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-rw-r--r--tdescreensaver/xsavers/xs_visual.c473
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diff --git a/tdescreensaver/xsavers/xs_visual.c b/tdescreensaver/xsavers/xs_visual.c
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+/* xscreensaver, Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
+ * by Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation. No representations are made about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ */
+
+/* This file contains some code for intelligently picking the best visual
+ (where "best" is biased in the direction of either: high color counts;
+ or: having writable color cells...)
+ */
+
+#include "xs_utils.h"
+
+#include "xs_visual.h"
+
+#include <X11/Xutil.h>
+
+/* extern char *progname; */
+
+
+#ifndef isupper
+# define isupper(c) ((c) >= 'A' && (c) <= 'Z')
+#endif
+#ifndef _tolower
+# define _tolower(c) ((c) - 'A' + 'a')
+#endif
+
+
+static Visual *pick_best_visual (Screen *, Bool, Bool);
+static Visual *pick_mono_visual (Screen *);
+static Visual *pick_best_visual_of_class (Screen *, int);
+static Visual *id_to_visual (Screen *, int);
+static Visual *id_to_visual (Screen *screen, int id);
+
+
+#define DEFAULT_VISUAL -1
+#define BEST_VISUAL -2
+#define MONO_VISUAL -3
+#define GRAY_VISUAL -4
+#define COLOR_VISUAL -5
+#define SPECIFIC_VISUAL -6
+
+Visual *
+get_visual (Screen *screen, const char *string, Bool prefer_writable_cells,
+ Bool verbose_p)
+{
+ char *v = (string ? strdup(string) : 0);
+ char c, *tmp;
+ int vclass;
+ unsigned long id;
+ Visual *result = 0;
+
+ if (v)
+ for (tmp = v; *tmp; tmp++)
+ if (isupper (*tmp)) *tmp = _tolower (*tmp);
+
+ if (!v) vclass = BEST_VISUAL;
+ else if (!strcmp (v, "default")) vclass = DEFAULT_VISUAL;
+ else if (!strcmp (v, "best")) vclass = BEST_VISUAL;
+ else if (!strcmp (v, "mono")) vclass = MONO_VISUAL;
+ else if (!strcmp (v, "monochrome")) vclass = MONO_VISUAL;
+ else if (!strcmp (v, "gray")) vclass = GRAY_VISUAL;
+ else if (!strcmp (v, "grey")) vclass = GRAY_VISUAL;
+ else if (!strcmp (v, "color")) vclass = COLOR_VISUAL;
+ else if (!strcmp (v, "staticgray")) vclass = StaticGray;
+ else if (!strcmp (v, "staticcolor")) vclass = StaticColor;
+ else if (!strcmp (v, "truecolor")) vclass = TrueColor;
+ else if (!strcmp (v, "grayscale")) vclass = GrayScale;
+ else if (!strcmp (v, "greyscale")) vclass = GrayScale;
+ else if (!strcmp (v, "pseudocolor")) vclass = PseudoColor;
+ else if (!strcmp (v, "directcolor")) vclass = DirectColor;
+ else if (1 == sscanf (v, " %ld %c", &id, &c)) vclass = SPECIFIC_VISUAL;
+ else if (1 == sscanf (v, " 0x%lx %c", &id, &c)) vclass = SPECIFIC_VISUAL;
+ else
+ {
+ fprintf (stderr, "%s: unrecognized visual \"%s\".\n", "tdescreensaver", v);
+ vclass = DEFAULT_VISUAL;
+ }
+
+ if (vclass == DEFAULT_VISUAL)
+ result = DefaultVisualOfScreen (screen);
+ else if (vclass == BEST_VISUAL)
+ result = pick_best_visual (screen, prefer_writable_cells, False);
+ else if (vclass == MONO_VISUAL)
+ {
+ result = pick_mono_visual (screen);
+ if (!result && verbose_p)
+ fprintf (stderr, "%s: no monochrome visuals.\n", "tdescreensaver");
+ }
+ else if (vclass == GRAY_VISUAL)
+ {
+ if (prefer_writable_cells)
+ result = pick_best_visual_of_class (screen, GrayScale);
+ if (!result)
+ result = pick_best_visual_of_class (screen, StaticGray);
+ if (!result)
+ result = pick_best_visual_of_class (screen, GrayScale);
+ if (!result && verbose_p)
