1 /**************************************************************************
2 *
3 * Copyright 2007 VMware, Inc.
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 VMWARE 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 <[email protected]>
29 */
30
31 /**
32 * Notes on wide points and sprite mode:
33 *
34 * In wide point/sprite mode we effectively need to convert each incoming
35 * vertex into four outgoing vertices specifying the corners of a quad.
36 * Since we don't (yet) have geometry shaders, we have to handle this here
37 * in the draw module.
38 *
39 * For sprites, it also means that this is where we have to handle texcoords
40 * for the vertices of the quad. OpenGL's GL_COORD_REPLACE state specifies
41 * if/how enabled texcoords are automatically generated for sprites. We pass
42 * that info through gallium in the pipe_rasterizer_state::sprite_coord_mode
43 * array.
44 *
45 * Additionally, GLSL's gl_PointCoord fragment attribute has to be handled
46 * here as well. This is basically an additional texture/generic attribute
47 * that varies .x from 0 to 1 horizontally across the point and varies .y
48 * vertically from 0 to 1 down the sprite.
49 *
50 * With geometry shaders, the gallium frontends could create a GS to do
51 * most/all of this.
52 */
53
54
55 #include "pipe/p_screen.h"
56 #include "pipe/p_context.h"
57 #include "util/u_math.h"
58 #include "util/u_memory.h"
59 #include "pipe/p_defines.h"
60 #include "pipe/p_shader_tokens.h"
61 #include "draw_fs.h"
62 #include "draw_vs.h"
63 #include "draw_pipe.h"
64
65
66 struct widepoint_stage {
67 struct draw_stage stage; /**< base class */
68
69 float half_point_size;
70
71 float xbias;
72 float ybias;
73
74 /** for automatic texcoord generation/replacement */
75 unsigned num_texcoord_gen;
76 unsigned texcoord_gen_slot[PIPE_MAX_SHADER_OUTPUTS];
77
78 /* TGSI_SEMANTIC to which sprite_coord_enable applies */
79 enum tgsi_semantic sprite_coord_semantic;
80
81 int psize_slot;
82 };
83
84
85
86 static inline struct widepoint_stage *
widepoint_stage(struct draw_stage * stage)87 widepoint_stage(struct draw_stage *stage)
88 {
89 return (struct widepoint_stage *)stage;
90 }
91
92
93 /**
94 * Set the vertex texcoords for sprite mode.
95 * Coords may be left untouched or set to a right-side-up or upside-down
96 * orientation.
97 */
98 static void
set_texcoords(const struct widepoint_stage * wide,struct vertex_header * v,const float tc[4])99 set_texcoords(const struct widepoint_stage *wide,
100 struct vertex_header *v, const float tc[4])
101 {
102 const struct draw_context *draw = wide->stage.draw;
103 const struct pipe_rasterizer_state *rast = draw->rasterizer;
104 const unsigned texcoord_mode = rast->sprite_coord_mode;
105
106 for (unsigned i = 0; i < wide->num_texcoord_gen; i++) {
107 const unsigned slot = wide->texcoord_gen_slot[i];
108 v->data[slot][0] = tc[0];
109 if (texcoord_mode == PIPE_SPRITE_COORD_LOWER_LEFT)
110 v->data[slot][1] = 1.0f - tc[1];
111 else
112 v->data[slot][1] = tc[1];
113 v->data[slot][2] = tc[2];
114 v->data[slot][3] = tc[3];
115 }
116 }
117
118
119 /* If there are lots of sprite points (and why wouldn't there be?) it
120 * would probably be more sensible to change hardware setup to
121 * optimize this rather than doing the whole thing in software like
122 * this.
