src/gallium/auxiliary/draw/draw_cliptest_tmp.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2010, VMware, inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
  29                                  struct draw_vertex_info *info )
  30 {
  31    struct vertex_header *out = info->verts;
  32    /* const */ float (*plane)[4] = pvs->draw->plane;
  33    const unsigned pos = draw_current_shader_position_output(pvs->draw);
  34    const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw);
  35    unsigned cd[2];
  36    const unsigned ef = pvs->draw->vs.edgeflag_output;
  37    const unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
  38    const unsigned flags = (FLAGS);
  39    unsigned need_pipeline = 0;
  40    unsigned j;
  41    unsigned i;
  42    bool have_cd = false;
  43    unsigned viewport_index_output =
  44       draw_current_shader_viewport_index_output(pvs->draw);
  45
  46    cd[0] = draw_current_shader_clipdistance_output(pvs->draw, 0);
  47    cd[1] = draw_current_shader_clipdistance_output(pvs->draw, 1);
  48
  49    if (cd[0] != pos || cd[1] != pos)
  50      have_cd = true;
  51
  52    for (j = 0; j < info->count; j++) {
  53       float *position = out->data[pos];
  54       int viewport_index =
  55          draw_current_shader_uses_viewport_index(pvs->draw) ?
  56          *((unsigned*)out->data[viewport_index_output]): 0;
  57       unsigned mask = 0x0;
  58       const float *scale = pvs->draw->viewports[
  59          draw_clamp_viewport_idx(viewport_index)].scale;
  60       const float *trans = pvs->draw->viewports[
  61          draw_clamp_viewport_idx(viewport_index)].translate;
  62
  63       initialize_vertex_header(out);
  64
  65       if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
  66                    DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
  67          float *clipvertex = position;
  68
  69          if ((flags & DO_CLIP_USER) && cv != pos)
  70             clipvertex = out->data[cv];
  71
  72          for (i = 0; i < 4; i++) {
  73             out->clip[i] = clipvertex[i];
  74             out->pre_clip_pos[i] = position[i];
  75          }
  76
  77          /* Do the hardwired planes first:
  78           */
  79          if (flags & DO_CLIP_XY_GUARD_BAND) {
  80             if (-0.50 * position[0] + position[3] < 0) mask |= (1<<0);
  81             if ( 0.50 * position[0] + position[3] < 0) mask |= (1<<1);
  82             if (-0.50 * position[1] + position[3] < 0) mask |= (1<<2);
  83             if ( 0.50 * position[1] + position[3] < 0) mask |= (1<<3);
  84          }
  85          else if (flags & DO_CLIP_XY) {
  86             if (-position[0] + position[3] < 0) mask |= (1<<0);
  87             if ( position[0] + position[3] < 0) mask |= (1<<1);
  88             if (-position[1] + position[3] < 0) mask |= (1<<2);
  89             if ( position[1] + position[3] < 0) mask |= (1<<3);
  90          }
  91
  92          /* Clip Z planes according to full cube, half cube or none.
  93           */
  94          if (flags & DO_CLIP_FULL_Z) {
  95             if ( position[2] + position[3] < 0) mask |= (1<<4);
  96             if (-position[2] + position[3] < 0) mask |= (1<<5);
  97          }
  98          else if (flags & DO_CLIP_HALF_Z) {
  99             if ( position[2]               < 0) mask |= (1<<4);
 100             if (-position[2] + position[3] < 0) mask |= (1<<5);
 101          }
 102
 103          if (flags & DO_CLIP_USER) {
 104             unsigned ucp_mask = ucp_enable;
 105             int num_written_clipdistance = pvs->draw->vs.vertex_shader->info.num_written_clipdistance;
 106             while (ucp_mask) {
 107                unsigned plane_idx = ffs(ucp_mask)-1;
 108                ucp_mask &= ~(1 << plane_idx);
 109                plane_idx += 6;
 110
 111                /*
 112                 * for user clipping check if we have a clip distance output
 113                 * and the shader has written to it, otherwise use clipvertex
 114                 * to decide when the plane is clipping.
 115                 */
 116                if (have_cd && num_written_clipdistance) {
 117                   float clipdist;
 118                   i = plane_idx - 6;
 119                   out->have_clipdist = 1;
 120                   /* first four clip distance in first vector etc. */
 121                   if (i < 4)
 122                      clipdist = out->data[cd[0]][i];
 123                   else
 124                      clipdist = out->data[cd[1]][i-4];
 125                   if (clipdist < 0)
 126                      mask |= 1 << plane_idx;
 127                } else {
 128                   if (dot4(clipvertex, plane[plane_idx]) < 0)
 129                      mask |= 1 << plane_idx;
 130                }
 131             }
 132          }
 133
 134          out->clipmask = mask;
 135          need_pipeline |= out->clipmask;
 136       }
 137
 138       /*
 139        * Transform the vertex position from clip coords to window coords,
 140        * if the vertex is unclipped.
 141        */
 142       if ((flags & DO_VIEWPORT) && mask == 0)
 143       {
 144          /* divide by w */
 145          float w = 1.0f / position[3];
 146
 147          /* Viewport mapping */
 148          position[0] = position[0] * w * scale[0] + trans[0];
 149          position[1] = position[1] * w * scale[1] + trans[1];
 150          position[2] = position[2] * w * scale[2] + trans[2];
 151          position[3] = w;
 152       }
 153 #ifdef DEBUG
 154       /* For debug builds, set the clipped vertex's window coordinate
 155        * to NaN to help catch potential errors later.
 156        */
 157       else {
 158          float zero = 0.0f;
 159          position[0] =
 160          position[1] =
 161          position[2] =
 162          position[3] = zero / zero; /* MSVC doesn't accept 0.0 / 0.0 */
 163       }
 164 #endif
 165
 166       if ((flags & DO_EDGEFLAG) && ef) {
 167          const float *edgeflag = out->data[ef];
 168          out->edgeflag = !(edgeflag[0] != 1.0f);
 169          need_pipeline |= !out->edgeflag;
 170       }
 171
 172       out = (struct vertex_header *)( (char *)out + info->stride );
 173    }
 174
 175    return need_pipeline != 0;
 176 }
 177
 178
 179 #undef FLAGS
 180 #undef TAG