+ fprintf (stderr, "%s: no GrayScale or StaticGray visuals.\n",
+ "tdescreensaver");
+ }
+ else if (vclass == COLOR_VISUAL)
+ {
+ int class;
+ /* First see if the default visual will do. */
+ result = DefaultVisualOfScreen (screen);
+ class = visual_class(screen, result);
+ if (class != TrueColor &&
+ class != PseudoColor &&
+ class != DirectColor &&
+ class != StaticColor)
+ result = 0;
+ if (result && visual_depth(screen, result) <= 1)
+ result = 0;
+
+ /* Else, find the best non-default color visual */
+ if (!result)
+ result = pick_best_visual (screen, prefer_writable_cells, True);
+
+ if (!result && verbose_p)
+ fprintf (stderr, "%s: no color visuals.\n", "tdescreensaver");
+ }
+ else if (vclass == SPECIFIC_VISUAL)
+ {
+ result = id_to_visual (screen, id);
+ if (!result && verbose_p)
+ fprintf (stderr, "%s: no visual with id 0x%x.\n", "tdescreensaver",
+ (unsigned int) id);
+ }
+ else
+ {
+ Visual *visual = pick_best_visual_of_class (screen, vclass);
+ if (visual)
+ result = visual;
+ else if (verbose_p)
+ fprintf (stderr, "%s: no visual of class %s.\n", "tdescreensaver", v);
+ }
+
+ if (v) free (v);
+ return result;
+}
+
+Visual *
+get_visual_resource (Screen *screen, char *name, char *class,
+ Bool prefer_writable_cells)
+{
+/*
+ char *string = get_string_resource (name, class);
+ Visual *v = get_visual (screen, string, prefer_writable_cells, True);
+ if (string)
+ free(string);
+ if (v)
+ return v;
+ else
+*/
+ return DefaultVisualOfScreen (screen);
+}
+
+
+static Visual *
+pick_best_visual (Screen *screen, Bool prefer_writable_cells, Bool color_only)
+{
+ Visual *visual;
+
+ if (!prefer_writable_cells)
+ {
+ /* If we don't prefer writable cells, then the "best" visual is the one
+ on which we can allocate the largest range and number of colors.
+
+ Therefore, a TrueColor visual which is at least 16 bits deep is best.
+ (The assumption here being that a TrueColor of less than 16 bits is
+ really just a PseudoColor visual with a pre-allocated color cube.)
+
+ The next best thing is a PseudoColor visual of any type. After that
+ come the non-colormappable visuals, and non-color visuals.
+ */
+ if ((visual = pick_best_visual_of_class (screen, TrueColor)) &&
+ visual_depth (screen, visual) >= 16)
+ return visual;
+ }
+
+#define TRY_CLASS(CLASS) \
+ if ((visual = pick_best_visual_of_class (screen, CLASS)) && \
+ (!color_only || visual_depth(screen, visual) > 1)) \
+ return visual
+ TRY_CLASS(PseudoColor);
+ TRY_CLASS(TrueColor);
+ TRY_CLASS(DirectColor);
+ TRY_CLASS(StaticColor);
+ if (!color_only)
+ {
+ TRY_CLASS(GrayScale);
+ TRY_CLASS(StaticGray);
+ }
+#undef TRY_CLASS
+
+ visual = DefaultVisualOfScreen (screen);
+ if (!color_only || visual_depth(screen, visual) > 1)
+ return visual;
+ else
+ return 0;
+}
+
+static Visual *
+pick_mono_visual (Screen *screen)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count;
+
+ vi_in.depth = 1;
+ vi_in.screen = screen_number (screen);
+ vi_out = XGetVisualInfo (dpy, (VisualDepthMask | VisualScreenMask),
+ &vi_in, &out_count);
+ if (vi_out)
+ {
+ Visual *v = (out_count > 0 ? vi_out [0].visual : 0);
+ if (v && vi_out[0].depth != 1)
+ v = 0;
+ XFree ((char *) vi_out);
+ return v;
+ }
+ else
+ return 0;
+}
+
+
+static Visual *
+pick_best_visual_of_class (Screen *screen, int visual_class)
+{
+ /* The best visual of a class is the one which on which we can allocate
+ the largest range and number of colors, which means the one with the
+ greatest depth and number of cells.
