1 /**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * Copyright 2010 VMware, Inc.
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
22 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
23 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29 /**
30 * Polygon stipple helper module. Drivers/GPUs which don't support polygon
31 * stipple natively can use this module to simulate it.
32 *
33 * Basically, modify fragment shader to sample the 32x32 stipple pattern
34 * texture and do a fragment kill for the 'off' bits.
35 *
36 * This was originally a 'draw' module stage, but since we don't need
37 * vertex window coords or anything, it can be a stand-alone utility module.
38 *
39 * Authors: Brian Paul
40 */
41
42
43 #include "pipe/p_context.h"
44 #include "pipe/p_defines.h"
45 #include "pipe/p_shader_tokens.h"
46 #include "util/u_inlines.h"
47
48 #include "util/u_format.h"
49 #include "util/u_memory.h"
50 #include "util/u_pstipple.h"
51 #include "util/u_sampler.h"
52
53 #include "tgsi/tgsi_transform.h"
54 #include "tgsi/tgsi_dump.h"
55 #include "tgsi/tgsi_scan.h"
56
57 /** Approx number of new tokens for instructions in pstip_transform_inst() */
58 #define NUM_NEW_TOKENS 53
59
60
61 void
util_pstipple_update_stipple_texture(struct pipe_context * pipe,struct pipe_resource * tex,const uint32_t pattern[32])62 util_pstipple_update_stipple_texture(struct pipe_context *pipe,
63 struct pipe_resource *tex,
64 const uint32_t pattern[32])
65 {
66 static const uint bit31 = 1u << 31;
67 struct pipe_transfer *transfer;
68 ubyte *data;
69 int i, j;
70
71 /* map texture memory */
72 data = pipe_transfer_map(pipe, tex, 0, 0,
73 PIPE_TRANSFER_WRITE, 0, 0, 32, 32, &transfer);
74
75 /*
76 * Load alpha texture.
77 * Note: 0 means keep the fragment, 255 means kill it.
78 * We'll negate the texel value and use KILL_IF which kills if value
79 * is negative.
80 */
81 for (i = 0; i < 32; i++) {
82 for (j = 0; j < 32; j++) {
83 if (pattern[i] & (bit31 >> j)) {
84 /* fragment "on" */
85 data[i * transfer->stride + j] = 0;
86 }
87 else {
88 /* fragment "off" */
89 data[i * transfer->stride + j] = 255;
90 }
91 }
92 }
93
94 /* unmap */
95 pipe->transfer_unmap(pipe, transfer);
96 }
97
98
99 /**
100 * Create a 32x32 alpha8 texture that encodes the given stipple pattern.
101 */
102 struct pipe_resource *
util_pstipple_create_stipple_texture(struct pipe_context * pipe,const uint32_t pattern[32])103 util_pstipple_create_stipple_texture(struct pipe_context *pipe,
104 const uint32_t pattern[32])
105 {
106 struct pipe_screen *screen = pipe->screen;
107 struct pipe_resource templat, *tex;
108
109 memset(&templat, 0, sizeof(templat));
110 templat.target = PIPE_TEXTURE_2D;
111 templat.format = PIPE_FORMAT_A8_UNORM;
112 templat.last_level = 0;
113 templat.width0 = 32;
114 templat.height0 = 32;
115 templat.depth0 = 1;
116 templat.array_size = 1;
117 templat.bind = PIPE_BIND_SAMPLER_VIEW;
118
119 tex = screen->resource_create(screen, &templat);
120
121 if (tex && pattern)
122 util_pstipple_update_stipple_texture(pipe, tex, pattern);
123
124 return tex;
125 }
126
127
128 /**
129 * Create sampler view to sample the stipple texture.
