summaryrefslogtreecommitdiff
path: root/src/gallium/auxiliary/draw/draw_pipe_wide_point.c
blob: 8dc50c0ab431b7fc1f6d4a04db5b06bcc12a96b9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
/**************************************************************************
 * 
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

/* Authors:  Keith Whitwell <keith@tungstengraphics.com>
 */

/**
 * Notes on wide points and sprite mode:
 *
 * In wide point/sprite mode we effectively need to convert each incoming
 * vertex into four outgoing vertices specifying the corners of a quad.
 * Since we don't (yet) have geometry shaders, we have to handle this here
 * in the draw module.
 *
 * For sprites, it also means that this is where we have to handle texcoords
 * for the vertices of the quad.  OpenGL's GL_COORD_REPLACE state specifies
 * if/how enabled texcoords are automatically generated for sprites.  We pass
 * that info through gallium in the pipe_rasterizer_state::sprite_coord_mode
 * array.
 *
 * Additionally, GLSL's gl_PointCoord fragment attribute has to be handled
 * here as well.  This is basically an additional texture/generic attribute
 * that varies .x from 0 to 1 horizontally across the point and varies .y
 * vertically from 0 to 1 down the sprite.
 *
 * With geometry shaders, the state tracker could create a GS to do
 * most/all of this.
 */


#include "util/u_math.h"
#include "util/u_memory.h"
#include "pipe/p_defines.h"
#include "pipe/p_shader_tokens.h"
#include "draw_vs.h"
#include "draw_pipe.h"


struct widepoint_stage {
   struct draw_stage stage;

   float half_point_size;
   float point_size_min;
   float point_size_max;

   float xbias;
   float ybias;

   uint texcoord_slot[PIPE_MAX_SHADER_OUTPUTS];
   uint texcoord_mode[PIPE_MAX_SHADER_OUTPUTS];
   uint num_texcoords;

   int psize_slot;

   int point_coord_fs_input;  /**< input for pointcoord */
};



static INLINE struct widepoint_stage *
widepoint_stage( struct draw_stage *stage )
{
   return (struct widepoint_stage *)stage;
}


/**
 * Set the vertex texcoords for sprite mode.
 * Coords may be left untouched or set to a right-side-up or upside-down
 * orientation.
 */
static void set_texcoords(const struct widepoint_stage *wide,
                          struct vertex_header *v, const float tc[4])
{
   uint i;
   for (i = 0; i < wide->num_texcoords; i++) {
      if (wide->texcoord_mode[i] != PIPE_SPRITE_COORD_NONE) {
         uint j = wide->texcoord_slot[i];
         v->data[j][0] = tc[0];
         if (wide->texcoord_mode[i] == PIPE_SPRITE_COORD_LOWER_LEFT)
            v->data[j][1] = 1.0f - tc[1];
         else
            v->data[j][1] = tc[1];
         v->data[j][2] = tc[2];
         v->data[j][3] = tc[3];
      }
   }

   if (wide->point_coord_fs_input >= 0) {
      /* put gl_PointCoord into the extra vertex slot */
      uint slot = wide->stage.draw->extra_shader_outputs.slot;
      v->data[slot][0] = tc[0];
      v->data[slot][1] = tc[1];
      v->data[slot][2] = 0.0F;
      v->data[slot][3] = 1.0F;
   }
}


/* If there are lots of sprite points (and why wouldn't there be?) it
 * would probably be more sensible to change hardware setup to
 * optimize this rather than doing the whole thing in software like
 * this.
 */
static void widepoint_point( struct draw_stage *stage,
                             struct prim_header *header )
{
   const struct widepoint_stage *wide = widepoint_stage(stage);
   const unsigned pos = draw_current_shader_position_output(stage->draw);
   const boolean sprite = (boolean) stage->draw->rasterizer->point_sprite;
   float half_size;
   float left_adj, right_adj, bot_adj, top_adj;

   struct prim_header tri;

   /* four dups of original vertex */
   struct vertex_header *v0 = dup_vert(stage, header->v[0], 0);
   struct vertex_header *v1 = dup_vert(stage, header->v[0], 1);
   struct vertex_header *v2 = dup_vert(stage, header->v[0], 2);
   struct vertex_header *v3 = dup_vert(stage, header->v[0], 3);

   float *pos0 = v0->data[pos];
   float *pos1 = v1->data[pos];
   float *pos2 = v2->data[pos];
   float *pos3 = v3->data[pos];

   /* point size is either per-vertex or fixed size */
   if (wide->psize_slot >= 0) {
      half_size = header->v[0]->data[wide->psize_slot][0];

