hvirtual/quicktime/decore50/gen_draw.c

   1 // gen_draw.c //
   2
   3 #include "mp4_decoder.h"
   4
   5 #include "gen_draw.h"
   6
   7 /**
   8  *
   9 **/
  10
  11 extern int MV[2][6][MBR+1][MBC+2]; // motion vectors
  12 extern int modemap[MBR+1][MBC+2]; // macroblock modes
  13
  14 /***/
  15
  16 static void colorBlock_mv(unsigned char *buff, int stride, int mb_xpos, int mb_ypos, int bnum, int xsize, int ysize);
  17 static void drawline(int stride, int x0, int y0, int dx, int dy, unsigned char *buff, char colour, int xsize, int ysize);
  18 static void check_and_colour(unsigned char *buff, int x0, int y0, int xsize, int ysize, char colour);
  19
  20 /***/
  21
  22 // Purpose: draw motion vectors in a displayable buffer
  23 void colorBuffer_mv(unsigned char *buff, int stride, int xsize, int ysize)
  24 {
  25         int mb_xsize, mb_ysize;
  26         int mb_xpos, mb_ypos;
  27         int bnum;
  28
  29         mb_xsize = xsize>>4;
  30         mb_ysize = ysize>>4;
  31
  32         for (mb_ypos = 0; mb_ypos < mb_ysize; mb_ypos++)
  33         {
  34                 for (mb_xpos = 0; mb_xpos < mb_xsize; mb_xpos++)
  35                 {
  36                         switch (modemap[mb_xpos+1][mb_ypos+1])
  37                         {
  38                         case MODE_INTER: case MODE_INTER_Q:
  39                                 {
  40                                         colorBlock_mv(buff, stride, mb_xpos, mb_ypos, -1, xsize, ysize);
  41                                 }
  42                                 break;
  43                         case MODE_INTER4V: case MODE_INTER4V_Q:
  44                                 {
  45                                         for (bnum = 0; bnum < 4; bnum++)
  46                                         {
  47                                                 colorBlock_mv(buff, stride, mb_xpos, mb_ypos, bnum, xsize, ysize);
  48                                         }
  49                                 }
  50                                 break;
  51                         default:
  52                                 break;
  53                         }
  54                 }
  55         }
  56 }
  57
  58 /***/
  59
  60 // Purpose: draw motion vector for this block, bnum is -1 if it's an entire macroblock
  61 static void colorBlock_mv(unsigned char *buff, int stride, int mb_xpos, int mb_ypos, int bnum, int xsize, int ysize)
  62 {
  63         int mvx, mvy;
  64         int xpos = mb_xpos<<4;
  65         int ypos = mb_ypos<<4;
  66
  67         if (bnum == -1) {
  68                 xpos += 8;
  69                 ypos += 8;
  70                 bnum = 0; // retrieve correct block number for MV extraction
  71         }
  72         else {
  73                 xpos += (bnum & 1) ? 12 : 4;
  74                 ypos += (bnum & 2) ? 12 : 4;
  75         }
  76
  77         mvx = MV[0][bnum][mb_xpos+1][mb_ypos+1];
  78         mvy = MV[1][bnum][mb_xpos+1][mb_ypos+1];
  79
  80         drawline(stride, xpos, ypos, mvx, mvy, buff, 0, xsize, ysize);
  81 }
  82
  83 /***/
  84
  85 // John Funnell < johnf@mail.nu >
  86 // Purpose: line drawing function - pilfered from the Net
  87 static void drawline(int stride, int x0, int y0, int dx, int dy, unsigned char *buff, char colour, int xsize, int ysize) {
  88         int y1 = y0 + dy;
  89         int x1 = x0 + dx;
  90         int stepx, stepy;
  91         int fraction;
  92
  93         if (dy < 0) {
  94                 dy = -dy;  stepy = -stride;
  95         }
  96         else {
  97                 stepy = stride;
  98         }
  99         if (dx < 0) {
 100                 dx = -dx;  stepx = -1;
 101         } else {
 102                 stepx = 1;
 103         }
 104
 105         // retrieve pixel coord
 106         dy <<= 1;
 107         dx <<= 1;
 108
 109         // retrieve image coordinates
 110         y0 *= stride;
 111         y1 *= stride;
 112
 113         check_and_colour(buff, x0, y0, xsize, ysize, colour);
 114         if (dx > dy) {
 115                 fraction = dy - (dx >> 1);
 116                 while (x0 != x1) {
 117                         if (fraction >= 0) {
 118                                 y0 += stepy;
 119                                 fraction -= dx;
 120                         }
 121                         x0 += stepx;
 122                         fraction += dy;
 123                         check_and_colour(buff, x0, y0, xsize, ysize, colour);
 124                 }
 125         } else {
 126                 fraction = dx - (dy >> 1);
 127                 while (y0 != y1) {
 128                         if (fraction >= 0) {
 129                                 x0 += stepx;
 130                                 fraction -= dy;
 131                         }
 132                         y0 += stepy;
 133                         fraction += dx;
 134                         check_and_colour(buff, x0, y0, xsize, ysize, colour);
 135                 }
 136         }
 137 }
 138
 139 /***/
 140
 141 static void check_and_colour(unsigned char *buff, int x0, int y0, int xsize, int ysize, char colour)
 142 {
 143         if (x0 < 0)
 144                 return;
 145         if (x0 > xsize)
 146                 return;
 147         if (y0 < 0)
 148                 return;
 149         if (y0 > (xsize*(ysize-1)))
 150                 return;
 151
 152         buff[x0+y0] = colour;
 153 }