sp_tex_sample.c revision 7925274da323d5a896b557181d4016e0391f026f
1/**************************************************************************
2 *
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
4 * All Rights Reserved.
5 * Copyright 2008 VMware, Inc.  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 TUNGSTEN GRAPHICS 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 * Texture sampling
31 *
32 * Authors:
33 *   Brian Paul
34 */
35
36#include "sp_context.h"
37#include "sp_quad.h"
38#include "sp_surface.h"
39#include "sp_texture.h"
40#include "sp_tex_sample.h"
41#include "sp_tile_cache.h"
42#include "pipe/p_context.h"
43#include "pipe/p_defines.h"
44#include "util/u_math.h"
45#include "util/u_memory.h"
46
47
48
49/*
50 * Note, the FRAC macro has to work perfectly.  Otherwise you'll sometimes
51 * see 1-pixel bands of improperly weighted linear-filtered textures.
52 * The tests/texwrap.c demo is a good test.
53 * Also note, FRAC(x) doesn't truly return the fractional part of x for x < 0.
54 * Instead, if x < 0 then FRAC(x) = 1 - true_frac(x).
55 */
56#define FRAC(f)  ((f) - util_ifloor(f))
57
58
59/**
60 * Linear interpolation macro
61 */
62static INLINE float
63lerp(float a, float v0, float v1)
64{
65   return v0 + a * (v1 - v0);
66}
67
68
69/**
70 * Do 2D/biliner interpolation of float values.
71 * v00, v10, v01 and v11 are typically four texture samples in a square/box.
72 * a and b are the horizontal and vertical interpolants.
73 * It's important that this function is inlined when compiled with
74 * optimization!  If we find that's not true on some systems, convert
75 * to a macro.
76 */
77static INLINE float
78lerp_2d(float a, float b,
79        float v00, float v10, float v01, float v11)
80{
81   const float temp0 = lerp(a, v00, v10);
82   const float temp1 = lerp(a, v01, v11);
83   return lerp(b, temp0, temp1);
84}
85
86
87/**
88 * As above, but 3D interpolation of 8 values.
89 */
90static INLINE float
91lerp_3d(float a, float b, float c,
92        float v000, float v100, float v010, float v110,
93        float v001, float v101, float v011, float v111)
94{
95   const float temp0 = lerp_2d(a, b, v000, v100, v010, v110);
96   const float temp1 = lerp_2d(a, b, v001, v101, v011, v111);
97   return lerp(c, temp0, temp1);
98}
99
100
101
102/**
103 * If A is a signed integer, A % B doesn't give the right value for A < 0
104 * (in terms of texture repeat).  Just casting to unsigned fixes that.
105 */
106#define REMAINDER(A, B) ((unsigned) (A) % (unsigned) (B))
107
108
109/**
110 * Apply texture coord wrapping mode and return integer texture indexes
111 * for a vector of four texcoords (S or T or P).
112 * \param wrapMode  PIPE_TEX_WRAP_x
113 * \param s  the incoming texcoords
114 * \param size  the texture image size
115 * \param icoord  returns the integer texcoords
116 * \return  integer texture index
117 */
118static INLINE void
119nearest_texcoord_4(unsigned wrapMode, const float s[4], unsigned size,
120                   int icoord[4])
121{
122   uint ch;
123   switch (wrapMode) {
124   case PIPE_TEX_WRAP_REPEAT:
125      /* s limited to [0,1) */
126      /* i limited to [0,size-1] */
127      for (ch = 0; ch < 4; ch++) {
128         int i = util_ifloor(s[ch] * size);
129         icoord[ch] = REMAINDER(i, size);
130      }
131      return;
132   case PIPE_TEX_WRAP_CLAMP:
133      /* s limited to [0,1] */
134      /* i limited to [0,size-1] */
135      for (ch = 0; ch < 4; ch++) {
136         if (s[ch] <= 0.0F)
137            icoord[ch] = 0;
138         else if (s[ch] >= 1.0F)
139            icoord[ch] = size - 1;
140         else
141            icoord[ch] = util_ifloor(s[ch] * size);
142      }
143      return;
144   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
145      {
146         /* s limited to [min,max] */
147         /* i limited to [0, size-1] */
148         const float min = 1.0F / (2.0F * size);
149         const float max = 1.0F - min;
150         for (ch = 0; ch < 4; ch++) {
151            if (s[ch] < min)
152               icoord[ch] = 0;
153            else if (s[ch] > max)
154               icoord[ch] = size - 1;
155            else
156               icoord[ch] = util_ifloor(s[ch] * size);
157         }
158      }
159      return;
160   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
161      {
162         /* s limited to [min,max] */
163         /* i limited to [-1, size] */
164         const float min = -1.0F / (2.0F * size);
165         const float max = 1.0F - min;
166         for (ch = 0; ch < 4; ch++) {
167            if (s[ch] <= min)
168               icoord[ch] = -1;
169            else if (s[ch] >= max)
170               icoord[ch] = size;
171            else
172               icoord[ch] = util_ifloor(s[ch] * size);
173         }
174      }
175      return;
176   case PIPE_TEX_WRAP_MIRROR_REPEAT:
177      {
178         const float min = 1.0F / (2.0F * size);
179         const float max = 1.0F - min;
180         for (ch = 0; ch < 4; ch++) {
181            const int flr = util_ifloor(s[ch]);
182            float u;
183            if (flr & 1)
184               u = 1.0F - (s[ch] - (float) flr);
185            else
186               u = s[ch] - (float) flr;
187            if (u < min)
188               icoord[ch] = 0;
189            else if (u > max)
190               icoord[ch] = size - 1;
191            else
192               icoord[ch] = util_ifloor(u * size);
193         }
194      }
195      return;
196   case PIPE_TEX_WRAP_MIRROR_CLAMP:
197      for (ch = 0; ch < 4; ch++) {
198         /* s limited to [0,1] */
199         /* i limited to [0,size-1] */
200         const float u = fabsf(s[ch]);
201         if (u <= 0.0F)
202            icoord[ch] = 0;
203         else if (u >= 1.0F)
204            icoord[ch] = size - 1;
205         else
206            icoord[ch] = util_ifloor(u * size);
207      }
208      return;
209   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
210      {
211         /* s limited to [min,max] */
212         /* i limited to [0, size-1] */
213         const float min = 1.0F / (2.0F * size);
214         const float max = 1.0F - min;
215         for (ch = 0; ch < 4; ch++) {
216            const float u = fabsf(s[ch]);
217            if (u < min)
218               icoord[ch] = 0;
219            else if (u > max)
220               icoord[ch] = size - 1;
221            else
222               icoord[ch] = util_ifloor(u * size);
223         }
224      }
225      return;
226   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
227      {
228         /* s limited to [min,max] */
229         /* i limited to [0, size-1] */
230         const float min = -1.0F / (2.0F * size);
231         const float max = 1.0F - min;
232         for (ch = 0; ch < 4; ch++) {
233            const float u = fabsf(s[ch]);
234            if (u < min)
235               icoord[ch] = -1;
236            else if (u > max)
237               icoord[ch] = size;
238            else
239               icoord[ch] = util_ifloor(u * size);
240         }
241      }
242      return;
243   default:
244      assert(0);
245   }
246}
247
248
249/**
250 * Used to compute texel locations for linear sampling for four texcoords.
