forked from AuroraMiddleware/gtk
a7d0944194
2001-12-16 Havoc Pennington <hp@pobox.com> * gdk-pixbuf/tmpl/scaling.sgml: small doc tweaks, specifically some "just do XYZ" advice next to the InterpMode technojargon. 2001-12-16 Havoc Pennington <hp@pobox.com> * gdk-pixbuf-scale.c: docs enhancements
297 lines
11 KiB
C
297 lines
11 KiB
C
/* GdkPixbuf library - Scaling and compositing functions
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*
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* Copyright (C) 1999 The Free Software Foundation
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*
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* Author: Owen Taylor <otaylor@redhat.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include <config.h>
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#include <math.h>
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#include "gdk-pixbuf-private.h"
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#include "pixops/pixops.h"
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/**
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* gdk_pixbuf_scale:
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* @src: a #GdkPixbuf
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* @dest: the #GdkPixbuf into which to render the results
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* @dest_x: the left coordinate for region to render
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* @dest_y: the top coordinate for region to render
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* @dest_width: the width of the region to render
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* @dest_height: the height of the region to render
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* @offset_x: the offset in the X direction (currently rounded to an integer)
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* @offset_y: the offset in the Y direction (currently rounded to an integer)
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* @scale_x: the scale factor in the X direction
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* @scale_y: the scale factor in the Y direction
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* @interp_type: the interpolation type for the transformation.
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*
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* Creates a transformation of the source image @src by scaling by
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* @scale_x and @scale_y then translating by @offset_x and @offset_y,
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* then renders the rectangle (@dest_x, @dest_y, @dest_width,
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* @dest_height) of the resulting image onto the destination image
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* replacing the previous contents.
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*
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* Try to use gdk_pixbuf_scale_simple() first, this function is
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* the industrial-strength power tool you can fall back to if
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* gdk_pixbuf_scale_simple() isn't powerful enough.
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**/
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void
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gdk_pixbuf_scale (const GdkPixbuf *src,
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GdkPixbuf *dest,
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int dest_x,
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int dest_y,
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int dest_width,
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int dest_height,
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double offset_x,
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double offset_y,
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double scale_x,
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double scale_y,
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GdkInterpType interp_type)
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{
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g_return_if_fail (src != NULL);
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g_return_if_fail (dest != NULL);
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g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
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g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
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offset_x = floor (offset_x + 0.5);
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offset_y = floor (offset_y + 0.5);
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pixops_scale (dest->pixels + dest_y * dest->rowstride + dest_x * dest->n_channels,
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dest_x - offset_x, dest_y - offset_y,
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dest_x + dest_width - offset_x, dest_y + dest_height - offset_y,
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dest->rowstride, dest->n_channels, dest->has_alpha,
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src->pixels, src->width, src->height,
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src->rowstride, src->n_channels, src->has_alpha,
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scale_x, scale_y, interp_type);
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}
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/**
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* gdk_pixbuf_composite:
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* @src: a #GdkPixbuf
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* @dest: the #GdkPixbuf into which to render the results
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* @dest_x: the left coordinate for region to render
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* @dest_y: the top coordinate for region to render
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* @dest_width: the width of the region to render
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* @dest_height: the height of the region to render
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* @offset_x: the offset in the X direction (currently rounded to an integer)
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* @offset_y: the offset in the Y direction (currently rounded to an integer)
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* @scale_x: the scale factor in the X direction
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* @scale_y: the scale factor in the Y direction
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* @interp_type: the interpolation type for the transformation.
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* @overall_alpha: overall alpha for source image (0..255)
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*
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* Creates a transformation of the source image @src by scaling by
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* @scale_x and @scale_y then translating by @offset_x and @offset_y,
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* then composites the rectangle (@dest_x, @dest_y, @dest_width,
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* @dest_height) of the resulting image onto the destination image.
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**/
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void
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gdk_pixbuf_composite (const GdkPixbuf *src,
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GdkPixbuf *dest,
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int dest_x,
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int dest_y,
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int dest_width,
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int dest_height,
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double offset_x,
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double offset_y,
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double scale_x,
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double scale_y,
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GdkInterpType interp_type,
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int overall_alpha)
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{
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g_return_if_fail (src != NULL);
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g_return_if_fail (dest != NULL);
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g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
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g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
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g_return_if_fail (overall_alpha >= 0 && overall_alpha <= 255);
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offset_x = floor (offset_x + 0.5);
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offset_y = floor (offset_y + 0.5);
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pixops_composite (dest->pixels + dest_y * dest->rowstride + dest_x * dest->n_channels,
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dest_x - offset_x, dest_y - offset_y,
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dest_x + dest_width - offset_x, dest_y + dest_height - offset_y,
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dest->rowstride, dest->n_channels, dest->has_alpha,
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src->pixels, src->width, src->height,
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src->rowstride, src->n_channels, src->has_alpha,
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scale_x, scale_y, interp_type, overall_alpha);
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}
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/**
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* gdk_pixbuf_composite_color:
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* @src: a #GdkPixbuf
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* @dest: the #GdkPixbuf into which to render the results
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* @dest_x: the left coordinate for region to render
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* @dest_y: the top coordinate for region to render
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* @dest_width: the width of the region to render
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* @dest_height: the height of the region to render
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* @offset_x: the offset in the X direction (currently rounded to an integer)
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* @offset_y: the offset in the Y direction (currently rounded to an integer)
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* @scale_x: the scale factor in the X direction
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* @scale_y: the scale factor in the Y direction
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* @interp_type: the interpolation type for the transformation.
