mutter/cogl-color.h
Robert Bragg 7b85da8b28 [cogl-color] Adds a cogl_color_equal() function
CoglColors shouldn't be compared using memcmp since they may contain
uninitialized padding bytes.

The prototype is also suitable for passing to g_hash_table_new as the
key_equal_func.

_cogl_pango_display_list_add_texture now uses this instead of memcmp.
2009-06-30 17:13:35 +01:00

262 lines
6.5 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2008,2009 Intel Corporation.
*
* 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 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
* 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_COLOR_H__
#define __COGL_COLOR_H__
#include <cogl/cogl-types.h>
G_BEGIN_DECLS
CoglColor *cogl_color_new (void);
CoglColor *cogl_color_copy (const CoglColor *color);
void cogl_color_free (CoglColor *color);
/**
* cogl_color_set_from_4ub:
* @dest: return location for a #CoglColor
* @red: value of the red channel, between 0 and 255
* @green: value of the green channel, between 0 and 255
* @blue: value of the blue channel, between 0 and 255
* @alpha: value of the alpha channel, between 0 and 255
*
* Sets the values of the passed channels into a #CoglColor.
*
* Since: 1.0
*/
void cogl_color_set_from_4ub (CoglColor *dest,
guint8 red,
guint8 green,
guint8 blue,
guint8 alpha);
/**
* cogl_color_set_from_4f:
* @dest: return location for a #CoglColor
* @red: value of the red channel, between 0 and %1.0
* @green: value of the green channel, between 0 and %1.0
* @blue: value of the blue channel, between 0 and %1.0
* @alpha: value of the alpha channel, between 0 and %1.0
*
* Sets the values of the passed channels into a #CoglColor
*
* Since: 1.0
*/
void cogl_color_set_from_4f (CoglColor *dest,
float red,
float green,
float blue,
float alpha);
/**
* cogl_color_get_red_byte:
* @color: a #CoglColor
*
* Retrieves the red channel of @color as a byte value
* between 0 and 255
*
* Return value: the red channel of the passed color
*
* Since: 1.0
*/
unsigned char cogl_color_get_red_byte (const CoglColor *color);
/**
* cogl_color_get_green_byte:
* @color: a #CoglColor
*
* Retrieves the green channel of @color as a byte value
* between 0 and 255
*
* Return value: the green channel of the passed color
*
* Since: 1.0
*/
unsigned char cogl_color_get_green_byte (const CoglColor *color);
/**
* cogl_color_get_blue_byte:
* @color: a #CoglColor
*
* Retrieves the blue channel of @color as a byte value
* between 0 and 255
*
* Return value: the blue channel of the passed color
*
* Since: 1.0
*/
unsigned char cogl_color_get_blue_byte (const CoglColor *color);
/**
* cogl_color_get_alpha_byte:
* @color: a #CoglColor
*
* Retrieves the alpha channel of @color as a byte value
* between 0 and 255
*
* Return value: the alpha channel of the passed color
*
* Since: 1.0
*/
unsigned char cogl_color_get_alpha_byte (const CoglColor *color);
/**
* cogl_color_get_red_float:
* @color: a #CoglColor
*
* Retrieves the red channel of @color as a floating point
* value between 0.0 and 1.0
*
* Return value: the red channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_red_float (const CoglColor *color);
/**
* cogl_color_get_green_float:
* @color: a #CoglColor
*
* Retrieves the green channel of @color as a floating point
* value between 0.0 and 1.0
*
* Return value: the green channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_green_float (const CoglColor *color);
/**
* cogl_color_get_blue_float:
* @color: a #CoglColor
*
* Retrieves the blue channel of @color as a floating point
* value between 0.0 and 1.0
*
* Return value: the blue channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_blue_float (const CoglColor *color);
/**
* cogl_color_get_alpha_float:
* @color: a #CoglColor
*
* Retrieves the alpha channel of @color as a floating point
* value between 0.0 and 1.0
*
* Return value: the alpha channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_alpha_float (const CoglColor *color);
/**
* cogl_color_get_red:
* @color: a #CoglColor
*
* Retrieves the red channel of @color as a fixed point
* value between 0 and %1.0.
*
* Return value: the red channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_red (const CoglColor *color);
/**
* cogl_color_get_green:
* @color: a #CoglColor
*
* Retrieves the green channel of @color as a fixed point
* value between 0 and %1.0.
*
* Return value: the green channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_green (const CoglColor *color);
/**
* cogl_color_get_blue:
* @color: a #CoglColor
*
* Retrieves the blue channel of @color as a fixed point
* value between 0 and %1.0.
*
* Return value: the blue channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_blue (const CoglColor *color);
/**
* cogl_color_get_alpha:
* @color: a #CoglColor
*
* Retrieves the alpha channel of @color as a fixed point
* value between 0 and %1.0.
*
* Return value: the alpha channel of the passed color
*
* Since: 1.0
*/
float cogl_color_get_alpha (const CoglColor *color);
/**
* cogl_color_premultiply:
* @color: the color to premultiply
*
* Converts a non-premultiplied color to a pre-multiplied color. For
* example, semi-transparent red is (1.0, 0, 0, 0.5) when non-premultiplied
* and (0.5, 0, 0, 0.5) when premultiplied.
*
* Since: 1.0
*/
void cogl_color_premultiply (CoglColor *color);
/**
* cogl_color_equal:
* @v1: a #CoglColor
* @v2: a #CoglColor
*
* Compares two #CoglColor<!-- -->s and checks if they are the same.
*
* This function can be passed to g_hash_table_new() as the @key_equal_func
* parameter, when using #CoglColor<!-- -->s as keys in a #GHashTable.
*
* Return value: %TRUE if the two colors are the same.
*
* Since: 1.0
*/
gboolean cogl_color_equal (gconstpointer v1, gconstpointer v2);
G_END_DECLS
#endif /* __COGL_COLOR_H__ */