251 * \param wrapMode  PIPE_TEX_WRAP_x
252 * \param s  the texcoords
253 * \param size  the texture image size
254 * \param icoord0  returns first texture indexes
255 * \param icoord1  returns second texture indexes (usually icoord0 + 1)
256 * \param w  returns blend factor/weight between texture indexes
257 * \param icoord  returns the computed integer texture coords
258 */
259static INLINE void
260linear_texcoord_4(unsigned wrapMode, const float s[4], unsigned size,
261                  int icoord0[4], int icoord1[4], float w[4])
262{
263   uint ch;
264
265   switch (wrapMode) {
266   case PIPE_TEX_WRAP_REPEAT:
267      for (ch = 0; ch < 4; ch++) {
268         float u = s[ch] * size - 0.5F;
269         icoord0[ch] = REMAINDER(util_ifloor(u), size);
270         icoord1[ch] = REMAINDER(icoord0[ch] + 1, size);
271         w[ch] = FRAC(u);
272      }
273      break;;
274   case PIPE_TEX_WRAP_CLAMP:
275      for (ch = 0; ch < 4; ch++) {
276         float u = CLAMP(s[ch], 0.0F, 1.0F);
277         u = u * size - 0.5f;
278         icoord0[ch] = util_ifloor(u);
279         icoord1[ch] = icoord0[ch] + 1;
280         w[ch] = FRAC(u);
281      }
282      break;;
283   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
284      for (ch = 0; ch < 4; ch++) {
285         float u = CLAMP(s[ch], 0.0F, 1.0F);
286         u = u * size - 0.5f;
287         icoord0[ch] = util_ifloor(u);
288         icoord1[ch] = icoord0[ch] + 1;
289         if (icoord0[ch] < 0)
290            icoord0[ch] = 0;
291         if (icoord1[ch] >= (int) size)
292            icoord1[ch] = size - 1;
293         w[ch] = FRAC(u);
294      }
295      break;;
296   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
297      {
298         const float min = -1.0F / (2.0F * size);
299         const float max = 1.0F - min;
300         for (ch = 0; ch < 4; ch++) {
301            float u = CLAMP(s[ch], min, max);
302            u = u * size - 0.5f;
303            icoord0[ch] = util_ifloor(u);
304            icoord1[ch] = icoord0[ch] + 1;
305            w[ch] = FRAC(u);
306         }
307      }
308      break;;
309   case PIPE_TEX_WRAP_MIRROR_REPEAT:
310      for (ch = 0; ch < 4; ch++) {
311         const int flr = util_ifloor(s[ch]);
312         float u;
313         if (flr & 1)
314            u = 1.0F - (s[ch] - (float) flr);
315         else
316            u = s[ch] - (float) flr;
317         u = u * size - 0.5F;
318         icoord0[ch] = util_ifloor(u);
319         icoord1[ch] = icoord0[ch] + 1;
320         if (icoord0[ch] < 0)
321            icoord0[ch] = 0;
322         if (icoord1[ch] >= (int) size)
323            icoord1[ch] = size - 1;
324         w[ch] = FRAC(u);
325      }
326      break;;
327   case PIPE_TEX_WRAP_MIRROR_CLAMP:
328      for (ch = 0; ch < 4; ch++) {
329         float u = fabsf(s[ch]);
330         if (u >= 1.0F)
331            u = (float) size;
332         else
333            u *= size;
334         u -= 0.5F;
335         icoord0[ch] = util_ifloor(u);
336         icoord1[ch] = icoord0[ch] + 1;
337         w[ch] = FRAC(u);
338      }
339      break;;
340   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
341      for (ch = 0; ch < 4; ch++) {
342         float u = fabsf(s[ch]);
343         if (u >= 1.0F)
344            u = (float) size;
345         else
346            u *= size;
347         u -= 0.5F;
348         icoord0[ch] = util_ifloor(u);
349         icoord1[ch] = icoord0[ch] + 1;
350         if (icoord0[ch] < 0)
351            icoord0[ch] = 0;
352         if (icoord1[ch] >= (int) size)
353            icoord1[ch] = size - 1;
354         w[ch] = FRAC(u);
355      }
356      break;;
357   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
358      {
359         const float min = -1.0F / (2.0F * size);
360         const float max = 1.0F - min;
361         for (ch = 0; ch < 4; ch++) {
362            float u = fabsf(s[ch]);
363            if (u <= min)
364               u = min * size;
365            else if (u >= max)
366               u = max * size;
367            else
368               u *= size;
369            u -= 0.5F;
370            icoord0[ch] = util_ifloor(u);
371            icoord1[ch] = icoord0[ch] + 1;
372            w[ch] = FRAC(u);
373         }
374      }
375      break;;
376   default:
377      assert(0);
378   }
379}
380
381
382/**
383 * For RECT textures / unnormalized texcoords
384 * Only a subset of wrap modes supported.
