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669a4955e9
git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/back/trunk@13249 72102866-910b-0410-8b05-ffd578937521
488 lines
12 KiB
C
488 lines
12 KiB
C
/* gradient.c - renders gradients
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*
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* Raster graphics library
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*
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* Copyright (c) 1997-2000 Alfredo K. Kojima
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* Copyright (c) 1998-2000 Dan Pascu
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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 Library 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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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free
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* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <config.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <assert.h>
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#include "xrtools.h"
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static RImage *renderHGradient(unsigned width, unsigned height,
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int r0, int g0, int b0,
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int rf, int gf, int bf);
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static RImage *renderVGradient(unsigned width, unsigned height,
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int r0, int g0, int b0,
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int rf, int gf, int bf);
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static RImage *renderDGradient(unsigned width, unsigned height,
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int r0, int g0, int b0,
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int rf, int gf, int bf);
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static RImage *renderMHGradient(unsigned width, unsigned height,
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RColor **colors, int count);
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static RImage *renderMVGradient(unsigned width, unsigned height,
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RColor **colors, int count);
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static RImage *renderMDGradient(unsigned width, unsigned height,
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RColor **colors, int count);
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RImage*
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RRenderMultiGradient(unsigned width, unsigned height, RColor **colors, int style)
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{
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int count;
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count = 0;
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while (colors[count]!=NULL) count++;
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if (count > 2) {
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switch (style) {
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case RHorizontalGradient:
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return renderMHGradient(width, height, colors, count);
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case RVerticalGradient:
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return renderMVGradient(width, height, colors, count);
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case RDiagonalGradient:
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return renderMDGradient(width, height, colors, count);
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}
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} else if (count > 1) {
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return RRenderGradient(width, height, colors[0], colors[1], style);
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} else if (count > 0) {
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return RRenderGradient(width, height, colors[0], colors[0], style);
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}
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assert(0);
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return NULL;
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}
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RImage*
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RRenderGradient(unsigned width, unsigned height, RColor *from, RColor *to,
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int style)
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{
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switch (style) {
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case RHorizontalGradient:
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return renderHGradient(width, height, from->red, from->green,
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from->blue, to->red, to->green, to->blue);
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case RVerticalGradient:
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return renderVGradient(width, height, from->red, from->green,
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from->blue, to->red, to->green, to->blue);
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case RDiagonalGradient:
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return renderDGradient(width, height, from->red, from->green,
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from->blue, to->red, to->green, to->blue);
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}
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assert(0);
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return NULL;
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}
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/*
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*----------------------------------------------------------------------
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* renderHGradient--
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* Renders a horizontal linear gradient of the specified size in the
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* RImage format with a border of the specified type.
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*
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* Returns:
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* A 24bit RImage with the gradient (no alpha channel).
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*
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* Side effects:
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* None
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*----------------------------------------------------------------------
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*/
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static RImage*
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renderHGradient(unsigned width, unsigned height, int r0, int g0, int b0,
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int rf, int gf, int bf)
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{
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int i;
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unsigned long r, g, b, dr, dg, db;
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RImage *image;
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unsigned char *ptr;
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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ptr = image->data;
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r = r0 << 16;
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g = g0 << 16;
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b = b0 << 16;
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dr = ((rf-r0)<<16)/(int)width;
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dg = ((gf-g0)<<16)/(int)width;
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db = ((bf-b0)<<16)/(int)width;
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/* render the first line */
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for (i=0; i<width; i++) {
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*(ptr++) = (unsigned char)(r>>16);
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*(ptr++) = (unsigned char)(g>>16);
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*(ptr++) = (unsigned char)(b>>16);
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r += dr;
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g += dg;
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b += db;
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}
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/* copy the first line to the other lines */
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for (i=1; i<height; i++) {
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memcpy(&(image->data[i*width*3]), image->data, width*3);
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}
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return image;
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}
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/*
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*----------------------------------------------------------------------
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* renderVGradient--
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* Renders a vertical linear gradient of the specified size in the
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* RImage format with a border of the specified type.
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*
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* Returns:
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* A 24bit RImage with the gradient (no alpha channel).
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*
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* Side effects:
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* None
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*----------------------------------------------------------------------
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*/
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static RImage*
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renderVGradient(unsigned width, unsigned height, int r0, int g0, int b0,
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int rf, int gf, int bf)
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{
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int i, j;
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unsigned long r, g, b, dr, dg, db;
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RImage *image;
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unsigned char *ptr;
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unsigned int *iptr;
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unsigned char rr, gg, bb;
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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iptr = (unsigned int*)ptr = image->data;
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r = r0<<16;
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g = g0<<16;
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b = b0<<16;
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dr = ((rf-r0)<<16)/(int)height;
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dg = ((gf-g0)<<16)/(int)height;
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db = ((bf-b0)<<16)/(int)height;
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for (i=0; i<height; i++) {
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rr = r>>16;
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gg = g>>16;
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bb = b>>16;
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for (j=0; j<width/8; j++) {
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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}
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switch (width%8) {
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case 7: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 6: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 5: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 4: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 3: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 2: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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case 1: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
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}
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r+=dr;
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g+=dg;
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b+=db;
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}
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return image;
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}
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/*
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*----------------------------------------------------------------------
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* renderDGradient--
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* Renders a diagonal linear gradient of the specified size in the
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* RImage format with a border of the specified type.
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*
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* Returns:
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* A 24bit RImage with the gradient (no alpha channel).
