src/gallium/auxiliary/draw/draw_pt_post_vs.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 TUNGSTEN GRAPHICS 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_memory.h"
  29 #include "pipe/p_context.h"
  30 #include "draw/draw_context.h"
  31 #include "draw/draw_private.h"
  32 #include "draw/draw_vbuf.h"
  33 #include "draw/draw_pt.h"
  34
  35 struct pt_post_vs {
  36    struct draw_context *draw;
  37
  38    boolean (*run)( struct pt_post_vs *pvs,
  39                 struct vertex_header *vertices,
  40                 unsigned count,
  41                 unsigned stride );
  42 };
  43
  44
  45
  46 static INLINE float
  47 dot4(const float *a, const float *b)
  48 {
  49    return (a[0]*b[0] +
  50            a[1]*b[1] +
  51            a[2]*b[2] +
  52            a[3]*b[3]);
  53 }
  54
  55
  56
  57 static INLINE unsigned
  58 compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr)
  59 {
  60    unsigned mask = 0x0;
  61    unsigned i;
  62
  63 #if 0
  64    debug_printf("compute clipmask %f %f %f %f\n",
  65                 clip[0], clip[1], clip[2], clip[3]);
  66    assert(clip[3] != 0.0);
  67 #endif
  68
  69    /* Do the hardwired planes first:
  70     */
  71    if (-clip[0] + clip[3] < 0) mask |= (1<<0);
  72    if ( clip[0] + clip[3] < 0) mask |= (1<<1);
  73    if (-clip[1] + clip[3] < 0) mask |= (1<<2);
  74    if ( clip[1] + clip[3] < 0) mask |= (1<<3);
  75    if ( clip[2] + clip[3] < 0) mask |= (1<<4); /* match mesa clipplane numbering - for now */
  76    if (-clip[2] + clip[3] < 0) mask |= (1<<5); /* match mesa clipplane numbering - for now */
  77
  78    /* Followed by any remaining ones:
  79     */
  80    for (i = 6; i < nr; i++) {
  81       if (dot4(clip, plane[i]) < 0)
  82          mask |= (1<<i);
  83    }
  84
  85    return mask;
  86 }
  87
  88
  89 /* The normal case - cliptest, rhw divide, viewport transform.
  90  *
  91  * Also handle identity viewport here at the expense of a few wasted
  92  * instructions
  93  */
  94 static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
  95                                           struct vertex_header *vertices,
  96                                           unsigned count,
  97                                           unsigned stride )
  98 {
  99    struct vertex_header *out = vertices;
 100    const float *scale = pvs->draw->viewport.scale;
 101    const float *trans = pvs->draw->viewport.translate;
 102    const unsigned pos = draw_current_shader_position_output(pvs->draw);
 103    unsigned clipped = 0;
 104    unsigned j;
 105
 106    if (0) debug_printf("%s\n", __FUNCTION__);
 107
 108    for (j = 0; j < count; j++) {
 109       float *position = out->data[pos];
 110
 111       out->clip[0] = position[0];
 112       out->clip[1] = position[1];
 113       out->clip[2] = position[2];
 114       out->clip[3] = position[3];
 115
 116       out->vertex_id = 0xffff;
 117       out->clipmask = compute_clipmask_gl(out->clip,
 118                                           pvs->draw->plane,
 119                                           pvs->draw->nr_planes);
 120       clipped += out->clipmask;
 121
 122       if (out->clipmask == 0)
 123       {
 124          /* divide by w */
 125          float w = 1.0f / position[3];
 126
 127          /* Viewport mapping */
 128          position[0] = position[0] * w * scale[0] + trans[0];
 129          position[1] = position[1] * w * scale[1] + trans[1];
 130          position[2] = position[2] * w * scale[2] + trans[2];
 131          position[3] = w;
 132 #if 0
 133          debug_printf("post viewport: %f %f %f %f\n",
 134                       position[0],
 135                       position[1],
 136                       position[2],
 137                       position[3]);
 138 #endif
 139       }
 140
 141       out = (struct vertex_header *)( (char *)out + stride );
 142    }
 143
 144    return clipped != 0;
 145 }
 146
 147
 148
 149 /* As above plus edgeflags
 150  */
 151 static boolean
 152 post_vs_cliptest_viewport_gl_edgeflag(struct pt_post_vs *pvs,
 153                                       struct vertex_header *vertices,
 154                                       unsigned count,
 155                                       unsigned stride )
 156 {
 157    unsigned j;
 158    boolean needpipe;
 159
 160    needpipe = post_vs_cliptest_viewport_gl( pvs, vertices, count, stride);
 161
 162    /* If present, copy edgeflag VS output into vertex header.