130 */
131 struct pipe_sampler_view *
util_pstipple_create_sampler_view(struct pipe_context * pipe,struct pipe_resource * tex)132 util_pstipple_create_sampler_view(struct pipe_context *pipe,
133 struct pipe_resource *tex)
134 {
135 struct pipe_sampler_view templat, *sv;
136
137 u_sampler_view_default_template(&templat, tex, tex->format);
138 sv = pipe->create_sampler_view(pipe, tex, &templat);
139
140 return sv;
141 }
142
143
144 /**
145 * Create the sampler CSO that'll be used for stippling.
146 */
147 void *
util_pstipple_create_sampler(struct pipe_context * pipe)148 util_pstipple_create_sampler(struct pipe_context *pipe)
149 {
150 struct pipe_sampler_state templat;
151 void *s;
152
153 memset(&templat, 0, sizeof(templat));
154 templat.wrap_s = PIPE_TEX_WRAP_REPEAT;
155 templat.wrap_t = PIPE_TEX_WRAP_REPEAT;
156 templat.wrap_r = PIPE_TEX_WRAP_REPEAT;
157 templat.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
158 templat.min_img_filter = PIPE_TEX_FILTER_NEAREST;
159 templat.mag_img_filter = PIPE_TEX_FILTER_NEAREST;
160 templat.normalized_coords = 1;
161 templat.min_lod = 0.0f;
162 templat.max_lod = 0.0f;
163
164 s = pipe->create_sampler_state(pipe, &templat);
165 return s;
166 }
167
168
169
170 /**
171 * Subclass of tgsi_transform_context, used for transforming the
172 * user's fragment shader to add the extra texture sample and fragment kill
173 * instructions.
174 */
175 struct pstip_transform_context {
176 struct tgsi_transform_context base;
177 struct tgsi_shader_info info;
178 uint tempsUsed; /**< bitmask */
179 int wincoordInput;
180 unsigned wincoordFile;
181 int maxInput;
182 uint samplersUsed; /**< bitfield of samplers used */
183 int freeSampler; /** an available sampler for the pstipple */
184 int numImmed;
185 uint coordOrigin;
186 unsigned fixedUnit;
187 bool hasFixedUnit;
188 };
189
190
191 /**
192 * TGSI declaration transform callback.
193 * Track samplers used, temps used, inputs used.
194 */
195 static void
pstip_transform_decl(struct tgsi_transform_context * ctx,struct tgsi_full_declaration * decl)196 pstip_transform_decl(struct tgsi_transform_context *ctx,
197 struct tgsi_full_declaration *decl)
198 {
199 struct pstip_transform_context *pctx =
200 (struct pstip_transform_context *) ctx;
201
202 /* XXX we can use tgsi_shader_info instead of some of this */
203
204 if (decl->Declaration.File == TGSI_FILE_SAMPLER) {
205 uint i;
206 for (i = decl->Range.First; i <= decl->Range.Last; i++) {
207 pctx->samplersUsed |= 1u << i;
208 }
209 }
210 else if (decl->Declaration.File == pctx->wincoordFile) {
211 pctx->maxInput = MAX2(pctx->maxInput, (int) decl->Range.Last);
212 if (decl->Semantic.Name == TGSI_SEMANTIC_POSITION)
213 pctx->wincoordInput = (int) decl->Range.First;
214 }
215 else if (decl->Declaration.File == TGSI_FILE_TEMPORARY) {
216 uint i;
217 for (i = decl->Range.First; i <= decl->Range.Last; i++) {
218 pctx->tempsUsed |= (1 << i);
219 }
220 }
221
222 ctx->emit_declaration(ctx, decl);
223 }
224
225
226 static void
pstip_transform_immed(struct tgsi_transform_context * ctx,struct tgsi_full_immediate * immed)227 pstip_transform_immed(struct tgsi_transform_context *ctx,
228 struct tgsi_full_immediate *immed)
229 {
230 struct pstip_transform_context *pctx =
231 (struct pstip_transform_context *) ctx;
232 pctx->numImmed++;
233 ctx->emit_immediate(ctx, immed);
234 }
235
236
237 /**
238 * Find the lowest zero bit in the given word, or -1 if bitfield is all ones.
