prj/tech/libsrc/g2/shadhack.c

   1 // $Header: x:/prj/tech/libsrc/g2/RCS/shadhack.c 1.6 1998/04/28 14:29:32 KEVIN Exp $
   2
   3 #include <g2d.h>
   4 #include <trirast.h>
   5 #include <plyshell.h>
   6 #include <tmapd.h>
   7 #include <dev2d.h>
   8 #include <genrast.h>
   9
  10 static void golf_shadow_hack_il(g2s_raster *r, g2s_poly_params *tp)
  11 {
  12    uint offset_max;
  13    fix u,v,du,dv;
  14    int row, left, right, x, x_last;
  15    ushort *dst;
  16    uchar *src;
  17
  18    if (r->n <= 0)
  19       return;
  20
  21    if ((r->y < grd_clip.top) || (r->y >= grd_clip.bot))
  22       return;
  23
  24    src = tp->bm->bits;
  25    row = tp->bm->row;
  26    offset_max = (uint )(row * tp->bm->h);
  27    left = grd_clip.left;
  28    right = grd_clip.right;
  29    dst = (ushort *)(grd_bm.bits + r->y * grd_bm.row);
  30
  31    x = r->x;
  32    u = r->u;
  33    v = r->v;
  34    du = tp->dux;
  35    dv = tp->dvx;
  36    x_last = x + r->n - 1;
  37    goto loop_start;
  38    do {
  39       uint offset;
  40       uchar c;
  41       ushort c16;
  42       ushort *clut;
  43
  44       u += du;
  45       v += dv;
  46       x++;
  47 loop_start:
  48       if ((x < left) || (x >= right))
  49          continue;
  50
  51       offset = (uint )(fix_int(u) + fix_int(v)*row);
  52       if (offset >= offset_max)
  53          offset = 0;
  54       c = src[offset];
  55       if (c==0)
  56          continue;
  57
  58       clut = (ushort *)(tluc8tab[c]);
  59       c16 = dst[x];
  60       dst[x] = clut[c16&0xff] + clut[256 + (c16>>8)];
  61    } while (x<x_last);
  62 }
  63
  64 void golf_shadow_hack(grs_bitmap *bm, int n, g2s_point **vpl)
  65 {
  66    g2s_poly_params tp;
  67
  68    tp.flags = PPF_UV;
  69    tp.dy = 1;
  70
  71    tp.bm = bm;
  72    tp.u_scale = bm->w;
  73    tp.v_scale = bm->h;
  74    tp.inner_loop = golf_shadow_hack_il;
  75    tp.raster_func = gen_raster_loop;
  76    tp.right_edge_func = gen_right_edge;
  77    tp.left_edge_func = gen_left_edge;
  78    tp.grad_func = gen_triangle_gradients;
  79
  80    g2_trifan(&tp, n, vpl);
  81 }