mirror of
https://gitlab.gnome.org/GNOME/gtk.git
synced 2024-12-25 13:11:13 +00:00
32b708985d
Wed Sep 19 16:12:16 2001 Owen Taylor <otaylor@redhat.com> * gdk/gdkpixbuf-render.c: Allow -1 for width/height to mean "width/height of pixbuf" (Patch from Matthias Clasen, #59723)
536 lines
17 KiB
C
536 lines
17 KiB
C
/* 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-private.h"
|
||
#include "gdkpixbuf.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)
|
||
{
|
||
GdkGC *gc;
|
||
GdkColor color;
|
||
int x, y;
|
||
guchar *p;
|
||
int start, start_status;
|
||
int status;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
|
||
g_return_if_fail (pixbuf->colorspace == GDK_COLORSPACE_RGB);
|
||
g_return_if_fail (pixbuf->n_channels == 3 || pixbuf->n_channels == 4);
|
||
g_return_if_fail (pixbuf->bits_per_sample == 8);
|
||
|
||
if (width == -1)
|
||
width = pixbuf->width;
|
||
if (height == -1)
|
||
height = pixbuf->height;
|
||
|
||
g_return_if_fail (bitmap != NULL);
|
||
g_return_if_fail (width >= 0 && height >= 0);
|
||
g_return_if_fail (src_x >= 0 && src_x + width <= pixbuf->width);
|
||
g_return_if_fail (src_y >= 0 && src_y + height <= pixbuf->height);
|
||
|
||
g_return_if_fail (alpha_threshold >= 0 && alpha_threshold <= 255);
|
||
|
||
if (width == 0 || height == 0)
|
||
return;
|
||
|
||
gc = gdk_gc_new (bitmap);
|
||
|
||
if (!pixbuf->has_alpha)
|
||
{
|
||
color.pixel = (alpha_threshold == 255) ? 0 : 1;
|
||
gdk_gc_set_foreground (gc, &color);
|
||
gdk_draw_rectangle (bitmap, gc, TRUE, dest_x, dest_y, width, height);
|
||
gdk_gc_unref (gc);
|
||
return;
|
||
}
|
||
|
||
color.pixel = 0;
|
||
gdk_gc_set_foreground (gc, &color);
|
||
gdk_draw_rectangle (bitmap, gc, TRUE, dest_x, dest_y, width, height);
|
||
|
||
color.pixel = 1;
|
||
gdk_gc_set_foreground (gc, &color);
|
||
|
||
for (y = 0; y < height; y++)
|
||
{
|
||
p = (pixbuf->pixels + (y + src_y) * pixbuf->rowstride + src_x * pixbuf->n_channels
|
||
+ pixbuf->n_channels - 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)
|
||
gdk_draw_line (bitmap, gc,
|
||
start + dest_x, y + dest_y,
|
||
x - 1 + dest_x, y + dest_y);
|
||
|
||
start = x;
|
||
start_status = status;
|
||
}
|
||
|
||
p += pixbuf->n_channels;
|
||
}
|
||
|
||
if (!start_status)
|
||
gdk_draw_line (bitmap, gc,
|
||
start + dest_x, y + dest_y,
|
||
x - 1 + dest_x, y + dest_y);
|
||
}
|
||
|
||
gdk_gc_unref (gc);
|
||
}
|
||
|
||
|
||
|
||
/**
|
||
* gdk_pixbuf_render_to_drawable:
|
||
* @pixbuf: A pixbuf.
|
||
* @drawable: Destination drawable.
|
||
* @gc: GC used for rendering.
|
||
* @src_x: Source X coordinate within pixbuf.
|
||
* @src_y: Source Y coordinate within pixbuf.
|
||
* @dest_x: Destination X coordinate within drawable.
|
||
* @dest_y: Destination Y coordinate within drawable.
|
||
* @width: Width of region to render, in pixels, or -1 to use pixbuf width
|
||
* @height: Height of region to render, in pixels, or -1 to use pixbuf height
|
||
* @dither: Dithering mode for GdkRGB.
|
||
* @x_dither: X offset for dither.
|
||
* @y_dither: Y offset for dither.
|
||
*
|
||
* Renders a rectangular portion of a pixbuf to a drawable while using the
|
||
* specified GC. This is done using GdkRGB, so the specified drawable must have
|
||
* the GdkRGB visual and colormap. Note that this function will ignore the
|
||
* opacity information for images with an alpha channel; the GC must already
|
||
* have the clipping mask set if you want transparent regions to show through.
