gtk/contrib/gdk-pixbuf-xlib/gdk-pixbuf-xlib-render.c
Havoc Pennington 518f32d97e contrib subdir
2000-10-06  Havoc Pennington  <hp@redhat.com>

	* Makefile.am (SRC_SUBDIRS): contrib subdir

	* gdk/gdkpixbuf.h: Move GdkPixbufAlphaMode to gdk-pixbuf library,
	so it can be used in Xlib version

	* demos/testpixbuf.c (update_timeout): error checking from 1.0
	tree

	* gtk/gdk-pixbuf-loader.c (gdk_pixbuf_loader_get_pixbuf): Sync
	change from 1.0 tree that returns first frame of animation
	if the loaded file is an animation.

        * contrib: add new directory to hold stuff that comes with GTK+
	but isn't really part of GTK+ (for now, gdk-pixbuf-xlib)

	* configure.in: add contrib/*

2000-10-06  Havoc Pennington  <hp@redhat.com>

	* gdk-pixbuf.h: add GdkPixbufAlphaMode

2000-10-06  Havoc Pennington  <hp@redhat.com>

        This entry is a summary of the merged-in changes from 1.0.
	Relevant original ChangeLog entries are spliced in after
	this entry; the files they refer to are from the 1.0
	gdk-pixbuf sources.

	* pixops/pixops.c (pixops_composite_nearest): sync a small fix
	from 1.0

	* io-xpm.c (xpm_seek_string): add fscanf error check from 1.0
	Add progressive loader from 1.0

	* io-tiff.c (gdk_pixbuf__tiff_image_begin_load): mem leak fixes
	from 1.0 tree

	* io-pnm.c: new version from 1.0 tree

	* io-jpeg.c (gdk_pixbuf__jpeg_image_load): sync from 1.0, use
	malloc not g_malloc

	* io-gif.c (lzw_read_byte): sync from 1.0, change a g_error to
	g_warning
	(gif_get_next_step): return 0 here, sync from 1.0

	* gdk-pixbuf-util.c: sync email address change for Cody
	Russell

2000-09-11  Jeffrey Stedfast  <fejj@helixcode.com>

	* gdk-pixbuf/io-pnm.c: Pretty much totally rewrote again because
	last nights code was still "broken". Should now properly handle
	all error conditions gracefully.

2000-09-10  Jeffrey Stedfast  <fejj@helixcode.com>

	* gdk-pixbuf/io-pnm.c: Rewrote.

2000-09-09  Federico Mena Quintero  <federico@helixcode.com>

	* gdk-pixbuf/pixops/pixops.c (pixops_composite_nearest): Compute
	the correct dest offset.

2000-08-25  Federico Mena Quintero  <federico@helixcode.com>

	* gdk-pixbuf/io-xpm.c: #include <unistd.h>

2000-08-05  Larry Ewing  <lewing@helixcode.com>

	* gdk-pixbuf/io-tiff.c: stop leaking context->tempname.

	* gdk-pixbuf/io-xpm.c: same as above.

2000-07-26  Michael Meeks  <michael@helixcode.com>

	* gdk-pixbuf/io-jpeg.c (gdk_pixbuf__jpeg_image_load): make
	g_malloc a malloc.

2000-07-21  Larry Ewing  <lewing@helixcode.com>

	* gdk-pixbuf/io-xpm.c: add a fake progressive loader so that
	xpm at least supports the progressive interface like the one in
	io-tiff.c. This should be reimplemented as an actual progressive
	loader.

2000-07-19  Jonathan Blandford  <jrb@redhat.com>

	* demo/pixbuf-demo.c (update_timeout): changed scaling level to
	make it look better.
	* gdk-pixbuf/testpixbuf.c (update_timeout): Patch from michael
	meeks to handle errors better.
2000-10-09 17:22:20 +00:00

