DEBUG_GLX
-    printf_dbgf("(%d): %#x overrides %#x, target %#x.\n", depth, (unsigned) pfbcfg->cfg, (ps->glx_fbconfigs[depth] ? (unsigned) ps->glx_fbconfigs[depth]->cfg: 0), pfbcfg->texture_tgts);
+    printf_dbgf("(%d): %#x overrides %#x, target %#x.\n", depth, (unsigned) pfbcfg->cfg, (ps->psglx->fbconfigs[depth] ? (unsigned) ps->psglx->fbconfigs[depth]->cfg: 0), pfbcfg->texture_tgts);
 #endif
-    if (!ps->glx_fbconfigs[depth]) {
-      ps->glx_fbconfigs[depth] = malloc(sizeof(glx_fbconfig_t));
-      allocchk(ps->glx_fbconfigs[depth]);
+    if (!ps->psglx->fbconfigs[depth]) {
+      ps->psglx->fbconfigs[depth] = malloc(sizeof(glx_fbconfig_t));
+      allocchk(ps->psglx->fbconfigs[depth]);
     }
-    (*ps->glx_fbconfigs[depth]) = *pfbcfg;
+    (*ps->psglx->fbconfigs[depth]) = *pfbcfg;
   }
 }
 
@@ -559,19 +668,19 @@ glx_update_fbconfig(session_t *ps) {
   cxfree(pfbcfgs);
 
   // Sanity checks
-  if (!ps->glx_fbconfigs[ps->depth]) {
+  if (!ps->psglx->fbconfigs[ps->depth]) {
     printf_errf("(): No FBConfig found for default depth %d.", ps->depth);
     return false;
   }
 
-  if (!ps->glx_fbconfigs[32]) {
+  if (!ps->psglx->fbconfigs[32]) {
     printf_errf("(): No FBConfig found for depth 32. Expect crazy things.");
   }
 
 #ifdef DEBUG_GLX
   printf_dbgf("(): %d-bit: %#3x, 32-bit: %#3x\n",
-      ps->depth, (int) ps->glx_fbconfigs[ps->depth]->cfg,
-      (int) ps->glx_fbconfigs[32]->cfg);
+      ps->depth, (int) ps->psglx->fbconfigs[ps->depth]->cfg,
+      (int) ps->psglx->fbconfigs[32]->cfg);
 #endif
 
   return true;
@@ -675,7 +784,7 @@ glx_bind_pixmap(session_t *ps, glx_texture_t **pptex, Pixmap pixmap,
       }
     }
 
-    const glx_fbconfig_t *pcfg = ps->glx_fbconfigs[depth];
+    const glx_fbconfig_t *pcfg = ps->psglx->fbconfigs[depth];
     if (!pcfg) {
       printf_errf("(%d): Couldn't find FBConfig with requested depth.", depth);
       return false;
@@ -686,7 +795,7 @@ glx_bind_pixmap(session_t *ps, glx_texture_t **pptex, Pixmap pixmap,
     // pixmap-specific parameters, and this may change in the future
     GLenum tex_tgt = 0;
     if (GLX_TEXTURE_2D_BIT_EXT & pcfg->texture_tgts
-        && ps->glx_has_texture_non_power_of_two)
+        && ps->psglx->has_texture_non_power_of_two)
       tex_tgt = GLX_TEXTURE_2D_EXT;
     else if (GLX_TEXTURE_RECTANGLE_BIT_EXT & pcfg->texture_tgts)
       tex_tgt = GLX_TEXTURE_RECTANGLE_EXT;
@@ -751,9 +860,9 @@ glx_bind_pixmap(session_t *ps, glx_texture_t **pptex, Pixmap pixmap,
   // The specification requires rebinding whenever the content changes...
   // We can't follow this, too slow.
   if (need_release)
-    ps->glXReleaseTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT);
+    ps->psglx->glXReleaseTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT);
 
-  ps->glXBindTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT, NULL);
+  ps->psglx->glXBindTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT, NULL);
 