|
||
*
|
||
* For an explanation of dither offsets, see the GdkRGB documentation. In
|
||
* brief, the dither offset is important when re-rendering partial regions of an
|
||
* image to a rendered version of the full image, or for when the offsets to a
|
||
* base position change, as in scrolling. The dither matrix has to be shifted
|
||
* for consistent visual results. If you do not have any of these cases, the
|
||
* dither offsets can be both zero.
|
||
**/
|
||
void
|
||
gdk_pixbuf_render_to_drawable (GdkPixbuf *pixbuf,
|
||
GdkDrawable *drawable,
|
||
GdkGC *gc,
|
||
int src_x, int src_y,
|
||
int dest_x, int dest_y,
|
||
int width, int height,
|
||
GdkRgbDither dither,
|
||
int x_dither, int y_dither)
|
||
{
|
||
int rowstride;
|
||
guchar *buf;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
|
||
g_return_if_fail (pixbuf->colorspace == GDK_COLORSPACE_RGB);
|
||
g_return_if_fail (pixbuf->n_channels == 3 || pixbuf->n_channels == 4);
|
||
g_return_if_fail (pixbuf->bits_per_sample == 8);
|
||
|
||
g_return_if_fail (drawable != NULL);
|
||
g_return_if_fail (gc != NULL);
|
||
|
||
if (width == -1)
|
||
width = pixbuf->width;
|
||
if (height == -1)
|
||
height = pixbuf->height;
|
||
|
||
g_return_if_fail (width >= 0 && height >= 0);
|
||
g_return_if_fail (src_x >= 0 && src_x + width <= pixbuf->width);
|
||
g_return_if_fail (src_y >= 0 && src_y + height <= pixbuf->height);
|
||
|
||
if (width == 0 || height == 0)
|
||
return;
|
||
|
||
/* This will have to be modified once we support other image types.
|
||
*/
|
||
|
||
if (pixbuf->n_channels == 4)
|
||
{
|
||
buf = pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 4;
|
||
rowstride = pixbuf->rowstride;
|
||
|
||
gdk_draw_rgb_32_image_dithalign (drawable, gc,
|
||
dest_x, dest_y,
|
||
width, height,
|
||
dither,
|
||
buf, rowstride,
|
||
x_dither, y_dither);
|
||
}
|
||
else /* n_channels == 3 */
|
||
{
|
||
buf = pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 3;
|
||
rowstride = pixbuf->rowstride;
|
||
|
||
gdk_draw_rgb_image_dithalign (drawable, gc,
|
||
dest_x, dest_y,
|
||
width, height,
|
||
dither,
|
||
buf, rowstride,
|
||
x_dither, y_dither);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/**
|
||
* gdk_pixbuf_render_to_drawable_alpha:
|
||
* @pixbuf: A pixbuf.
|
||
* @drawable: Destination drawable.
|
||
* @src_x: Source X coordinate within pixbuf.
|
||
* @src_y: Source Y coordinates within pixbuf.
|
||
* @dest_x: Destination X coordinate within drawable.
|
||
* @dest_y: Destination Y coordinate within drawable.
|
||
* @width: Width of region to render, in pixels, or -1 to use pixbuf width.
|
||
* @height: Height of region to render, in pixels, or -1 to use pixbuf height.
|
||
* @alpha_mode: If the image does not have opacity information, this is ignored.
|
||
* Otherwise, specifies how to handle transparency when rendering.
|
||
* @alpha_threshold: If the image does have opacity information and @alpha_mode
|
||
* is GDK_PIXBUF_ALPHA_BILEVEL, specifies the threshold value for opacity
|
||
* values.
|
||
* @dither: Dithering mode for GdkRGB.
|
||
* @x_dither: X offset for dither.
|
||
* @y_dither: Y offset for dither.
|
||
*
|
||
* Renders a rectangular portion of a pixbuf to a drawable. This is done using
|
||
* GdkRGB, so the specified drawable must have the GdkRGB visual and colormap.