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*
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* Side effects:
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* None
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*----------------------------------------------------------------------
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*/
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static RImage*
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renderDGradient(unsigned width, unsigned height, int r0, int g0, int b0,
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int rf, int gf, int bf)
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{
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RImage *image, *tmp;
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int j;
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float a, offset;
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char *ptr;
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if (width == 1)
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return renderVGradient(width, height, r0, g0, b0, rf, gf, bf);
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else if (height == 1)
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return renderHGradient(width, height, r0, g0, b0, rf, gf, bf);
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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tmp = renderHGradient(2*width-1, 1, r0, g0, b0, rf, gf, bf);
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if (!tmp) {
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RDestroyImage(image);
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return NULL;
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}
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ptr = tmp->data;
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a = ((float)(width - 1))/((float)(height - 1));
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width = width * 3;
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/* copy the first line to the other lines with corresponding offset */
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for (j=0, offset=0.0; j<width*height; j += width) {
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memcpy(&(image->data[j]), &ptr[3*(int)offset], width);
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offset += a;
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}
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RDestroyImage(tmp);
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return image;
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}
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static RImage*
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renderMHGradient(unsigned width, unsigned height, RColor **colors, int count)
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{
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int i, j, k;
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unsigned long r, g, b, dr, dg, db;
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RImage *image;
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unsigned char *ptr;
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unsigned width2;
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assert(count > 2);
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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ptr = image->data;
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if (count > width)
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count = width;
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if (count > 1)
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width2 = width/(count-1);
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else
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width2 = width;
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k = 0;
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r = colors[0]->red << 16;
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g = colors[0]->green << 16;
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b = colors[0]->blue << 16;
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/* render the first line */
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for (i=1; i<count; i++) {
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dr = ((int)(colors[i]->red - colors[i-1]->red) <<16)/(int)width2;
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dg = ((int)(colors[i]->green - colors[i-1]->green)<<16)/(int)width2;
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db = ((int)(colors[i]->blue - colors[i-1]->blue) <<16)/(int)width2;
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for (j=0; j<width2; j++) {
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*ptr++ = (unsigned char)(r>>16);
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*ptr++ = (unsigned char)(g>>16);
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*ptr++ = (unsigned char)(b>>16);
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r += dr;
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g += dg;
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b += db;
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k++;
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}
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r = colors[i]->red << 16;
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g = colors[i]->green << 16;
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b = colors[i]->blue << 16;
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}
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for (j=k; j<width; j++) {
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*ptr++ = (unsigned char)(r>>16);
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*ptr++ = (unsigned char)(g>>16);
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*ptr++ = (unsigned char)(b>>16);
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}
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/* copy the first line to the other lines */
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for (i=1; i<height; i++) {
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memcpy(&(image->data[i*width*3]), image->data, width*3);
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}
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return image;
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}
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static RImage*
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renderMVGradient(unsigned width, unsigned height, RColor **colors, int count)
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{
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int i, j, k;
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unsigned long r, g, b, dr, dg, db;
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RImage *image;
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unsigned char *ptr, *tmp;
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unsigned height2;
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int x;
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unsigned char rr, gg, bb;
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assert(count > 2);
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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ptr = image->data;
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if (count > height)
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count = height;
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if (count > 1)
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height2 = height/(count-1);
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else
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height2 = height;
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k = 0;
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r = colors[0]->red << 16;
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g = colors[0]->green << 16;
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b = colors[0]->blue << 16;
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for (i=1; i<count; i++) {
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dr = ((int)(colors[i]->red - colors[i-1]->red) <<16)/(int)height2;
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dg = ((int)(colors[i]->green - colors[i-1]->green)<<16)/(int)height2;
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db = ((int)(colors[i]->blue - colors[i-1]->blue) <<16)/(int)height2;
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for (j=0; j<height2; j++) {
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rr = r>>16;
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gg = g>>16;
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bb = b>>16;
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for (x=0; x<width/4; x++) {
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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}
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switch (width%4) {
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case 3: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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case 2: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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case 1: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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}
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r += dr;
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g += dg;
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b += db;
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k++;
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}
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r = colors[i]->red << 16;
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g = colors[i]->green << 16;
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b = colors[i]->blue << 16;
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}
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rr = r>>16;
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gg = g>>16;
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bb = b>>16;
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if (k<height) {
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tmp = ptr;
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for (x=0; x<width/4; x++) {
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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}
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switch (width%4) {
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case 3: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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case 2: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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case 1: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
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default: break;
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}
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for (j=k+1; j<height; j++) {
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memcpy(ptr, tmp, width*3);
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ptr += width*3;
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}
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}
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return image;
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}
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static RImage*
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renderMDGradient(unsigned width, unsigned height, RColor **colors, int count)
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{
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RImage *image, *tmp;
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float a, offset;
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int j;
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unsigned char *ptr;
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assert(count > 2);
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if (width == 1)
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return renderMVGradient(width, height, colors, count);
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else if (height == 1)
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return renderMHGradient(width, height, colors, count);
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image = RCreateImage(width, height, False);
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if (!image) {
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return NULL;
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}
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if (count > width)
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count = width;
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if (count > height)
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count = height;
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if (count > 2)
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tmp = renderMHGradient(2*width-1, 1, colors, count);
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else
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tmp = renderHGradient(2*width-1, 1, colors[0]->red<<8,
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colors[0]->green<<8, colors[0]->blue<<8,
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colors[1]->red<<8, colors[1]->green<<8,
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colors[1]->blue<<8);
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if (!tmp) {
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RDestroyImage(image);
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return NULL;
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}
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ptr = tmp->data;
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a = ((float)(width - 1))/((float)(height - 1));
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width = width * 3;
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/* copy the first line to the other lines with corresponding offset */
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for (j=0, offset=0; j<width*height; j += width) {
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memcpy(&(image->data[j]), &ptr[3*(int)offset], width);
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offset += a;
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}
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RDestroyImage(tmp);
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return image;
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}
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