   // Cleanup
   glBindTexture(ptex->target, 0);
@@ -772,7 +881,7 @@ glx_release_pixmap(session_t *ps, glx_texture_t *ptex) {
   // Release binding
   if (ptex->glpixmap && ptex->texture) {
     glBindTexture(ptex->target, ptex->texture);
-    ps->glXReleaseTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT);
+    ps->psglx->glXReleaseTexImageProc(ps->dpy, ptex->glpixmap, GLX_FRONT_LEFT_EXT);
     glBindTexture(ptex->target, 0);
   }
 
@@ -790,7 +899,7 @@ glx_release_pixmap(session_t *ps, glx_texture_t *ptex) {
  */
 void
 glx_paint_pre(session_t *ps, XserverRegion *preg) {
-  ps->glx_z = 0.0;
+  ps->psglx->z = 0.0;
   // glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   // Get buffer age
@@ -1058,8 +1167,8 @@ glx_blur_dst(session_t *ps, int dx, int dy, int width, int height, float z,
     GLfloat factor_center,
     XserverRegion reg_tgt, const reg_data_t *pcache_reg,
     glx_blur_cache_t *pbc) {
-  assert(ps->glx_blur_passes[0].prog);
-  const bool more_passes = ps->glx_blur_passes[1].prog;
+  assert(ps->psglx->blur_passes[0].prog);
+  const bool more_passes = ps->psglx->blur_passes[1].prog;
   const bool have_scissors = glIsEnabled(GL_SCISSOR_TEST);
   const bool have_stencil = glIsEnabled(GL_STENCIL_TEST);
   bool ret = false;
@@ -1096,7 +1205,7 @@ glx_blur_dst(session_t *ps, int dx, int dy, int width, int height, float z,
   */
 
   GLenum tex_tgt = GL_TEXTURE_RECTANGLE;
-  if (ps->glx_has_texture_non_power_of_two)
+  if (ps->psglx->has_texture_non_power_of_two)
     tex_tgt = GL_TEXTURE_2D;
 
   // Free textures if size inconsistency discovered
@@ -1159,9 +1268,9 @@ glx_blur_dst(session_t *ps, int dx, int dy, int width, int height, float z,
 
   bool last_pass = false;
   for (int i = 0; !last_pass; ++i) {
-    last_pass = !ps->glx_blur_passes[i + 1].prog;
+    last_pass = !ps->psglx->blur_passes[i + 1].prog;
     assert(i < MAX_BLUR_PASS - 1);
-    const glx_blur_pass_t *ppass = &ps->glx_blur_passes[i];
+    const glx_blur_pass_t *ppass = &ps->psglx->blur_passes[i];
     assert(ppass->prog);
 
     assert(tex_scr);
@@ -1315,10 +1424,14 @@ glx_dim_dst(session_t *ps, int dx, int dy, int width, int height, float z,
  * @brief Render a region with texture data.
  */
 bool
-glx_render(session_t *ps, const glx_texture_t *ptex,
+glx_render_(session_t *ps, const glx_texture_t *ptex,
     int x, int y, int dx, int dy, int width, int height, int z,
-    double opacity, bool neg,
-    XserverRegion reg_tgt, const reg_data_t *pcache_reg) {
+    double opacity, bool argb, bool neg,
+    XserverRegion reg_tgt, const reg_data_t *pcache_reg
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+    , const glx_prog_main_t *pprogram
+#endif
+    ) {
   if (!ptex || !ptex->texture) {
     printf_errf("(): Missing texture.");
     return false;
@@ -1329,8 +1442,11 @@ glx_render(session_t *ps, const glx_texture_t *ptex,
   return true;
 #endif
 
-  const bool argb = (GLX_TEXTURE_FORMAT_RGBA_EXT ==
-      ps->glx_fbconfigs[ptex->depth]->texture_fmt);
+  argb = argb || (GLX_TEXTURE_FORMAT_RGBA_EXT ==
+      ps->psglx->fbconfigs[ptex->depth]->texture_fmt);
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  const bool has_prog = pprogram && pprogram->prog;
+#endif
   bool dual_texture = false;
 
   // It's required by legacy versions of OpenGL to enable texture target
@@ -1351,77 +1467,95 @@ glx_render(session_t *ps, const glx_texture_t *ptex,
     glColor4f(opacity, opacity, opacity, opacity);
   }
 
