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 "util/u_math.h"
  32 #include "util/u_memory.h"
  33 #include "pipe/p_defines.h"
  34 #include "pipe/p_shader_tokens.h"
  35 #include "draw_vs.h"
  36 #include "draw_pipe.h"
  37
  38
  39 struct widepoint_stage {
  40    struct draw_stage stage;
  41
  42    float half_point_size;
  43    float point_size_min;
  44    float point_size_max;
  45
  46    float xbias;
  47    float ybias;
  48
  49    uint texcoord_slot[PIPE_MAX_SHADER_OUTPUTS];
  50    uint texcoord_mode[PIPE_MAX_SHADER_OUTPUTS];
  51    uint num_texcoords;
  52
  53    int psize_slot;
  54
  55    int point_coord_fs_input;  /**< input for pointcoord (and fog) */
  56 };
  57
  58
  59
  60 static INLINE struct widepoint_stage *
  61 widepoint_stage( struct draw_stage *stage )
  62 {
  63    return (struct widepoint_stage *)stage;
  64 }
  65
  66
  67
  68
  69 /**
  70  * Set the vertex texcoords for sprite mode.
  71  * Coords may be left untouched or set to a right-side-up or upside-down
  72  * orientation.
  73  */
  74 static void set_texcoords(const struct widepoint_stage *wide,
  75                           struct vertex_header *v, const float tc[4])
  76 {
  77    uint i;
  78    for (i = 0; i < wide->num_texcoords; i++) {
  79       if (wide->texcoord_mode[i] != PIPE_SPRITE_COORD_NONE) {
  80          uint j = wide->texcoord_slot[i];
  81          v->data[j][0] = tc[0];
  82          if (wide->texcoord_mode[i] == PIPE_SPRITE_COORD_LOWER_LEFT)
  83             v->data[j][1] = 1.0f - tc[1];
  84          else
  85             v->data[j][1] = tc[1];
  86          v->data[j][2] = tc[2];
  87          v->data[j][3] = tc[3];
  88       }
  89    }
  90
  91    if (wide->point_coord_fs_input >= 0) {
  92       /* put gl_PointCoord into extra vertex output's zw components */
  93       uint k = wide->stage.draw->extra_vp_outputs.slot;
  94       v->data[k][2] = tc[0];
  95       v->data[k][3] = tc[1];
  96    }
  97 }
  98
  99
 100 /* If there are lots of sprite points (and why wouldn't there be?) it
 101  * would probably be more sensible to change hardware setup to
 102  * optimize this rather than doing the whole thing in software like
 103  * this.
 104  */
 105 static void widepoint_point( struct draw_stage *stage,
 106                              struct prim_header *header )
 107 {
 108    const struct widepoint_stage *wide = widepoint_stage(stage);
 109    const unsigned pos = stage->draw->vs.position_output;
 110    const boolean sprite = (boolean) stage->draw->rasterizer->point_sprite;
 111    float half_size;
 112    float left_adj, right_adj, bot_adj, top_adj;
 113
 114    struct prim_header tri;
 115
 116    /* four dups of original vertex */
 117    struct vertex_header *v0 = dup_vert(stage, header->v[0], 0);
 118    struct vertex_header *v1 = dup_vert(stage, header->v[0], 1);
 119    struct vertex_header *v2 = dup_vert(stage, header->v[0], 2);
 120    struct vertex_header *v3 = dup_vert(stage, header->v[0], 3);
 121
 122    float *pos0 = v0->data[pos];
 123    float *pos1 = v1->data[pos];
 124    float *pos2 = v2->data[pos];
 125    float *pos3 = v3->data[pos];
 126
 127    /* point size is either per-vertex or fixed size */
 128    if (wide->psize_slot >= 0) {
 129       half_size = header->v[0]->data[wide->psize_slot][0];
 130
 131       /* XXX: temporary -- do this in the vertex shader??
