--- /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.h"
+
+#include <string.h> /* for memset */
+
+/* Basic operators for manipulating 24-bit packed RGB buffers. */
+
+#define COLOR_RUN_COMPLEX
+
+#ifdef COLOR_RUN_SIMPLE
+/* This is really slow. Is there any way we might speed it up?
+ Two ideas:
+
+ First, maybe we should be working at 32-bit alignment. Then,
+ this can be a simple loop over word stores.
+
+ Second, we can keep working at 24-bit alignment, but have some
+ intelligence about storing. For example, we can iterate over
+ 4-pixel chunks (aligned at 4 pixels), with an inner loop
+ something like:
+
+ *buf++ = v1;
+ *buf++ = v2;
+ *buf++ = v3;
+
+ One source of extra complexity is the need to make sure linebuf is
+ aligned to a 32-bit boundary.
+
+ This second alternative has some complexity to it, but is
+ appealing because it really minimizes the memory bandwidth. */
+void
+art_rgb_fill_run (art_u8 *buf, art_u8 r, art_u8 g, art_u8 b, gint n)
+{
+ int i;
+
+ if (r == g && g == b)
+ {
+ memset (buf, g, n + n + n);
+ }
+ else
+ {
+ for (i = 0; i < n; i++)
+ {
+ *buf++ = r;
+ *buf++ = g;
+ *buf++ = b;
+ }
+ }
+}
+#endif
+
+#ifdef COLOR_RUN_COMPLEX
+/* This implements the second of the two ideas above. The test results
+ are _very_ encouraging - it seems the speed is within 10% of
+ memset, which is quite good! */
+/**
+ * art_rgb_fill_run: fill a buffer a solid RGB color.
+ * @buf: Buffer to fill.
+ * @r: Red, range 0..255.
+ * @g: Green, range 0..255.
+ * @b: Blue, range 0..255.
+ * @n: Number of RGB triples to fill.
+ *
+ * Fills a buffer with @n copies of the (@r, @g, @b) triple. Thus,
+ * locations @buf (inclusive) through @buf + 3 * @n (exclusive) are
+ * written.
+ *
+ * The implementation of this routine is very highly optimized.
+ **/
+void
+art_rgb_fill_run (art_u8 *buf, art_u8 r, art_u8 g, art_u8 b, int n)
+{
+ int i;
+ unsigned int v1, v2, v3;
+
+ if (r == g && g == b)
+ {
+ memset (buf, g, n + n + n);
+ }
+ else
+ {
+ if (n < 8)
+ {
+ for (i = 0; i < n; i++)
+ {
+ *buf++ = r;
+ *buf++ = g;
+ *buf++ = b;
+ }
+ } else {
+ /* handle prefix up to byte alignment */
+ /* I'm worried about this cast on sizeof(long) != sizeof(uchar *)
+ architectures, but it _should_ work. */
+ for (i = 0; ((unsigned long)buf) & 3; i++)
+ {
+ *buf++ = r;
+ *buf++ = g;
+ *buf++ = b;
+ }
+#ifndef WORDS_BIGENDIAN
+ v1 = r | (g << 8) | (b << 16) | (r << 24);
+ v3 = (v1 << 8) | b;
+ v2 = (v3 << 8) | g;
+#else
+ v1 = (r << 24) | (g << 16) | (b << 8) | r;
+ v2 = (v1 << 8) | g;
+ v3 = (v2 << 8) | b;
+#endif
+ for (; i < n - 3; i += 4)
+ {
+ ((art_u32 *)buf)[0] = v1;
+ ((art_u32 *)buf)[1] = v2;
+ ((art_u32 *)buf)[2] = v3;
+ buf += 12;
+ }
+ /* handle postfix */
+ for (; i < n; i++)
+ {
+ *buf++ = r;
+ *buf++ = g;
+ *buf++ = b;
+ }
+ }
+ }
+}
+#endif
+
+/**
+ * art_rgb_run_alpha: Render semitransparent color over RGB buffer.
+ * @buf: Buffer for rendering.
+ * @r: Red, range 0..255.
+ * @g: Green, range 0..255.
+ * @b: Blue, range 0..255.
+ * @alpha: Alpha, range 0..256.
+ * @n: Number of RGB triples to render.
+ *
+ * Renders a sequential run of solid (@r, @g, @b) color over @buf with
+ * opacity @alpha.
+ **/
+void
+art_rgb_run_alpha (art_u8 *buf, art_u8 r, art_u8 g, art_u8 b, int alpha, int n)
+{
+ int i;
+ int v;
+
+ for (i = 0; i < n; i++)
+ {
+ v = *buf;
+ *buf++ = v + (((r - v) * alpha + 0x80) >> 8);
+ v = *buf;
+ *buf++ = v + (((g - v) * alpha + 0x80) >> 8);
+ v = *buf;
+ *buf++ = v + (((b - v) * alpha + 0x80) >> 8);
+ }
+}
+
git.asbjorn.biz / swftools.git / blobdiff