This is intended mainly for GNU/Linux distros who will remove GTK2 support in the near future.
564 lines
19 KiB
C
564 lines
19 KiB
C
/* GdkPixbuf library - Scaling and compositing functions
|
||
*
|
||
* Copyright (C) 1999 The Free Software Foundation
|
||
*
|
||
* Author: Owen Taylor <otaylor@redhat.com>
|
||
*
|
||
* 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, see <http://www.gnu.org/licenses/>.
|
||
*/
|
||
|
||
#include "config.h"
|
||
#include <math.h>
|
||
#include <string.h>
|
||
#include "gdk-pixbuf-transform.h"
|
||
#include "gdk-pixbuf-private.h"
|
||
#include "pixops/pixops.h"
|
||
|
||
/**
|
||
* SECTION:scaling
|
||
* @Short_description: Scaling pixbufs and scaling and compositing pixbufs
|
||
* @Title: Scaling
|
||
* @See_also: <link linkend="gdk-GdkRGB">GdkRGB</link>.
|
||
*
|
||
* The GdkPixBuf contains functions to scale pixbufs, to scale
|
||
* pixbufs and composite against an existing image, and to scale
|
||
* pixbufs and composite against a solid color or checkerboard.
|
||
* Compositing a checkerboard is a common way to show an image with
|
||
* an alpha channel in image-viewing and editing software.
|
||
*
|
||
*
|
||
* Since the full-featured functions (gdk_pixbuf_scale(),
|
||
* gdk_pixbuf_composite(), and gdk_pixbuf_composite_color()) are
|
||
* rather complex to use and have many arguments, two simple
|
||
* convenience functions are provided, gdk_pixbuf_scale_simple() and
|
||
* gdk_pixbuf_composite_color_simple() which create a new pixbuf of a
|
||
* given size, scale an original image to fit, and then return the
|
||
* new pixbuf.
|
||
*
|
||
* If the destination pixbuf was created from a readonly source, these
|
||
* operations will force a copy into a mutable buffer.
|
||
*
|
||
* Scaling and compositing functions take advantage of MMX hardware
|
||
* acceleration on systems where MMX is supported. If gdk-pixbuf is built
|
||
* with the Sun mediaLib library, these functions are instead accelerated
|
||
* using mediaLib, which provides hardware acceleration on Intel, AMD,
|
||
* and Sparc chipsets. If desired, mediaLib support can be turned off by
|
||
* setting the `GDK_DISABLE_MEDIALIB` environment variable.
|
||
*
|
||
*
|
||
* The following example demonstrates handling an expose event by
|
||
* rendering the appropriate area of a source image (which is scaled
|
||
* to fit the widget) onto the widget's window. The source image is
|
||
* rendered against a checkerboard, which provides a visual
|
||
* representation of the alpha channel if the image has one. If the
|
||
* image doesn't have an alpha channel, calling
|
||
* gdk_pixbuf_composite_color() function has exactly the same effect
|
||
* as calling gdk_pixbuf_scale().
|
||
*
|
||
* ## Handling an expose event
|
||
*
|
||
* |[
|
||
* gboolean
|
||
* expose_cb (GtkWidget *widget, GdkEventExpose *event, gpointer data)
|
||
* {
|
||
* GdkPixbuf *dest;
|
||
*
|
||
* dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, event->area.width, event->area.height);
|
||
*
|
||
* gdk_pixbuf_composite_color (pixbuf, dest,
|
||
* 0, 0, event->area.width, event->area.height,
|
||
* -event->area.x, -event->area.y,
|
||
* (double) widget->allocation.width / gdk_pixbuf_get_width (pixbuf),
|
||
* (double) widget->allocation.height / gdk_pixbuf_get_height (pixbuf),
|
||
* GDK_INTERP_BILINEAR, 255,
|
||
* event->area.x, event->area.y, 16, 0xaaaaaa, 0x555555);
|
||
*
|
||
* gdk_draw_pixbuf (widget->window, widget->style->fg_gc[GTK_STATE_NORMAL], dest,
|
||
* 0, 0, event->area.x, event->area.y,
|
||
* event->area.width, event->area.height,
|
||
* GDK_RGB_DITHER_NORMAL, event->area.x, event->area.y);
|
||
*
|
||
* gdk_pixbuf_unref (dest);
|
||
*
|
||
* return TRUE;
|
||
* }
|
||
* ]|
|
||
*/
|
||
|
||
|
||
/**
|
||
* gdk_pixbuf_scale:
|
||
* @src: a #GdkPixbuf
|
||
* @dest: the #GdkPixbuf into which to render the results
|
||
* @dest_x: the left coordinate for region to render
|
||
* @dest_y: the top coordinate for region to render
|
||
* @dest_width: the width of the region to render
|
||
* @dest_height: the height of the region to render
|
||
* @offset_x: the offset in the X direction (currently rounded to an integer)
|
||
* @offset_y: the offset in the Y direction (currently rounded to an integer)
|
||
* @scale_x: the scale factor in the X direction
|
||
* @scale_y: the scale factor in the Y direction
|
||
* @interp_type: the interpolation type for the transformation.
