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 static INLINE void
  42 initialize_vertex_header(struct vertex_header *header)
  43 {
  44    header->clipmask = 0;
  45    header->edgeflag = 1;
  46    header->pad = 0;
  47    header->vertex_id = UNDEFINED_VERTEX_ID;
  48 }
  49
  50 static INLINE float
  51 dot4(const float *a, const float *b)
  52 {
  53    return (a[0]*b[0] +
  54            a[1]*b[1] +
  55            a[2]*b[2] +
  56            a[3]*b[3]);
  57 }
  58
  59 static INLINE unsigned
  60 compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr)
  61 {
  62    unsigned mask = 0x0;
  63    unsigned i;
  64
  65 #if 0
  66    debug_printf("compute clipmask %f %f %f %f\n",
  67                 clip[0], clip[1], clip[2], clip[3]);
  68    assert(clip[3] != 0.0);
  69 #endif
  70
  71    /* Do the hardwired planes first:
  72     */
  73    if (-clip[0] + clip[3] < 0) mask |= (1<<0);
  74    if ( clip[0] + clip[3] < 0) mask |= (1<<1);
  75    if (-clip[1] + clip[3] < 0) mask |= (1<<2);
  76    if ( clip[1] + clip[3] < 0) mask |= (1<<3);
  77    if ( clip[2] + clip[3] < 0) mask |= (1<<4); /* match mesa clipplane numbering - for now */
  78    if (-clip[2] + clip[3] < 0) mask |= (1<<5); /* match mesa clipplane numbering - for now */
  79
  80    /* Followed by any remaining ones:
  81     */
  82    for (i = 6; i < nr; i++) {
  83       if (dot4(clip, plane[i]) < 0)
  84          mask |= (1<<i);
  85    }
  86
  87    return mask;
  88 }
  89
  90
  91 /* The normal case - cliptest, rhw divide, viewport transform.
  92  *
  93  * Also handle identity viewport here at the expense of a few wasted
  94  * instructions
  95  */
  96 static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
  97                                              struct draw_vertex_info *info )
  98 {
  99    struct vertex_header *out = info->verts;
 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 count, %d\n", __FUNCTION__, info->count);
 107
 108    for (j = 0; j < info->count; j++) {
 109       float *position = out->data[pos];
 110
 111       initialize_vertex_header(out);
 112 #if 0
 113       debug_printf("%d) io = %p, data = %p = [%f, %f, %f, %f]\n",
 114                    j, out, position, position[0], position[1], position[2], position[3]);
 115 #endif
 116
 117       out->clip[0] = position[0];
 118       out->clip[1] = position[1];
 119       out->clip[2] = position[2];
 120       out->clip[3] = position[3];
 121
 122       out->vertex_id = 0xffff;
 123       out->clipmask = compute_clipmask_gl(out->clip,
 124                                           pvs->draw->plane,
 125                                           pvs->draw->nr_planes);
 126       clipped += out->clipmask;
 127
 128       if (out->clipmask == 0)
 129       {
 130          /* divide by w */
 131          float w = 1.0f / position[3];
 132
 133          /* Viewport mapping */
 134          position[0] = position[0] * w * scale[0] + trans[0];
 135          position[1] = position[1] * w * scale[1] + trans[1];
 136          position[2] = position[2] * w * scale[2] + trans[2];
 137          position[3] = w;
 138 #if 0
 139          debug_printf("post viewport: %f %f %f %f\n",
 140                       position[0],
 141                       position[1],
 142                       position[2],
 143                       position[3]);
 144 #endif
 145       }
 146
 147       out = (struct vertex_header *)( (char *)out + info->stride );
 148    }
 149
 150    return clipped != 0;
 151 }
 152
 153
 154
 155 /* As above plus edgeflags
 156  */
 157 static boolean
 158 post_vs_cliptest_viewport_gl_edgeflag(struct pt_post_vs *pvs,
 159                                       struct draw_vertex_info *info)
 160 {
 161    unsigned j;
 162    boolean needpipe;
 163
 164    needpipe = post_vs_cliptest_viewport_gl(pvs, info);
 165
 166    /* If present, copy edgeflag VS output into vertex header.
