1 /* GDK - The GIMP Drawing Kit
2 * Copyright (C) 2005 Red Hat, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
21 #include "gdkdrawable.h"
22 #include "gdkinternals.h"
23 #include "gdkregion-generic.h"
28 * @drawable: a #GdkDrawable
30 * Creates a Cairo context for drawing to @drawable.
33 * Note that due to double-buffering, Cairo contexts created
34 * in a GTK+ expose event handler cannot be cached and reused
35 * between different expose events.
38 * Return value: A newly created Cairo context. Free with
39 * cairo_destroy() when you are done drawing.
44 gdk_cairo_create (GdkDrawable *drawable)
46 cairo_surface_t *surface;
49 g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
51 surface = _gdk_drawable_ref_cairo_surface (drawable);
52 cr = cairo_create (surface);
53 cairo_surface_destroy (surface);
59 * gdk_cairo_set_source_color:
63 * Sets the specified #GdkColor as the source color of @cr.
68 gdk_cairo_set_source_color (cairo_t *cr,
69 const GdkColor *color)
71 g_return_if_fail (cr != NULL);
72 g_return_if_fail (color != NULL);
74 cairo_set_source_rgb (cr,
76 color->green / 65535.,
77 color->blue / 65535.);
81 * gdk_cairo_rectangle:
83 * @rectangle: a #GdkRectangle
85 * Adds the given rectangle to the current path of @cr.
90 gdk_cairo_rectangle (cairo_t *cr,
91 const GdkRectangle *rectangle)
93 g_return_if_fail (cr != NULL);
94 g_return_if_fail (rectangle != NULL);
97 rectangle->x, rectangle->y,
98 rectangle->width, rectangle->height);
104 * @region: a #GdkRegion
106 * Adds the given region to the current path of @cr.
111 gdk_cairo_region (cairo_t *cr,
112 const GdkRegion *region)
117 g_return_if_fail (cr != NULL);
118 g_return_if_fail (region != NULL);
120 boxes = region->rects;
121 n_boxes = region->numRects;
123 for (i = 0; i < n_boxes; i++)
127 boxes[i].x2 - boxes[i].x1,
128 boxes[i].y2 - boxes[i].y1);
132 * gdk_cairo_set_source_pixbuf:
133 * @cr: a #Cairo context
134 * @pixbuf: a #GdkPixbuf
135 * @pixbuf_x: X coordinate of location to place upper left corner of @pixbuf
136 * @pixbuf_y: Y coordinate of location to place upper left corner of @pixbuf
138 * Sets the given pixbuf as the source pattern for the Cairo context.
139 * The pattern has an extend mode of %CAIRO_EXTEND_NONE and is aligned
140 * so that the origin of @pixbuf is @pixbuf_x, @pixbuf_y
145 gdk_cairo_set_source_pixbuf (cairo_t *cr,
146 const GdkPixbuf *pixbuf,
150 gint width = gdk_pixbuf_get_width (pixbuf);
151 gint height = gdk_pixbuf_get_height (pixbuf);
152 guchar *gdk_pixels = gdk_pixbuf_get_pixels (pixbuf);
153 int gdk_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
154 int n_channels = gdk_pixbuf_get_n_channels (pixbuf);
156 guchar *cairo_pixels;
157 cairo_format_t format;
158 cairo_surface_t *surface;
159 static const cairo_user_data_key_t key;
163 format = CAIRO_FORMAT_RGB24;
165 format = CAIRO_FORMAT_ARGB32;
167 cairo_stride = cairo_format_stride_for_width (format, width);
168 cairo_pixels = g_malloc (height * cairo_stride);
169 surface = cairo_image_surface_create_for_data ((unsigned char *)cairo_pixels,
171 width, height, cairo_stride);
173 cairo_surface_set_user_data (surface, &key,
174 cairo_pixels, (cairo_destroy_func_t)g_free);
176 for (j = height; j; j--)
178 guchar *p = gdk_pixels;
179 guchar *q = cairo_pixels;
183 guchar *end = p + 3 * width;
187 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
202 guchar *end = p + 4 * width;
205 #define MULT(d,c,a,t) G_STMT_START { t = c * a + 0x7f; d = ((t >> 8) + t) >> 8; } G_STMT_END
209 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
210 MULT(q[0], p[2], p[3], t1);
211 MULT(q[1], p[1], p[3], t2);
212 MULT(q[2], p[0], p[3], t3);
216 MULT(q[1], p[0], p[3], t1);
217 MULT(q[2], p[1], p[3], t2);
218 MULT(q[3], p[2], p[3], t3);
228 gdk_pixels += gdk_rowstride;
229 cairo_pixels += cairo_stride;
232 cairo_set_source_surface (cr, surface, pixbuf_x, pixbuf_y);
233 cairo_surface_destroy (surface);
237 * gdk_cairo_set_source_pixmap:
238 * @cr: a #Cairo context
239 * @pixmap: a #GdkPixmap
240 * @pixmap_x: X coordinate of location to place upper left corner of @pixmap
241 * @pixmap_y: Y coordinate of location to place upper left corner of @pixmap
243 * Sets the given pixmap as the source pattern for the Cairo context.
244 * The pattern has an extend mode of %CAIRO_EXTEND_NONE and is aligned
245 * so that the origin of @pixmap is @pixmap_x, @pixmap_y
250 gdk_cairo_set_source_pixmap (cairo_t *cr,
255 cairo_surface_t *surface;
257 surface = _gdk_drawable_ref_cairo_surface (GDK_DRAWABLE (pixmap));
258 cairo_set_source_surface (cr, surface, pixmap_x, pixmap_y);
259 cairo_surface_destroy (surface);
263 #define __GDK_CAIRO_C__
264 #include "gdkaliasdef.c"