|
||
*
|
||
* Creates a transformation of the source image @src by scaling by
|
||
* @scale_x and @scale_y then translating by @offset_x and @offset_y,
|
||
* then renders the rectangle (@dest_x, @dest_y, @dest_width,
|
||
* @dest_height) of the resulting image onto the destination image
|
||
* replacing the previous contents.
|
||
*
|
||
* Try to use gdk_pixbuf_scale_simple() first, this function is
|
||
* the industrial-strength power tool you can fall back to if
|
||
* gdk_pixbuf_scale_simple() isn't powerful enough.
|
||
*
|
||
* If the source rectangle overlaps the destination rectangle on the
|
||
* same pixbuf, it will be overwritten during the scaling which
|
||
* results in rendering artifacts.
|
||
**/
|
||
void
|
||
gdk_pixbuf_scale (const GdkPixbuf *src,
|
||
GdkPixbuf *dest,
|
||
int dest_x,
|
||
int dest_y,
|
||
int dest_width,
|
||
int dest_height,
|
||
double offset_x,
|
||
double offset_y,
|
||
double scale_x,
|
||
double scale_y,
|
||
GdkInterpType interp_type)
|
||
{
|
||
const guint8 *src_pixels;
|
||
guint8 *dest_pixels;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (src));
|
||
g_return_if_fail (GDK_IS_PIXBUF (dest));
|
||
g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
|
||
g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
|
||
|
||
offset_x = floor (offset_x + 0.5);
|
||
offset_y = floor (offset_y + 0.5);
|
||
|
||
/* Force an implicit copy */
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
src_pixels = gdk_pixbuf_read_pixels (src);
|
||
|
||
_pixops_scale (dest_pixels, dest->width, dest->height, dest->rowstride,
|
||
dest->n_channels, dest->has_alpha, src_pixels, src->width,
|
||
src->height, src->rowstride, src->n_channels, src->has_alpha,
|
||
dest_x, dest_y, dest_width, dest_height, offset_x, offset_y,
|
||
scale_x, scale_y, (PixopsInterpType)interp_type);
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_composite:
|
||
* @src: a #GdkPixbuf
|
||
* @dest: the #GdkPixbuf into which to render the results
|
||
* @dest_x: the left coordinate for region to render
|
||
* @dest_y: the top coordinate for region to render
|
||
* @dest_width: the width of the region to render
|
||
* @dest_height: the height of the region to render
|
||
* @offset_x: the offset in the X direction (currently rounded to an integer)
|
||
* @offset_y: the offset in the Y direction (currently rounded to an integer)
|
||
* @scale_x: the scale factor in the X direction
|
||
* @scale_y: the scale factor in the Y direction
|
||
* @interp_type: the interpolation type for the transformation.
|
||
* @overall_alpha: overall alpha for source image (0..255)
|
||
*
|
||
* Creates a transformation of the source image @src by scaling by
|
||
* @scale_x and @scale_y then translating by @offset_x and @offset_y.
|
||
* This gives an image in the coordinates of the destination pixbuf.
|
||
* The rectangle (@dest_x, @dest_y, @dest_width, @dest_height)
|
||
* is then composited onto the corresponding rectangle of the
|
||
* original destination image.
|
||
*
|
||
* When the destination rectangle contains parts not in the source
|
||
* image, the data at the edges of the source image is replicated
|
||
* to infinity.