 167     * Otherwise, leave header as is.
 168     */
 169    if (pvs->draw->vs.edgeflag_output) {
 170       struct vertex_header *out = info->verts;
 171       int ef = pvs->draw->vs.edgeflag_output;
 172
 173       for (j = 0; j < info->count; j++) {
 174          const float *edgeflag = out->data[ef];
 175          out->edgeflag = !(edgeflag[0] != 1.0f);
 176          needpipe |= !out->edgeflag;
 177          out = (struct vertex_header *)( (char *)out + info->stride );
 178       }
 179    }
 180    return needpipe;
 181 }
 182
 183
 184
 185
 186 /* If bypass_clipping is set, skip cliptest and rhw divide.
 187  */
 188 static boolean post_vs_viewport( struct pt_post_vs *pvs,
 189                                  struct draw_vertex_info *info )
 190 {
 191    struct vertex_header *out = info->verts;
 192    const float *scale = pvs->draw->viewport.scale;
 193    const float *trans = pvs->draw->viewport.translate;
 194    const unsigned pos = draw_current_shader_position_output(pvs->draw);
 195    unsigned j;
 196
 197    if (0) debug_printf("%s\n", __FUNCTION__);
 198    for (j = 0; j < info->count; j++) {
 199       float *position = out->data[pos];
 200
 201       initialize_vertex_header(out);
 202       /* Viewport mapping only, no cliptest/rhw divide
 203        */
 204       position[0] = position[0] * scale[0] + trans[0];
 205       position[1] = position[1] * scale[1] + trans[1];
 206       position[2] = position[2] * scale[2] + trans[2];
 207
 208       out = (struct vertex_header *)((char *)out + info->stride);
 209    }
 210
 211    return FALSE;
 212 }
 213
 214
 215 /* If bypass_clipping is set and we have an identity viewport, nothing
 216  * to do.
 217  */
 218 static boolean post_vs_none( struct pt_post_vs *pvs,
 219                              struct draw_vertex_info *info )
 220 {
 221    struct vertex_header *out = info->verts;
 222    unsigned j;
 223
 224    if (0) debug_printf("%s\n", __FUNCTION__);
 225    /* just initialize the vertex_id in all headers */
 226    for (j = 0; j < info->count; j++) {
 227       initialize_vertex_header(out);
 228
 229       out = (struct vertex_header *)((char *)out + info->stride);
 230    }
 231    return FALSE;
 232 }
 233
 234 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 235                              struct draw_vertex_info *info )
 236 {
 237    return pvs->run( pvs, info );
 238 }
 239
 240
 241 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
 242                               boolean bypass_clipping,
 243                               boolean bypass_viewport,
 244                               boolean opengl,
 245                               boolean need_edgeflags )
 246 {
 247    if (!need_edgeflags) {
 248       if (bypass_clipping) {
 249          if (bypass_viewport)
 250             pvs->run = post_vs_none;
 251          else
 252             pvs->run = post_vs_viewport;
 253       }
 254       else {
 255          /* if (opengl) */
 256          pvs->run = post_vs_cliptest_viewport_gl;
 257       }
 258    }
 259    else {
 260       /* If we need to copy edgeflags to the vertex header, it should
 261        * mean we're running the primitive pipeline.  Hence the bypass
 262        * flags should be false.
 263        */
 264       assert(!bypass_clipping);
 265       assert(!bypass_viewport);
 266       pvs->run = post_vs_cliptest_viewport_gl_edgeflag;
 267    }
 268 }
 269
 270
 271 struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw )
 272 {
 273    struct pt_post_vs *pvs = CALLOC_STRUCT( pt_post_vs );
 274    if (!pvs)
 275       return NULL;
 276
 277    pvs->draw = draw;
 278
 279    return pvs;
 280 }
 281
 282 void draw_pt_post_vs_destroy( struct pt_post_vs *pvs )
 283 {
 284    FREE(pvs);
 285 }