385 */
386static INLINE void
387nearest_texcoord_unnorm_4(unsigned wrapMode, const float s[4], unsigned size,
388                          int icoord[4])
389{
390   uint ch;
391   switch (wrapMode) {
392   case PIPE_TEX_WRAP_CLAMP:
393      for (ch = 0; ch < 4; ch++) {
394         int i = util_ifloor(s[ch]);
395         icoord[ch]= CLAMP(i, 0, (int) size-1);
396      }
397      return;
398   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
399      /* fall-through */
400   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
401      for (ch = 0; ch < 4; ch++) {
402         icoord[ch]= util_ifloor( CLAMP(s[ch], 0.5F, (float) size - 0.5F) );
403      }
404      return;
405   default:
406      assert(0);
407   }
408}
409
410
411/**
412 * For RECT textures / unnormalized texcoords.
413 * Only a subset of wrap modes supported.
414 */
415static INLINE void
416linear_texcoord_unnorm_4(unsigned wrapMode, const float s[4], unsigned size,
417                         int icoord0[4], int icoord1[4], float w[4])
418{
419   uint ch;
420   switch (wrapMode) {
421   case PIPE_TEX_WRAP_CLAMP:
422      for (ch = 0; ch < 4; ch++) {
423         /* Not exactly what the spec says, but it matches NVIDIA output */
424         float u = CLAMP(s[ch] - 0.5F, 0.0f, (float) size - 1.0f);
425         icoord0[ch] = util_ifloor(u);
426         icoord1[ch] = icoord0[ch] + 1;
427         w[ch] = FRAC(u);
428      }
429      return;
430   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
431      /* fall-through */
432   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
433      for (ch = 0; ch < 4; ch++) {
434         float u = CLAMP(s[ch], 0.5F, (float) size - 0.5F);
435         u -= 0.5F;
436         icoord0[ch] = util_ifloor(u);
437         icoord1[ch] = icoord0[ch] + 1;
438         if (icoord1[ch] > (int) size - 1)
439            icoord1[ch] = size - 1;
440         w[ch] = FRAC(u);
441      }
442      break;
443   default:
444      assert(0);
445   }
446}
447
448
449static unsigned
450choose_cube_face(float rx, float ry, float rz, float *newS, float *newT)
451{
452   /*
453      major axis
454      direction     target                             sc     tc    ma
455      ----------    -------------------------------    ---    ---   ---
456       +rx          TEXTURE_CUBE_MAP_POSITIVE_X_EXT    -rz    -ry   rx
457       -rx          TEXTURE_CUBE_MAP_NEGATIVE_X_EXT    +rz    -ry   rx
458       +ry          TEXTURE_CUBE_MAP_POSITIVE_Y_EXT    +rx    +rz   ry
459       -ry          TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT    +rx    -rz   ry
460       +rz          TEXTURE_CUBE_MAP_POSITIVE_Z_EXT    +rx    -ry   rz
461       -rz          TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT    -rx    -ry   rz
462   */
463   const float arx = fabsf(rx), ary = fabsf(ry), arz = fabsf(rz);
464   unsigned face;
465   float sc, tc, ma;
466
467   if (arx > ary && arx > arz) {
468      if (rx >= 0.0F) {
469         face = PIPE_TEX_FACE_POS_X;
470         sc = -rz;
471         tc = -ry;
472         ma = arx;
473      }
474      else {
475         face = PIPE_TEX_FACE_NEG_X;
476         sc = rz;
477         tc = -ry;
478         ma = arx;
479      }
480   }
481   else if (ary > arx && ary > arz) {
482      if (ry >= 0.0F) {
483         face = PIPE_TEX_FACE_POS_Y;
484         sc = rx;
485         tc = rz;
486         ma = ary;
487      }
488      else {
489         face = PIPE_TEX_FACE_NEG_Y;
490         sc = rx;
491         tc = -rz;
492         ma = ary;
493      }
494   }
495   else {
496      if (rz > 0.0F) {
497         face = PIPE_TEX_FACE_POS_Z;
498         sc = rx;
499         tc = -ry;
500         ma = arz;
501      }
502      else {
503         face = PIPE_TEX_FACE_NEG_Z;
504         sc = -rx;
505         tc = -ry;
506         ma = arz;
507      }
508   }
509
510   *newS = ( sc / ma + 1.0F ) * 0.5F;
511   *newT = ( tc / ma + 1.0F ) * 0.5F;
512
513   return face;
514}
515
516
517/**
518 * Examine the quad's texture coordinates to compute the partial
519 * derivatives w.r.t X and Y, then compute lambda (level of detail).
520 *
521 * This is only done for fragment shaders, not vertex shaders.
