root/ext/gd/libgd/gd_transform.c

DEFINITIONS

1. gdImageFlipVertical
2. gdImageFlipHorizontal
3. gdImageFlipBoth

   1 #include "gd.h"
   2 
   3 void gdImageFlipVertical(gdImagePtr im)
   4 {
   5         register int x, y;
   6 
   7         if (im->trueColor) {
   8                 for (y = 0; y < im->sy / 2; y++) {
   9                         int *row_dst = im->tpixels[y];
  10                         int *row_src = im->tpixels[im->sy - 1 - y];
  11                         for (x = 0; x < im->sx; x++) {
  12                                 register int p;
  13                                 p = row_dst[x];
  14                                 row_dst[x] = im->tpixels[im->sy - 1 - y][x];
  15                                 row_src[x] = p;
  16                         }
  17                 }
  18         } else {
  19                 unsigned char p;
  20                 for (y = 0; y < im->sy / 2; y++) {
  21                         for (x = 0; x < im->sx; x++) {
  22                                 p = im->pixels[y][x];
  23                                 im->pixels[y][x] =      im->pixels[im->sy - 1 - y][x];
  24                                 im->pixels[im->sy - 1 - y][x] = p;
  25                         }
  26                 }
  27         }
  28         return;
  29 }
  30 
  31 void gdImageFlipHorizontal(gdImagePtr im)
  32 {
  33 
  34         int x, y;
  35 
  36         if (im->trueColor) {
  37                 int *px1, *px2, tmp;
  38 
  39                 for (y = 0; y < im->sy; y++) {
  40                         px1 = im->tpixels[y];
  41                         px2 = im->tpixels[y] + im->sx - 1;
  42                         for (x = 0; x < (im->sx >> 1); x++) {
  43                                 tmp = *px1;
  44                                 *px1 = *px2;
  45                                 *px2 = tmp;
  46                                 px1++;
  47                                 px2--;
  48                         }
  49                 }
  50         } else {
  51                 unsigned char *px1, *px2, tmp;
  52 
  53                 for (y = 0; y < im->sy; y++) {
  54                         px1 = im->pixels[y];
  55                         px2 = im->pixels[y] + im->sx - 1;
  56                         for (x = 0; x < (im->sx >> 1); x++) {
  57                                 tmp = *px1;
  58                                 *px1 = *px2;
  59                                 *px2 = tmp;
  60                                 px1++;
  61                                 px2--;
  62                         }
  63                 }
  64         }
  65 }
  66 
  67 void gdImageFlipBoth(gdImagePtr im)
  68 {
  69         gdImageFlipVertical(im);
  70         gdImageFlipHorizontal(im);
  71 }
  72 
  73