|
||
*
|
||
* ![](composite.png)
|
||
*/
|
||
void
|
||
gdk_pixbuf_composite (const GdkPixbuf *src,
|
||
GdkPixbuf *dest,
|
||
int dest_x,
|
||
int dest_y,
|
||
int dest_width,
|
||
int dest_height,
|
||
double offset_x,
|
||
double offset_y,
|
||
double scale_x,
|
||
double scale_y,
|
||
GdkInterpType interp_type,
|
||
int overall_alpha)
|
||
{
|
||
const guint8 *src_pixels;
|
||
guint8 *dest_pixels;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (src));
|
||
g_return_if_fail (GDK_IS_PIXBUF (dest));
|
||
g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
|
||
g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
|
||
g_return_if_fail (overall_alpha >= 0 && overall_alpha <= 255);
|
||
|
||
offset_x = floor (offset_x + 0.5);
|
||
offset_y = floor (offset_y + 0.5);
|
||
|
||
/* Force an implicit copy */
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
src_pixels = gdk_pixbuf_read_pixels (src);
|
||
|
||
_pixops_composite (dest_pixels, dest->width, dest->height, dest->rowstride,
|
||
dest->n_channels, dest->has_alpha, src_pixels,
|
||
src->width, src->height, src->rowstride, src->n_channels,
|
||
src->has_alpha, dest_x, dest_y, dest_width, dest_height,
|
||
offset_x, offset_y, scale_x, scale_y,
|
||
(PixopsInterpType)interp_type, overall_alpha);
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_composite_color:
|
||
* @src: a #GdkPixbuf
|
||
* @dest: the #GdkPixbuf into which to render the results
|
||
* @dest_x: the left coordinate for region to render
|
||
* @dest_y: the top coordinate for region to render
|
||
* @dest_width: the width of the region to render
|
||
* @dest_height: the height of the region to render
|
||
* @offset_x: the offset in the X direction (currently rounded to an integer)
|
||
* @offset_y: the offset in the Y direction (currently rounded to an integer)
|
||
* @scale_x: the scale factor in the X direction
|
||
* @scale_y: the scale factor in the Y direction
|
||
* @interp_type: the interpolation type for the transformation.
|
||
* @overall_alpha: overall alpha for source image (0..255)
|
||
* @check_x: the X offset for the checkboard (origin of checkboard is at -@check_x, -@check_y)
|
||
* @check_y: the Y offset for the checkboard
|
||
* @check_size: the size of checks in the checkboard (must be a power of two)
|
||
* @color1: the color of check at upper left
|
||
* @color2: the color of the other check
|
||
*
|
||
* Creates a transformation of the source image @src by scaling by
|
||
* @scale_x and @scale_y then translating by @offset_x and @offset_y,
|
||
* then composites the rectangle (@dest_x ,@dest_y, @dest_width,
|
||
* @dest_height) of the resulting image with a checkboard of the
|
||
* colors @color1 and @color2 and renders it onto the destination
|
||
* image.
|
||
*
|
||
* See gdk_pixbuf_composite_color_simple() for a simpler variant of this
|
||
* function suitable for many tasks.
|
||
*
|
||
**/
|
||
void
|
||
gdk_pixbuf_composite_color (const GdkPixbuf *src,
|
||
GdkPixbuf *dest,
|
||
int dest_x,
|
||
int dest_y,
|
||
int dest_width,
|
||
int dest_height,
|
||
double offset_x,
|
||
double offset_y,
|
||
double scale_x,
|
||
double scale_y,
|
||
GdkInterpType interp_type,
|
||
int overall_alpha,
|
||
int check_x,
|
||
int check_y,
|
||
int check_size,
|
||
guint32 color1,
|
||
guint32 color2)
|
||
{
|
||
const guint8 *src_pixels;
|
||
guint8 *dest_pixels;
|
||
|
||
g_return_if_fail (GDK_IS_PIXBUF (src));
|
||
g_return_if_fail (GDK_IS_PIXBUF (dest));
|
||
g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
|
||
g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
|
||
g_return_if_fail (overall_alpha >= 0 && overall_alpha <= 255);
|
||
|
||
offset_x = floor (offset_x + 0.5);
|
||
offset_y = floor (offset_y + 0.5);
|
||
|
||
/* Force an implicit copy */
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
src_pixels = gdk_pixbuf_read_pixels (src);
|
||
|
||
_pixops_composite_color (dest_pixels, dest_width, dest_height,
|
||
dest->rowstride, dest->n_channels, dest->has_alpha,
|
||
src_pixels, src->width, src->height,
|
||
src->rowstride, src->n_channels, src->has_alpha,
|
||
dest_x, dest_y, dest_width, dest_height, offset_x,
|
||
offset_y, scale_x, scale_y,
|
||
(PixopsInterpType)interp_type, overall_alpha,
|
||
check_x, check_y, check_size, color1, color2);
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_scale_simple:
|
||
* @src: a #GdkPixbuf
|
||
* @dest_width: the width of destination image
|
||
* @dest_height: the height of destination image
|
||
* @interp_type: the interpolation type for the transformation.