123 */
124 static void
widepoint_point(struct draw_stage * stage,struct prim_header * header)125 widepoint_point(struct draw_stage *stage,
126 struct prim_header *header)
127 {
128 const struct widepoint_stage *wide = widepoint_stage(stage);
129 const unsigned pos = draw_current_shader_position_output(stage->draw);
130 const bool sprite = (bool) stage->draw->rasterizer->point_quad_rasterization;
131 float half_size;
132 float left_adj, right_adj, bot_adj, top_adj;
133
134 struct prim_header tri;
135
136 /* four dups of original vertex */
137 struct vertex_header *v0 = dup_vert(stage, header->v[0], 0);
138 struct vertex_header *v1 = dup_vert(stage, header->v[0], 1);
139 struct vertex_header *v2 = dup_vert(stage, header->v[0], 2);
140 struct vertex_header *v3 = dup_vert(stage, header->v[0], 3);
141
142 float *pos0 = v0->data[pos];
143 float *pos1 = v1->data[pos];
144 float *pos2 = v2->data[pos];
145 float *pos3 = v3->data[pos];
146
147 /* point size is either per-vertex or fixed size */
148 if (wide->psize_slot >= 0) {
149 half_size = header->v[0]->data[wide->psize_slot][0];
150 half_size *= 0.5f;
151 }
152 else {
153 half_size = wide->half_point_size;
154 }
155
156 left_adj = -half_size + wide->xbias;
157 right_adj = half_size + wide->xbias;
158 bot_adj = half_size + wide->ybias;
159 top_adj = -half_size + wide->ybias;
160
161 pos0[0] += left_adj;
162 pos0[1] += top_adj;
163
164 pos1[0] += left_adj;
165 pos1[1] += bot_adj;
166
167 pos2[0] += right_adj;
168 pos2[1] += top_adj;
169
170 pos3[0] += right_adj;
171 pos3[1] += bot_adj;
172
173 if (sprite) {
174 static const float tex00[4] = { 0, 0, 0, 1 };
175 static const float tex01[4] = { 0, 1, 0, 1 };
176 static const float tex11[4] = { 1, 1, 0, 1 };
177 static const float tex10[4] = { 1, 0, 0, 1 };
178 set_texcoords(wide, v0, tex00);
179 set_texcoords(wide, v1, tex01);
180 set_texcoords(wide, v2, tex10);
181 set_texcoords(wide, v3, tex11);
182 }
183
184 tri.det = header->det; /* only the sign matters */
185 tri.v[0] = v0;
186 tri.v[1] = v2;
187 tri.v[2] = v3;
188 stage->next->tri(stage->next, &tri);
189
190 tri.v[0] = v0;
191 tri.v[1] = v3;
192 tri.v[2] = v1;
193 stage->next->tri(stage->next, &tri);
194 }
195
196
197 static void
widepoint_first_point(struct draw_stage * stage,struct prim_header * header)198 widepoint_first_point(struct draw_stage *stage,
199 struct prim_header *header)
200 {
201 struct widepoint_stage *wide = widepoint_stage(stage);
202 struct draw_context *draw = stage->draw;
203 struct pipe_context *pipe = draw->pipe;
204 const struct pipe_rasterizer_state *rast = draw->rasterizer;
205 void *r;
206
207 wide->half_point_size = 0.5f * rast->point_size;
208 wide->xbias = 0.0;
209 wide->ybias = 0.0;
210
211 if (rast->half_pixel_center) {
212 wide->xbias = 0.125;
213 wide->ybias = -0.125;
214 }
215
216 /* Disable triangle culling, stippling, unfilled mode etc. */
217 r = draw_get_rasterizer_no_cull(draw, rast);
218 draw->suspend_flushing = true;
219 pipe->bind_rasterizer_state(pipe, r);
220 draw->suspend_flushing = false;
221
222 /* XXX we won't know the real size if it's computed by the vertex shader! */
223 if ((rast->point_size > draw->pipeline.wide_point_threshold) ||
224 (rast->point_quad_rasterization && draw->pipeline.point_sprite)) {
225 stage->point = widepoint_point;
226 }
227 else {
228 stage->point = draw_pipe_passthrough_point;
229 }
230
231 draw_remove_extra_vertex_attribs(draw);
232
233 if (rast->point_quad_rasterization) {
234 const struct draw_fragment_shader *fs = draw->fs.fragment_shader;
235
236 assert(fs);
237
238 wide->num_texcoord_gen = 0;
239
240 /* Loop over fragment shader inputs looking for the PCOORD input or inputs
241 * for which bit 'k' in sprite_coord_enable is set.