 163     * Otherwise, leave header as is.
 164     */
 165    if (pvs->draw->vs.edgeflag_output) {
 166       struct vertex_header *out = vertices;
 167       int ef = pvs->draw->vs.edgeflag_output;
 168
 169       for (j = 0; j < count; j++) {
 170          const float *edgeflag = out->data[ef];
 171          out->edgeflag = !(edgeflag[0] != 1.0f);
 172          needpipe |= !out->edgeflag;
 173          out = (struct vertex_header *)( (char *)out + stride );
 174       }
 175    }
 176    return needpipe;
 177 }
 178
 179
 180
 181
 182 /* If bypass_clipping is set, skip cliptest and rhw divide.
 183  */
 184 static boolean post_vs_viewport( struct pt_post_vs *pvs,
 185                               struct vertex_header *vertices,
 186                               unsigned count,
 187                               unsigned stride )
 188 {
 189    struct vertex_header *out = vertices;
 190    const float *scale = pvs->draw->viewport.scale;
 191    const float *trans = pvs->draw->viewport.translate;
 192    const unsigned pos = draw_current_shader_position_output(pvs->draw);
 193    unsigned j;
 194
 195    if (0) debug_printf("%s\n", __FUNCTION__);
 196    for (j = 0; j < count; j++) {
 197       float *position = out->data[pos];
 198
 199       /* Viewport mapping only, no cliptest/rhw divide
 200        */
 201       position[0] = position[0] * scale[0] + trans[0];
 202       position[1] = position[1] * scale[1] + trans[1];
 203       position[2] = position[2] * scale[2] + trans[2];
 204
 205       out = (struct vertex_header *)((char *)out + stride);
 206    }
 207
 208    return FALSE;
 209 }
 210
 211
 212 /* If bypass_clipping is set and we have an identity viewport, nothing
 213  * to do.
 214  */
 215 static boolean post_vs_none( struct pt_post_vs *pvs,
 216                              struct vertex_header *vertices,
 217                              unsigned count,
 218                              unsigned stride )
 219 {
 220    if (0) debug_printf("%s\n", __FUNCTION__);
 221    return FALSE;
 222 }
 223
 224 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 225                              struct vertex_header *pipeline_verts,
 226                              unsigned count,
 227                              unsigned stride )
 228 {
 229    return pvs->run( pvs, pipeline_verts, count, stride );
 230 }
 231
 232
 233 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
 234                               boolean bypass_clipping,
 235                               boolean bypass_viewport,
 236                               boolean opengl,
 237                               boolean need_edgeflags )
 238 {
 239    if (!need_edgeflags) {
 240       if (bypass_clipping) {
 241          if (bypass_viewport)
 242             pvs->run = post_vs_none;
 243          else
 244             pvs->run = post_vs_viewport;
 245       }
 246       else {
 247          /* if (opengl) */
 248          pvs->run = post_vs_cliptest_viewport_gl;
 249       }
 250    }
 251    else {
 252       /* If we need to copy edgeflags to the vertex header, it should
 253        * mean we're running the primitive pipeline.  Hence the bypass
 254        * flags should be false.
 255        */
 256       assert(!bypass_clipping);
 257       assert(!bypass_viewport);
 258       pvs->run = post_vs_cliptest_viewport_gl_edgeflag;
 259    }
 260 }
 261
 262
 263 struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw )
 264 {
 265    struct pt_post_vs *pvs = CALLOC_STRUCT( pt_post_vs );
 266    if (!pvs)
 267       return NULL;
 268
 269    pvs->draw = draw;
 270
 271    return pvs;
 272 }
 273
 274 void draw_pt_post_vs_destroy( struct pt_post_vs *pvs )
 275 {
 276    FREE(pvs);
 277 }