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* @overall_alpha: overall alpha for source image (0..255)
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* @check_x: the X offset for the checkboard (origin of checkboard is at -@check_x, -@check_y)
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* @check_y: the Y offset for the checkboard
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* @check_size: the size of checks in the checkboard (must be a power of two)
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* @color1: the color of check at upper left
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* @color2: the color of the other check
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*
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* Creates a transformation of the source image @src by scaling by
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* @scale_x and @scale_y then translating by @offset_x and @offset_y,
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* then composites the rectangle (@dest_x ,@dest_y, @dest_width,
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* @dest_height) of the resulting image with a checkboard of the
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* colors @color1 and @color2 and renders it onto the destination
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* image.
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*
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* See gdk_pixbuf_composite_color_simple() for a simpler variant of this
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* function suitable for many tasks.
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*
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**/
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void
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gdk_pixbuf_composite_color (const GdkPixbuf *src,
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GdkPixbuf *dest,
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int dest_x,
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int dest_y,
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int dest_width,
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int dest_height,
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double offset_x,
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double offset_y,
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double scale_x,
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double scale_y,
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GdkInterpType interp_type,
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int overall_alpha,
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int check_x,
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int check_y,
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int check_size,
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guint32 color1,
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guint32 color2)
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{
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g_return_if_fail (src != NULL);
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g_return_if_fail (dest != NULL);
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g_return_if_fail (dest_x >= 0 && dest_x + dest_width <= dest->width);
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g_return_if_fail (dest_y >= 0 && dest_y + dest_height <= dest->height);
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g_return_if_fail (overall_alpha >= 0 && overall_alpha <= 255);
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offset_x = floor (offset_x + 0.5);
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offset_y = floor (offset_y + 0.5);
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pixops_composite_color (dest->pixels + dest_y * dest->rowstride + dest_x * dest->n_channels,
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dest_x - offset_x, dest_y - offset_y,
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dest_x + dest_width - offset_x, dest_y + dest_height - offset_y,
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dest->rowstride, dest->n_channels, dest->has_alpha,
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src->pixels, src->width, src->height,
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src->rowstride, src->n_channels, src->has_alpha,
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scale_x, scale_y, interp_type, overall_alpha, check_x, check_y,
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check_size, color1, color2);
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}
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/**
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* gdk_pixbuf_scale_simple:
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* @src: a #GdkPixbuf
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* @dest_width: the width of destination image
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* @dest_height: the height of destination image
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* @interp_type: the interpolation type for the transformation.
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*
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* Create a new #GdkPixbuf containing a copy of @src scaled to
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* @dest_width x @dest_height. Leaves @src unaffected. @interp_type
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* should be #GDK_INTERP_NEAREST if you want maximum speed (but when
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* scaling down #GDK_INTERP_NEAREST is usually unusably ugly). The
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* default @interp_type should be #GDK_INTERP_BILINEAR which offers
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* reasonable quality and speed.
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*
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* You can scale a sub-portion of @src by creating a sub-pixbuf
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* pointing into @src; see gdk_pixbuf_new_subpixbuf().
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*
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* For more complicated scaling/compositing see gdk_pixbuf_scale()
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* and gdk_pixbuf_composite().
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*
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* Return value: the new #GdkPixbuf, or NULL if not enough memory could be
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* allocated for it.
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**/
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GdkPixbuf *
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gdk_pixbuf_scale_simple (const GdkPixbuf *src,
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int dest_width,
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int dest_height,
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GdkInterpType interp_type)
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{
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GdkPixbuf *dest;
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g_return_val_if_fail (src != NULL, NULL);
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g_return_val_if_fail (dest_width > 0, NULL);
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g_return_val_if_fail (dest_height > 0, NULL);
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dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, src->has_alpha, 8, dest_width, dest_height);
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if (!dest)
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return NULL;
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gdk_pixbuf_scale (src, dest, 0, 0, dest_width, dest_height, 0, 0,
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(double) dest_width / src->width,
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(double) dest_height / src->height,
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interp_type);
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return dest;
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}
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/**
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* gdk_pixbuf_composite_color_simple:
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* @src: a #GdkPixbuf
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* @dest_width: the width of destination image
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* @dest_height: the height of destination image
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* @interp_type: the interpolation type for the transformation.
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* @overall_alpha: overall alpha for source image (0..255)
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* @check_size: the size of checks in the checkboard (must be a power of two)
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* @color1: the color of check at upper left
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* @color2: the color of the other check
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*
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* Creates a new #GdkPixbuf by scaling @src to @dest_width x
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* @dest_height and compositing the result with a checkboard of colors
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* @color1 and @color2.
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*
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* Return value: the new #GdkPixbuf, or NULL if not enough memory could be
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* allocated for it.
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**/
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GdkPixbuf *
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gdk_pixbuf_composite_color_simple (const GdkPixbuf *src,
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int dest_width,
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int dest_height,
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GdkInterpType interp_type,
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int overall_alpha,
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int check_size,
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guint32 color1,
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guint32 color2)
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{
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GdkPixbuf *dest;
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g_return_val_if_fail (src != NULL, NULL);
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g_return_val_if_fail (dest_width > 0, NULL);
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g_return_val_if_fail (dest_height > 0, NULL);
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g_return_val_if_fail (overall_alpha >= 0 && overall_alpha <= 255, NULL);
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dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, src->has_alpha, 8, dest_width, dest_height);
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if (!dest)
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return NULL;
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gdk_pixbuf_composite_color (src, dest, 0, 0, dest_width, dest_height, 0, 0,
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(double) dest_width / src->width,
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(double) dest_height / src->height,
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interp_type, overall_alpha, 0, 0, check_size, color1, color2);
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return dest;
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}
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