src/gallium/auxiliary/draw/draw_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_private.h"
  35
  36
  37 struct widepoint_stage {
  38    struct draw_stage stage;
  39
  40    float half_point_size;
  41
  42    uint texcoord_slot[PIPE_MAX_SHADER_OUTPUTS];
  43    uint texcoord_mode[PIPE_MAX_SHADER_OUTPUTS];
  44    uint num_texcoords;
  45
  46    int psize_slot;
  47 };
  48
  49
  50
  51 static INLINE struct widepoint_stage *
  52 widepoint_stage( struct draw_stage *stage )
  53 {
  54    return (struct widepoint_stage *)stage;
  55 }
  56
  57
  58 static void passthrough_point( struct draw_stage *stage,
  59                              struct prim_header *header )
  60 {
  61    stage->next->point( stage->next, header );
  62 }
  63
  64 static void widepoint_line( struct draw_stage *stage,
  65                             struct prim_header *header )
  66 {
  67    stage->next->line(stage->next, header);
  68 }
  69
  70 static void widepoint_tri( struct draw_stage *stage,
  71                            struct prim_header *header )
  72 {
  73    stage->next->tri(stage->next, header);
  74 }
  75
  76
  77 /**
  78  * Set the vertex texcoords for sprite mode.
  79  * Coords may be left untouched or set to a right-side-up or upside-down
  80  * orientation.
  81  */
  82 static void set_texcoords(const struct widepoint_stage *wide,
  83                           struct vertex_header *v, const float tc[4])
  84 {
  85    uint i;
  86    for (i = 0; i < wide->num_texcoords; i++) {
  87       if (wide->texcoord_mode[i] != PIPE_SPRITE_COORD_NONE) {
  88          uint j = wide->texcoord_slot[i];
  89          v->data[j][0] = tc[0];
  90          if (wide->texcoord_mode[i] == PIPE_SPRITE_COORD_LOWER_LEFT)
  91             v->data[j][1] = 1.0f - tc[1];
  92          else
  93             v->data[j][1] = tc[1];
  94          v->data[j][2] = tc[2];
  95          v->data[j][3] = tc[3];
  96       }
  97    }
  98 }
  99
 100
 101 /* If there are lots of sprite points (and why wouldn't there be?) it
 102  * would probably be more sensible to change hardware setup to
 103  * optimize this rather than doing the whole thing in software like
 104  * this.
 105  */
 106 static void widepoint_point( struct draw_stage *stage,
 107                              struct prim_header *header )
 108 {
 109    const struct widepoint_stage *wide = widepoint_stage(stage);
 110    const boolean sprite = (boolean) stage->draw->rasterizer->point_sprite;
 111    float half_size;
 112    float left_adj, right_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[0];
 123    float *pos1 = v1->data[0];
 124    float *pos2 = v2->data[0];
 125    float *pos3 = v3->data[0];
 126
 127    /* point size is either per-vertex or fixed size */
 128    if (wide->psize_slot >= 0) {
 129       half_size = 0.5f * header->v[0]->data[wide->psize_slot][0];
 130    }
 131    else {
 132       half_size = wide->half_point_size;
 133    }
 134
 135    left_adj = -half_size; /* + 0.25f;*/
 136    right_adj = half_size; /* + 0.25f;*/
 137
 138    pos0[0] += left_adj;
 139    pos0[1] -= half_size;
 140
 141    pos1[0] += left_adj;
 142    pos1[1] += half_size;
 143
 144    pos2[0] += right_adj;
 145    pos2[1] -= half_size;
 146
 147    pos3[0] += right_adj;
 148    pos3[1] += half_size;
 149
 150    if (sprite) {
 151       static const float tex00[4] = { 0, 0, 0, 1 };
 152       static const float tex01[4] = { 0, 1, 0, 1 };
 153       static const float tex11[4] = { 1, 1, 0, 1 };
 154       static const float tex10[4] = { 1, 0, 0, 1 };
 155       set_texcoords( wide, v0, tex00 );
 156       set_texcoords( wide, v1, tex01 );
 157       set_texcoords( wide, v2, tex10 );
 158       set_texcoords( wide, v3, tex11 );
 159    }
 160
 161    tri.det = header->det;  /* only the sign matters */
 162    tri.v[0] = v0;
 163    tri.v[1] = v2;
 164    tri.v[2] = v3;
 165    stage->next->tri( stage->next, &tri );
 166
 167    tri.v[0] = v0;
 168    tri.v[1] = v3;
 169    tri.v[2] = v1;
 170    stage->next->tri( stage->next, &tri );
 171 }
 172
 173
 174 static void widepoint_first_point( struct draw_stage *stage,
 175                               struct prim_header *header )
 176 {
 177    struct widepoint_stage *wide = widepoint_stage(stage);
 178    struct draw_context *draw = stage->draw;
 179
 180    wide->half_point_size = 0.5f * draw->rasterizer->point_size;
 181
 182    /* XXX we won't know the real size if it's computed by the vertex shader! */
 183    if (draw->rasterizer->point_size > draw->wide_point_threshold) {
 184       stage->point = widepoint_point;
 185    }
 186    else {
 187       stage->point = passthrough_point;
 188    }
 189
 190    if (draw->rasterizer->point_sprite) {
 191       /* find vertex shader texcoord outputs */
 192       const struct draw_vertex_shader *vs = draw->vertex_shader;
 193       uint i, j = 0;
 194       for (i = 0; i < vs->info.num_outputs; i++) {
 195          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_GENERIC) {
 196             wide->texcoord_slot[j] = i;
 197             wide->texcoord_mode[j] = draw->rasterizer->sprite_coord_mode[j];
 198             j++;
 199          }
 200       }
 201       wide->num_texcoords = j;
 202    }
 203
 204    wide->psize_slot = -1;
 205    if (draw->rasterizer->point_size_per_vertex) {
 206       /* find PSIZ vertex output */
 207       const struct draw_vertex_shader *vs = draw->vertex_shader;
 208       uint i;
 209       for (i = 0; i < vs->info.num_outputs; i++) {
 210          if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_PSIZE) {
 211             wide->psize_slot = i;
 212             break;
 213          }
 214       }
 215    }
 216
 217    stage->point( stage, header );
 218 }
 219
 220
 221 static void widepoint_flush( struct draw_stage *stage, unsigned flags )
 222 {
 223    stage->point = widepoint_first_point;
 224    stage->next->flush( stage->next, flags );
 225 }
 226
 227
 228 static void widepoint_reset_stipple_counter( struct draw_stage *stage )
 229 {
 230    stage->next->reset_stipple_counter( stage->next );
 231 }
 232
 233
 234 static void widepoint_destroy( struct draw_stage *stage )
 235 {
 236    draw_free_temp_verts( stage );
 237    FREE( stage );
 238 }
 239
 240
 241 struct draw_stage *draw_wide_point_stage( struct draw_context *draw )
 242 {
 243    struct widepoint_stage *wide = CALLOC_STRUCT(widepoint_stage);
 244
 245    draw_alloc_temp_verts( &wide->stage, 4 );
 246
 247    wide->stage.draw = draw;
 248    wide->stage.next = NULL;
 249    wide->stage.point = widepoint_first_point;
 250    wide->stage.line = widepoint_line;
 251    wide->stage.tri = widepoint_tri;
 252    wide->stage.flush = widepoint_flush;
 253    wide->stage.reset_stipple_counter = widepoint_reset_stipple_counter;
 254    wide->stage.destroy = widepoint_destroy;
 255
 256    return &wide->stage;
 257 }