+
+ (But actually, for XDaliClock, all visuals of the same class are
+ probably equivalent - either we have writable cells or we don't.)
+ */
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count;
+
+ vi_in.class = visual_class;
+ vi_in.screen = screen_number (screen);
+ vi_out = XGetVisualInfo (dpy, (VisualClassMask | VisualScreenMask),
+ &vi_in, &out_count);
+ if (vi_out)
+ {
+ /* choose the 'best' one, if multiple */
+ int i, best;
+ Visual *visual;
+ for (i = 0, best = 0; i < out_count; i++)
+ /* It's better if it's deeper, or if it's the same depth with
+ more cells (does that ever happen? Well, it could...) */
+ if ((vi_out [i].depth > vi_out [best].depth) ||
+ ((vi_out [i].depth == vi_out [best].depth) &&
+ (vi_out [i].colormap_size > vi_out [best].colormap_size)))
+ best = i;
+ visual = (best < out_count ? vi_out [best].visual : 0);
+ XFree ((char *) vi_out);
+ return visual;
+ }
+ else
+ return 0;
+}
+
+static Visual *
+id_to_visual (Screen *screen, int id)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count;
+ vi_in.screen = screen_number (screen);
+ vi_in.visualid = id;
+ vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualIDMask),
+ &vi_in, &out_count);
+ if (vi_out)
+ {
+ Visual *v = vi_out[0].visual;
+ XFree ((char *) vi_out);
+ return v;
+ }
+ return 0;
+}
+
+int
+visual_depth (Screen *screen, Visual *visual)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count, d;
+ vi_in.screen = screen_number (screen);
+ vi_in.visualid = XVisualIDFromVisual (visual);
+ vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
+ &vi_in, &out_count);
+ if (! vi_out) abort ();
+ d = vi_out [0].depth;
+ XFree ((char *) vi_out);
+ return d;
+}
+
+
+#if 0
+/* You very probably don't want to be using this.
+ Pixmap depth doesn't refer to the depths of pixmaps, but rather, to
+ the depth of protocol-level on-the-wire pixmap data, that is, XImages.
+ To get this info, you should be looking at XImage->bits_per_pixel
+ instead. (And allocating the data for your XImage structures by
+ multiplying ximage->bytes_per_line by ximage->height.)
+ */
+int
+visual_pixmap_depth (Screen *screen, Visual *visual)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ int vdepth = visual_depth (screen, visual);
+ int pdepth = vdepth;
+ int i, pfvc = 0;
+ XPixmapFormatValues *pfv = XListPixmapFormats (dpy, &pfvc);
+
+ /* Return the first matching depth in the pixmap formats. If there are no
+ matching pixmap formats (which shouldn't be able to happen at all) then
+ return the visual depth instead. */
+ for (i = 0; i < pfvc; i++)
+ if (pfv[i].depth == vdepth)
+ {
+ pdepth = pfv[i].bits_per_pixel;
+ break;
+ }
+ if (pfv)
+ XFree (pfv);
+ return pdepth;
+}
+#endif /* 0 */
+
+
+int
+visual_class (Screen *screen, Visual *visual)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count, c;
+ vi_in.screen = screen_number (screen);
+ vi_in.visualid = XVisualIDFromVisual (visual);
+ vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
+ &vi_in, &out_count);
+ if (! vi_out) abort ();
+ c = vi_out [0].class;
+ XFree ((char *) vi_out);
+ return c;
+}
+
+Bool
+has_writable_cells (Screen *screen, Visual *visual)
+{
+ switch (visual_class (screen, visual))
+ {
+ case GrayScale: /* Mappable grays. */
+ case PseudoColor: /* Mappable colors. */
+ return True;
+ case StaticGray: /* Fixed grays. */
+ case TrueColor: /* Fixed colors. */
+ case StaticColor: /* (What's the difference again?) */
+ case DirectColor: /* DirectColor visuals are like TrueColor, but have
+ three colormaps - one for each component of RGB.
