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Diffstat (limited to 'Build/source/libs/cairo/cairo-1.12.8/src/cairo-color.c')
-rw-r--r-- | Build/source/libs/cairo/cairo-1.12.8/src/cairo-color.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/Build/source/libs/cairo/cairo-1.12.8/src/cairo-color.c b/Build/source/libs/cairo/cairo-1.12.8/src/cairo-color.c new file mode 100644 index 00000000000..9c852559e28 --- /dev/null +++ b/Build/source/libs/cairo/cairo-1.12.8/src/cairo-color.c @@ -0,0 +1,198 @@ +/* cairo - a vector graphics library with display and print output + * + * Copyright © 2002 University of Southern California + * Copyright © 2005 Red Hat, Inc. + * + * 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, 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> + */ + +#include "cairoint.h" + +static cairo_color_t const cairo_color_white = { + 1.0, 1.0, 1.0, 1.0, + 0xffff, 0xffff, 0xffff, 0xffff +}; + +static cairo_color_t const cairo_color_black = { + 0.0, 0.0, 0.0, 1.0, + 0x0, 0x0, 0x0, 0xffff +}; + +static cairo_color_t const cairo_color_transparent = { + 0.0, 0.0, 0.0, 0.0, + 0x0, 0x0, 0x0, 0x0 +}; + +static cairo_color_t const cairo_color_magenta = { + 1.0, 0.0, 1.0, 1.0, + 0xffff, 0x0, 0xffff, 0xffff +}; + +const cairo_color_t * +_cairo_stock_color (cairo_stock_t stock) +{ + switch (stock) { + case CAIRO_STOCK_WHITE: + return &cairo_color_white; + case CAIRO_STOCK_BLACK: + return &cairo_color_black; + case CAIRO_STOCK_TRANSPARENT: + return &cairo_color_transparent; + + case CAIRO_STOCK_NUM_COLORS: + default: + ASSERT_NOT_REACHED; + /* If the user can get here somehow, give a color that indicates a + * problem. */ + return &cairo_color_magenta; + } +} + +/* Convert a double in [0.0, 1.0] to an integer in [0, 65535] + * The conversion is designed to divide the input range into 65536 + * equally-sized regions. This is achieved by multiplying by 65536 and + * then special-casing the result of an input value of 1.0 so that it + * maps to 65535 instead of 65536. + */ +uint16_t +_cairo_color_double_to_short (double d) +{ + uint32_t i; + i = (uint32_t) (d * 65536); + i -= (i >> 16); + return i; +} + +static void +_cairo_color_compute_shorts (cairo_color_t *color) +{ + color->red_short = _cairo_color_double_to_short (color->red * color->alpha); + color->green_short = _cairo_color_double_to_short (color->green * color->alpha); + color->blue_short = _cairo_color_double_to_short (color->blue * color->alpha); + color->alpha_short = _cairo_color_double_to_short (color->alpha); +} + +void +_cairo_color_init_rgba (cairo_color_t *color, + double red, double green, double blue, + double alpha) +{ + color->red = red; + color->green = green; + color->blue = blue; + color->alpha = alpha; + + _cairo_color_compute_shorts (color); +} + +void +_cairo_color_multiply_alpha (cairo_color_t *color, + double alpha) +{ + color->alpha *= alpha; + + _cairo_color_compute_shorts (color); +} + +void +_cairo_color_get_rgba (cairo_color_t *color, + double *red, + double *green, + double *blue, + double *alpha) +{ + *red = color->red; + *green = color->green; + *blue = color->blue; + *alpha = color->alpha; +} + +void +_cairo_color_get_rgba_premultiplied (cairo_color_t *color, + double *red, + double *green, + double *blue, + double *alpha) +{ + *red = color->red * color->alpha; + *green = color->green * color->alpha; + *blue = color->blue * color->alpha; + *alpha = color->alpha; +} + +/* NB: This function works both for unmultiplied and premultiplied colors */ +cairo_bool_t +_cairo_color_equal (const cairo_color_t *color_a, + const cairo_color_t *color_b) +{ + if (color_a == color_b) + return TRUE; + + if (color_a->alpha_short != color_b->alpha_short) + return FALSE; + + if (color_a->alpha_short == 0) + return TRUE; + + return color_a->red_short == color_b->red_short && + color_a->green_short == color_b->green_short && + color_a->blue_short == color_b->blue_short; +} + +cairo_bool_t +_cairo_color_stop_equal (const cairo_color_stop_t *color_a, + const cairo_color_stop_t *color_b) +{ + if (color_a == color_b) + return TRUE; + + return color_a->alpha_short == color_b->alpha_short && + color_a->red_short == color_b->red_short && + color_a->green_short == color_b->green_short && + color_a->blue_short == color_b->blue_short; +} + +cairo_content_t +_cairo_color_get_content (const cairo_color_t *color) +{ + if (CAIRO_COLOR_IS_OPAQUE (color)) + return CAIRO_CONTENT_COLOR; + + if (color->red_short == 0 && + color->green_short == 0 && + color->blue_short == 0) + { + return CAIRO_CONTENT_ALPHA; + } + + return CAIRO_CONTENT_COLOR_ALPHA; +} |