gimp/app/core/gimp-cairo.c

151 lines
4.2 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimp-cairo.c
* Copyright (C) 2010-2012 Michael Natterer <mitch@gimp.org>
*
* Some code here is based on code from librsvg that was originally
* written by Raph Levien <raph@artofcode.com> for Gill.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <cairo.h>
#include <gegl.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "libgimpmath/gimpmath.h"
#include "libgimpcolor/gimpcolor.h"
#include "core-types.h"
#include "gimp-cairo.h"
static cairo_user_data_key_t surface_data_key = { 0, };
cairo_pattern_t *
gimp_cairo_stipple_pattern_create (const GimpRGB *fg,
const GimpRGB *bg,
gint index,
gdouble offset_x,
gdouble offset_y)
{
cairo_surface_t *surface;
cairo_pattern_t *pattern;
guchar *data;
guchar *d;
guchar fg_r, fg_g, fg_b, fg_a;
guchar bg_r, bg_g, bg_b, bg_a;
gint x, y;
g_return_val_if_fail (fg != NULL, NULL);
g_return_val_if_fail (bg != NULL, NULL);
data = g_malloc (8 * 8 * 4);
gimp_rgba_get_uchar (fg, &fg_r, &fg_g, &fg_b, &fg_a);
gimp_rgba_get_uchar (bg, &bg_r, &bg_g, &bg_b, &bg_a);
d = data;
for (y = 0; y < 8; y++)
{
for (x = 0; x < 8; x++)
{
if ((x + y + index) % 8 >= 4)
GIMP_CAIRO_ARGB32_SET_PIXEL (d, fg_r, fg_g, fg_b, fg_a);
else
GIMP_CAIRO_ARGB32_SET_PIXEL (d, bg_r, bg_g, bg_b, bg_a);
d += 4;
}
}
surface = cairo_image_surface_create_for_data (data,
CAIRO_FORMAT_ARGB32,
8, 8, 8 * 4);
cairo_surface_set_user_data (surface, &surface_data_key,
data, (cairo_destroy_func_t) g_free);
pattern = cairo_pattern_create_for_surface (surface);
cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REPEAT);
cairo_surface_destroy (surface);
if (offset_x != 0.0 || offset_y != 0.0)
{
cairo_matrix_t matrix;
cairo_matrix_init_translate (&matrix,
fmod (offset_x, 8),
fmod (offset_y, 8));
cairo_pattern_set_matrix (pattern, &matrix);
}
return pattern;
}
void
gimp_cairo_add_arc (cairo_t *cr,
gdouble center_x,
gdouble center_y,
gdouble radius,
gdouble start_angle,
gdouble slice_angle)
{
g_return_if_fail (cr != NULL);
if (slice_angle >= 0)
{
cairo_arc_negative (cr, center_x, center_y, radius,
- start_angle,
- start_angle - slice_angle);
}
else
{
cairo_arc (cr, center_x, center_y, radius,
- start_angle,
- start_angle - slice_angle);
}
}
void
gimp_cairo_add_segments (cairo_t *cr,
GimpSegment *segs,
gint n_segs)
{
gint i;
g_return_if_fail (cr != NULL);
g_return_if_fail (segs != NULL && n_segs > 0);
for (i = 0; i < n_segs; i++)
{
if (segs[i].x1 == segs[i].x2)
{
cairo_move_to (cr, segs[i].x1 + 0.5, segs[i].y1 + 0.5);
cairo_line_to (cr, segs[i].x2 + 0.5, segs[i].y2 - 0.5);
}
else
{
cairo_move_to (cr, segs[i].x1 + 0.5, segs[i].y1 + 0.5);
cairo_line_to (cr, segs[i].x2 - 0.5, segs[i].y2 + 0.5);
}
}
}