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 "pipe/p_util.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    unsigned clipped = 0;
 104    unsigned j;
 105
 106    if (0) debug_printf("%s\n");
 107
 108    for (j = 0; j < count; j++) {
 109       out->clip[0] = out->data[0][0];
 110       out->clip[1] = out->data[0][1];
 111       out->clip[2] = out->data[0][2];
 112       out->clip[3] = out->data[0][3];
 113
 114       out->vertex_id = 0xffff;
 115       out->clipmask = compute_clipmask_gl(out->clip,
 116                                           pvs->draw->plane,
 117                                           pvs->draw->nr_planes);
 118       clipped += out->clipmask;
 119
 120       if (out->clipmask == 0)
 121       {
 122          /* divide by w */
 123          float w = 1.0f / out->data[0][3];
 124
 125          /* Viewport mapping */
 126          out->data[0][0] = out->data[0][0] * w * scale[0] + trans[0];
 127          out->data[0][1] = out->data[0][1] * w * scale[1] + trans[1];
 128          out->data[0][2] = out->data[0][2] * w * scale[2] + trans[2];
 129          out->data[0][3] = w;
 130 #if 0
 131          debug_printf("post viewport: %f %f %f %f\n",
 132                       out->data[0][0],
 133                       out->data[0][1],
 134                       out->data[0][2],
 135                       out->data[0][3]);
 136 #endif
 137       }
 138
 139       out = (struct vertex_header *)( (char *)out + stride );
 140    }
 141
 142    return clipped != 0;
 143 }
 144
 145
 146
 147 /* If bypass_clipping is set, skip cliptest and rhw divide.
 148  */
 149 static boolean post_vs_viewport( struct pt_post_vs *pvs,
 150                               struct vertex_header *vertices,
 151                               unsigned count,
 152                               unsigned stride )
 153 {
 154    struct vertex_header *out = vertices;
 155    const float *scale = pvs->draw->viewport.scale;
 156    const float *trans = pvs->draw->viewport.translate;
 157    unsigned j;
 158
 159    if (0) debug_printf("%s\n", __FUNCTION__);
 160    for (j = 0; j < count; j++) {
 161       /* Viewport mapping only, no cliptest/rhw divide
 162        */
 163       out->data[0][0] = out->data[0][0] * scale[0] + trans[0];
 164       out->data[0][1] = out->data[0][1] * scale[1] + trans[1];
 165       out->data[0][2] = out->data[0][2] * scale[2] + trans[2];
 166
 167       out = (struct vertex_header *)((char *)out + stride);
 168    }
 169
 170    return FALSE;
 171 }
 172
 173
 174 /* If bypass_clipping is set and we have an identity viewport, nothing
 175  * to do.
 176  */
 177 static boolean post_vs_none( struct pt_post_vs *pvs,
 178                              struct vertex_header *vertices,
 179                              unsigned count,
 180                              unsigned stride )
 181 {
 182    if (0) debug_printf("%s\n", __FUNCTION__);
 183    return FALSE;
 184 }
 185
 186 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 187                              struct vertex_header *pipeline_verts,
 188                              unsigned count,
 189                              unsigned stride )
 190 {
 191    return pvs->run( pvs, pipeline_verts, count, stride );
 192 }
 193
 194
 195 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
 196                               boolean bypass_clipping,
 197                               boolean identity_viewport,
 198                               boolean opengl )
 199 {
 200    if (bypass_clipping) {
 201       if (identity_viewport)
 202          pvs->run = post_vs_none;
 203       else
 204          pvs->run = post_vs_viewport;
 205    }
 206    else {
 207       //if (opengl)
 208       pvs->run = post_vs_cliptest_viewport_gl;
 209    }
 210 }
 211
 212
 213 struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw )
 214 {
 215    struct pt_post_vs *pvs = CALLOC_STRUCT( pt_post_vs );
 216    if (!pvs)
 217       return NULL;
 218
 219    pvs->draw = draw;
 220
 221    return pvs;
 222 }
 223
 224 void draw_pt_post_vs_destroy( struct pt_post_vs *pvs )
 225 {
 226    FREE(pvs);
 227 }