522 */
523static float
524compute_lambda(const struct pipe_texture *tex,
525               const struct pipe_sampler_state *sampler,
526               const float s[QUAD_SIZE],
527               const float t[QUAD_SIZE],
528               const float p[QUAD_SIZE],
529               float lodbias)
530{
531   float rho, lambda;
532
533   assert(sampler->normalized_coords);
534
535   assert(s);
536   {
537      float dsdx = s[QUAD_BOTTOM_RIGHT] - s[QUAD_BOTTOM_LEFT];
538      float dsdy = s[QUAD_TOP_LEFT]     - s[QUAD_BOTTOM_LEFT];
539      dsdx = fabsf(dsdx);
540      dsdy = fabsf(dsdy);
541      rho = MAX2(dsdx, dsdy) * tex->width[0];
542   }
543   if (t) {
544      float dtdx = t[QUAD_BOTTOM_RIGHT] - t[QUAD_BOTTOM_LEFT];
545      float dtdy = t[QUAD_TOP_LEFT]     - t[QUAD_BOTTOM_LEFT];
546      float max;
547      dtdx = fabsf(dtdx);
548      dtdy = fabsf(dtdy);
549      max = MAX2(dtdx, dtdy) * tex->height[0];
550      rho = MAX2(rho, max);
551   }
552   if (p) {
553      float dpdx = p[QUAD_BOTTOM_RIGHT] - p[QUAD_BOTTOM_LEFT];
554      float dpdy = p[QUAD_TOP_LEFT]     - p[QUAD_BOTTOM_LEFT];
555      float max;
556      dpdx = fabsf(dpdx);
557      dpdy = fabsf(dpdy);
558      max = MAX2(dpdx, dpdy) * tex->depth[0];
559      rho = MAX2(rho, max);
560   }
561
562   lambda = util_fast_log2(rho);
563   lambda += lodbias + sampler->lod_bias;
564   lambda = CLAMP(lambda, sampler->min_lod, sampler->max_lod);
565
566   return lambda;
567}
568
569
570/**
571 * Do several things here:
572 * 1. Compute lambda from the texcoords, if needed
573 * 2. Determine if we're minifying or magnifying
574 * 3. If minifying, choose mipmap levels
575 * 4. Return image filter to use within mipmap images
576 * \param level0  Returns first mipmap level to sample from
577 * \param level1  Returns second mipmap level to sample from
578 * \param levelBlend  Returns blend factor between levels, in [0,1]
579 * \param imgFilter  Returns either the min or mag filter, depending on lambda
580 */
581static void
582choose_mipmap_levels(const struct pipe_texture *texture,
583                     const struct pipe_sampler_state *sampler,
584                     const float s[QUAD_SIZE],
585                     const float t[QUAD_SIZE],
586                     const float p[QUAD_SIZE],
587                     boolean computeLambda,
588                     float lodbias,
589                     unsigned *level0, unsigned *level1, float *levelBlend,
590                     unsigned *imgFilter)
591{
592   if (sampler->min_mip_filter == PIPE_TEX_MIPFILTER_NONE) {
593      /* no mipmap selection needed */
594      *level0 = *level1 = CLAMP((int) sampler->min_lod,
595                                0, (int) texture->last_level);
596
597      if (sampler->min_img_filter != sampler->mag_img_filter) {
598         /* non-mipmapped texture, but still need to determine if doing
599          * minification or magnification.
600          */
601         float lambda = compute_lambda(texture, sampler, s, t, p, lodbias);
602         if (lambda <= 0.0) {
603            *imgFilter = sampler->mag_img_filter;
604         }
605         else {
606            *imgFilter = sampler->min_img_filter;
607         }
608      }
609      else {
610         *imgFilter = sampler->mag_img_filter;
611      }
612   }
613   else {
614      float lambda;
615
616      if (computeLambda)
617         /* fragment shader */
618         lambda = compute_lambda(texture, sampler, s, t, p, lodbias);
619      else
620         /* vertex shader */
621         lambda = lodbias; /* not really a bias, but absolute LOD */
622
623      if (lambda <= 0.0) { /* XXX threshold depends on the filter */
624         /* magnifying */
625         *imgFilter = sampler->mag_img_filter;
626         *level0 = *level1 = 0;
627      }
628      else {
629         /* minifying */
630         *imgFilter = sampler->min_img_filter;
631
632         /* choose mipmap level(s) and compute the blend factor between them */
633         if (sampler->min_mip_filter == PIPE_TEX_MIPFILTER_NEAREST) {
634            /* Nearest mipmap level */
635            const int lvl = (int) (lambda + 0.5);
636            *level0 =
637            *level1 = CLAMP(lvl, 0, (int) texture->last_level);
638         }
639         else {
640            /* Linear interpolation between mipmap levels */
641            const int lvl = (int) lambda;
642            *level0 = CLAMP(lvl,     0, (int) texture->last_level);
643            *level1 = CLAMP(lvl + 1, 0, (int) texture->last_level);
644            *levelBlend = FRAC(lambda);  /* blending weight between levels */
645         }
646      }
647   }
648}
649
650
651/**
652 * Get a texel from a texture, using the texture tile cache.
653 *
654 * \param face  the cube face in 0..5
655 * \param level  the mipmap level
656 * \param x  the x coord of texel within 2D image
657 * \param y  the y coord of texel within 2D image
658 * \param z  which slice of a 3D texture
659 * \param rgba  the quad to put the texel/color into
660 * \param j  which element of the rgba quad to write to
661 *
662 * XXX maybe move this into sp_tile_cache.c and merge with the
663 * sp_get_cached_tile_tex() function.  Also, get 4 texels instead of 1...
664 */
665static void
666get_texel(const struct tgsi_sampler *tgsi_sampler,
667          unsigned face, unsigned level, int x, int y, int z,
668          float rgba[NUM_CHANNELS][QUAD_SIZE], unsigned j)
669{
670   const struct sp_shader_sampler *samp = sp_shader_sampler(tgsi_sampler);
671   struct softpipe_context *sp = samp->sp;
672   const uint unit = samp->unit;
673   const struct pipe_texture *texture = sp->texture[unit];
674   const struct pipe_sampler_state *sampler = sp->sampler[unit];
675
676   if (x < 0 || x >= (int) texture->width[level] ||
677       y < 0 || y >= (int) texture->height[level] ||
678       z < 0 || z >= (int) texture->depth[level]) {
679      rgba[0][j] = sampler->border_color[0];
680      rgba[1][j] = sampler->border_color[1];
681      rgba[2][j] = sampler->border_color[2];
682      rgba[3][j] = sampler->border_color[3];
683   }
684   else {
685      const int tx = x % TILE_SIZE;
686      const int ty = y % TILE_SIZE;
687      const struct softpipe_cached_tile *tile
688         = sp_get_cached_tile_tex(sp, samp->cache,
689                                  x, y, z, face, level);
690      rgba[0][j] = tile->data.color[ty][tx][0];
691      rgba[1][j] = tile->data.color[ty][tx][1];
692      rgba[2][j] = tile->data.color[ty][tx][2];
693      rgba[3][j] = tile->data.color[ty][tx][3];
694      if (0)
695      {
696         debug_printf("Get texel %f %f %f %f from %s\n",
697                      rgba[0][j], rgba[1][j], rgba[2][j], rgba[3][j],
698                      pf_name(texture->format));
699      }
700   }
701}
702
703
704/**
705 * Compare texcoord 'p' (aka R) against texture value 'rgba[0]'
706 * When we sampled the depth texture, the depth value was put into all
707 * RGBA channels.  We look at the red channel here.