|
||
*
|
||
* When used with #GDK_PIXBUF_ALPHA_BILEVEL, this function has to create a bitmap
|
||
* out of the thresholded alpha channel of the image and, it has to set this
|
||
* bitmap as the clipping mask for the GC used for drawing. This can be a
|
||
* significant performance penalty depending on the size and the complexity of
|
||
* the alpha channel of the image. If performance is crucial, consider handling
|
||
* the alpha channel yourself (possibly by caching it in your application) and
|
||
* using gdk_pixbuf_render_to_drawable() or GdkRGB directly instead.
|
||
*
|
||
* The #GDK_PIXBUF_ALPHA_FULL mode involves round trips to the X
|
||
* server, and may also be somewhat slow in its current implementation
|
||
* (though in the future it could be made significantly faster, in
|
||
* principle).
|
||
**/
|
||
void
|
||
gdk_pixbuf_render_to_drawable_alpha (GdkPixbuf *pixbuf,
|
||
GdkDrawable *drawable,
|
||
int src_x, int src_y,
|
||
int dest_x, int dest_y,
|
||
int width, int height,
|
||
GdkPixbufAlphaMode alpha_mode,
|
||
int alpha_threshold,
|
||
GdkRgbDither dither,
|
||
int x_dither, int y_dither)
|
||
{
|
||
GdkBitmap *bitmap = NULL;
|
||
GdkGC *gc;
|
||
GdkPixbuf *composited = NULL;
|
||
gint dwidth, dheight;
|
||
GdkRegion *clip;
|
||
GdkRegion *drect;
|
||
GdkRectangle tmp_rect;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (pixbuf));
|
||
g_return_if_fail (pixbuf->colorspace == GDK_COLORSPACE_RGB);
|
||
g_return_if_fail (pixbuf->n_channels == 3 || pixbuf->n_channels == 4);
|
||
g_return_if_fail (pixbuf->bits_per_sample == 8);
|
||
|
||
g_return_if_fail (drawable != NULL);
|
||
|
||
if (width == -1)
|
||
width = pixbuf->width;
|
||
if (height == -1)
|
||
height = pixbuf->height;
|
||
|
||
g_return_if_fail (width >= 0 && height >= 0);
|
||
g_return_if_fail (src_x >= 0 && src_x + width <= pixbuf->width);
|
||
g_return_if_fail (src_y >= 0 && src_y + height <= pixbuf->height);
|
||
|
||
/* Clip to the drawable; this is required for get_from_drawable() so
|
||
* can't be done implicitly
|
||
*/
|
||
|
||
if (dest_x < 0)
|
||
{
|
||
src_x -= dest_x;
|
||
width += dest_x;
|
||
dest_x = 0;
|
||
}
|
||
|
||
if (dest_y < 0)
|
||
{
|
||
src_y -= dest_y;
|
||
height += dest_y;
|
||
dest_y = 0;
|
||
}
|
||
|
||
gdk_drawable_get_size (drawable, &dwidth, &dheight);
|
||
|
||
if ((dest_x + width) > dwidth)
|
||
width = dwidth - dest_x;
|
||
|
||
if ((dest_y + height) > dheight)
|
||
height = dheight - dest_y;
|
||
|
||
if (width <= 0 || height <= 0)
|
||
return;
|
||
|
||
/* Clip to the clip region; this avoids getting more
|
||
* image data from the server than we need to.