239 */
240 static int
free_bit(uint bitfield)241 free_bit(uint bitfield)
242 {
243 return ffs(~bitfield) - 1;
244 }
245
246
247 /**
248 * TGSI transform prolog
249 * Before the first instruction, insert our new code to sample the
250 * stipple texture (using the fragment coord register) then kill the
251 * fragment if the stipple texture bit is off.
252 *
253 * Insert:
254 * declare new registers
255 * MUL texTemp, INPUT[wincoord], 1/32;
256 * TEX texTemp, texTemp, sampler;
257 * KILL_IF -texTemp; # if -texTemp < 0, kill fragment
258 * [...original code...]
259 */
260 static void
pstip_transform_prolog(struct tgsi_transform_context * ctx)261 pstip_transform_prolog(struct tgsi_transform_context *ctx)
262 {
263 struct pstip_transform_context *pctx =
264 (struct pstip_transform_context *) ctx;
265 int wincoordInput;
266 int texTemp;
267 int sampIdx;
268
269 STATIC_ASSERT(sizeof(pctx->samplersUsed) * 8 >= PIPE_MAX_SAMPLERS);
270
271 /* find free texture sampler */
272 pctx->freeSampler = free_bit(pctx->samplersUsed);
273 if (pctx->freeSampler < 0 || pctx->freeSampler >= PIPE_MAX_SAMPLERS)
274 pctx->freeSampler = PIPE_MAX_SAMPLERS - 1;
275
276 if (pctx->wincoordInput < 0)
277 wincoordInput = pctx->maxInput + 1;
278 else
279 wincoordInput = pctx->wincoordInput;
280
281 if (pctx->wincoordInput < 0) {
282 struct tgsi_full_declaration decl;
283
284 decl = tgsi_default_full_declaration();
285 /* declare new position input reg */
286 decl.Declaration.File = pctx->wincoordFile;
287 decl.Declaration.Semantic = 1;
288 decl.Semantic.Name = TGSI_SEMANTIC_POSITION;
289 decl.Range.First =
290 decl.Range.Last = wincoordInput;
291
292 if (pctx->wincoordFile == TGSI_FILE_INPUT) {
293 decl.Declaration.Interpolate = 1;
294 decl.Interp.Interpolate = TGSI_INTERPOLATE_LINEAR;
295 }
296
297 ctx->emit_declaration(ctx, &decl);
298 }
299
300 sampIdx = pctx->hasFixedUnit ? (int)pctx->fixedUnit : pctx->freeSampler;
301
302 /* declare new sampler */
303 tgsi_transform_sampler_decl(ctx, sampIdx);
304
305 /* if the src shader has SVIEW decl's for each SAMP decl, we
306 * need to continue the trend and ensure there is a matching
307 * SVIEW for the new SAMP we just created
308 */
309 if (pctx->info.file_max[TGSI_FILE_SAMPLER_VIEW] != -1) {
310 tgsi_transform_sampler_view_decl(ctx,
311 sampIdx,
312 TGSI_TEXTURE_2D,
313 TGSI_RETURN_TYPE_FLOAT);
314 }
315
316 /* Declare temp[0] reg if not already declared.
317 * We can always use temp[0] since this code is before
318 * the rest of the shader.
319 */
320 texTemp = 0;
321 if ((pctx->tempsUsed & (1 << texTemp)) == 0) {
322 tgsi_transform_temp_decl(ctx, texTemp);
323 }
324
325 /* emit immediate = {1/32, 1/32, 1, 1}
326 * The index/position of this immediate will be pctx->numImmed
327 */
328 tgsi_transform_immediate_decl(ctx, 1.0/32.0, 1.0/32.0, 1.0, 1.0);
329
330 /*
331 * Insert new MUL/TEX/KILL_IF instructions at start of program
332 * Take gl_FragCoord, divide by 32 (stipple size), sample the
333 * texture and kill fragment if needed.
