394889/s_triangle.i.17

   1 static __inline__ int IS_INF_OR_NAN(float x)
   2 {
   3         union {
   4                 float f;
   5                 int i;
   6         } tmp;
   7         tmp.f = x;
   8         return tmp.i;
   9 }
  10
  11 static void simple_textured_triangle( float ** v1)
  12 {
  13         float **v0;
  14         float **v2;
  15         typedef struct {
  16                 float dx;
  17                 float dy;
  18                 int fsx;
  19                 int fx0;
  20                 int lines;
  21         } EdgeT;
  22         EdgeT eMaj;
  23         EdgeT eTop;
  24         EdgeT eBot;
  25         float oneOverArea;
  26         float **vMin;
  27         float **vMid;
  28         float **vMax;
  29         int vMin_fx;
  30         int vMin_fy;
  31         int vMid_fx;
  32         int vMid_fy;
  33         int vMax_fx;
  34         int vMax_fy;
  35         if (v1[0][1] <= v2[0][1]) {
  36                 vMin = v0;
  37                 vMax = v1;
  38                 vMin_fy = v0[0][1];
  39         }
  40         vMin_fx = vMin[0][0];
  41         vMid_fx =
  42               vMid[4][0] ?
  43                 ((vMid[4][0] * (float)2048) + 0.5F) :
  44                 ((vMid[4][0] * (float)2048) - 0.5F);
  45         eMaj.dx = (vMax_fx - vMin_fx) * (1.0F / (float)2048);
  46         eMaj.dy = (vMax_fy - vMin_fy) * (1.0F / (float)2048);
  47         eTop.dx = (vMax_fx - vMid_fx) * (1.0F / (float)2048);
  48         eBot.dy = (vMid_fy - vMin_fy) * (1.0F / (float)2048);
  49         float area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
  50         if (IS_INF_OR_NAN(area))
  51                 return;
  52         oneOverArea = 1.0F / area;
  53         eBot.fx0 = vMin_fx;
  54         int scan_from_left_to_right;
  55         void (*PutRowRGB)();
  56         float eMaj_ds = (vMax[4][0] - vMin[4][0]);
  57         float eBot_ds;
  58         float stepx =
  59             oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
  60         int step = (stepx >= 0.0F) ? stepx : (stepx * (float)2048) - 0.5F;
  61         int subTriangle;
  62         int fxRightEdge = 0;
  63         for (subTriangle = 0; subTriangle <= 1; subTriangle++) {
  64                 EdgeT *eRight;
  65                 int lines;
  66                 if (subTriangle == 0) {
  67                         if (scan_from_left_to_right) {
  68                                 eRight = &eBot;
  69                                 lines = eRight->lines;
  70                         } else {
  71                                 eRight = &eMaj;
  72                         }
  73                 } else {
  74                         if (scan_from_left_to_right) {
  75                                 eRight = &eTop;
  76                         }
  77                         fxRightEdge = eRight->fsx;
  78                 }
  79                 while (lines > 0) {
  80                         int end; int x; int y;
  81                         x = 0;
  82                         if (fxRightEdge <= x)
  83                                 end = 0;
  84                         else
  85                                 end = fxRightEdge - x;
  86                         if (end > 0 && y >= 0) {
  87                                 int i;
  88                                 char *rgb;
  89                                 for (i = 0; i < end; i++) {
  90                                         int it;
  91                                         char *texture;
  92                                         rgb[i] = texture[it];
  93                                         it += step;
  94                                 }
  95                                 PutRowRGB(rgb);
  96                         }
  97                 }
  98         }
  99 }
 100
 101 void *foo()
 102 {
 103         return simple_textured_triangle;
 104 }