| 1 | /** @file
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| 2 | * Image resampling code, used for snapshot thumbnails.
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| 3 | */
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| 4 |
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| 5 | /*
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| 6 | * Copyright (C) 2011 Oracle Corporation
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| 7 | *
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| 8 | * This file is part of VirtualBox Open Source Edition (OSE), as
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| 9 | * available from http://www.virtualbox.org. This file is free software;
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| 10 | * you can redistribute it and/or modify it under the terms of the GNU
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| 11 | * General Public License (GPL) as published by the Free Software
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| 12 | * Foundation, in version 2 as it comes in the "COPYING" file of the
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| 13 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
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| 14 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
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| 15 | */
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| 16 |
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| 17 | /*
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| 18 | * Based on gdImageCopyResampled from libgd.
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| 19 | * Original copyright notice follows:
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| 20 |
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| 21 | Portions copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
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| 22 | Pierre-Alain Joye (pierre@libgd.org).
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| 23 |
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| 24 | Permission has been granted to copy, distribute and modify gd in
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| 25 | any context without fee, including a commercial application,
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| 26 | provided that this notice is present in user-accessible supporting
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| 27 | documentation.
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| 28 |
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| 29 | This does not affect your ownership of the derived work itself, and
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| 30 | the intent is to assure proper credit for the authors of gd, not to
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| 31 | interfere with your productive use of gd. If you have questions,
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| 32 | ask. "Derived works" includes all programs that utilize the
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| 33 | library. Credit must be given in user-accessible documentation.
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| 34 |
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| 35 | This software is provided "AS IS." The copyright holders disclaim
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| 36 | all warranties, either express or implied, including but not
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| 37 | limited to implied warranties of merchantability and fitness for a
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| 38 | particular purpose, with respect to this code and accompanying
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| 39 | documentation.
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| 40 | */
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| 41 |
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| 42 | /*
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| 43 | *
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| 44 | * @todo Simplify: Offsets of images are 0,0 => no dstX, dstY, srcX, srcY;
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| 45 | * Screenshot has no alpha channel => no processing of alpha byte.
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| 46 | */
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| 47 |
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| 48 | #include <iprt/types.h>
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| 49 |
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| 50 | /* 2.0.10: cast instead of floor() yields 35% performance improvement.
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| 51 | Thanks to John Buckman. */
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| 52 |
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| 53 | #define floor2(exp) ((long) exp)
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| 54 | /*#define floor2(exp) floor(exp)*/
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| 55 |
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| 56 | typedef uint8_t *gdImagePtr;
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| 57 |
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| 58 | DECLINLINE(int) gdImageGetTrueColorPixel (gdImagePtr im, int x, int y, int w)
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| 59 | {
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| 60 | return *(int32_t *)(im + y * w * 4 + x * 4);
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| 61 | }
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| 62 |
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| 63 | DECLINLINE(void) gdImageSetPixel (gdImagePtr im, int x, int y, int color, int w)
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| 64 | {
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| 65 | *(int32_t *)(im + y * w * 4 + x * 4) = color;
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| 66 | }
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| 67 |
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| 68 | #define gdAlphaMax 127
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| 69 | #define gdAlphaOpaque 0
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| 70 | #define gdAlphaTransparent 127
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| 71 | #define gdRedMax 255
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| 72 | #define gdGreenMax 255
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| 73 | #define gdBlueMax 255
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| 74 | #define gdTrueColorGetAlpha(c) (((c) & 0x7F000000) >> 24)
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| 75 | #define gdTrueColorGetRed(c) (((c) & 0xFF0000) >> 16)
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| 76 | #define gdTrueColorGetGreen(c) (((c) & 0x00FF00) >> 8)
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| 77 | #define gdTrueColorGetBlue(c) ((c) & 0x0000FF)
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| 78 | #define gdTrueColorAlpha(r, g, b, a) (((a) << 24) + \
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| 79 | ((r) << 16) + \
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| 80 | ((g) << 8) + \
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| 81 | (b))
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| 82 |
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| 83 | void gdImageCopyResampled (uint8_t *dst,
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| 84 | uint8_t *src,
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| 85 | int dstX, int dstY,
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| 86 | int srcX, int srcY,
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| 87 | int dstW, int dstH, int srcW, int srcH)
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| 88 | {
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| 89 | int x, y;
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| 90 | double sy1, sy2, sx1, sx2;
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| 91 | for (y = dstY; (y < dstY + dstH); y++)
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| 92 | {
