src/gallium/auxiliary/draw/draw_pipe_wide_point.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 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 /* Authors:  Keith Whitwell <keith@tungstengraphics.com>
  29  */
  30
  31 #include "pipe/p_util.h"
  32 #include "pipe/p_defines.h"
  33 #include "pipe/p_shader_tokens.h"
  34 #include "draw_vs.h"
  35 #include "draw_pipe.h"
  36
  37
  38 struct widepoint_stage {
  39    struct draw_stage stage;
  40
  41    float half_point_size;
  42    float point_size_min;
  43    float point_size_max;
  44
  45    float xbias;
  46    float ybias;
  47
  48    uint texcoord_slot[PIPE_MAX_SHADER_OUTPUTS];
  49    uint texcoord_mode[PIPE_MAX_SHADER_OUTPUTS];
  50    uint num_texcoords;
  51
  52    int psize_slot;
  53 };
  54
  55
  56
  57 static INLINE struct widepoint_stage *
  58 widepoint_stage( struct draw_stage *stage )
  59 {
  60    return (struct widepoint_stage *)stage;
  61 }
  62
  63
  64 static void passthrough_point( struct draw_stage *stage,
  65                              struct prim_header *header )
  66 {
  67    stage->next->point( stage->next, header );
  68 }
  69
  70 static void widepoint_line( struct draw_stage *stage,
  71                             struct prim_header *header )
  72 {
  73    stage->next->line(stage->next, header);
  74 }
  75
  76 static void widepoint_tri( struct draw_stage *stage,
  77                            struct prim_header *header )
  78 {
  79    stage->next->tri(stage->next, header);
  80 }
  81
  82
  83 /**
  84  * Set the vertex texcoords for sprite mode.
  85  * Coords may be left untouched or set to a right-side-up or upside-down
  86  * orientation.
  87  */
  88 static void set_texcoords(const struct widepoint_stage *wide,
  89                           struct vertex_header *v, const float tc[4])
  90 {
  91    uint i;
  92    for (i = 0; i < wide->num_texcoords; i++) {
  93       if (wide->texcoord_mode[i] != PIPE_SPRITE_COORD_NONE) {
  94          uint j = wide->texcoord_slot[i];
  95          v->data[j][0] = tc[0];
  96          if (wide->texcoord_mode[i] == PIPE_SPRITE_COORD_LOWER_LEFT)
  97             v->data[j][1] = 1.0f - tc[1];
  98          else
  99             v->data[j][1] = tc[1];
 100          v->data[j][2] = tc[2];
 101          v->data[j][3] = tc[3];
 102       }
 103    }
 104 }
 105
 106
 107 /* If there are lots of sprite points (and why wouldn't there be?) it
 108  * would probably be more sensible to change hardware setup to
 109  * optimize this rather than doing the whole thing in software like
 110  * this.
 111  */
 112 static void widepoint_point( struct draw_stage *stage,
 113                              struct prim_header *header )
 114 {
 115    const struct widepoint_stage *wide = widepoint_stage(stage);
 116    const boolean sprite = (boolean) stage->draw->rasterizer->point_sprite;
 117    float half_size;
 118    float left_adj, right_adj, bot_adj, top_adj;
 119
 120    struct prim_header tri;
 121
 122    /* four dups of original vertex */
 123    struct vertex_header *v0 = dup_vert(stage, header->v[0], 0);
 124    struct vertex_header *v1 = dup_vert(stage, header->v[0], 1);
 125    struct vertex_header *v2 = dup_vert(stage, header->v[0], 2);
 126    struct vertex_header *v3 = dup_vert(stage, header->v[0], 3);
 127
 128    float *pos0 = v0->data[0];
 129    float *pos1 = v1->data[0];
 130    float *pos2 = v2->data[0];
 131    float *pos3 = v3->data[0];
 132
 133    /* point size is either per-vertex or fixed size */
 134    if (wide->psize_slot >= 0) {
 135       half_size = header->v[0]->data[wide->psize_slot][0];
 136
 137       /* XXX: temporary -- do this in the vertex shader??
