+++ /dev/null
-/* GdkPixbuf library - Rendering functions
- *
- * Copyright (C) 1999 The Free Software Foundation
- *
- * Author: Federico Mena-Quintero <federico@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 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.
- */
-
-#include "config.h"
-#include <gdk/gdk.h>
-#include <gdk-pixbuf/gdk-pixbuf.h>
-#include "gdkpixbuf.h"
-#include "gdkscreen.h"
-#include "gdkinternals.h"
-
-
-/**
- * gdk_pixbuf_render_threshold_alpha:
- * @pixbuf: A pixbuf.
- * @bitmap: Bitmap where the bilevel mask will be painted to.
- * @src_x: Source X coordinate.
- * @src_y: source Y coordinate.
- * @dest_x: Destination X coordinate.
- * @dest_y: Destination Y coordinate.
- * @width: Width of region to threshold, or -1 to use pixbuf width
- * @height: Height of region to threshold, or -1 to use pixbuf height
- * @alpha_threshold: Opacity values below this will be painted as zero; all
- * other values will be painted as one.
- *
- * Takes the opacity values in a rectangular portion of a pixbuf and thresholds
- * them to produce a bi-level alpha mask that can be used as a clipping mask for
- * a drawable.
- *
- **/
-void
-gdk_pixbuf_render_threshold_alpha (GdkPixbuf *pixbuf,
- GdkBitmap *bitmap,
- int src_x,
- int src_y,
- int dest_x,
- int dest_y,
- int width,
- int height,
- int alpha_threshold)
-{
- cairo_t *cr;
- int x, y;
- guchar *p;
- int start, start_status;
- int status;
-
- g_return_if_fail (gdk_pixbuf_get_colorspace (pixbuf) == GDK_COLORSPACE_RGB);
- g_return_if_fail (gdk_pixbuf_get_n_channels (pixbuf) == 3 ||
- gdk_pixbuf_get_n_channels (pixbuf) == 4);
- g_return_if_fail (gdk_pixbuf_get_bits_per_sample (pixbuf) == 8);
-
- if (width == -1)
- width = gdk_pixbuf_get_width (pixbuf);
- if (height == -1)
- height = gdk_pixbuf_get_height (pixbuf);
-
- g_return_if_fail (bitmap != NULL);
- g_return_if_fail (width >= 0 && height >= 0);
- g_return_if_fail (src_x >= 0 && src_x + width <= gdk_pixbuf_get_width (pixbuf));
- g_return_if_fail (src_y >= 0 && src_y + height <= gdk_pixbuf_get_height (pixbuf));
-
- g_return_if_fail (alpha_threshold >= 0 && alpha_threshold <= 255);
-
- if (width == 0 || height == 0)
- return;
-
- cr = gdk_cairo_create (bitmap);
- cairo_rectangle (cr, dest_x, dest_y, width, height);
- cairo_clip (cr);
-
- if (!gdk_pixbuf_get_has_alpha (pixbuf))
- {
- cairo_set_source_rgba (cr, 0, 0, 0, alpha_threshold == 255 ? 0 : 1);
- cairo_paint (cr);
- cairo_destroy (cr);
- return;
- }
-
- cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
- cairo_paint (cr);
-
- cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
- if (alpha_threshold == 128)
- {
- gdk_cairo_set_source_pixbuf (cr, pixbuf, src_x - dest_x, src_y - dest_y);
- cairo_paint (cr);
- cairo_destroy (cr);
- return;
- }
-
- cairo_set_source_rgb (cr, 0, 0, 0);
-
- for (y = 0; y < height; y++)
- {
- p = (gdk_pixbuf_get_pixels (pixbuf) + (y + src_y) * gdk_pixbuf_get_rowstride (pixbuf) + src_x * gdk_pixbuf_get_n_channels (pixbuf)
- + gdk_pixbuf_get_n_channels (pixbuf) - 1);
-
- start = 0;
- start_status = *p < alpha_threshold;
-
- for (x = 0; x < width; x++)
- {
- status = *p < alpha_threshold;
-
- if (status != start_status)
- {
- if (!start_status)
- cairo_rectangle (cr,
- start + dest_x, y + dest_y,
- x + dest_x, y + dest_y + 1);
-
- start = x;
- start_status = status;
- }
-
- p += gdk_pixbuf_get_n_channels (pixbuf);
- }
-
- if (!start_status)
- cairo_rectangle (cr,
- start + dest_x, y + dest_y,
- x + dest_x, y + dest_y + 1);
- }
-
- cairo_fill (cr);
- cairo_destroy (cr);
-}
-
-/**
- * gdk_pixbuf_render_pixmap_and_mask:
- * @pixbuf: A pixbuf.
- * @pixmap_return: Location to store a pointer to the created pixmap,
- * or %NULL if the pixmap is not needed.
- * @mask_return: Location to store a pointer to the created mask,
- * or %NULL if the mask is not needed.
- * @alpha_threshold: Threshold value for opacity values.
