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 #include "util/u_bitcast.h"
  29
  30 static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
  31                                  struct draw_vertex_info *info,
  32                                  const struct draw_prim_info *prim_info )
  33 {
  34    struct vertex_header *out = info->verts;
  35    /* const */ float (*plane)[4] = pvs->draw->plane;
  36    const unsigned pos = draw_current_shader_position_output(pvs->draw);
  37    const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw);
  38    unsigned cd[2];
  39    const unsigned ef = pvs->draw->vs.edgeflag_output;
  40    unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
  41    unsigned flags = (FLAGS);
  42    unsigned need_pipeline = 0;
  43    unsigned j;
  44    unsigned i;
  45    bool have_cd = false;
  46    unsigned viewport_index_output =
  47       draw_current_shader_viewport_index_output(pvs->draw);
  48    int viewport_index =
  49       draw_current_shader_uses_viewport_index(pvs->draw) ?
  50       u_bitcast_f2u(out->data[viewport_index_output][0]): 0;
  51    int num_written_clipdistance =
  52       draw_current_shader_num_written_clipdistances(pvs->draw);
  53
  54    cd[0] = draw_current_shader_ccdistance_output(pvs->draw, 0);
  55    cd[1] = draw_current_shader_ccdistance_output(pvs->draw, 1);
  56
  57    if (cd[0] != pos || cd[1] != pos)
  58       have_cd = true;
  59
  60    /* If clipdistance semantic has been written by the shader
  61     * that means we're expected to do 'user plane clipping' */
  62    if (num_written_clipdistance && !(flags & DO_CLIP_USER)) {
  63       flags |= DO_CLIP_USER;
  64       ucp_enable = (1 << num_written_clipdistance) - 1;
  65    }
  66
  67    assert(pos != -1);
  68    for (j = 0; j < info->count; j++) {
  69       float *position = out->data[pos];
  70       unsigned mask = 0x0;
  71       float *scale = pvs->draw->viewports[0].scale;
  72       float *trans = pvs->draw->viewports[0].translate;
  73       if (draw_current_shader_uses_viewport_index(pvs->draw)) {
  74          unsigned verts_per_prim = u_vertices_per_prim(prim_info->prim);
  75          /* only change the viewport_index for the leading vertex */
  76          if (!(j % verts_per_prim)) {
  77             viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]);
  78             viewport_index = draw_clamp_viewport_idx(viewport_index);
  79          }
  80          scale = pvs->draw->viewports[viewport_index].scale;
  81          trans = pvs->draw->viewports[viewport_index].translate;
  82       }
  83
  84       initialize_vertex_header(out);
  85
  86       if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
  87                    DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
  88          float *clipvertex = position;
  89
  90          if ((flags & DO_CLIP_USER) && cv != pos) {
  91             assert(cv != -1);
  92             clipvertex = out->data[cv];
  93          }
  94
  95          for (i = 0; i < 4; i++) {
  96             out->clip_pos[i] = position[i];
  97          }
  98
  99          /* Be careful with NaNs. Comparisons must be true for them. */
 100          /* Do the hardwired planes first:
 101           */
 102          if (flags & DO_CLIP_XY_GUARD_BAND) {
 103             if (!(-0.50 * position[0] + position[3] >= 0)) mask |= (1<<0);
 104             if (!( 0.50 * position[0] + position[3] >= 0)) mask |= (1<<1);
 105             if (!(-0.50 * position[1] + position[3] >= 0)) mask |= (1<<2);
 106             if (!( 0.50 * position[1] + position[3] >= 0)) mask |= (1<<3);
 107          }
 108          else if (flags & DO_CLIP_XY) {
 109             if (!(-position[0] + position[3] >= 0)) mask |= (1<<0);
 110             if (!( position[0] + position[3] >= 0)) mask |= (1<<1);
 111             if (!(-position[1] + position[3] >= 0)) mask |= (1<<2);
 112             if (!( position[1] + position[3] >= 0)) mask |= (1<<3);
 113          }
 114
 115          /* Clip Z planes according to full cube, half cube or none.
 116           */
 117          if (flags & DO_CLIP_FULL_Z) {
 118             if (!( position[2] + position[3] >= 0)) mask |= (1<<4);
 119             if (!(-position[2] + position[3] >= 0)) mask |= (1<<5);
 120          }
 121          else if (flags & DO_CLIP_HALF_Z) {
 122             if (!( position[2]               >= 0)) mask |= (1<<4);
 123             if (!(-position[2] + position[3] >= 0)) mask |= (1<<5);
 124          }
 125
 126          if (flags & DO_CLIP_USER) {
 127             unsigned ucp_mask = ucp_enable;
 128
 129             while (ucp_mask) {
 130                unsigned plane_idx = ffs(ucp_mask)-1;
 131                ucp_mask &= ~(1 << plane_idx);
 132                plane_idx += 6;
 133
 134                /*
 135                 * for user clipping check if we have a clip distance output
 136                 * and the shader has written to it, otherwise use clipvertex
 137                 * to decide when the plane is clipping.
 138                 */
 139                if (have_cd && num_written_clipdistance) {
 140                   float clipdist;
 141                   i = plane_idx - 6;
 142                   /* first four clip distance in first vector etc. */
 143                   if (i < 4)
 144                      clipdist = out->data[cd[0]][i];
 145                   else
 146                      clipdist = out->data[cd[1]][i-4];
 147                   if (clipdist < 0 || util_is_inf_or_nan(clipdist))
 148                      mask |= 1 << plane_idx;
 149                } else {
 150                   if (!(dot4(clipvertex, plane[plane_idx]) >= 0))
 151                      mask |= 1 << plane_idx;
 152                }
 153             }
 154          }
 155
 156          out->clipmask = mask;
 157          need_pipeline |= out->clipmask;
 158       }
 159
 160       /*
 161        * Transform the vertex position from clip coords to window coords,
 162        * if the vertex is unclipped.
 163        */
 164       if ((flags & DO_VIEWPORT) && mask == 0)
 165       {
 166          /* divide by w */
 167          float w = 1.0f / position[3];
 168
 169          /* Viewport mapping */
 170          position[0] = position[0] * w * scale[0] + trans[0];
 171          position[1] = position[1] * w * scale[1] + trans[1];
 172          position[2] = position[2] * w * scale[2] + trans[2];
 173          position[3] = w;
 174       }
 175 #ifdef DEBUG
 176       /* For debug builds, set the clipped vertex's window coordinate
 177        * to NaN to help catch potential errors later.
 178        */
 179       else {
 180          float zero = 0.0f;
 181          position[0] =
 182          position[1] =
 183          position[2] =
 184          position[3] = zero / zero; /* MSVC doesn't accept 0.0 / 0.0 */
 185       }
 186 #endif
 187
 188       if ((flags & DO_EDGEFLAG) && ef) {
 189          const float *edgeflag = out->data[ef];
 190          out->edgeflag = !(edgeflag[0] != 1.0f);
 191          need_pipeline |= !out->edgeflag;
 192       }
 193
 194       out = (struct vertex_header *)( (char *)out + info->stride );
 195    }
 196    return need_pipeline != 0;
 197 }
 198
 199
 200 #undef FLAGS
 201 #undef TAG