-  // Color negation
-  if (neg) {
-    // Simple color negation
-    if (!glIsEnabled(GL_BLEND)) {
-      glEnable(GL_COLOR_LOGIC_OP);
-      glLogicOp(GL_COPY_INVERTED);
-    }
-    // ARGB texture color negation
-    else if (argb) {
-      dual_texture = true;
-
-      // Use two texture stages because the calculation is too complicated,
-      // thanks to madsy for providing code
-      // Texture stage 0
-      glActiveTexture(GL_TEXTURE0);
-
-      // Negation for premultiplied color: color = A - C
-      glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_SUBTRACT);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_ALPHA);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_TEXTURE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
-
-      // Pass texture alpha through
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_TEXTURE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
-
-      // Texture stage 1
-      glActiveTexture(GL_TEXTURE1);
-      glEnable(ptex->target);
-      glBindTexture(ptex->target, ptex->texture);
-
-      glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
-
-      // Modulation with constant factor
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_PREVIOUS);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_PRIMARY_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_ALPHA);
-
-      // Modulation with constant factor
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_PREVIOUS);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA, GL_PRIMARY_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA);
-
-      glActiveTexture(GL_TEXTURE0);
-    }
-    // RGB blend color negation
-    else {
-      glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
-
-      // Modulation with constant factor
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_ONE_MINUS_SRC_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_PRIMARY_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
-
-      // Modulation with constant factor
-      glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_TEXTURE);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
-      glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA, GL_PRIMARY_COLOR);
-      glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA);
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  if (!has_prog)
+#endif
+  {
+    // Color negation
+    if (neg) {
+      // Simple color negation
+      if (!glIsEnabled(GL_BLEND)) {
+        glEnable(GL_COLOR_LOGIC_OP);
+        glLogicOp(GL_COPY_INVERTED);
+      }
+      // ARGB texture color negation
+      else if (argb) {
+        dual_texture = true;
+
+        // Use two texture stages because the calculation is too complicated,
+        // thanks to madsy for providing code
+        // Texture stage 0
+        glActiveTexture(GL_TEXTURE0);
+
+        // Negation for premultiplied color: color = A - C
+        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_SUBTRACT);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_ALPHA);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_TEXTURE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
+
+        // Pass texture alpha through
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_TEXTURE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
+
+        // Texture stage 1
+        glActiveTexture(GL_TEXTURE1);
+        glEnable(ptex->target);
+        glBindTexture(ptex->target, ptex->texture);
+
+        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
+
+        // Modulation with constant factor
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_PREVIOUS);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_PRIMARY_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_ALPHA);
+
+        // Modulation with constant factor
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_PREVIOUS);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA, GL_PRIMARY_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA);
+
+        glActiveTexture(GL_TEXTURE0);
+      }
+      // RGB blend color negation
+      else {
+        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
+
+        // Modulation with constant factor
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_ONE_MINUS_SRC_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_RGB, GL_PRIMARY_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
+
+        // Modulation with constant factor
+        glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_TEXTURE);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
+        glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE1_ALPHA, GL_PRIMARY_COLOR);
+        glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA);
+      }
     }
   }
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  else {
+    // Programmable path
+    assert(pprogram->prog);
+    glUseProgram(pprogram->prog);
+    if (pprogram->unifm_opacity >= 0)
+      glUniform1f(pprogram->unifm_opacity, opacity);
+    if (pprogram->unifm_invert_color >= 0)
+      glUniform1i(pprogram->unifm_invert_color, neg);
+    if (pprogram->unifm_tex >= 0)
+      glUniform1i(pprogram->unifm_tex, 0);
+  }
+#endif
 
 #ifdef DEBUG_GLX
   printf_dbgf("(): Draw: %d, %d, %d, %d -> %d, %d (%d, %d) z %d\n", x, y, width, height, dx, dy, ptex->width, ptex->height, z);
@@ -1504,6 +1638,11 @@ glx_render(session_t *ps, const glx_texture_t *ptex,
     glActiveTexture(GL_TEXTURE0);
   }
 
