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+/* Libart_LGPL - library of basic graphic primitives
+ * Copyright (C) 1998 Raph Levien
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "art_rgb_bitmap_affine.h"
+
+#include <math.h>
+#include "art_misc.h"
+#include "art_point.h"
+#include "art_affine.h"
+#include "art_rgb_affine_private.h"
+
+/* This module handles compositing of affine-transformed bitmap images
+ over rgb pixel buffers. */
+
+/* Composite the source image over the destination image, applying the
+ affine transform. Foreground color is given and assumed to be
+ opaque, background color is assumed to be fully transparent. */
+
+static void
+art_rgb_bitmap_affine_opaque (art_u8 *dst,
+ int x0, int y0, int x1, int y1,
+ int dst_rowstride,
+ const art_u8 *src,
+ int src_width, int src_height, int src_rowstride,
+ art_u32 rgb,
+ const double affine[6],
+ ArtFilterLevel level,
+ ArtAlphaGamma *alphagamma)
+{
+ /* Note: this is a slow implementation, and is missing all filter
+ levels other than NEAREST. It is here for clarity of presentation
+ and to establish the interface. */
+ int x, y;
+ double inv[6];
+ art_u8 *dst_p, *dst_linestart;
+ const art_u8 *src_p;
+ ArtPoint pt, src_pt;
+ int src_x, src_y;
+ art_u8 r, g, b;
+ int run_x0, run_x1;
+
+ r = rgb >> 16;
+ g = (rgb >> 8) & 0xff;
+ b = rgb & 0xff;
+ dst_linestart = dst;
+ art_affine_invert (inv, affine);
+ for (y = y0; y < y1; y++)
+ {
+ pt.y = y + 0.5;
+ run_x0 = x0;
+ run_x1 = x1;
+ art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height,
+ inv);
+ dst_p = dst_linestart + (run_x0 - x0) * 3;
+ for (x = run_x0; x < run_x1; x++)
+ {
+ pt.x = x + 0.5;
+ art_affine_point (&src_pt, &pt, inv);
+ src_x = floor (src_pt.x);
+ src_y = floor (src_pt.y);
+ src_p = src + (src_y * src_rowstride) + (src_x >> 3);
+ if (*src_p & (128 >> (src_x & 7)))
+ {
+ dst_p[0] = r;
+ dst_p[1] = g;
+ dst_p[2] = b;
+ }
+ dst_p += 3;
+ }
+ dst_linestart += dst_rowstride;
+ }
+}
+/* Composite the source image over the destination image, applying the
+ affine transform. Foreground color is given, background color is
+ assumed to be fully transparent. */
+
+/**
+ * art_rgb_bitmap_affine: Affine transform source bitmap image and composite.
+ * @dst: Destination image RGB buffer.
+ * @x0: Left coordinate of destination rectangle.
+ * @y0: Top coordinate of destination rectangle.
+ * @x1: Right coordinate of destination rectangle.
+ * @y1: Bottom coordinate of destination rectangle.
+ * @dst_rowstride: Rowstride of @dst buffer.
+ * @src: Source image bitmap buffer.
+ * @src_width: Width of source image.
+ * @src_height: Height of source image.
+ * @src_rowstride: Rowstride of @src buffer.
+ * @rgba: RGBA foreground color, in 0xRRGGBBAA.
+ * @affine: Affine transform.
+ * @level: Filter level.
+ * @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
+ *
+ * Affine transform the source image stored in @src, compositing over
+ * the area of destination image @dst specified by the rectangle
+ * (@x0, @y0) - (@x1, @y1).
+ *
+ * The source bitmap stored with MSB as the leftmost pixel. Source 1
+ * bits correspond to the semitransparent color @rgba, while source 0
+ * bits are transparent.
+ *
+ * See art_rgb_affine() for a description of additional parameters.
+ **/
+void
+art_rgb_bitmap_affine (art_u8 *dst,
+ int x0, int y0, int x1, int y1, int dst_rowstride,
+ const art_u8 *src,
+ int src_width, int src_height, int src_rowstride,
+ art_u32 rgba,
+ const double affine[6],
+ ArtFilterLevel level,
+ ArtAlphaGamma *alphagamma)
+{
+ /* Note: this is a slow implementation, and is missing all filter
+ levels other than NEAREST. It is here for clarity of presentation
+ and to establish the interface. */
+ int x, y;
+ double inv[6];
+ art_u8 *dst_p, *dst_linestart;
+ const art_u8 *src_p;
+ ArtPoint pt, src_pt;
+ int src_x, src_y;
+ int alpha;
+ art_u8 bg_r, bg_g, bg_b;
+ art_u8 fg_r, fg_g, fg_b;
+ art_u8 r, g, b;
+ int run_x0, run_x1;
+
+ alpha = rgba & 0xff;
+ if (alpha == 0xff)
+ {
+ art_rgb_bitmap_affine_opaque (dst, x0, y0, x1, y1, dst_rowstride,
+ src,
+ src_width, src_height, src_rowstride,
+ rgba >> 8,
+ affine,
+ level,
+ alphagamma);
+ return;
+ }
+ /* alpha = (65536 * alpha) / 255; */
+ alpha = (alpha << 8) + alpha + (alpha >> 7);
+ r = rgba >> 24;
+ g = (rgba >> 16) & 0xff;
+ b = (rgba >> 8) & 0xff;
+ dst_linestart = dst;
+ art_affine_invert (inv, affine);
+ for (y = y0; y < y1; y++)
+ {
+ pt.y = y + 0.5;
+ run_x0 = x0;
+ run_x1 = x1;
+ art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height,
+ inv);
+ dst_p = dst_linestart + (run_x0 - x0) * 3;
+ for (x = run_x0; x < run_x1; x++)
+ {
+ pt.x = x + 0.5;
+ art_affine_point (&src_pt, &pt, inv);
+ src_x = floor (src_pt.x);
+ src_y = floor (src_pt.y);
+ src_p = src + (src_y * src_rowstride) + (src_x >> 3);
+ if (*src_p & (128 >> (src_x & 7)))
+ {
+ bg_r = dst_p[0];
+ bg_g = dst_p[1];
+ bg_b = dst_p[2];
+
+ fg_r = bg_r + (((r - bg_r) * alpha + 0x8000) >> 16);
+ fg_g = bg_g + (((g - bg_g) * alpha + 0x8000) >> 16);
+ fg_b = bg_b + (((b - bg_b) * alpha + 0x8000) >> 16);
+
+ dst_p[0] = fg_r;
+ dst_p[1] = fg_g;
+ dst_p[2] = fg_b;
+ }
+ dst_p += 3;
+ }
+ dst_linestart += dst_rowstride;
+ }
+}