708 */
709static INLINE void
710shadow_compare(uint compare_func,
711               float rgba[NUM_CHANNELS][QUAD_SIZE],
712               const float p[QUAD_SIZE],
713               uint j)
714{
715   int k;
716   switch (compare_func) {
717   case PIPE_FUNC_LESS:
718      k = p[j] < rgba[0][j];
719      break;
720   case PIPE_FUNC_LEQUAL:
721      k = p[j] <= rgba[0][j];
722      break;
723   case PIPE_FUNC_GREATER:
724      k = p[j] > rgba[0][j];
725      break;
726   case PIPE_FUNC_GEQUAL:
727      k = p[j] >= rgba[0][j];
728      break;
729   case PIPE_FUNC_EQUAL:
730      k = p[j] == rgba[0][j];
731      break;
732   case PIPE_FUNC_NOTEQUAL:
733      k = p[j] != rgba[0][j];
734      break;
735   case PIPE_FUNC_ALWAYS:
736      k = 1;
737      break;
738   case PIPE_FUNC_NEVER:
739      k = 0;
740      break;
741   default:
742      k = 0;
743      assert(0);
744      break;
745   }
746
747   rgba[0][j] = rgba[1][j] = rgba[2][j] = (float) k;
748}
749
750
751/**
752 * Common code for sampling 1D/2D/cube textures.
753 * Could probably extend for 3D...
754 */
755static void
756sp_get_samples_2d_common(const struct tgsi_sampler *tgsi_sampler,
757                         const float s[QUAD_SIZE],
758                         const float t[QUAD_SIZE],
759                         const float p[QUAD_SIZE],
760                         boolean computeLambda,
761                         float lodbias,
762                         float rgba[NUM_CHANNELS][QUAD_SIZE],
763                         const unsigned faces[4])
764{
765   const struct sp_shader_sampler *samp = sp_shader_sampler(tgsi_sampler);
766   const struct softpipe_context *sp = samp->sp;
767   const uint unit = samp->unit;
768   const struct pipe_texture *texture = sp->texture[unit];
769   const struct pipe_sampler_state *sampler = sp->sampler[unit];
770   const uint compare_func = sampler->compare_func;
771   unsigned level0, level1, j, imgFilter;
772   int width, height;
773   float levelBlend;
774
775   choose_mipmap_levels(texture, sampler, s, t, p, computeLambda, lodbias,
776                        &level0, &level1, &levelBlend, &imgFilter);
777
778   assert(sampler->normalized_coords);
779
780   width = texture->width[level0];
781   height = texture->height[level0];
782
783   assert(width > 0);
784
785   switch (imgFilter) {
786   case PIPE_TEX_FILTER_NEAREST:
787      {
788         int x[4], y[4];
789         nearest_texcoord_4(sampler->wrap_s, s, width, x);
790         nearest_texcoord_4(sampler->wrap_t, t, height, y);
791
792         for (j = 0; j < QUAD_SIZE; j++) {
793            get_texel(tgsi_sampler, faces[j], level0, x[j], y[j], 0, rgba, j);
794            if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
795               shadow_compare(compare_func, rgba, p, j);
796            }
797
798            if (level0 != level1) {
799               /* get texels from second mipmap level and blend */
800               float rgba2[4][4];
801               unsigned c;
802               x[j] /= 2;
803               y[j] /= 2;
804               get_texel(tgsi_sampler, faces[j], level1, x[j], y[j], 0,
805                         rgba2, j);
806               if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE){
807                  shadow_compare(compare_func, rgba2, p, j);
808               }
809
810               for (c = 0; c < NUM_CHANNELS; c++) {
811                  rgba[c][j] = lerp(levelBlend, rgba[c][j], rgba2[c][j]);
812               }
813            }
814         }
815      }
816      break;
817   case PIPE_TEX_FILTER_LINEAR:
818   case PIPE_TEX_FILTER_ANISO:
819      {
820         int x0[4], y0[4], x1[4], y1[4];
821         float xw[4], yw[4]; /* weights */
822
823         linear_texcoord_4(sampler->wrap_s, s, width, x0, x1, xw);
824         linear_texcoord_4(sampler->wrap_t, t, height, y0, y1, yw);
825
826         for (j = 0; j < QUAD_SIZE; j++) {
827            float tx[4][4]; /* texels */
828            int c;
829            get_texel(tgsi_sampler, faces[j], level0, x0[j], y0[j], 0, tx, 0);
830            get_texel(tgsi_sampler, faces[j], level0, x1[j], y0[j], 0, tx, 1);
831            get_texel(tgsi_sampler, faces[j], level0, x0[j], y1[j], 0, tx, 2);
832            get_texel(tgsi_sampler, faces[j], level0, x1[j], y1[j], 0, tx, 3);
833            if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
834               shadow_compare(compare_func, tx, p, 0);
835               shadow_compare(compare_func, tx, p, 1);
836               shadow_compare(compare_func, tx, p, 2);
837               shadow_compare(compare_func, tx, p, 3);
838            }
839
840            /* interpolate R, G, B, A */
841            for (c = 0; c < 4; c++) {
842               rgba[c][j] = lerp_2d(xw[j], yw[j],
843                                    tx[c][0], tx[c][1],
844                                    tx[c][2], tx[c][3]);
845            }
846
847            if (level0 != level1) {
848               /* get texels from second mipmap level and blend */
849               float rgba2[4][4];
850               x0[j] /= 2;