|
||
*
|
||
* Create a new #GdkPixbuf containing a copy of @src scaled to
|
||
* @dest_width x @dest_height. Leaves @src unaffected. @interp_type
|
||
* should be #GDK_INTERP_NEAREST if you want maximum speed (but when
|
||
* scaling down #GDK_INTERP_NEAREST is usually unusably ugly). The
|
||
* default @interp_type should be #GDK_INTERP_BILINEAR which offers
|
||
* reasonable quality and speed.
|
||
*
|
||
* You can scale a sub-portion of @src by creating a sub-pixbuf
|
||
* pointing into @src; see gdk_pixbuf_new_subpixbuf().
|
||
*
|
||
* For more complicated scaling/compositing see gdk_pixbuf_scale()
|
||
* and gdk_pixbuf_composite().
|
||
*
|
||
* Return value: (transfer full): the new #GdkPixbuf, or %NULL if not enough memory could be
|
||
* allocated for it.
|
||
**/
|
||
GdkPixbuf *
|
||
gdk_pixbuf_scale_simple (const GdkPixbuf *src,
|
||
int dest_width,
|
||
int dest_height,
|
||
GdkInterpType interp_type)
|
||
{
|
||
GdkPixbuf *dest;
|
||
|
||
g_return_val_if_fail (GDK_IS_PIXBUF (src), NULL);
|
||
g_return_val_if_fail (dest_width > 0, NULL);
|
||
g_return_val_if_fail (dest_height > 0, NULL);
|
||
|
||
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, src->has_alpha, 8, dest_width, dest_height);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
gdk_pixbuf_scale (src, dest, 0, 0, dest_width, dest_height, 0, 0,
|
||
(double) dest_width / src->width,
|
||
(double) dest_height / src->height,
|
||
interp_type);
|
||
|
||
return dest;
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_composite_color_simple:
|
||
* @src: a #GdkPixbuf
|
||
* @dest_width: the width of destination image
|
||
* @dest_height: the height of destination image
|
||
* @interp_type: the interpolation type for the transformation.
|
||
* @overall_alpha: overall alpha for source image (0..255)
|
||
* @check_size: the size of checks in the checkboard (must be a power of two)
|
||
* @color1: the color of check at upper left
|
||
* @color2: the color of the other check
|
||
*
|
||
* Creates a new #GdkPixbuf by scaling @src to @dest_width x
|
||
* @dest_height and compositing the result with a checkboard of colors
|
||
* @color1 and @color2.
|
||
*
|
||
* Return value: (transfer full): the new #GdkPixbuf, or %NULL if not enough memory could be
|
||
* allocated for it.
|
||
**/
|
||
GdkPixbuf *
|
||
gdk_pixbuf_composite_color_simple (const GdkPixbuf *src,
|
||
int dest_width,
|
||
int dest_height,
|
||
GdkInterpType interp_type,
|
||
int overall_alpha,
|
||
int check_size,
|
||
guint32 color1,
|
||
guint32 color2)
|
||
{
|
||
GdkPixbuf *dest;
|
||
|
||
g_return_val_if_fail (GDK_IS_PIXBUF (src), NULL);
|
||
g_return_val_if_fail (dest_width > 0, NULL);
|
||
g_return_val_if_fail (dest_height > 0, NULL);
|
||
g_return_val_if_fail (overall_alpha >= 0 && overall_alpha <= 255, NULL);
|
||
|
||
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, src->has_alpha, 8, dest_width, dest_height);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
gdk_pixbuf_composite_color (src, dest, 0, 0, dest_width, dest_height, 0, 0,
|
||
(double) dest_width / src->width,
|
||
(double) dest_height / src->height,
|
||
interp_type, overall_alpha, 0, 0, check_size, color1, color2);
|
||
|
||
return dest;
|
||
}
|
||
|
||
#define OFFSET(pb, x, y) ((x) * (pb)->n_channels + (y) * (pb)->rowstride)
|
||
|
||
/**
|
||
* gdk_pixbuf_rotate_simple:
|
||
* @src: a #GdkPixbuf
|
||
* @angle: the angle to rotate by
|
||
*
|
||
* Rotates a pixbuf by a multiple of 90 degrees, and returns the
|
||
* result in a new pixbuf.
|
||
*
|
||
* Returns: (nullable) (transfer full): the new #GdkPixbuf, or %NULL
|
||
* if not enough memory could be allocated for it.