242 */
243 for (unsigned i = 0; i < fs->info.num_inputs; i++) {
244 int slot;
245 const enum tgsi_semantic sn = fs->info.input_semantic_name[i];
246 const unsigned si = fs->info.input_semantic_index[i];
247
248 if (sn == wide->sprite_coord_semantic) {
249 /* Note that sprite_coord_enable is a bitfield of 32 bits. */
250 if (si >= 32 || !(rast->sprite_coord_enable & (1 << si)))
251 continue;
252 } else if (sn != TGSI_SEMANTIC_PCOORD) {
253 continue;
254 }
255
256 /* OK, this generic attribute needs to be replaced with a
257 * sprite coord (see above).
258 */
259 slot = draw_alloc_extra_vertex_attrib(draw, sn, si);
260
261 /* add this slot to the texcoord-gen list */
262 wide->texcoord_gen_slot[wide->num_texcoord_gen++] = slot;
263 }
264 }
265
266 wide->psize_slot = -1;
267 if (rast->point_size_per_vertex) {
268 /* find PSIZ vertex output */
269 wide->psize_slot = draw_find_shader_output(draw, TGSI_SEMANTIC_PSIZE, 0);
270 }
271
272 stage->point(stage, header);
273 }
274
275
276 static void
widepoint_flush(struct draw_stage * stage,unsigned flags)277 widepoint_flush(struct draw_stage *stage, unsigned flags)
278 {
279 struct draw_context *draw = stage->draw;
280 struct pipe_context *pipe = draw->pipe;
281
282 stage->point = widepoint_first_point;
283 stage->next->flush(stage->next, flags);
284
285 draw_remove_extra_vertex_attribs(draw);
286
287 /* restore original rasterizer state */
288 if (draw->rast_handle) {
289 draw->suspend_flushing = true;
290 pipe->bind_rasterizer_state(pipe, draw->rast_handle);
291 draw->suspend_flushing = false;
292 }
293 }
294
295
296 static void
widepoint_reset_stipple_counter(struct draw_stage * stage)297 widepoint_reset_stipple_counter(struct draw_stage *stage)
298 {
299 stage->next->reset_stipple_counter(stage->next);
300 }
301
302
303 static void
widepoint_destroy(struct draw_stage * stage)304 widepoint_destroy(struct draw_stage *stage)
305 {
306 draw_free_temp_verts(stage);
307 FREE(stage);
308 }
309
310
draw_wide_point_stage(struct draw_context * draw)311 struct draw_stage *draw_wide_point_stage(struct draw_context *draw)
312 {
313 struct widepoint_stage *wide = CALLOC_STRUCT(widepoint_stage);
314 if (!wide)
315 goto fail;
316
317 wide->stage.draw = draw;
318 wide->stage.name = "wide-point";
319 wide->stage.next = NULL;
320 wide->stage.point = widepoint_first_point;
321 wide->stage.line = draw_pipe_passthrough_line;
322 wide->stage.tri = draw_pipe_passthrough_tri;
323 wide->stage.flush = widepoint_flush;
324 wide->stage.reset_stipple_counter = widepoint_reset_stipple_counter;
325 wide->stage.destroy = widepoint_destroy;
326
327 if (!draw_alloc_temp_verts(&wide->stage, 4))
328 goto fail;
329
330 wide->sprite_coord_semantic =
331 draw->pipe->screen->get_param(draw->pipe->screen, PIPE_CAP_TGSI_TEXCOORD)
332 ?
333 TGSI_SEMANTIC_TEXCOORD : TGSI_SEMANTIC_GENERIC;
334
335 return &wide->stage;
336
337 fail:
338 if (wide)
339 wide->stage.destroy(&wide->stage);
340
341 return NULL;
342 }
343