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_vertex.h"
  34 #include "draw/draw_pt.h"
  35
  36 struct pt_post_vs {
  37    struct draw_context *draw;
  38
  39    boolean (*run)( struct pt_post_vs *pvs,
  40                 struct vertex_header *vertices,
  41                 unsigned count,
  42                 unsigned stride );
  43 };
  44
  45
  46
  47 static INLINE float
  48 dot4(const float *a, const float *b)
  49 {
  50    return (a[0]*b[0] +
  51            a[1]*b[1] +
  52            a[2]*b[2] +
  53            a[3]*b[3]);
  54 }
  55
  56
  57
  58 static INLINE unsigned
  59 compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr)
  60 {
  61    unsigned mask = 0x0;
  62    unsigned i;
  63
  64 #if 0
  65    debug_printf("compute clipmask %f %f %f %f\n",
  66                 clip[0], clip[1], clip[2], clip[3]);
  67    assert(clip[3] != 0.0);
  68 #endif
  69
  70    /* Do the hardwired planes first:
  71     */
  72    if (-clip[0] + clip[3] < 0) mask |= (1<<0);
  73    if ( clip[0] + clip[3] < 0) mask |= (1<<1);
  74    if (-clip[1] + clip[3] < 0) mask |= (1<<2);
  75    if ( clip[1] + clip[3] < 0) mask |= (1<<3);
  76    if ( clip[2] + clip[3] < 0) mask |= (1<<4); /* match mesa clipplane numbering - for now */
  77    if (-clip[2] + clip[3] < 0) mask |= (1<<5); /* match mesa clipplane numbering - for now */
  78
  79    /* Followed by any remaining ones:
  80     */
  81    for (i = 6; i < nr; i++) {
  82       if (dot4(clip, plane[i]) < 0)
  83          mask |= (1<<i);
  84    }
  85
  86    return mask;
  87 }
  88
  89
  90 /* The normal case - cliptest, rhw divide, viewport transform.
  91  *
  92  * Also handle identity viewport here at the expense of a few wasted
  93  * instructions
  94  */
  95 static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
  96                                           struct vertex_header *vertices,
  97                                           unsigned count,
  98                                           unsigned stride )
  99 {
 100    struct vertex_header *out = vertices;
 101    const float *scale = pvs->draw->viewport.scale;
 102    const float *trans = pvs->draw->viewport.translate;
 103    const unsigned pos = pvs->draw->vs.position_output;
 104    unsigned clipped = 0;
 105    unsigned j;
 106
 107    if (0) debug_printf("%s\n", __FUNCTION__);
 108
 109    for (j = 0; j < count; j++) {
 110       float *position = out->data[pos];
 111
 112       out->clip[0] = position[0];
 113       out->clip[1] = position[1];
 114       out->clip[2] = position[2];
 115       out->clip[3] = position[3];
 116
 117       out->vertex_id = 0xffff;
 118       out->clipmask = compute_clipmask_gl(out->clip,
 119                                           pvs->draw->plane,
 120                                           pvs->draw->nr_planes);
 121       clipped += out->clipmask;
 122
 123       if (out->clipmask == 0)
 124       {
 125          /* divide by w */
 126          float w = 1.0f / position[3];
 127
 128          /* Viewport mapping */
 129          position[0] = position[0] * w * scale[0] + trans[0];
 130          position[1] = position[1] * w * scale[1] + trans[1];
 131          position[2] = position[2] * w * scale[2] + trans[2];
 132          position[3] = w;
 133 #if 0
 134          debug_printf("post viewport: %f %f %f %f\n",
 135                       position[0],
 136                       position[1],
 137                       position[2],
 138                       position[3]);
 139 #endif
 140       }
 141
 142       out = (struct vertex_header *)( (char *)out + stride );
 143    }
 144
 145    return clipped != 0;
 146 }
 147
 148
 149
 150 /* As above plus edgeflags
 151  */
 152 static boolean
 153 post_vs_cliptest_viewport_gl_edgeflag(struct pt_post_vs *pvs,
 154                                       struct vertex_header *vertices,
 155                                       unsigned count,
 156                                       unsigned stride )
 157 {
 158    unsigned j;
 159    boolean needpipe;
 160
 161    needpipe = post_vs_cliptest_viewport_gl( pvs, vertices, count, stride);
 162
 163    /* If present, copy edgeflag VS output into vertex header.