851               y0[j] /= 2;
852               x1[j] /= 2;
853               y1[j] /= 2;
854               get_texel(tgsi_sampler, faces[j], level1, x0[j], y0[j], 0, tx, 0);
855               get_texel(tgsi_sampler, faces[j], level1, x1[j], y0[j], 0, tx, 1);
856               get_texel(tgsi_sampler, faces[j], level1, x0[j], y1[j], 0, tx, 2);
857               get_texel(tgsi_sampler, faces[j], level1, x1[j], y1[j], 0, tx, 3);
858               if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE){
859                  shadow_compare(compare_func, tx, p, 0);
860                  shadow_compare(compare_func, tx, p, 1);
861                  shadow_compare(compare_func, tx, p, 2);
862                  shadow_compare(compare_func, tx, p, 3);
863               }
864
865               /* interpolate R, G, B, A */
866               for (c = 0; c < 4; c++) {
867                  rgba2[c][j] = lerp_2d(xw[j], yw[j],
868                                        tx[c][0], tx[c][1], tx[c][2], tx[c][3]);
869               }
870
871               for (c = 0; c < NUM_CHANNELS; c++) {
872                  rgba[c][j] = lerp(levelBlend, rgba[c][j], rgba2[c][j]);
873               }
874            }
875         }
876      }
877      break;
878   default:
879      assert(0);
880   }
881}
882
883
884static INLINE void
885sp_get_samples_1d(const struct tgsi_sampler *sampler,
886                  const float s[QUAD_SIZE],
887                  const float t[QUAD_SIZE],
888                  const float p[QUAD_SIZE],
889                  boolean computeLambda,
890                  float lodbias,
891                  float rgba[NUM_CHANNELS][QUAD_SIZE])
892{
893   static const unsigned faces[4] = {0, 0, 0, 0};
894   static const float tzero[4] = {0, 0, 0, 0};
895   sp_get_samples_2d_common(sampler, s, tzero, NULL,
896                            computeLambda, lodbias, rgba, faces);
897}
898
899
900static INLINE void
901sp_get_samples_2d(const struct tgsi_sampler *sampler,
902                  const float s[QUAD_SIZE],
903                  const float t[QUAD_SIZE],
904                  const float p[QUAD_SIZE],
905                  boolean computeLambda,
906                  float lodbias,
907                  float rgba[NUM_CHANNELS][QUAD_SIZE])
908{
909   static const unsigned faces[4] = {0, 0, 0, 0};
910   sp_get_samples_2d_common(sampler, s, t, p,
911                            computeLambda, lodbias, rgba, faces);
912}
913
914
915static INLINE void
916sp_get_samples_3d(const struct tgsi_sampler *tgsi_sampler,
917                  const float s[QUAD_SIZE],
918                  const float t[QUAD_SIZE],
919                  const float p[QUAD_SIZE],
920                  boolean computeLambda,
921                  float lodbias,
922                  float rgba[NUM_CHANNELS][QUAD_SIZE])
923{
924   const struct sp_shader_sampler *samp = sp_shader_sampler(tgsi_sampler);
925   const struct softpipe_context *sp = samp->sp;
926   const uint unit = samp->unit;
927   const struct pipe_texture *texture = sp->texture[unit];
928   const struct pipe_sampler_state *sampler = sp->sampler[unit];
929   /* get/map pipe_surfaces corresponding to 3D tex slices */
930   unsigned level0, level1, j, imgFilter;
931   int width, height, depth;
932   float levelBlend;
933   const uint face = 0;
934
935   choose_mipmap_levels(texture, sampler, s, t, p, computeLambda, lodbias,
936                        &level0, &level1, &levelBlend, &imgFilter);
937
938   assert(sampler->normalized_coords);
939
940   width = texture->width[level0];
941   height = texture->height[level0];
942   depth = texture->depth[level0];
943
944   assert(width > 0);
945   assert(height > 0);
946   assert(depth > 0);
947
948   switch (imgFilter) {
949   case PIPE_TEX_FILTER_NEAREST:
950      {
951         int x[4], y[4], z[4];
952         nearest_texcoord_4(sampler->wrap_s, s, width, x);
953         nearest_texcoord_4(sampler->wrap_t, t, height, y);
954         nearest_texcoord_4(sampler->wrap_r, p, depth, z);
955         for (j = 0; j < QUAD_SIZE; j++) {
956            get_texel(tgsi_sampler, face, level0, x[j], y[j], z[j], rgba, j);
957            if (level0 != level1) {
958               /* get texels from second mipmap level and blend */
959               float rgba2[4][4];
960               unsigned c;
961               x[j] /= 2;
962               y[j] /= 2;
963               z[j] /= 2;
964               get_texel(tgsi_sampler, face, level1, x[j], y[j], z[j], rgba2, j);
965               for (c = 0; c < NUM_CHANNELS; c++) {
966                  rgba[c][j] = lerp(levelBlend, rgba2[c][j], rgba[c][j]);
967               }
968            }
969         }
970      }
971      break;
972   case PIPE_TEX_FILTER_LINEAR:
973   case PIPE_TEX_FILTER_ANISO:
974      {
975         int x0[4], x1[4], y0[4], y1[4], z0[4], z1[4];
976         float xw[4], yw[4], zw[4]; /* interpolation weights */
977         linear_texcoord_4(sampler->wrap_s, s, width,  x0, x1, xw);
978         linear_texcoord_4(sampler->wrap_t, t, height, y0, y1, yw);
979         linear_texcoord_4(sampler->wrap_r, p, depth,  z0, z1, zw);