334 *
335 * We'd like to use non-normalized texcoords to index into a RECT
336 * texture, but we can only use REPEAT wrap mode with normalized
337 * texcoords. Darn.
338 */
339
340 /* XXX invert wincoord if origin isn't lower-left... */
341
342 /* MUL texTemp, INPUT[wincoord], 1/32; */
343 tgsi_transform_op2_inst(ctx, TGSI_OPCODE_MUL,
344 TGSI_FILE_TEMPORARY, texTemp,
345 TGSI_WRITEMASK_XYZW,
346 pctx->wincoordFile, wincoordInput,
347 TGSI_FILE_IMMEDIATE, pctx->numImmed, false);
348
349 /* TEX texTemp, texTemp, sampler, 2D; */
350 tgsi_transform_tex_inst(ctx,
351 TGSI_FILE_TEMPORARY, texTemp,
352 TGSI_FILE_TEMPORARY, texTemp,
353 TGSI_TEXTURE_2D, sampIdx);
354
355 /* KILL_IF -texTemp; # if -texTemp < 0, kill fragment */
356 tgsi_transform_kill_inst(ctx,
357 TGSI_FILE_TEMPORARY, texTemp,
358 TGSI_SWIZZLE_W, TRUE);
359 }
360
361
362 /**
363 * Given a fragment shader, return a new fragment shader which
364 * samples a stipple texture and executes KILL.
365 *
366 * \param samplerUnitOut returns the index of the sampler unit which
367 * will be used to sample the stipple texture;
368 * if NULL, the fixed unit is used
369 * \param fixedUnit fixed texture unit used for the stipple texture
370 * \param wincoordFile TGSI_FILE_INPUT or TGSI_FILE_SYSTEM_VALUE,
371 * depending on which one is supported by the driver
372 * for TGSI_SEMANTIC_POSITION in the fragment shader
373 */
374 struct tgsi_token *
util_pstipple_create_fragment_shader(const struct tgsi_token * tokens,unsigned * samplerUnitOut,unsigned fixedUnit,unsigned wincoordFile)375 util_pstipple_create_fragment_shader(const struct tgsi_token *tokens,
376 unsigned *samplerUnitOut,
377 unsigned fixedUnit,
378 unsigned wincoordFile)
379 {
380 struct pstip_transform_context transform;
381 const uint newLen = tgsi_num_tokens(tokens) + NUM_NEW_TOKENS;
382 struct tgsi_token *new_tokens;
383
384 new_tokens = tgsi_alloc_tokens(newLen);
385 if (!new_tokens) {
386 return NULL;
387 }
388
389 /* Setup shader transformation info/context.
390 */
391 memset(&transform, 0, sizeof(transform));
392 transform.wincoordInput = -1;
393 transform.wincoordFile = wincoordFile;
394 transform.maxInput = -1;
395 transform.coordOrigin = TGSI_FS_COORD_ORIGIN_UPPER_LEFT;
396 transform.hasFixedUnit = !samplerUnitOut;
397 transform.fixedUnit = fixedUnit;
398 transform.base.prolog = pstip_transform_prolog;
399 transform.base.transform_declaration = pstip_transform_decl;
400 transform.base.transform_immediate = pstip_transform_immed;
401
402 tgsi_scan_shader(tokens, &transform.info);
403
404 transform.coordOrigin =
405 transform.info.properties[TGSI_PROPERTY_FS_COORD_ORIGIN];
406
407 tgsi_transform_shader(tokens, new_tokens, newLen, &transform.base);
408
409 #if 0 /* DEBUG */
410 tgsi_dump(fs->tokens, 0);
411 tgsi_dump(new_fs->tokens, 0);
412 #endif
413
414 if (samplerUnitOut) {
415 assert(transform.freeSampler < PIPE_MAX_SAMPLERS);
416 *samplerUnitOut = transform.freeSampler;
417 }
418
419 return new_tokens;
420 }
421