 164     * Otherwise, leave header as is.
 165     */
 166    if (pvs->draw->vs.edgeflag_output) {
 167       struct vertex_header *out = vertices;
 168       int ef = pvs->draw->vs.edgeflag_output;
 169
 170       for (j = 0; j < count; j++) {
 171          const float *edgeflag = out->data[ef];
 172          out->edgeflag = !(edgeflag[0] != 1.0f);
 173          needpipe |= !out->edgeflag;
 174          out = (struct vertex_header *)( (char *)out + stride );
 175       }
 176    }
 177    return needpipe;
 178 }
 179
 180
 181
 182
 183 /* If bypass_clipping is set, skip cliptest and rhw divide.
 184  */
 185 static boolean post_vs_viewport( struct pt_post_vs *pvs,
 186                               struct vertex_header *vertices,
 187                               unsigned count,
 188                               unsigned stride )
 189 {
 190    struct vertex_header *out = vertices;
 191    const float *scale = pvs->draw->viewport.scale;
 192    const float *trans = pvs->draw->viewport.translate;
 193    const unsigned pos = pvs->draw->vs.position_output;
 194    unsigned j;
 195
 196    if (0) debug_printf("%s\n", __FUNCTION__);
 197    for (j = 0; j < count; j++) {
 198       float *position = out->data[pos];
 199
 200       /* Viewport mapping only, no cliptest/rhw divide
 201        */
 202       position[0] = position[0] * scale[0] + trans[0];
 203       position[1] = position[1] * scale[1] + trans[1];
 204       position[2] = position[2] * scale[2] + trans[2];
 205
 206       out = (struct vertex_header *)((char *)out + stride);
 207    }
 208
 209    return FALSE;
 210 }
 211
 212
 213 /* If bypass_clipping is set and we have an identity viewport, nothing
 214  * to do.
 215  */
 216 static boolean post_vs_none( struct pt_post_vs *pvs,
 217                              struct vertex_header *vertices,
 218                              unsigned count,
 219                              unsigned stride )
 220 {
 221    if (0) debug_printf("%s\n", __FUNCTION__);
 222    return FALSE;
 223 }
 224
 225 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 226                              struct vertex_header *pipeline_verts,
 227                              unsigned count,
 228                              unsigned stride )
 229 {
 230    return pvs->run( pvs, pipeline_verts, count, stride );
 231 }
 232
 233
 234 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
 235                               boolean bypass_clipping,
 236                               boolean bypass_viewport,
 237                               boolean opengl,
 238                               boolean need_edgeflags )
 239 {
 240    if (!need_edgeflags) {
 241       if (bypass_clipping) {
 242          if (bypass_viewport)
 243             pvs->run = post_vs_none;
 244          else
 245             pvs->run = post_vs_viewport;
 246       }
 247       else {
 248          /* if (opengl) */
 249          pvs->run = post_vs_cliptest_viewport_gl;
 250       }
 251    }
 252    else {
 253       /* If we need to copy edgeflags to the vertex header, it should
 254        * mean we're running the primitive pipeline.  Hence the bypass
 255        * flags should be false.
 256        */
 257       assert(!bypass_clipping);
 258       assert(!bypass_viewport);
 259       pvs->run = post_vs_cliptest_viewport_gl_edgeflag;
 260    }
 261 }
 262
 263
 264 struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw )
 265 {
 266    struct pt_post_vs *pvs = CALLOC_STRUCT( pt_post_vs );
 267    if (!pvs)
 268       return NULL;
 269
 270    pvs->draw = draw;
 271
 272    return pvs;
 273 }
 274
 275 void draw_pt_post_vs_destroy( struct pt_post_vs *pvs )
 276 {
 277    FREE(pvs);
 278 }