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                                  const struct draw_prim_info *prim_info )
  31 {
  32    struct vertex_header *out = info->verts;
  33    /* const */ float (*plane)[4] = pvs->draw->plane;
  34    const unsigned pos = draw_current_shader_position_output(pvs->draw);
  35    const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw);
  36    unsigned cd[2];
  37    const unsigned ef = pvs->draw->vs.edgeflag_output;
  38    unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
  39    unsigned flags = (FLAGS);
  40    unsigned need_pipeline = 0;
  41    unsigned j;
  42    unsigned i;
  43    bool have_cd = false;
  44    unsigned viewport_index_output =
  45       draw_current_shader_viewport_index_output(pvs->draw);
  46    int viewport_index =
  47       draw_current_shader_uses_viewport_index(pvs->draw) ?
  48       *((unsigned*)out->data[viewport_index_output]): 0;
  49    int num_written_clipdistance =
  50       draw_current_shader_num_written_clipdistances(pvs->draw);
  51
  52    cd[0] = draw_current_shader_clipdistance_output(pvs->draw, 0);
  53    cd[1] = draw_current_shader_clipdistance_output(pvs->draw, 1);
  54
  55    if (cd[0] != pos || cd[1] != pos)
  56       have_cd = true;
  57
  58    /* If clipdistance semantic has been written by the shader
  59     * that means we're expected to do 'user plane clipping' */
  60    if (num_written_clipdistance && !(flags & DO_CLIP_USER)) {
  61       flags |= DO_CLIP_USER;
  62       ucp_enable = (1 << num_written_clipdistance) - 1;
  63    }
  64
  65    for (j = 0; j < info->count; j++) {
  66       float *position = out->data[pos];
  67       unsigned mask = 0x0;
  68       float *scale = pvs->draw->viewports[0].scale;
  69       float *trans = pvs->draw->viewports[0].translate;
  70       if (draw_current_shader_uses_viewport_index(pvs->draw)) {
  71          unsigned verts_per_prim = u_vertices_per_prim(prim_info->prim);
  72          /* only change the viewport_index for the leading vertex */
  73          if (!(j % verts_per_prim)) {
  74             viewport_index = *((unsigned*)out->data[viewport_index_output]);
  75             viewport_index = draw_clamp_viewport_idx(viewport_index);
  76          }
  77          scale = pvs->draw->viewports[viewport_index].scale;
  78          trans = pvs->draw->viewports[viewport_index].translate;
  79       }
  80
  81       initialize_vertex_header(out);
  82
  83       if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
  84                    DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
  85          float *clipvertex = position;
  86
  87          if ((flags & DO_CLIP_USER) && cv != pos)
  88             clipvertex = out->data[cv];
  89
  90          for (i = 0; i < 4; i++) {
  91             out->clip[i] = clipvertex[i];
  92             out->pre_clip_pos[i] = position[i];
  93          }
  94
  95          /* Do the hardwired planes first:
  96           */
  97          if (flags & DO_CLIP_XY_GUARD_BAND) {
  98             if (-0.50 * position[0] + position[3] < 0) mask |= (1<<0);
  99             if ( 0.50 * position[0] + position[3] < 0) mask |= (1<<1);
 100             if (-0.50 * position[1] + position[3] < 0) mask |= (1<<2);
 101             if ( 0.50 * position[1] + position[3] < 0) mask |= (1<<3);
 102          }
 103          else if (flags & DO_CLIP_XY) {
 104             if (-position[0] + position[3] < 0) mask |= (1<<0);
 105             if ( position[0] + position[3] < 0) mask |= (1<<1);
 106             if (-position[1] + position[3] < 0) mask |= (1<<2);
 107             if ( position[1] + position[3] < 0) mask |= (1<<3);
 108          }
 109
 110          /* Clip Z planes according to full cube, half cube or none.
 111           */
 112          if (flags & DO_CLIP_FULL_Z) {
 113             if ( position[2] + position[3] < 0) mask |= (1<<4);
 114             if (-position[2] + position[3] < 0) mask |= (1<<5);
 115          }
 116          else if (flags & DO_CLIP_HALF_Z) {
 117             if ( position[2]               < 0) mask |= (1<<4);
 118             if (-position[2] + position[3] < 0) mask |= (1<<5);
 119          }
 120
 121          if (flags & DO_CLIP_USER) {
 122             unsigned ucp_mask = ucp_enable;
 123
 124             while (ucp_mask) {
 125                unsigned plane_idx = ffs(ucp_mask)-1;
 126                ucp_mask &= ~(1 << plane_idx);
 127                plane_idx += 6;
 128
 129                /*
 130                 * for user clipping check if we have a clip distance output
 131                 * and the shader has written to it, otherwise use clipvertex
 132                 * to decide when the plane is clipping.
 133                 */
 134                if (have_cd && num_written_clipdistance) {
 135                   float clipdist;
 136                   i = plane_idx - 6;
 137                   out->have_clipdist = 1;
 138                   /* first four clip distance in first vector etc. */
 139                   if (i < 4)
 140                      clipdist = out->data[cd[0]][i];
 141                   else
 142                      clipdist = out->data[cd[1]][i-4];
 143                   if (clipdist < 0)
 144                      mask |= 1 << plane_idx;
 145                } else {
 146                   if (dot4(clipvertex, plane[plane_idx]) < 0)
 147                      mask |= 1 << plane_idx;
 148                }
 149             }
 150          }
 151
 152          out->clipmask = mask;
 153          need_pipeline |= out->clipmask;
 154       }
 155
 156       /*
 157        * Transform the vertex position from clip coords to window coords,
 158        * if the vertex is unclipped.
 159        */
 160       if ((flags & DO_VIEWPORT) && mask == 0)
 161       {
 162          /* divide by w */
 163          float w = 1.0f / position[3];
 164
 165          /* Viewport mapping */
 166          position[0] = position[0] * w * scale[0] + trans[0];
 167          position[1] = position[1] * w * scale[1] + trans[1];
 168          position[2] = position[2] * w * scale[2] + trans[2];
 169          position[3] = w;
 170       }
 171 #ifdef DEBUG
 172       /* For debug builds, set the clipped vertex's window coordinate
 173        * to NaN to help catch potential errors later.
 174        */
 175       else {
 176          float zero = 0.0f;
 177          position[0] =
 178          position[1] =
 179          position[2] =
 180          position[3] = zero / zero; /* MSVC doesn't accept 0.0 / 0.0 */
 181       }
 182 #endif
 183
 184       if ((flags & DO_EDGEFLAG) && ef) {
 185          const float *edgeflag = out->data[ef];
 186          out->edgeflag = !(edgeflag[0] != 1.0f);
 187          need_pipeline |= !out->edgeflag;
 188       }
 189
 190       out = (struct vertex_header *)( (char *)out + info->stride );
 191    }
 192
 193    return need_pipeline != 0;
 194 }
 195
 196
 197 #undef FLAGS
 198 #undef TAG