gimp/libgimpcolor/gimpcairo.h

160 lines
5.6 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* gimpcairo.h
* Copyright (C) 2007 Sven Neumann <sven@gimp.org>
* 2010-2012 Michael Natterer <mitch@gimp.org>
*
* This library is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#ifndef __GIMP_CAIRO_H__
#define __GIMP_CAIRO_H__
void gimp_cairo_set_source_rgb (cairo_t *cr,
const GimpRGB *color);
void gimp_cairo_set_source_rgba (cairo_t *cr,
const GimpRGB *color);
cairo_pattern_t * gimp_cairo_checkerboard_create (cairo_t *cr,
gint size,
const GimpRGB *light,
const GimpRGB *dark);
const Babl * gimp_cairo_surface_get_format (cairo_surface_t *surface);
GeglBuffer * gimp_cairo_surface_create_buffer (cairo_surface_t *surface);
/* some useful macros for writing directly to a Cairo surface */
/**
* GIMP_CAIRO_RGB24_SET_PIXEL:
* @d: pointer to the destination buffer
* @r: red component
* @g: green component
* @b: blue component
*
* Sets a single pixel in an Cairo image surface in %CAIRO_FORMAT_RGB24.
*
* Since: GIMP 2.6
**/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GIMP_CAIRO_RGB24_SET_PIXEL(d, r, g, b) \
G_STMT_START { d[0] = (b); d[1] = (g); d[2] = (r); } G_STMT_END
#else
#define GIMP_CAIRO_RGB24_SET_PIXEL(d, r, g, b) \
G_STMT_START { d[1] = (r); d[2] = (g); d[3] = (b); } G_STMT_END
#endif
/**
* GIMP_CAIRO_RGB24_GET_PIXEL:
* @s: pointer to the source buffer
* @r: red component
* @g: green component
* @b: blue component
*
* Gets a single pixel from a Cairo image surface in %CAIRO_FORMAT_RGB24.
*
* Since: GIMP 2.8
**/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GIMP_CAIRO_RGB24_GET_PIXEL(s, r, g, b) \
G_STMT_START { (b) = s[0]; (g) = s[1]; (r) = s[2]; } G_STMT_END
#else
#define GIMP_CAIRO_RGB24_GET_PIXEL(s, r, g, b) \
G_STMT_START { (r) = s[1]; (g) = s[2]; (b) = s[3]; } G_STMT_END
#endif
/**
* GIMP_CAIRO_ARGB32_SET_PIXEL:
* @d: pointer to the destination buffer
* @r: red component, not pre-multiplied
* @g: green component, not pre-multiplied
* @b: blue component, not pre-multiplied
* @a: alpha component
*
* Sets a single pixel in an Cairo image surface in %CAIRO_FORMAT_ARGB32.
*
* Since: GIMP 2.6
**/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GIMP_CAIRO_ARGB32_SET_PIXEL(d, r, g, b, a) \
G_STMT_START { \
const guint tr = (a) * (r) + 0x80; \
const guint tg = (a) * (g) + 0x80; \
const guint tb = (a) * (b) + 0x80; \
(d)[0] = (((tb) >> 8) + (tb)) >> 8; \
(d)[1] = (((tg) >> 8) + (tg)) >> 8; \
(d)[2] = (((tr) >> 8) + (tr)) >> 8; \
(d)[3] = (a); \
} G_STMT_END
#else
#define GIMP_CAIRO_ARGB32_SET_PIXEL(d, r, g, b, a) \
G_STMT_START { \
const guint tr = (a) * (r) + 0x80; \
const guint tg = (a) * (g) + 0x80; \
const guint tb = (a) * (b) + 0x80; \
(d)[0] = (a); \
(d)[1] = (((tr) >> 8) + (tr)) >> 8; \
(d)[2] = (((tg) >> 8) + (tg)) >> 8; \
(d)[3] = (((tb) >> 8) + (tb)) >> 8; \
} G_STMT_END
#endif
/**
* GIMP_CAIRO_ARGB32_GET_PIXEL:
* @s: pointer to the source buffer
* @r: red component, not pre-multiplied
* @g: green component, not pre-multiplied
* @b: blue component, not pre-multiplied
* @a: alpha component
*
* Gets a single pixel from a Cairo image surface in %CAIRO_FORMAT_ARGB32.
*
* Since: GIMP 2.8
**/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GIMP_CAIRO_ARGB32_GET_PIXEL(s, r, g, b, a) \
G_STMT_START { \
const guint tb = (s)[0]; \
const guint tg = (s)[1]; \
const guint tr = (s)[2]; \
const guint ta = (s)[3]; \
(r) = (tr << 8) / (ta + 1); \
(g) = (tg << 8) / (ta + 1); \
(b) = (tb << 8) / (ta + 1); \
(a) = ta; \
} G_STMT_END
#else
#define GIMP_CAIRO_ARGB32_GET_PIXEL(s, r, g, b, a) \
G_STMT_START { \
const guint ta = (s)[0]; \
const guint tr = (s)[1]; \
const guint tg = (s)[2]; \
const guint tb = (s)[3]; \
(r) = (tr << 8) / (ta + 1); \
(g) = (tg << 8) / (ta + 1); \
(b) = (tb << 8) / (ta + 1); \
(a) = ta; \
} G_STMT_END
#endif
#endif /* __GIMP_CAIRO_H__ */