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/* 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 Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
/* Trivially ported to Xlib(RGB) by John Harper. */
#include <config.h>
#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-xlib-private.h"
/**
* gdk_pixbuf_xlib_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.
* @height: Height of region to threshold.
* @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_xlib_render_threshold_alpha (GdkPixbuf *pixbuf, Pixmap bitmap,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
int alpha_threshold)
{
GC gc;
XColor color;
int x, y;
guchar *p;
int start, start_status;
int status;
XGCValues gcv;
g_return_if_fail (pixbuf != NULL);
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 (bitmap != 0);
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 = XCreateGC (gdk_pixbuf_dpy, bitmap, 0, &gcv);
if (!pixbuf->has_alpha) {
color.pixel = (alpha_threshold == 255) ? 0 : 1;
XSetForeground (gdk_pixbuf_dpy, gc, color.pixel);
XFillRectangle (gdk_pixbuf_dpy, bitmap, gc,
dest_x, dest_y, width, height);
XFreeGC (gdk_pixbuf_dpy, gc);
return;
}
color.pixel = 0;
XSetForeground (gdk_pixbuf_dpy, gc, color.pixel);
XFillRectangle (gdk_pixbuf_dpy, bitmap, gc,
dest_x, dest_y, width, height);
color.pixel = 1;
XSetForeground (gdk_pixbuf_dpy, gc, color.pixel);
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)
XDrawLine (gdk_pixbuf_dpy, 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)
XDrawLine (gdk_pixbuf_dpy, bitmap, gc,
start + dest_x, y + dest_y,
x - 1 + dest_x, y + dest_y);
}
XFreeGC (gdk_pixbuf_dpy, gc);
}
/* Creates a buffer by stripping the alpha channel of a pixbuf */
static guchar *
remove_alpha (GdkPixbuf *pixbuf, int x, int y, int width, int height, int *rowstride)
{
guchar *buf;
int xx, yy;
guchar *src, *dest;
g_assert (pixbuf->n_channels == 4);
g_assert (pixbuf->has_alpha);
g_assert (width > 0 && height > 0);
g_assert (x >= 0 && x + width <= pixbuf->width);
g_assert (y >= 0 && y + height <= pixbuf->height);
*rowstride = 4 * ((width * 3 + 3) / 4);
buf = g_new (guchar, *rowstride * height);
for (yy = 0; yy < height; yy++) {
src = pixbuf->pixels + pixbuf->rowstride * (yy + y) + x * pixbuf->n_channels;
dest = buf + *rowstride * yy;
for (xx = 0; xx < width; xx++) {
*dest++ = *src++;
*dest++ = *src++;
*dest++ = *src++;
src++;
}
}
return buf;
}
/**
* gdk_pixbuf_xlib_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.
* @height: Height of region to render, in pixels.
* @dither: Dithering mode for XlibRGB.
* @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 XlibRGB, so the specified drawable must
* have the XlibRGB 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 XlibRGB 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_xlib_render_to_drawable (GdkPixbuf *pixbuf,
Drawable drawable, GC gc,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
XlibRgbDither dither,
int x_dither, int y_dither)
{
guchar *buf;
int rowstride;
g_return_if_fail (pixbuf != NULL);
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 != 0);
g_return_if_fail (gc != 0);
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.
* Also, GdkRGB does not have gdk_draw_rgb_32_image_dithalign(), so we
* have to pack the buffer first. Sigh.
*/
if (pixbuf->has_alpha)
buf = remove_alpha (pixbuf, src_x, src_y, width, height, &rowstride);
else {
buf = pixbuf->pixels + src_y * pixbuf->rowstride + src_x * 3;
rowstride = pixbuf->rowstride;
}
xlib_draw_rgb_image_dithalign (drawable, gc,
dest_x, dest_y,
width, height,
dither,
buf, rowstride,
x_dither, y_dither);
if (pixbuf->has_alpha)
g_free (buf);
}
/**
* gdk_pixbuf_xlib_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.
* @height: Height of region to render, in pixels.
* @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 XlibRGB.
* @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
* XlibRGB, so the specified drawable must have the XlibRGB 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_xlib_render_to_drawable() or GdkRGB directly instead.
**/
void
gdk_pixbuf_xlib_render_to_drawable_alpha (GdkPixbuf *pixbuf, Drawable drawable,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
GdkPixbufAlphaMode alpha_mode,
int alpha_threshold,
XlibRgbDither dither,
int x_dither, int y_dither)
{
Pixmap bitmap = 0;
GC gc;
XGCValues gcv;
g_return_if_fail (pixbuf != NULL);
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 != 0);
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;
gc = XCreateGC (gdk_pixbuf_dpy, drawable, 0, &gcv);
if (pixbuf->has_alpha) {
/* Right now we only support GDK_PIXBUF_ALPHA_BILEVEL, so we
* unconditionally create the clipping mask.
*/
bitmap = XCreatePixmap (gdk_pixbuf_dpy,
RootWindow (gdk_pixbuf_dpy,
gdk_pixbuf_screen),
width, height, 1);
gdk_pixbuf_xlib_render_threshold_alpha (pixbuf, bitmap,
src_x, src_y,
0, 0,
width, height,
alpha_threshold);
XSetClipMask (gdk_pixbuf_dpy, gc, bitmap);
XSetClipOrigin (gdk_pixbuf_dpy, gc, dest_x, dest_y);
}
gdk_pixbuf_xlib_render_to_drawable (pixbuf, drawable, gc,
src_x, src_y,
dest_x, dest_y,
width, height,
dither,
x_dither, y_dither);
if (bitmap)
XFreePixmap (gdk_pixbuf_dpy, bitmap);
XFreeGC (gdk_pixbuf_dpy, gc);
}
/**
* gdk_pixbuf_xlib_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 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_xlib_render_to_drawable_alpha() or
* gdk_pixbuf_xlib_render_to_drawable(), and
* gdk_pixbuf_xlib_render_threshold_alpha().
*
* If the pixbuf does not have an alpha channel, then *@mask_return will be set
* to None.
**/
void
gdk_pixbuf_xlib_render_pixmap_and_mask (GdkPixbuf *pixbuf,
Pixmap *pixmap_return,
Pixmap *mask_return,
int alpha_threshold)
{
g_return_if_fail (pixbuf != NULL);
if (pixmap_return) {
GC gc;
XGCValues gcv;
*pixmap_return = XCreatePixmap (gdk_pixbuf_dpy,
RootWindow (gdk_pixbuf_dpy,
gdk_pixbuf_screen),
pixbuf->width,
pixbuf->height,
xlib_rgb_get_depth ());
gc = XCreateGC (gdk_pixbuf_dpy, *pixmap_return, 0, &gcv);
gdk_pixbuf_xlib_render_to_drawable (pixbuf, *pixmap_return, gc,
0, 0, 0, 0,
pixbuf->width,
pixbuf->height,
XLIB_RGB_DITHER_NORMAL,
0, 0);
XFreeGC (gdk_pixbuf_dpy, gc);
}
if (mask_return) {
if (pixbuf->has_alpha) {
*mask_return = XCreatePixmap (gdk_pixbuf_dpy,
RootWindow (gdk_pixbuf_dpy,
gdk_pixbuf_screen),
pixbuf->width,
pixbuf->height, 1);
gdk_pixbuf_xlib_render_threshold_alpha (pixbuf,
*mask_return,
0, 0, 0, 0,
pixbuf->width,
pixbuf->height,
alpha_threshold);
} else
*mask_return = 0;
}
}