src/gallium/auxiliary/draw/draw_cliptest_tmp.h

   1 /**************************************************************************
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   3  * Copyright 2010, VMware, inc.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  13  *
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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  25  *
  26  **************************************************************************/
  27
  28
  29
  30 static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
  31                                  struct draw_vertex_info *info )
  32 {
  33    struct vertex_header *out = info->verts;
  34    const float *scale = pvs->draw->viewport.scale;
  35    const float *trans = pvs->draw->viewport.translate;
  36    /* const */ float (*plane)[4] = pvs->draw->plane;
  37    const unsigned pos = draw_current_shader_position_output(pvs->draw);
  38    const unsigned ef = pvs->draw->vs.edgeflag_output;
  39    const unsigned nr = pvs->draw->nr_planes;
  40    const unsigned flags = (FLAGS);
  41    unsigned need_pipeline = 0;
  42    unsigned j;
  43
  44    for (j = 0; j < info->count; j++) {
  45       float *position = out->data[pos];
  46       unsigned mask = 0x0;
  47
  48       initialize_vertex_header(out);
  49
  50       if (flags & (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
  51          out->clip[0] = position[0];
  52          out->clip[1] = position[1];
  53          out->clip[2] = position[2];
  54          out->clip[3] = position[3];
  55
  56          /* Do the hardwired planes first:
  57           */
  58          if (flags & DO_CLIP_XY) {
  59             if (-position[0] + position[3] < 0) mask |= (1<<0);
  60             if ( position[0] + position[3] < 0) mask |= (1<<1);
  61             if (-position[1] + position[3] < 0) mask |= (1<<2);
  62             if ( position[1] + position[3] < 0) mask |= (1<<3);
  63          }
  64
  65          /* Clip Z planes according to full cube, half cube or none.
  66           */
  67          if (flags & DO_CLIP_FULL_Z) {
  68             if ( position[2] + position[3] < 0) mask |= (1<<4);
  69             if (-position[2] + position[3] < 0) mask |= (1<<5);
  70          }
  71          else if (flags & DO_CLIP_HALF_Z) {
  72             if ( position[2]               < 0) mask |= (1<<4);
  73             if (-position[2] + position[3] < 0) mask |= (1<<5);
  74          }
  75
  76          if (flags & DO_CLIP_USER) {
  77             unsigned i;
  78             for (i = 6; i < nr; i++) {
  79                if (dot4(position, plane[i]) < 0)
  80                   mask |= (1<<i);
  81             }
  82          }
  83
  84          out->clipmask = mask;
  85          need_pipeline |= out->clipmask;
  86       }
  87
  88       if ((flags & DO_VIEWPORT) && mask == 0)
  89       {
  90          /* divide by w */
  91          float w = 1.0f / position[3];
  92
  93          /* Viewport mapping */
  94          position[0] = position[0] * w * scale[0] + trans[0];
  95          position[1] = position[1] * w * scale[1] + trans[1];
  96          position[2] = position[2] * w * scale[2] + trans[2];
  97          position[3] = w;
  98       }
  99
 100       if ((flags & DO_EDGEFLAG) && ef) {
 101          const float *edgeflag = out->data[ef];
 102          out->edgeflag = !(edgeflag[0] != 1.0f);
 103          need_pipeline |= !out->edgeflag;
 104       }
 105
 106       out = (struct vertex_header *)( (char *)out + info->stride );
 107    }
 108
 109    return need_pipeline != 0;
 110 }
 111
 112
 113 #undef FLAGS
 114 #undef TAG