gimp/libgimpcolor/gimpcairocolor.c

/* LIBGIMP - The GIMP Library
 * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
 *
 * gimpcairocolor.c
 * Copyright (C) 2007 Sven Neumann <sven@gimp.org>
 *               2010 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/>.
 */

#include "config.h"

#include <glib-object.h>
#include <cairo.h>

#include "libgimpbase/gimpbase.h"

#include "gimpcolortypes.h"

#include "gimpcairocolor.h"


/**
 * SECTION: gimpcairocolor
 * @title: GimpCairoColor
 * @short_description: Color utility functions for cairo
 *
 * Utility functions that make cairo easier to use with GIMP color
 * data types.
 **/


/**
 * gimp_cairo_set_source_rgb:
 * @cr:    Cairo context
 * @color: GimpRGB color
 *
 * Sets the source pattern within @cr to the solid opaque color
 * described by @color.
 *
 * This function calls cairo_set_source_rgb() for you.
 *
 * Since: GIMP 2.6
 **/
void
gimp_cairo_set_source_rgb (cairo_t       *cr,
                           const GimpRGB *color)
{
  cairo_set_source_rgb (cr, color->r, color->g, color->b);
}

/**
 * gimp_cairo_set_source_rgba:
 * @cr:    Cairo context
 * @color: GimpRGB color
 *
 * Sets the source pattern within @cr to the solid translucent color
 * described by @color.
 *
 * This function calls cairo_set_source_rgba() for you.
 *
 * Since: GIMP 2.6
 **/
void
gimp_cairo_set_source_rgba (cairo_t       *cr,
                            const GimpRGB *color)
{
  cairo_set_source_rgba (cr, color->r, color->g, color->b, color->a);
}

/**
 * gimp_cairo_checkerboard_create:
 * @cr:    Cairo context
 * @size:  check size
 * @light: light check color or %NULL to use the default light gray
 * @dark:  dark check color or %NULL to use the default dark gray
 *
 * Create a repeating checkerboard pattern.
 *
 * Return value: a new Cairo pattern that can be used as a source on @cr.
 *
 * Since: GIMP 2.6
 **/
cairo_pattern_t *
gimp_cairo_checkerboard_create (cairo_t       *cr,
                                gint           size,
                                const GimpRGB *light,
                                const GimpRGB *dark)
{
  cairo_t         *context;
  cairo_surface_t *surface;
  cairo_pattern_t *pattern;

  g_return_val_if_fail (cr != NULL, NULL);
  g_return_val_if_fail (size > 0, NULL);

  surface = cairo_surface_create_similar (cairo_get_target (cr),
                                          CAIRO_CONTENT_COLOR,
                                          2 * size, 2 * size);
  context = cairo_create (surface);

  if (light)
    gimp_cairo_set_source_rgb (context, light);
  else
    cairo_set_source_rgb (context,
                          GIMP_CHECK_LIGHT, GIMP_CHECK_LIGHT, GIMP_CHECK_LIGHT);

  cairo_rectangle (context, 0,    0,    size, size);
  cairo_rectangle (context, size, size, size, size);
  cairo_fill (context);

  if (dark)
    gimp_cairo_set_source_rgb (context, dark);
  else
    cairo_set_source_rgb (context,
                          GIMP_CHECK_DARK, GIMP_CHECK_DARK, GIMP_CHECK_DARK);

  cairo_rectangle (context, 0,    size, size, size);
  cairo_rectangle (context, size, 0,    size, size);
  cairo_fill (context);

  cairo_destroy (context);

  pattern = cairo_pattern_create_for_surface (surface);
  cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REPEAT);

  cairo_surface_destroy (surface);

  return pattern;
}