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| 93 | sy1 = ((double) y - (double) dstY) * (double) srcH / (double) dstH;
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| 94 | sy2 = ((double) (y + 1) - (double) dstY) * (double) srcH /
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| 95 | (double) dstH;
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| 96 | for (x = dstX; (x < dstX + dstW); x++)
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| 97 | {
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| 98 | double sx, sy;
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| 99 | double spixels = 0;
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| 100 | double red = 0.0, green = 0.0, blue = 0.0, alpha = 0.0;
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| 101 | sx1 = ((double) x - (double) dstX) * (double) srcW / dstW;
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| 102 | sx2 = ((double) (x + 1) - (double) dstX) * (double) srcW / dstW;
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| 103 | sy = sy1;
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| 104 | do
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| 105 | {
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| 106 | double yportion;
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| 107 | if (floor2 (sy) == floor2 (sy1))
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| 108 | {
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| 109 | yportion = 1.0 - (sy - floor2 (sy));
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| 110 | if (yportion > sy2 - sy1)
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| 111 | {
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| 112 | yportion = sy2 - sy1;
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| 113 | }
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| 114 | sy = floor2 (sy);
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| 115 | }
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| 116 | else if (sy == floor2 (sy2))
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| 117 | {
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| 118 | yportion = sy2 - floor2 (sy2);
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| 119 | }
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| 120 | else
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| 121 | {
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| 122 | yportion = 1.0;
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| 123 | }
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| 124 | sx = sx1;
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| 125 | do
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| 126 | {
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| 127 | double xportion;
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| 128 | double pcontribution;
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| 129 | int p;
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| 130 | if (floor2 (sx) == floor2 (sx1))
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| 131 | {
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| 132 | xportion = 1.0 - (sx - floor2 (sx));
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| 133 | if (xportion > sx2 - sx1)
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| 134 | {
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| 135 | xportion = sx2 - sx1;
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| 136 | }
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| 137 | sx = floor2 (sx);
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| 138 | }
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| 139 | else if (sx == floor2 (sx2))
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| 140 | {
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| 141 | xportion = sx2 - floor2 (sx2);
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| 142 | }
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| 143 | else
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| 144 | {
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| 145 | xportion = 1.0;
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| 146 | }
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| 147 | pcontribution = xportion * yportion;
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| 148 | /* 2.08: previously srcX and srcY were ignored.
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| 149 | Andrew Pattison */
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| 150 | p = gdImageGetTrueColorPixel (src,
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| 151 | (int) sx + srcX,
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| 152 | (int) sy + srcY, srcW);
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| 153 | red += gdTrueColorGetRed (p) * pcontribution;
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| 154 | green += gdTrueColorGetGreen (p) * pcontribution;
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| 155 | blue += gdTrueColorGetBlue (p) * pcontribution;
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| 156 | alpha += gdTrueColorGetAlpha (p) * pcontribution;
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| 157 | spixels += xportion * yportion;
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| 158 | sx += 1.0;
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| 159 | }
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| 160 | while (sx < sx2);
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| 161 | sy += 1.0;
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| 162 | }
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| 163 | while (sy < sy2);
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| 164 | if (spixels != 0.0)
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| 165 | {
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| 166 | red /= spixels;
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| 167 | green /= spixels;
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| 168 | blue /= spixels;
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| 169 | alpha /= spixels;
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| 170 | }
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| 171 | /* Clamping to allow for rounding errors above */
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| 172 | if (red > 255.0)
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| 173 | {
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| 174 | red = 255.0;
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| 175 | }
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| 176 | if (green > 255.0)
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| 177 | {
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| 178 | green = 255.0;
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| 179 | }
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| 180 | if (blue > 255.0)
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| 181 | {
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| 182 | blue = 255.0;
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| 183 | }
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| 184 | if (alpha > gdAlphaMax)
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| 185 | {
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| 186 | alpha = gdAlphaMax;
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| 187 | }
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| 188 | gdImageSetPixel (dst,
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| 189 | x, y,
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| 190 | gdTrueColorAlpha ((int) red,
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| 191 | (int) green,
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| 192 | (int) blue, (int) alpha), dstW);
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| 193 | }
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| 194 | }
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| 195 | }
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| 196 |
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| 197 | /* Fast integer implementation for 32 bpp bitmap scaling.
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| 198 | * Use fixed point values * 16.