      /* XXX: temporary -- do this in the vertex shader??
       */
      half_size = CLAMP(half_size,
                        wide->point_size_min,
                        wide->point_size_max);
      
      half_size *= 0.5f; 
   }
   else {
      half_size = wide->half_point_size;
   }

   left_adj = -half_size + wide->xbias;
   right_adj = half_size + wide->xbias;
   bot_adj = half_size + wide->ybias;
   top_adj = -half_size + wide->ybias;

   pos0[0] += left_adj;
   pos0[1] += top_adj;

   pos1[0] += left_adj;
   pos1[1] += bot_adj;

   pos2[0] += right_adj;
   pos2[1] += top_adj;

   pos3[0] += right_adj;
   pos3[1] += bot_adj;

   if (sprite) {
      static const float tex00[4] = { 0, 0, 0, 1 };
      static const float tex01[4] = { 0, 1, 0, 1 };
      static const float tex11[4] = { 1, 1, 0, 1 };
      static const float tex10[4] = { 1, 0, 0, 1 };
      set_texcoords( wide, v0, tex00 );
      set_texcoords( wide, v1, tex01 );
      set_texcoords( wide, v2, tex10 );
      set_texcoords( wide, v3, tex11 );
   }

   tri.det = header->det;  /* only the sign matters */
   tri.v[0] = v0;
   tri.v[1] = v2;
   tri.v[2] = v3;
   stage->next->tri( stage->next, &tri );

   tri.v[0] = v0;
   tri.v[1] = v3;
   tri.v[2] = v1;
   stage->next->tri( stage->next, &tri );
}


static int
find_pntc_input_attrib(struct draw_context *draw)
{
   /* Scan the fragment program's input decls to find the pointcoord
    * attribute.  The xy components will store the point coord.
    */
   return 0; /* XXX fix this */
}


static void widepoint_first_point( struct draw_stage *stage, 
			      struct prim_header *header )
{
   struct widepoint_stage *wide = widepoint_stage(stage);
   struct draw_context *draw = stage->draw;

   wide->half_point_size = 0.5f * draw->rasterizer->point_size;
   wide->point_size_min = draw->rasterizer->point_size_min;
   wide->point_size_max = draw->rasterizer->point_size_max;
   wide->xbias = 0.0;
   wide->ybias = 0.0;

   if (draw->rasterizer->gl_rasterization_rules) {
      wide->xbias = 0.125;
   }

   /* XXX we won't know the real size if it's computed by the vertex shader! */
   if ((draw->rasterizer->point_size > draw->pipeline.wide_point_threshold) ||
       (draw->rasterizer->point_sprite && draw->pipeline.point_sprite)) {
      stage->point = widepoint_point;
   }
   else {
      stage->point = draw_pipe_passthrough_point;
   }

   if (draw->rasterizer->point_sprite) {
      /* find vertex shader texcoord outputs */
      const struct draw_vertex_shader *vs = draw->vs.vertex_shader;
      uint i, j = 0;
      for (i = 0; i < vs->info.num_outputs; i++) {
         if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_GENERIC) {
            wide->texcoord_slot[j] = i;
            wide->texcoord_mode[j] = draw->rasterizer->sprite_coord_mode[j];
            j++;
         }
      }
      wide->num_texcoords = j;

      /* find fragment shader PointCoord input */
      wide->point_coord_fs_input = find_pntc_input_attrib(draw);

      /* setup extra vp output (point coord implemented as a texcoord) */
      draw->extra_shader_outputs.semantic_name = TGSI_SEMANTIC_GENERIC;
      draw->extra_shader_outputs.semantic_index = 0;
      draw->extra_shader_outputs.slot = draw_current_shader_outputs(draw);
   }
   else {
      wide->point_coord_fs_input = -1;
      draw->extra_shader_outputs.slot = 0;
   }

   wide->psize_slot = -1;
   if (draw->rasterizer->point_size_per_vertex) {
      /* find PSIZ vertex output */
      const struct draw_vertex_shader *vs = draw->vs.vertex_shader;
      uint i;
      for (i = 0; i < vs->info.num_outputs; i++) {
         if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_PSIZE) {
            wide->psize_slot = i;
            break;
         }
      }
   }
   
   stage->point( stage, header );
}


static void widepoint_flush( struct draw_stage *stage, unsigned flags )
{
   stage->point = widepoint_first_point;
   stage->next->flush( stage->next, flags );
   stage->draw->extra_shader_outputs.slot = 0;
}


static void widepoint_reset_stipple_counter( struct draw_stage *stage )
{
   stage->next->reset_stipple_counter( stage->next );
}


static void widepoint_destroy( struct draw_stage *stage )
{
   draw_free_temp_verts( stage );
   FREE( stage );
}


struct draw_stage *draw_wide_point_stage( struct draw_context *draw )
{
   struct widepoint_stage *wide = CALLOC_STRUCT(widepoint_stage);
   if (wide == NULL)
      goto fail;

   if (!draw_alloc_temp_verts( &wide->stage, 4 ))
      goto fail;

   wide->stage.draw = draw;
   wide->stage.name = "wide-point";
   wide->stage.next = NULL;
   wide->stage.point = widepoint_first_point;
   wide->stage.line = draw_pipe_passthrough_line;
   wide->stage.tri = draw_pipe_passthrough_tri;
   wide->stage.flush = widepoint_flush;
   wide->stage.reset_stipple_counter = widepoint_reset_stipple_counter;
   wide->stage.destroy = widepoint_destroy;

   return &wide->stage;

 fail:
   if (wide)
      wide->stage.destroy( &wide->stage );
   
   return NULL;
}