- *
- * Creates a pixmap and a mask bitmap which are returned in the @pixmap_return
- * and @mask_return arguments, respectively, and renders a pixbuf and its
- * corresponding thresholded alpha mask to them. This is merely a convenience
- * function; applications that need to render pixbufs with dither offsets or to
- * given drawables should use Cairo and gdk_pixbuf_render_threshold_alpha().
- *
- * The pixmap that is created is created for the colormap returned
- * by gdk_colormap_get_system(). You normally will want to instead use
- * the actual colormap for a widget, and use
- * gdk_pixbuf_render_pixmap_and_mask_for_colormap().
- *
- * If the pixbuf does not have an alpha channel, then *@mask_return will be set
- * to %NULL.
- **/
-void
-gdk_pixbuf_render_pixmap_and_mask (GdkPixbuf *pixbuf,
- GdkPixmap **pixmap_return,
- GdkBitmap **mask_return,
- int alpha_threshold)
-{
- gdk_pixbuf_render_pixmap_and_mask_for_colormap (pixbuf,
- gdk_colormap_get_system (),
- pixmap_return, mask_return,
- alpha_threshold);
-}
-
-static GdkPixbuf *
-remove_alpha_channel (GdkPixbuf *orig)
-{
- GdkPixbuf *pixbuf;
-
- unsigned int x, y, width, height, stride;
- unsigned char *data;
-
- if (!gdk_pixbuf_get_has_alpha (orig))
- return g_object_ref (orig);
-
- pixbuf = gdk_pixbuf_copy (orig);
-
- width = gdk_pixbuf_get_width (pixbuf);
- height = gdk_pixbuf_get_height (pixbuf);
- stride = gdk_pixbuf_get_rowstride (pixbuf);
- data = gdk_pixbuf_get_pixels (pixbuf);
-
- for (y = 0; y < height; y++)
- {
- for (x = 0; x < width; x++)
- {
- data[x * 4 + 3] = 0xFF;
- }
-
- data += stride;
- }
-
- return pixbuf;
-}
-
-/**
- * gdk_pixbuf_render_pixmap_and_mask_for_colormap:
- * @pixbuf: A pixbuf.
- * @colormap: A #GdkColormap
- * @pixmap_return: Location to store a pointer to the created pixmap,
- * or %NULL if the pixmap is not needed.
- * @mask_return: Location to store a pointer to the created mask,
- * or %NULL if the mask is not needed.
- * @alpha_threshold: Threshold value for opacity values.
- *
- * Creates a pixmap and a mask bitmap which are returned in the @pixmap_return
- * and @mask_return arguments, respectively, and renders a pixbuf and its
- * corresponding tresholded alpha mask to them. This is merely a convenience
- * function; applications that need to render pixbufs with dither offsets or to
- * given drawables should use Cairo and gdk_pixbuf_render_threshold_alpha().
- *
- * The pixmap that is created uses the #GdkColormap specified by @colormap.
- * This colormap must match the colormap of the window where the pixmap
- * will eventually be used or an error will result.
- *
- * If the pixbuf does not have an alpha channel, then *@mask_return will be set
- * to %NULL.
- **/
-void
-gdk_pixbuf_render_pixmap_and_mask_for_colormap (GdkPixbuf *pixbuf,
- GdkColormap *colormap,
- GdkPixmap **pixmap_return,
- GdkBitmap **mask_return,
- int alpha_threshold)
-{
- GdkScreen *screen;
-
- g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
- g_return_if_fail (GDK_IS_COLORMAP (colormap));
-
- screen = gdk_colormap_get_screen (colormap);
-
- if (pixmap_return)
- {
- GdkPixbuf *tmp_pixbuf;
- cairo_t *cr;
-
- *pixmap_return = gdk_pixmap_new (gdk_screen_get_root_window (screen),
- gdk_pixbuf_get_width (pixbuf), gdk_pixbuf_get_height (pixbuf),
- gdk_colormap_get_visual (colormap)->depth);
-
- gdk_drawable_set_colormap (GDK_DRAWABLE (*pixmap_return), colormap);
-
- /* If the pixbuf has an alpha channel, using gdk_cairo_set_source_pixbuf()
- * would give
- * random pixel values in the area that are within the mask, but semi-
- * transparent. So we treat the pixbuf like a pixbuf without alpha channel;
- * see bug #487865.
- */
- tmp_pixbuf = remove_alpha_channel (pixbuf);
-
- cr = gdk_cairo_create (*pixmap_return);
- gdk_cairo_set_source_pixbuf (cr, pixbuf, 0, 0);
- cairo_paint (cr);
-
- cairo_destroy (cr);
- g_object_unref (tmp_pixbuf);
- }
-
- if (mask_return)
- {
- if (gdk_pixbuf_get_has_alpha (pixbuf))
- {
- *mask_return = gdk_pixmap_new (gdk_screen_get_root_window (screen),
- gdk_pixbuf_get_width (pixbuf), gdk_pixbuf_get_height (pixbuf), 1);
-
- gdk_pixbuf_render_threshold_alpha (pixbuf, *mask_return,
- 0, 0, 0, 0,
- gdk_pixbuf_get_width (pixbuf), gdk_pixbuf_get_height (pixbuf),
- alpha_threshold);
- }
- else
- *mask_return = NULL;
- }
-}
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