+ Screw it. */
+ return False;
+ default:
+ abort();
+ }
+}
+
+void
+describe_visual (FILE *f, Screen *screen, Visual *visual, Bool private_cmap_p)
+{
+ char n[10];
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count;
+ vi_in.screen = screen_number (screen);
+ vi_in.visualid = XVisualIDFromVisual (visual);
+ vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualIDMask),
+ &vi_in, &out_count);
+ if (! vi_out) abort ();
+ if (private_cmap_p)
+ sprintf(n, "%3d", vi_out->colormap_size);
+ else
+ strcpy(n, "default");
+
+ fprintf (f, "0x%02x (%s depth: %2d, cmap: %s)\n",
+ (unsigned int) vi_out->visualid,
+ (vi_out->class == StaticGray ? "StaticGray, " :
+ vi_out->class == StaticColor ? "StaticColor," :
+ vi_out->class == TrueColor ? "TrueColor, " :
+ vi_out->class == GrayScale ? "GrayScale, " :
+ vi_out->class == PseudoColor ? "PseudoColor," :
+ vi_out->class == DirectColor ? "DirectColor," :
+ "UNKNOWN: "),
+ vi_out->depth, n);
+ XFree ((char *) vi_out);
+}
+
+int
+screen_number (Screen *screen)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ int i;
+ for (i = 0; i < ScreenCount (dpy); i++)
+ if (ScreenOfDisplay (dpy, i) == screen)
+ return i;
+ abort ();
+}
+
+int
+visual_cells (Screen *screen, Visual *visual)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ int out_count, c;
+ vi_in.screen = screen_number (screen);
+ vi_in.visualid = XVisualIDFromVisual (visual);
+ vi_out = XGetVisualInfo (dpy, VisualScreenMask|VisualIDMask,
+ &vi_in, &out_count);
+ if (! vi_out) abort ();
+ c = vi_out [0].colormap_size;
+ XFree ((char *) vi_out);
+ return c;
+}
+
+Visual *
+find_similar_visual(Screen *screen, Visual *old_visual)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ XVisualInfo vi_in, *vi_out;
+ Visual *result = 0;
+ int out_count;
+
+ vi_in.screen = screen_number (screen);
+ vi_in.class = visual_class (screen, old_visual);
+ vi_in.depth = visual_depth (screen, old_visual);
+
+ /* Look for a visual of the same class and depth.
+ */
+ vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask |
+ VisualDepthMask),
+ &vi_in, &out_count);
+ if (vi_out && out_count > 0)
+ result = vi_out[0].visual;
+ if (vi_out) XFree (vi_out);
+ vi_out = 0;
+
+ /* Failing that, look for a visual of the same class.
+ */
+ if (!result)
+ {
+ vi_out = XGetVisualInfo (dpy, (VisualScreenMask | VisualClassMask),
+ &vi_in, &out_count);
+ if (vi_out && out_count > 0)
+ result = vi_out[0].visual;
+ if (vi_out) XFree (vi_out);
+ vi_out = 0;
+ }
+
+ /* Failing that, return the default visual. */
+ if (!result)
+ result = DefaultVisualOfScreen (screen);
+
+ return result;
+}