--- /dev/null
+/* Copyright 2006 Google Inc. All Rights Reserved.
+ * amcrae@google.com (Andrew McRae)
+ * Converted from cairo-lut.c
+ * Author: yangzh@google.com (Zhonghao Yang)
+ *
+ * Inlines and defines for pre-multiplied alpha color conversion.
+ * The naming convention is:
+ * rgb - separate values for red, green, blue
+ * argb - separate values for alpha, red, green, blue
+ * pixel - 32 bit combined value, no premultiplication
+ * rgbpixel - 24 bit RGB, no alpha.
+ * cairo - pixel that has alpha premultiplication
+ */
+
+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2003 University of Southern California
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is University of Southern
+ * California.
+ *
+ * Contributor(s):
+ * Carl D. Worth <cworth@cworth.org>
+ * Kristian Høgsberg <krh@redhat.com>
+ */
+
+#ifndef CAIRO_LUT_PRIVATE_H
+#define CAIRO_LUT_PRIVATE_H
+
+extern const uint8_t color_lut[256][256];
+extern const uint8_t reverse_color_lut[256][256];
+
+static inline uint8_t _get_alpha (uint32_t pixel)
+{
+ return (pixel >> 24) & 0xFF;
+}
+
+static inline uint8_t _get_red (uint32_t pixel)
+{
+ return (pixel >> 16) & 0xFF;
+}
+
+static inline uint8_t _get_green (uint32_t pixel)
+{
+ return (pixel >> 8) & 0xFF;
+}
+
+static inline uint8_t _get_blue (uint32_t pixel)
+{
+ return pixel & 0xFF;
+}
+
+static inline uint32_t
+rgb_to_pixel (uint8_t r, uint8_t g, uint8_t b)
+{
+ return ((r << 16) + (g << 8) + b);
+}
+
+static inline uint32_t
+argb_to_pixel (uint8_t alpha, uint8_t r, uint8_t g, uint8_t b)
+{
+ return ((alpha << 24) + rgb_to_pixel(r, g, b));
+}
+
+static inline void
+pixel_to_rgb (uint32_t pixel, uint8_t *r, uint8_t *g, uint8_t *b)
+{
+ *r = _get_red(pixel);
+ *g = _get_green(pixel);
+ *b = _get_blue(pixel);
+}
+
+/*
+ * alpha_cairo_to_rgb:
+ * @al: The alpha value to apply to the pixel
+ * @pixel: the regular RGB pixel value
+ *
+ * return regular R/G/B channel. (non-pre-multiplied)
+ *
+ */
+static inline void
+alpha_cairo_to_rgb (uint8_t al, uint32_t pixel,
+ uint8_t *r, uint8_t *g, uint8_t *b)
+{
+ if (al != 0xFF) {
+ if (al == 0) {
+ *r = 0;
+ *g = 0;
+ *b = 0;
+ } else {
+ *r = color_lut[al][_get_red(pixel)];
+ *g = color_lut[al][_get_green(pixel)];
+ *b = color_lut[al][_get_blue(pixel)];
+ }
+ } else {
+ pixel_to_rgb(pixel, r, g, b);
+ }
+}
+
+/*
+ * cairo_to_rgb:
+ * @pixel: the regular ARGB pixel value
+ *
+ * return regular R/G/B channel. (non-pre-multiplied)
+ *
+ */
+static inline void
+cairo_to_rgb (uint32_t pixel, uint8_t *r, uint8_t *g, uint8_t *b)
+{
+ alpha_cairo_to_rgb(_get_alpha(pixel), pixel, r, g, b);
+}
+
+/*
+ * cairo_to_pixel:
+ * @pixel: the premultiplied ARGB pixel value
+ *
+ * return regular Alpha/R/G/B channel. (non-pre-multiplied)
+ *
+ */
+static inline uint32_t
+cairo_to_pixel (uint32_t pixel)
+{
+ uint8_t alpha, r, g, b;
+ alpha = _get_alpha (pixel);
+
+ if (alpha != 0xFF) {
+ if (alpha == 0) {
+ return(0);
+ }
+ r = color_lut[alpha][_get_red(pixel)];
+ g = color_lut[alpha][_get_green(pixel)];
+ b = color_lut[alpha][_get_blue(pixel)];
+ pixel = argb_to_pixel(alpha, r, g, b);
+ }
+ return(pixel);
+}
+
+/*
+ * cairo_to_rgbpixel:
+ * @pixel: the premultiplied ARGB pixel value
+ *
+ * return R/G/B channel.
+ *
+ */
+static inline uint32_t
+cairo_to_rgbpixel (uint32_t pixel)
+{
+ return(cairo_to_pixel(pixel) & 0xFFFFFF);
+}
+
+/*
+ * argb_to_cairo:
+ * @a: the alpha value
+ * @r: the red value
+ * @g: the green value
+ * @b: the blue value
+ *
+ * given a regular ARGB, return corresponding pre-multipled pixel value.
+ * this is the reverse function for cairo_to_rgb.
+ *
+ * Return value: internal pre-multiplied pixel value.
+ *
+ */
+static inline uint32_t
+argb_to_cairo (uint8_t a, uint8_t r, uint8_t g, uint8_t b)
+{
+ if (a != 0xFF) {
+ r = reverse_color_lut[a][r];
+ g = reverse_color_lut[a][g];
+ b = reverse_color_lut[a][b];
+ }
+ return argb_to_pixel (a, r, g, b);
+}
+
+/*
+ * pixel_to_cairo:
+ * @pixel_r: the regular ARGB pixel value.
+ *
+ * given a regular ARGB, return corresponding pre-multipled pixel value.
+ * this is the reverse function for cairo_to_pixel.
+ *
+ * Return value: internal pre-multiplied pixel value.
+ *
+ */
+static inline uint32_t
+pixel_to_cairo (uint32_t pixel_r)
+{
+ uint8_t alpha;
+
+ alpha = _get_alpha (pixel_r);
+ if (alpha == 0xFF)
+ return pixel_r;
+
+ return argb_to_cairo (_get_alpha(pixel_r),
+ _get_red(pixel_r),
+ _get_green(pixel_r),
+ _get_blue(pixel_r));
+}
+
+#endif /* CAIRO_LUT_PRIVATE_H */
~mdw / clg / blobdiff