|
||
*
|
||
* Since: 2.6
|
||
*/
|
||
GdkPixbuf *
|
||
gdk_pixbuf_rotate_simple (const GdkPixbuf *src,
|
||
GdkPixbufRotation angle)
|
||
{
|
||
const guint8 *src_pixels;
|
||
guint8 *dest_pixels;
|
||
GdkPixbuf *dest;
|
||
const guchar *p;
|
||
guchar *q;
|
||
gint x, y;
|
||
|
||
src_pixels = gdk_pixbuf_read_pixels (src);
|
||
|
||
switch (angle % 360)
|
||
{
|
||
case 0:
|
||
dest = gdk_pixbuf_copy (src);
|
||
break;
|
||
case 90:
|
||
dest = gdk_pixbuf_new (src->colorspace,
|
||
src->has_alpha,
|
||
src->bits_per_sample,
|
||
src->height,
|
||
src->width);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
|
||
for (y = 0; y < src->height; y++)
|
||
{
|
||
for (x = 0; x < src->width; x++)
|
||
{
|
||
p = src_pixels + OFFSET (src, x, y);
|
||
q = dest_pixels + OFFSET (dest, y, src->width - x - 1);
|
||
memcpy (q, p, dest->n_channels);
|
||
}
|
||
}
|
||
break;
|
||
case 180:
|
||
dest = gdk_pixbuf_new (src->colorspace,
|
||
src->has_alpha,
|
||
src->bits_per_sample,
|
||
src->width,
|
||
src->height);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
|
||
for (y = 0; y < src->height; y++)
|
||
{
|
||
for (x = 0; x < src->width; x++)
|
||
{
|
||
p = src_pixels + OFFSET (src, x, y);
|
||
q = dest_pixels + OFFSET (dest, src->width - x - 1, src->height - y - 1);
|
||
memcpy (q, p, dest->n_channels);
|
||
}
|
||
}
|
||
break;
|
||
case 270:
|
||
dest = gdk_pixbuf_new (src->colorspace,
|
||
src->has_alpha,
|
||
src->bits_per_sample,
|
||
src->height,
|
||
src->width);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
|
||
for (y = 0; y < src->height; y++)
|
||
{
|
||
for (x = 0; x < src->width; x++)
|
||
{
|
||
p = src_pixels + OFFSET (src, x, y);
|
||
q = dest_pixels + OFFSET (dest, src->height - y - 1, x);
|
||
memcpy (q, p, dest->n_channels);
|
||
}
|
||
}
|
||
break;
|
||
default:
|
||
dest = NULL;
|
||
g_warning ("gdk_pixbuf_rotate_simple() can only rotate "
|
||
"by multiples of 90 degrees");
|
||
g_assert_not_reached ();
|
||
}
|
||
|
||
return dest;
|
||
}
|
||
|
||
/**
|
||
* gdk_pixbuf_flip:
|
||
* @src: a #GdkPixbuf
|
||
* @horizontal: %TRUE to flip horizontally, %FALSE to flip vertically
|
||
*
|
||
* Flips a pixbuf horizontally or vertically and returns the
|
||
* result in a new pixbuf.
|
||
*
|
||
* Returns: (nullable) (transfer full): the new #GdkPixbuf, or %NULL
|
||
* if not enough memory could be allocated for it.
|
||
*
|
||
* Since: 2.6
|
||
*/
|
||
GdkPixbuf *
|
||
gdk_pixbuf_flip (const GdkPixbuf *src,
|
||
gboolean horizontal)
|
||
{
|
||
const guint8 *src_pixels;
|
||
guint8 *dest_pixels;
|
||
GdkPixbuf *dest;
|
||
const guchar *p;
|
||
guchar *q;
|
||
gint x, y;
|
||
|
||
dest = gdk_pixbuf_new (src->colorspace,
|
||
src->has_alpha,
|
||
src->bits_per_sample,
|
||
src->width,
|
||
src->height);
|
||
if (!dest)
|
||
return NULL;
|
||
|
||
dest_pixels = gdk_pixbuf_get_pixels (dest);
|
||
src_pixels = gdk_pixbuf_read_pixels (src);
|
||
|
||
if (!horizontal) /* flip vertical */
|
||
{
|
||
for (y = 0; y < dest->height; y++)
|
||
{
|
||
p = src_pixels + OFFSET (src, 0, y);
|
||
q = dest_pixels + OFFSET (dest, 0, dest->height - y - 1);
|
||
memcpy (q, p, dest->rowstride);
|
||
}
|
||
}
|
||
else /* flip horizontal */
|
||
{
|
||
for (y = 0; y < dest->height; y++)
|
||
{
|
||
for (x = 0; x < dest->width; x++)
|
||
{
|
||
p = src_pixels + OFFSET (src, x, y);
|
||
q = dest_pixels + OFFSET (dest, dest->width - x - 1, y);
|
||
memcpy (q, p, dest->n_channels);
|
||
}
|
||
}
|
||
}
|
||
|
||
return dest;
|
||
}
|