+#ifdef CONFIG_VSYNC_OPENGL_GLSL
+  if (has_prog)
+    glUseProgram(0);
+#endif
+
   glx_check_err(ps);
 
   return true;
@@ -1641,7 +1780,7 @@ glx_swap_copysubbuffermesa(session_t *ps, XserverRegion reg) {
 #ifdef DEBUG_GLX
       printf_dbgf("(): %d, %d, %d, %d\n", x, y, wid, hei);
 #endif
-      ps->glXCopySubBufferProc(ps->dpy, get_tgt_window(ps), x, y, wid, hei);
+      ps->psglx->glXCopySubBufferProc(ps->dpy, get_tgt_window(ps), x, y, wid, hei);
     }
   }
 
@@ -1650,6 +1789,32 @@ glx_swap_copysubbuffermesa(session_t *ps, XserverRegion reg) {
   cxfree(rects);
 }
 
+/**
+ * @brief Get tightly packed RGB888 data from GL front buffer.
+ *
+ * Don't expect any sort of decent performance.
+ *
+ * @returns tightly packed RGB888 data of the size of the screen,
+ *          to be freed with `free()`
+ */
+unsigned char *
+glx_take_screenshot(session_t *ps, int *out_length) {
+  int length = 3 * ps->root_width * ps->root_height;
+  GLint unpack_align_old = 0;
+  glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpack_align_old);
+  assert(unpack_align_old > 0);
+  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+  unsigned char *buf = cmalloc(length, unsigned char);
+  glReadBuffer(GL_FRONT);
+  glReadPixels(0, 0, ps->root_width, ps->root_height, GL_RGB,
+      GL_UNSIGNED_BYTE, buf);
+  glReadBuffer(GL_BACK);
+  glPixelStorei(GL_UNPACK_ALIGNMENT, unpack_align_old);
+  if (out_length)
+    *out_length = sizeof(unsigned char) * length;
+  return buf;
+}
+
 #ifdef CONFIG_VSYNC_OPENGL_GLSL
 GLuint
 glx_create_shader(GLenum shader_type, const char *shader_str) {
@@ -1661,7 +1826,7 @@ glx_create_shader(GLenum shader_type, const char *shader_str) {
   bool success = false;
   GLuint shader = glCreateShader(shader_type);
   if (!shader) {
-    printf_errf("(): Failed to create shader with type %d.", shader_type);
+    printf_errf("(): Failed to create shader with type %#x.", shader_type);
     goto glx_create_shader_end;
   }
   glShaderSource(shader, 1, &shader_str, NULL);
@@ -1737,5 +1902,40 @@ glx_create_program_end:
 
   return program;
 }
+
+/**
+ * @brief Create a program from vertex and fragment shader strings.
+ */
+GLuint
+glx_create_program_from_str(const char *vert_shader_str,
+    const char *frag_shader_str) {
+  GLuint vert_shader = 0;
+  GLuint frag_shader = 0;
+  GLuint prog = 0;
+
+  if (vert_shader_str)
+    vert_shader = glx_create_shader(GL_VERTEX_SHADER, vert_shader_str);
+  if (frag_shader_str)
+    frag_shader = glx_create_shader(GL_FRAGMENT_SHADER, frag_shader_str);
+
+  {
+    GLuint shaders[2];
+    int count = 0;
+    if (vert_shader)
+      shaders[count++] = vert_shader;
+    if (frag_shader)
+      shaders[count++] = frag_shader;
+    assert(count <= sizeof(shaders) / sizeof(shaders[0]));
+    if (count)
+      prog = glx_create_program(shaders, count);
+  }
+
+  if (vert_shader)
+    glDeleteShader(vert_shader);
+  if (frag_shader)
+    glDeleteShader(frag_shader);
+
+  return prog;
+}
 #endif
 
diff --git a/twin/compton-tde/opengl.h b/twin/compton-tde/opengl.h
index 8628e36d3..b4e04440a 100644
--- a/twin/compton-tde/opengl.h
+++ b/twin/compton-tde/opengl.h
@@ -41,10 +41,10 @@ glx_dump_err_str(GLenum err) {
  */
 static inline void
 glx_check_err_(session_t *ps, const char *func, int line) {
-  if (!ps->glx_context) return;
+  if (!ps->psglx->context) return;
 
   GLenum err = GL_NO_ERROR;
-  
+
   while (GL_NO_ERROR != (err = glGetError())) {
     print_timestamp(ps);
     printf("%s():%d: GLX error ", func, line);