 138        */
 139       half_size = CLAMP(half_size,
 140                         wide->point_size_min,
 141                         wide->point_size_max);
 142
 143       half_size *= 0.5f;
 144    }
 145    else {
 146       half_size = wide->half_point_size;
 147    }
 148
 149    left_adj = -half_size + wide->xbias;
 150    right_adj = half_size + wide->xbias;
 151    bot_adj = half_size + wide->ybias;
 152    top_adj = -half_size + wide->ybias;
 153
 154    pos0[0] += left_adj;
 155    pos0[1] += top_adj;
 156
 157    pos1[0] += left_adj;
 158    pos1[1] += bot_adj;
 159
 160    pos2[0] += right_adj;
 161    pos2[1] += top_adj;
 162
 163    pos3[0] += right_adj;
 164    pos3[1] += bot_adj;
 165
 166    if (sprite) {
 167       static const float tex00[4] = { 0, 0, 0, 1 };
 168       static const float tex01[4] = { 0, 1, 0, 1 };
 169       static const float tex11[4] = { 1, 1, 0, 1 };
 170       static const float tex10[4] = { 1, 0, 0, 1 };
 171       set_texcoords( wide, v0, tex00 );
 172       set_texcoords( wide, v1, tex01 );
 173       set_texcoords( wide, v2, tex10 );
 174       set_texcoords( wide, v3, tex11 );
 175    }
 176
 177    tri.det = header->det;  /* only the sign matters */
 178    tri.v[0] = v0;
 179    tri.v[1] = v2;
 180    tri.v[2] = v3;
 181    stage->next->tri( stage->next, &tri );
 182
 183    tri.v[0] = v0;
 184    tri.v[1] = v3;
 185    tri.v[2] = v1;
 186    stage->next->tri( stage->next, &tri );
 187 }
 188
 189
 190 static void widepoint_first_point( struct draw_stage *stage,
 191                               struct prim_header *header )
 192 {
 193    struct widepoint_stage *wide = widepoint_stage(stage);
 194    struct draw_context *draw = stage->draw;
 195
 196    wide->half_point_size = 0.5f * draw->rasterizer->point_size;
 197    wide->point_size_min = draw->rasterizer->point_size_min;
 198    wide->point_size_max = draw->rasterizer->point_size_max;
 199    wide->xbias = 0.0;
 200    wide->ybias = 0.0;
 201
 202    if (draw->rasterizer->gl_rasterization_rules) {
 203       wide->xbias = 0.125;
 204    }
 205
 206    /* XXX we won't know the real size if it's computed by the vertex shader! */
 207    if ((draw->rasterizer->point_size > draw->pipeline.wide_point_threshold) ||
 208        (draw->rasterizer->point_sprite && draw->pipeline.point_sprite)) {
 209       stage->point = widepoint_point;
 210    }
 211    else {
 212       stage->point = passthrough_point;
 213    }
 214
 215    if (draw->rasterizer->point_sprite) {
 216       /* find vertex shader texcoord outputs */
 217       const struct draw_vertex_shader *vs = draw->vertex_shader;
 218       uint i, j = 0;
 219       for (i = 0; i < vs->info.num_outputs; i++) {
 220          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_GENERIC) {
 221             wide->texcoord_slot[j] = i;
 222             wide->texcoord_mode[j] = draw->rasterizer->sprite_coord_mode[j];
 223             j++;
 224          }
 225       }
 226       wide->num_texcoords = j;
 227    }
 228
 229    wide->psize_slot = -1;
 230    if (draw->rasterizer->point_size_per_vertex) {
 231       /* find PSIZ vertex output */
 232       const struct draw_vertex_shader *vs = draw->vertex_shader;
 233       uint i;
 234       for (i = 0; i < vs->info.num_outputs; i++) {
 235          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_PSIZE) {
 236             wide->psize_slot = i;
 237             break;
 238          }
 239       }
 240    }
 241
 242    stage->point( stage, header );
 243 }
 244
 245
 246 static void widepoint_flush( struct draw_stage *stage, unsigned flags )
 247 {
 248    stage->point = widepoint_first_point;
 249    stage->next->flush( stage->next, flags );
 250 }
 251
 252
 253 static void widepoint_reset_stipple_counter( struct draw_stage *stage )
 254 {
 255    stage->next->reset_stipple_counter( stage->next );
 256 }
 257
 258
 259 static void widepoint_destroy( struct draw_stage *stage )
 260 {
 261    draw_free_temp_verts( stage );
 262    FREE( stage );
 263 }
 264
 265
 266 struct draw_stage *draw_wide_point_stage( struct draw_context *draw )
 267 {
 268    struct widepoint_stage *wide = CALLOC_STRUCT(widepoint_stage);
 269
 270    draw_alloc_temp_verts( &wide->stage, 4 );
 271
 272    wide->stage.draw = draw;
 273    wide->stage.next = NULL;
 274    wide->stage.point = widepoint_first_point;
 275    wide->stage.line = widepoint_line;
 276    wide->stage.tri = widepoint_tri;
 277    wide->stage.flush = widepoint_flush;
 278    wide->stage.reset_stipple_counter = widepoint_reset_stipple_counter;
 279    wide->stage.destroy = widepoint_destroy;
 280
 281    return &wide->stage;
 282 }