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