|
||
*/
|
||
|
||
tmp_rect.x = dest_x;
|
||
tmp_rect.y = dest_y;
|
||
tmp_rect.width = width;
|
||
tmp_rect.height = height;
|
||
|
||
drect = gdk_region_rectangle (&tmp_rect);
|
||
clip = gdk_drawable_get_clip_region (drawable);
|
||
|
||
gdk_region_intersect (drect, clip);
|
||
|
||
gdk_region_get_clipbox (drect, &tmp_rect);
|
||
|
||
gdk_region_destroy (drect);
|
||
gdk_region_destroy (clip);
|
||
|
||
if (tmp_rect.width == 0 ||
|
||
tmp_rect.height == 0)
|
||
return;
|
||
|
||
/* Actually draw */
|
||
|
||
gc = gdk_gc_new (drawable);
|
||
|
||
if (pixbuf->has_alpha)
|
||
{
|
||
if (alpha_mode == GDK_PIXBUF_ALPHA_FULL)
|
||
{
|
||
GdkPixbuf *sub = NULL;
|
||
|
||
composited = gdk_pixbuf_get_from_drawable (NULL,
|
||
drawable,
|
||
NULL,
|
||
dest_x, dest_y,
|
||
0, 0,
|
||
width, height);
|
||
|
||
if (composited)
|
||
{
|
||
if (src_x != 0 || src_y != 0)
|
||
{
|
||
sub = gdk_pixbuf_new_subpixbuf (pixbuf, src_x, src_y,
|
||
width, height);
|
||
}
|
||
|
||
gdk_pixbuf_composite (sub ? sub : pixbuf,
|
||
composited,
|
||
0, 0,
|
||
width, height,
|
||
0, 0,
|
||
1.0, 1.0,
|
||
GDK_INTERP_BILINEAR,
|
||
255);
|
||
|
||
if (sub)
|
||
g_object_unref (G_OBJECT (sub));
|
||
}
|
||
else
|
||
alpha_mode = GDK_PIXBUF_ALPHA_BILEVEL; /* fall back */
|
||
}
|
||
|
||
if (alpha_mode == GDK_PIXBUF_ALPHA_BILEVEL)
|
||
{
|
||
bitmap = gdk_pixmap_new (NULL, width, height, 1);
|
||
gdk_pixbuf_render_threshold_alpha (pixbuf, bitmap,
|
||
src_x, src_y,
|
||
0, 0,
|
||
width, height,
|
||
alpha_threshold);
|
||
|
||
gdk_gc_set_clip_mask (gc, bitmap);
|
||
gdk_gc_set_clip_origin (gc, dest_x, dest_y);
|
||
}
|
||
}
|
||
|
||
if (composited)
|
||
{
|
||
gdk_pixbuf_render_to_drawable (composited,
|
||
drawable, gc,
|
||
0, 0,
|
||
dest_x, dest_y,
|
||
width, height,
|
||
dither,
|
||
x_dither, y_dither);
|
||
}
|
||
else
|
||
{
|
||
gdk_pixbuf_render_to_drawable (pixbuf,
|
||
drawable, gc,
|
||
src_x, src_y,
|
||
dest_x, dest_y,
|
||
width, height,
|
||
dither,
|
||
x_dither, y_dither);
|
||
}
|
||
|
||
if (bitmap)
|
||
gdk_bitmap_unref (bitmap);
|
||
|
||
if (composited)
|
||
g_object_unref (G_OBJECT (composited));
|
||
|
||
gdk_gc_unref (gc);
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_render_pixmap_and_mask:
|
||
* @pixbuf: A pixbuf.
|
||
* @pixmap_return: Return value for the created pixmap.
|
||
* @mask_return: Return value for the created mask.
|
||
* @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 gdk_pixbuf_render_to_drawable_alpha() or
|
||
* gdk_pixbuf_render_to_drawable(), and gdk_pixbuf_render_threshold_alpha().
|
||
*
|
||
* The pixmap that is created is created for the colormap returned
|
||
* by gdk_rgb_get_colormap(). 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_rgb_get_colormap (),
|
||
pixmap_return, mask_return,
|
||
alpha_threshold);
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_render_pixmap_and_mask_for_colormap:
|
||
* @pixbuf: A pixbuf.
|
||
* @colormap: A #GdkColormap
|
||
* @pixmap_return: Return value for the created pixmap.
|
||
* @mask_return: Return value for the created mask.
|
||
* @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 gdk_pixbuf_render_to_drawable_alpha() or
|
||
* gdk_pixbuf_render_to_drawable(), 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)
|
||
{
|
||
g_return_if_fail (pixbuf != NULL);
|
||
|
||
if (pixmap_return)
|
||
{
|
||
GdkGC *gc;
|
||
|
||
*pixmap_return = gdk_pixmap_new (NULL, 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);
|
||
gc = gdk_gc_new (*pixmap_return);
|
||
gdk_pixbuf_render_to_drawable (pixbuf, *pixmap_return, gc,
|
||
0, 0, 0, 0,
|
||
gdk_pixbuf_get_width (pixbuf), gdk_pixbuf_get_height (pixbuf),
|
||
GDK_RGB_DITHER_NORMAL,
|
||
0, 0);
|
||
gdk_gc_unref (gc);
|
||
}
|
||
|
||
if (mask_return)
|
||
{
|
||
if (gdk_pixbuf_get_has_alpha (pixbuf))
|
||
{
|
||
*mask_return = gdk_pixmap_new (NULL, 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;
|
||
}
|
||
}
|
||
|
||
|