980
981         for (j = 0; j < QUAD_SIZE; j++) {
982            int c;
983            float tx0[4][4], tx1[4][4];
984            get_texel(tgsi_sampler, face, level0, x0[j], y0[j], z0[j], tx0, 0);
985            get_texel(tgsi_sampler, face, level0, x1[j], y0[j], z0[j], tx0, 1);
986            get_texel(tgsi_sampler, face, level0, x0[j], y1[j], z0[j], tx0, 2);
987            get_texel(tgsi_sampler, face, level0, x1[j], y1[j], z0[j], tx0, 3);
988            get_texel(tgsi_sampler, face, level0, x0[j], y0[j], z1[j], tx1, 0);
989            get_texel(tgsi_sampler, face, level0, x1[j], y0[j], z1[j], tx1, 1);
990            get_texel(tgsi_sampler, face, level0, x0[j], y1[j], z1[j], tx1, 2);
991            get_texel(tgsi_sampler, face, level0, x1[j], y1[j], z1[j], tx1, 3);
992
993            /* interpolate R, G, B, A */
994            for (c = 0; c < 4; c++) {
995               rgba[c][j] = lerp_3d(xw[j], yw[j], zw[j],
996                                    tx0[c][0], tx0[c][1],
997                                    tx0[c][2], tx0[c][3],
998                                    tx1[c][0], tx1[c][1],
999                                    tx1[c][2], tx1[c][3]);
1000            }
1001
1002            if (level0 != level1) {
1003               /* get texels from second mipmap level and blend */
1004               float rgba2[4][4];
1005               x0[j] /= 2;
1006               y0[j] /= 2;
1007               z0[j] /= 2;
1008               x1[j] /= 2;
1009               y1[j] /= 2;
1010               z1[j] /= 2;
1011               get_texel(tgsi_sampler, face, level1, x0[j], y0[j], z0[j], tx0, 0);
1012               get_texel(tgsi_sampler, face, level1, x1[j], y0[j], z0[j], tx0, 1);
1013               get_texel(tgsi_sampler, face, level1, x0[j], y1[j], z0[j], tx0, 2);
1014               get_texel(tgsi_sampler, face, level1, x1[j], y1[j], z0[j], tx0, 3);
1015               get_texel(tgsi_sampler, face, level1, x0[j], y0[j], z1[j], tx1, 0);
1016               get_texel(tgsi_sampler, face, level1, x1[j], y0[j], z1[j], tx1, 1);
1017               get_texel(tgsi_sampler, face, level1, x0[j], y1[j], z1[j], tx1, 2);
1018               get_texel(tgsi_sampler, face, level1, x1[j], y1[j], z1[j], tx1, 3);
1019
1020               /* interpolate R, G, B, A */
1021               for (c = 0; c < 4; c++) {
1022                  rgba2[c][j] = lerp_3d(xw[j], yw[j], zw[j],
1023                                        tx0[c][0], tx0[c][1],
1024                                        tx0[c][2], tx0[c][3],
1025                                        tx1[c][0], tx1[c][1],
1026                                        tx1[c][2], tx1[c][3]);
1027               }
1028
1029               /* blend mipmap levels */
1030               for (c = 0; c < NUM_CHANNELS; c++) {
1031                  rgba[c][j] = lerp(levelBlend, rgba[c][j], rgba2[c][j]);
1032               }
1033            }
1034         }
1035      }
1036      break;
1037   default:
1038      assert(0);
1039   }
1040}
1041
1042
1043static void
1044sp_get_samples_cube(const struct tgsi_sampler *sampler,
1045                    const float s[QUAD_SIZE],
1046                    const float t[QUAD_SIZE],
1047                    const float p[QUAD_SIZE],
1048                    boolean computeLambda,
1049                    float lodbias,
1050                    float rgba[NUM_CHANNELS][QUAD_SIZE])
1051{
1052   unsigned faces[QUAD_SIZE], j;
1053   float ssss[4], tttt[4];
1054   for (j = 0; j < QUAD_SIZE; j++) {
1055      faces[j] = choose_cube_face(s[j], t[j], p[j], ssss + j, tttt + j);
1056   }
1057   sp_get_samples_2d_common(sampler, ssss, tttt, NULL,
1058                            computeLambda, lodbias, rgba, faces);
1059}
1060
1061
1062static void
1063sp_get_samples_rect(const struct tgsi_sampler *tgsi_sampler,
1064                    const float s[QUAD_SIZE],
1065                    const float t[QUAD_SIZE],
1066                    const float p[QUAD_SIZE],
1067                    boolean computeLambda,
1068                    float lodbias,
1069                    float rgba[NUM_CHANNELS][QUAD_SIZE])
1070{
1071   const struct sp_shader_sampler *samp = sp_shader_sampler(tgsi_sampler);
1072   const struct softpipe_context *sp = samp->sp;
1073   const uint unit = samp->unit;
1074   const struct pipe_texture *texture = sp->texture[unit];
1075   const struct pipe_sampler_state *sampler = sp->sampler[unit];
1076   const uint face = 0;
1077   const uint compare_func = sampler->compare_func;
1078   unsigned level0, level1, j, imgFilter;
1079   int width, height;
1080   float levelBlend;
1081
1082   choose_mipmap_levels(texture, sampler, s, t, p, computeLambda, lodbias,
1083                        &level0, &level1, &levelBlend, &imgFilter);
1084
1085   /* texture RECTS cannot be mipmapped */
1086   assert(level0 == level1);
1087
1088   width = texture->width[level0];
1089   height = texture->height[level0];
1090
1091   assert(width > 0);
1092
1093   switch (imgFilter) {
1094   case PIPE_TEX_FILTER_NEAREST:
1095      {
1096         int x[4], y[4];
