--- /dev/null
+/* 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_a_affine.h"
+
+#include <math.h>
+
+#include "art_affine.h"
+#include "art_point.h"
+#include "art_rgb_affine_private.h"
+
+/* This module handles compositing of affine-transformed alpha only images
+ over rgb pixel buffers. */
+
+/* Composite the source image over the destination image, applying the
+ affine transform. */
+
+/**
+ * art_rgb_a_affine: Affine transform source Alpha 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 alpha buffer.
+ * @src_width: Width of source image.
+ * @src_height: Height of source image.
+ * @src_rowstride: Rowstride of @src buffer.
+ * @rgb: RGB foreground color, in 0xRRGGBB.
+ * @affine: Affine transform.
+ * @level: Filter level.
+ * @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
+ *
+ * Affine transform the solid color rgb with alpha specified by the
+ * source image stored in @src, compositing over the area of destination
+ * image @dst specified by the rectangle (@x0, @y0) - (@x1, @y1).
+ * As usual in libart, the left and top edges of this rectangle are
+ * included, and the right and bottom edges are excluded.
+ *
+ * The @alphagamma parameter specifies that the alpha compositing be
+ * done in a gamma-corrected color space. In the current
+ * implementation, it is ignored.
+ *
+ * The @level parameter specifies the speed/quality tradeoff of the
+ * image interpolation. Currently, only ART_FILTER_NEAREST is
+ * implemented.
+ **/
+void
+art_rgb_a_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 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;
+ int alpha;
+ art_u8 bg_r, bg_g, bg_b;
+ art_u8 fg_r, fg_g, fg_b;
+ int tmp;
+ int run_x0, run_x1;
+ art_u8 r, g, b;
+
+ r = (rgb>>16)&0xff;
+ 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;
+ if (src_x >= 0 && src_x < src_width &&
+ src_y >= 0 && src_y < src_height)
+ {
+
+ alpha = *src_p;
+ if (alpha)
+ {
+ if (alpha == 255)
+ {
+ dst_p[0] = r;
+ dst_p[1] = g;
+ dst_p[2] = b;
+ }
+ else
+ {
+ bg_r = dst_p[0];
+ bg_g = dst_p[1];
+ bg_b = dst_p[2];
+
+ tmp = (r - bg_r) * alpha;
+ fg_r = bg_r + ((tmp + (tmp >> 8) + 0x80) >> 8);
+ tmp = (g - bg_g) * alpha;
+ fg_g = bg_g + ((tmp + (tmp >> 8) + 0x80) >> 8);
+ tmp = (b - bg_b) * alpha;
+ fg_b = bg_b + ((tmp + (tmp >> 8) + 0x80) >> 8);
+
+ dst_p[0] = fg_r;
+ dst_p[1] = fg_g;
+ dst_p[2] = fg_b;
+ }
+ }
+ } else { dst_p[0] = 255; dst_p[1] = 0; dst_p[2] = 0; }
+ dst_p += 3;
+ }
+ dst_linestart += dst_rowstride;
+ }
+}
git.asbjorn.biz / swftools.git / blobdiff