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    /* Do the hardwired planes first:
  65     */
  66    if (-clip[0] + clip[3] < 0) mask |= (1<<0);
  67    if ( clip[0] + clip[3] < 0) mask |= (1<<1);
  68    if (-clip[1] + clip[3] < 0) mask |= (1<<2);
  69    if ( clip[1] + clip[3] < 0) mask |= (1<<3);
  70    if ( clip[2] + clip[3] < 0) mask |= (1<<4); /* match mesa clipplane numbering - for now */
  71    if (-clip[2] + clip[3] < 0) mask |= (1<<5); /* match mesa clipplane numbering - for now */
  72
  73    /* Followed by any remaining ones:
  74     */
  75    for (i = 6; i < nr; i++) {
  76       if (dot4(clip, plane[i]) < 0)
  77          mask |= (1<<i);
  78    }
  79
  80    return mask;
  81 }
  82
  83
  84 /* The normal case - cliptest, rhw divide, viewport transform.
  85  *
  86  * Also handle identity viewport here at the expense of a few wasted
  87  * instructions
  88  */
  89 static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
  90                                           struct vertex_header *vertices,
  91                                           unsigned count,
  92                                           unsigned stride )
  93 {
  94    struct vertex_header *out = vertices;
  95    const float *scale = pvs->draw->viewport.scale;
  96    const float *trans = pvs->draw->viewport.translate;
  97    unsigned j;
  98    unsigned clipped = 0;
  99
 100    for (j = 0; j < count; j++) {
 101       out->clip[0] = out->data[0][0];
 102       out->clip[1] = out->data[0][1];
 103       out->clip[2] = out->data[0][2];
 104       out->clip[3] = out->data[0][3];
 105
 106       out->vertex_id = 0xffff;
 107       out->edgeflag = 1;
 108       out->clipmask = compute_clipmask_gl(out->clip,
 109                                           pvs->draw->plane,
 110                                           pvs->draw->nr_planes);
 111       clipped += out->clipmask;
 112
 113       if (out->clipmask == 0)
 114       {
 115          /* divide by w */
 116          float w = 1.0f / out->data[0][3];
 117
 118          /* Viewport mapping */
 119          out->data[0][0] = out->data[0][0] * w * scale[0] + trans[0];
 120          out->data[0][1] = out->data[0][1] * w * scale[1] + trans[1];
 121          out->data[0][2] = out->data[0][2] * w * scale[2] + trans[2];
 122          out->data[0][3] = w;
 123       }
 124
 125       out = (struct vertex_header *)( (char *)out + stride );
 126    }
 127
 128    return clipped != 0;
 129 }
 130
 131
 132
 133 /* If bypass_clipping is set, skip cliptest and rhw divide.
 134  */
 135 static boolean post_vs_viewport( struct pt_post_vs *pvs,
 136                               struct vertex_header *vertices,
 137                               unsigned count,
 138                               unsigned stride )
 139 {
 140    struct vertex_header *out = vertices;
 141    const float *scale = pvs->draw->viewport.scale;
 142    const float *trans = pvs->draw->viewport.translate;
 143    unsigned j;
 144
 145    debug_printf("%s\n", __FUNCTION__);
 146    for (j = 0; j < count; j++) {
 147       /* Viewport mapping only, no cliptest/rhw divide
 148        */
 149       out->data[0][0] = out->data[0][0] * scale[0] + trans[0];
 150       out->data[0][1] = out->data[0][1] * scale[1] + trans[1];
 151       out->data[0][2] = out->data[0][2] * scale[2] + trans[2];
 152
 153       out = (struct vertex_header *)((char *)out + stride);
 154    }
 155
 156    return FALSE;
 157 }
 158
 159
 160 /* If bypass_clipping is set and we have an identity viewport, nothing
 161  * to do.
 162  */
 163 static boolean post_vs_none( struct pt_post_vs *pvs,
 164                              struct vertex_header *vertices,
 165                              unsigned count,
 166                              unsigned stride )
 167 {
 168    debug_printf("%s\n", __FUNCTION__);
 169    return FALSE;
 170 }
 171
 172 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 173                              struct vertex_header *pipeline_verts,
 174                              unsigned count,
 175                              unsigned stride )
 176 {
 177    return pvs->run( pvs, pipeline_verts, count, stride );
 178 }
 179
 180
 181 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
 182                               boolean bypass_clipping,
 183                               boolean identity_viewport,
 184                               boolean opengl )
 185 {
 186    if (bypass_clipping) {
 187       if (identity_viewport)
 188          pvs->run = post_vs_none;
 189       else
 190          pvs->run = post_vs_viewport;
 191    }
 192    else {
 193       //if (opengl)
 194       pvs->run = post_vs_cliptest_viewport_gl;
 195    }
 196 }
 197
 198
 199 struct pt_post_vs *draw_pt_post_vs_create( struct draw_context *draw )
 200 {
 201    struct pt_post_vs *pvs = CALLOC_STRUCT( pt_post_vs );
 202    if (!pvs)
 203       return NULL;
 204
 205    pvs->draw = draw;
 206
 207    return pvs;
 208 }
 209
 210 void draw_pt_post_vs_destroy( struct pt_post_vs *pvs )
 211 {
 212    FREE(pvs);
 213 }