1097         nearest_texcoord_unnorm_4(sampler->wrap_s, s, width, x);
1098         nearest_texcoord_unnorm_4(sampler->wrap_t, t, height, y);
1099         for (j = 0; j < QUAD_SIZE; j++) {
1100            get_texel(tgsi_sampler, face, level0, x[j], y[j], 0, rgba, j);
1101            if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
1102               shadow_compare(compare_func, rgba, p, j);
1103            }
1104         }
1105      }
1106      break;
1107   case PIPE_TEX_FILTER_LINEAR:
1108   case PIPE_TEX_FILTER_ANISO:
1109      {
1110         int x0[4], y0[4], x1[4], y1[4];
1111         float xw[4], yw[4]; /* weights */
1112         linear_texcoord_unnorm_4(sampler->wrap_s, s, width,  x0, x1, xw);
1113         linear_texcoord_unnorm_4(sampler->wrap_t, t, height, y0, y1, yw);
1114         for (j = 0; j < QUAD_SIZE; j++) {
1115            float tx[4][4]; /* texels */
1116            int c;
1117            get_texel(tgsi_sampler, face, level0, x0[j], y0[j], 0, tx, 0);
1118            get_texel(tgsi_sampler, face, level0, x1[j], y0[j], 0, tx, 1);
1119            get_texel(tgsi_sampler, face, level0, x0[j], y1[j], 0, tx, 2);
1120            get_texel(tgsi_sampler, face, level0, x1[j], y1[j], 0, tx, 3);
1121            if (sampler->compare_mode == PIPE_TEX_COMPARE_R_TO_TEXTURE) {
1122               shadow_compare(compare_func, tx, p, 0);
1123               shadow_compare(compare_func, tx, p, 1);
1124               shadow_compare(compare_func, tx, p, 2);
1125               shadow_compare(compare_func, tx, p, 3);
1126            }
1127            for (c = 0; c < 4; c++) {
1128               rgba[c][j] = lerp_2d(xw[j], yw[j],
1129                                    tx[c][0], tx[c][1], tx[c][2], tx[c][3]);
1130            }
1131         }
1132      }
1133      break;
1134   default:
1135      assert(0);
1136   }
1137}
1138
1139
1140/**
1141 * Common code for vertex/fragment program texture sampling.
1142 */
1143static INLINE void
1144sp_get_samples(struct tgsi_sampler *tgsi_sampler,
1145               const float s[QUAD_SIZE],
1146               const float t[QUAD_SIZE],
1147               const float p[QUAD_SIZE],
1148               boolean computeLambda,
1149               float lodbias,
1150               float rgba[NUM_CHANNELS][QUAD_SIZE])
1151{
1152   const struct sp_shader_sampler *samp = sp_shader_sampler(tgsi_sampler);
1153   const struct softpipe_context *sp = samp->sp;
1154   const uint unit = samp->unit;
1155   const struct pipe_texture *texture = sp->texture[unit];
1156   const struct pipe_sampler_state *sampler = sp->sampler[unit];
1157
1158   if (!texture)
1159      return;
1160
1161   switch (texture->target) {
1162   case PIPE_TEXTURE_1D:
1163      assert(sampler->normalized_coords);
1164      sp_get_samples_1d(tgsi_sampler, s, t, p, computeLambda, lodbias, rgba);
1165      break;
1166   case PIPE_TEXTURE_2D:
1167      if (sampler->normalized_coords)
1168         sp_get_samples_2d(tgsi_sampler, s, t, p, computeLambda, lodbias, rgba);
1169      else
1170         sp_get_samples_rect(tgsi_sampler, s, t, p, computeLambda, lodbias, rgba);
1171      break;
1172   case PIPE_TEXTURE_3D:
1173      assert(sampler->normalized_coords);
1174      sp_get_samples_3d(tgsi_sampler, s, t, p, computeLambda, lodbias, rgba);
1175      break;
1176   case PIPE_TEXTURE_CUBE:
1177      assert(sampler->normalized_coords);
1178      sp_get_samples_cube(tgsi_sampler, s, t, p, computeLambda, lodbias, rgba);
1179      break;
1180   default:
1181      assert(0);
1182   }
1183
1184#if 0 /* DEBUG */
1185   {
1186      int i;
1187      printf("Sampled at %f, %f, %f:\n", s[0], t[0], p[0]);
1188      for (i = 0; i < 4; i++) {
1189         printf("Frag %d: %f %f %f %f\n", i,
1190                rgba[0][i],
1191                rgba[1][i],
1192                rgba[2][i],
1193                rgba[3][i]);
1194      }
1195   }
1196#endif
1197}
1198
1199
1200/**
1201 * Called via tgsi_sampler::get_samples() when running a fragment shader.
1202 * Get four filtered RGBA values from the sampler's texture.
1203 */
1204void
1205sp_get_samples_fragment(struct tgsi_sampler *tgsi_sampler,
1206                        const float s[QUAD_SIZE],
1207                        const float t[QUAD_SIZE],
1208                        const float p[QUAD_SIZE],
1209                        float lodbias,
1210                        float rgba[NUM_CHANNELS][QUAD_SIZE])
1211{
1212   sp_get_samples(tgsi_sampler, s, t, p, TRUE, lodbias, rgba);
1213}
1214
1215
1216/**
1217 * Called via tgsi_sampler::get_samples() when running a vertex shader.
1218 * Get four filtered RGBA values from the sampler's texture.
1219 */
1220void
1221sp_get_samples_vertex(struct tgsi_sampler *tgsi_sampler,
1222                      const float s[QUAD_SIZE],
1223                      const float t[QUAD_SIZE],
1224                      const float p[QUAD_SIZE],
1225                      float lodbias,
1226                      float rgba[NUM_CHANNELS][QUAD_SIZE])
1227{
1228   sp_get_samples(tgsi_sampler, s, t, p, FALSE, lodbias, rgba);
1229}
1230