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| 199 | */
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| 200 | typedef int32_t FIXEDPOINT;
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| 201 | #define INT_TO_FIXEDPOINT(i) (FIXEDPOINT)((i) << 4)
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| 202 | #define FIXEDPOINT_TO_INT(v) (int)((v) >> 4)
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| 203 | #define FIXEDPOINT_FLOOR(v) ((v) & ~0xF)
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| 204 | #define FIXEDPOINT_FRACTION(v) ((v) & 0xF)
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| 205 |
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| 206 | /* For 32 bit source only. */
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| 207 | void BitmapScale32 (uint8_t *dst,
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| 208 | int dstW, int dstH,
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| 209 | const uint8_t *src,
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| 210 | int iDeltaLine,
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| 211 | int srcW, int srcH)
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| 212 | {
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| 213 | int x, y;
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| 214 |
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| 215 | for (y = 0; y < dstH; y++)
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| 216 | {
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| 217 | FIXEDPOINT sy1 = INT_TO_FIXEDPOINT(y * srcH) / dstH;
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| 218 | FIXEDPOINT sy2 = INT_TO_FIXEDPOINT((y + 1) * srcH) / dstH;
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| 219 |
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| 220 | for (x = 0; x < dstW; x++)
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| 221 | {
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| 222 | FIXEDPOINT red = 0, green = 0, blue = 0;
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| 223 |
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| 224 | FIXEDPOINT sx1 = INT_TO_FIXEDPOINT(x * srcW) / dstW;
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| 225 | FIXEDPOINT sx2 = INT_TO_FIXEDPOINT((x + 1) * srcW) / dstW;
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| 226 |
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| 227 | FIXEDPOINT spixels = (sx2 - sx1) * (sy2 - sy1);
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| 228 |
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| 229 | FIXEDPOINT sy = sy1;
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| 230 |
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| 231 | do
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| 232 | {
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| 233 | FIXEDPOINT yportion;
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| 234 | if (FIXEDPOINT_FLOOR (sy) == FIXEDPOINT_FLOOR (sy1))
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| 235 | {
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| 236 | yportion = INT_TO_FIXEDPOINT(1) - FIXEDPOINT_FRACTION(sy);
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| 237 | if (yportion > sy2 - sy1)
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| 238 | {
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| 239 | yportion = sy2 - sy1;
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| 240 | }
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| 241 | sy = FIXEDPOINT_FLOOR (sy);
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| 242 | }
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| 243 | else if (sy == FIXEDPOINT_FLOOR (sy2))
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| 244 | {
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| 245 | yportion = FIXEDPOINT_FRACTION(sy2);
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| 246 | }
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| 247 | else
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| 248 | {
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| 249 | yportion = INT_TO_FIXEDPOINT(1);
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| 250 | }
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| 251 |
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| 252 | const uint8_t *pu8SrcLine = src + iDeltaLine * FIXEDPOINT_TO_INT(sy);
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| 253 | FIXEDPOINT sx = sx1;
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| 254 | do
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| 255 | {
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| 256 | FIXEDPOINT xportion;
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| 257 | FIXEDPOINT pcontribution;
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| 258 | int p;
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| 259 | if (FIXEDPOINT_FLOOR (sx) == FIXEDPOINT_FLOOR (sx1))
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| 260 | {
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| 261 | xportion = INT_TO_FIXEDPOINT(1) - FIXEDPOINT_FRACTION(sx);
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| 262 | if (xportion > sx2 - sx1)
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| 263 | {
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| 264 | xportion = sx2 - sx1;
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| 265 | }
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| 266 | pcontribution = xportion * yportion;
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| 267 | sx = FIXEDPOINT_FLOOR (sx);
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| 268 | }
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| 269 | else if (sx == FIXEDPOINT_FLOOR (sx2))
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| 270 | {
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| 271 | xportion = FIXEDPOINT_FRACTION(sx2);
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| 272 | pcontribution = xportion * yportion;
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| 273 | }
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| 274 | else
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| 275 | {
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| 276 | xportion = INT_TO_FIXEDPOINT(1);
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| 277 | pcontribution = xportion * yportion;
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| 278 | }
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| 279 | /* Color depth specific code begin */
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| 280 | p = *(uint32_t *)(pu8SrcLine + FIXEDPOINT_TO_INT(sx) * 4);
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| 281 | /* Color depth specific code end */
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| 282 | red += gdTrueColorGetRed (p) * pcontribution;
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| 283 | green += gdTrueColorGetGreen (p) * pcontribution;
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| 284 | blue += gdTrueColorGetBlue (p) * pcontribution;
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| 285 |
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| 286 | sx += INT_TO_FIXEDPOINT(1);
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| 287 | } while (sx < sx2);
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| 288 |
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| 289 | sy += INT_TO_FIXEDPOINT(1);
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| 290 | } while (sy < sy2);
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| 291 |
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| 292 | if (spixels != 0)
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| 293 | {
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| 294 | red /= spixels;
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| 295 | green /= spixels;
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| 296 | blue /= spixels;
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| 297 | }
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| 298 | /* Clamping to allow for rounding errors above */
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| 299 | if (red > 255)
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| 300 | {
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| 301 | red = 255;
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| 302 | }
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| 303 | if (green > 255)
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| 304 | {
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| 305 | green = 255;
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| 306 | }
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| 307 | if (blue > 255)
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| 308 | {
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| 309 | blue = 255;
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| 310 | }
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| 311 | gdImageSetPixel (dst,
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| 312 | x, y,
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| 313 | ( ((int) red) << 16) + (((int) green) << 8) + ((int) blue),
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| 314 | dstW);
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| 315 | }
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| 316 | }
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| 317 | }
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| 318 |
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