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