 132        */
 133       half_size = CLAMP(half_size,
 134                         wide->point_size_min,
 135                         wide->point_size_max);
 136
 137       half_size *= 0.5f;
 138    }
 139    else {
 140       half_size = wide->half_point_size;
 141    }
 142
 143    left_adj = -half_size + wide->xbias;
 144    right_adj = half_size + wide->xbias;
 145    bot_adj = half_size + wide->ybias;
 146    top_adj = -half_size + wide->ybias;
 147
 148    pos0[0] += left_adj;
 149    pos0[1] += top_adj;
 150
 151    pos1[0] += left_adj;
 152    pos1[1] += bot_adj;
 153
 154    pos2[0] += right_adj;
 155    pos2[1] += top_adj;
 156
 157    pos3[0] += right_adj;
 158    pos3[1] += bot_adj;
 159
 160    if (sprite) {
 161       static const float tex00[4] = { 0, 0, 0, 1 };
 162       static const float tex01[4] = { 0, 1, 0, 1 };
 163       static const float tex11[4] = { 1, 1, 0, 1 };
 164       static const float tex10[4] = { 1, 0, 0, 1 };
 165       set_texcoords( wide, v0, tex00 );
 166       set_texcoords( wide, v1, tex01 );
 167       set_texcoords( wide, v2, tex10 );
 168       set_texcoords( wide, v3, tex11 );
 169    }
 170
 171    tri.det = header->det;  /* only the sign matters */
 172    tri.v[0] = v0;
 173    tri.v[1] = v2;
 174    tri.v[2] = v3;
 175    stage->next->tri( stage->next, &tri );
 176
 177    tri.v[0] = v0;
 178    tri.v[1] = v3;
 179    tri.v[2] = v1;
 180    stage->next->tri( stage->next, &tri );
 181 }
 182
 183
 184 static void widepoint_first_point( struct draw_stage *stage,
 185                               struct prim_header *header )
 186 {
 187    struct widepoint_stage *wide = widepoint_stage(stage);
 188    struct draw_context *draw = stage->draw;
 189
 190    wide->half_point_size = 0.5f * draw->rasterizer->point_size;
 191    wide->point_size_min = draw->rasterizer->point_size_min;
 192    wide->point_size_max = draw->rasterizer->point_size_max;
 193    wide->xbias = 0.0;
 194    wide->ybias = 0.0;
 195
 196    if (draw->rasterizer->gl_rasterization_rules) {
 197       wide->xbias = 0.125;
 198    }
 199
 200    /* XXX we won't know the real size if it's computed by the vertex shader! */
 201    if ((draw->rasterizer->point_size > draw->pipeline.wide_point_threshold) ||
 202        (draw->rasterizer->point_sprite && draw->pipeline.point_sprite)) {
 203       stage->point = widepoint_point;
 204    }
 205    else {
 206       stage->point = draw_pipe_passthrough_point;
 207    }
 208
 209    if (draw->rasterizer->point_sprite) {
 210       /* find vertex shader texcoord outputs */
 211       const struct draw_vertex_shader *vs = draw->vs.vertex_shader;
 212       uint i, j = 0;
 213       for (i = 0; i < vs->info.num_outputs; i++) {
 214          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_GENERIC) {
 215             wide->texcoord_slot[j] = i;
 216             wide->texcoord_mode[j] = draw->rasterizer->sprite_coord_mode[j];
 217             j++;
 218          }
 219       }
 220       wide->num_texcoords = j;
 221
 222       /* find fragment shader PointCoord/Fog input */
 223       wide->point_coord_fs_input = 0; /* XXX fix this! */
 224
 225       /* setup extra vp output (point coord implemented as a texcoord) */
 226       draw->extra_vp_outputs.semantic_name = TGSI_SEMANTIC_GENERIC;
 227       draw->extra_vp_outputs.semantic_index = 0;
 228       draw->extra_vp_outputs.slot = draw->vs.num_vs_outputs;
 229    }
 230    else {
 231       wide->point_coord_fs_input = -1;
 232       draw->extra_vp_outputs.slot = 0;
 233    }
 234
 235    wide->psize_slot = -1;
 236    if (draw->rasterizer->point_size_per_vertex) {
 237       /* find PSIZ vertex output */
 238       const struct draw_vertex_shader *vs = draw->vs.vertex_shader;
 239       uint i;
 240       for (i = 0; i < vs->info.num_outputs; i++) {
 241          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_PSIZE) {
 242             wide->psize_slot = i;
 243             break;
 244          }
 245       }
 246    }
 247
 248    stage->point( stage, header );
 249 }
 250
 251
 252 static void widepoint_flush( struct draw_stage *stage, unsigned flags )
 253 {
 254    stage->point = widepoint_first_point;
 255    stage->next->flush( stage->next, flags );
 256 }
 257
 258
 259 static void widepoint_reset_stipple_counter( struct draw_stage *stage )
 260 {
 261    stage->next->reset_stipple_counter( stage->next );
 262 }
 263
 264
 265 static void widepoint_destroy( struct draw_stage *stage )
 266 {
 267    draw_free_temp_verts( stage );
 268    FREE( stage );
 269 }
 270
 271
 272 struct draw_stage *draw_wide_point_stage( struct draw_context *draw )
 273 {
 274    struct widepoint_stage *wide = CALLOC_STRUCT(widepoint_stage);
 275    if (wide == NULL)
 276       goto fail;
 277
 278    if (!draw_alloc_temp_verts( &wide->stage, 4 ))
 279       goto fail;
 280
 281    wide->stage.draw = draw;
 282    wide->stage.next = NULL;
 283    wide->stage.point = widepoint_first_point;
 284    wide->stage.line = draw_pipe_passthrough_line;
 285    wide->stage.tri = draw_pipe_passthrough_tri;
 286    wide->stage.flush = widepoint_flush;
 287    wide->stage.reset_stipple_counter = widepoint_reset_stipple_counter;
 288    wide->stage.destroy = widepoint_destroy;
 289
 290    return &wide->stage;
 291
 292  fail:
 293    if (wide)
 294       wide->stage.destroy( &wide->stage );
 295
 296    return NULL;
 297 }