src/mesa/main/texfetch.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.7
   4  *
   5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   6  * Copyright (c) 2009  VMware, Inc.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions 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 MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file texfetch.c
  29  *
  30  * Texel fetch/store functions
  31  *
  32  * \author Gareth Hughes
  33  */
  34
  35
  36 #include "colormac.h"
  37 #include "context.h"
  38 #include "macros.h"
  39 #include "texcompress.h"
  40 #include "texcompress_fxt1.h"
  41 #include "texcompress_s3tc.h"
  42 #include "texfetch.h"
  43
  44
  45 /**
  46  * Convert an 8-bit sRGB value from non-linear space to a
  47  * linear RGB value in [0, 1].
  48  * Implemented with a 256-entry lookup table.
  49  */
  50 static INLINE GLfloat
  51 nonlinear_to_linear(GLubyte cs8)
  52 {
  53    static GLfloat table[256];
  54    static GLboolean tableReady = GL_FALSE;
  55    if (!tableReady) {
  56       /* compute lookup table now */
  57       GLuint i;
  58       for (i = 0; i < 256; i++) {
  59          const GLfloat cs = UBYTE_TO_FLOAT(i);
  60          if (cs <= 0.04045) {
  61             table[i] = cs / 12.92f;
  62          }
  63          else {
  64             table[i] = (GLfloat) pow((cs + 0.055) / 1.055, 2.4);
  65          }
  66       }
  67       tableReady = GL_TRUE;
  68    }
  69    return table[cs8];
  70 }
  71
  72
  73
  74 /* Texel fetch routines for all supported formats
  75  */
  76 #define DIM 1
  77 #include "texfetch_tmp.h"
  78
  79 #define DIM 2
  80 #include "texfetch_tmp.h"
  81
  82 #define DIM 3
  83 #include "texfetch_tmp.h"
  84
  85 /**
  86  * Null texel fetch function.
  87  *
  88  * Have to have this so the FetchTexel function pointer is never NULL.
  89  */
  90 static void fetch_null_texelf( const struct gl_texture_image *texImage,
  91                                GLint i, GLint j, GLint k, GLfloat *texel )
  92 {
  93    (void) texImage; (void) i; (void) j; (void) k;
  94    texel[RCOMP] = 0.0;
  95    texel[GCOMP] = 0.0;
  96    texel[BCOMP] = 0.0;
  97    texel[ACOMP] = 0.0;
  98    _mesa_warning(NULL, "fetch_null_texelf() called!");
  99 }
 100
 101 static void store_null_texel(struct gl_texture_image *texImage,
 102                              GLint i, GLint j, GLint k, const void *texel)
 103 {
 104    (void) texImage;
 105    (void) i;
 106    (void) j;
 107    (void) k;
 108    (void) texel;
 109    /* no-op */
 110 }
 111
 112
 113
 114 /**
 115  * Table to map MESA_FORMAT_ to texel fetch/store funcs.
 116  * XXX this is somewhat temporary.
 117  */
 118 static struct {
 119    gl_format Name;
 120    FetchTexelFuncF Fetch1D;
 121    FetchTexelFuncF Fetch2D;
 122    FetchTexelFuncF Fetch3D;
 123    StoreTexelFunc StoreTexel;
 124 }
 125 texfetch_funcs[MESA_FORMAT_COUNT] =
 126 {
 127    {
 128       MESA_FORMAT_NONE,
 129       fetch_null_texelf,
 130       fetch_null_texelf,
 131       fetch_null_texelf,
 132       store_null_texel
 133    },
 134
 135    {
 136       MESA_FORMAT_RGBA8888,
 137       fetch_texel_1d_f_rgba8888,
 138       fetch_texel_2d_f_rgba8888,
 139       fetch_texel_3d_f_rgba8888,
 140       store_texel_rgba8888
 141    },
 142    {
 143       MESA_FORMAT_RGBA8888_REV,
 144       fetch_texel_1d_f_rgba8888_rev,
 145       fetch_texel_2d_f_rgba8888_rev,
 146       fetch_texel_3d_f_rgba8888_rev,
 147       store_texel_rgba8888_rev
 148    },
 149    {
 150       MESA_FORMAT_ARGB8888,
 151       fetch_texel_1d_f_argb8888,
 152       fetch_texel_2d_f_argb8888,
 153       fetch_texel_3d_f_argb8888,
 154       store_texel_argb8888
 155    },
 156    {
 157       MESA_FORMAT_ARGB8888_REV,
 158       fetch_texel_1d_f_argb8888_rev,
 159       fetch_texel_2d_f_argb8888_rev,
 160       fetch_texel_3d_f_argb8888_rev,
 161       store_texel_argb8888_rev
 162    },
 163    {
 164       MESA_FORMAT_XRGB8888,
 165       fetch_texel_1d_f_xrgb8888,
 166       fetch_texel_2d_f_xrgb8888,
 167       fetch_texel_3d_f_xrgb8888,
 168       store_texel_xrgb8888
 169    },
 170    {
 171       MESA_FORMAT_XRGB8888_REV,
 172       fetch_texel_1d_f_xrgb8888_rev,
 173       fetch_texel_2d_f_xrgb8888_rev,
 174       fetch_texel_3d_f_xrgb8888_rev,
 175       store_texel_xrgb8888_rev,
 176    },
 177    {
 178       MESA_FORMAT_RGB888,
 179       fetch_texel_1d_f_rgb888,
 180       fetch_texel_2d_f_rgb888,
 181       fetch_texel_3d_f_rgb888,
 182       store_texel_rgb888
 183    },
 184    {
 185       MESA_FORMAT_BGR888,
 186       fetch_texel_1d_f_bgr888,
 187       fetch_texel_2d_f_bgr888,
 188       fetch_texel_3d_f_bgr888,
 189       store_texel_bgr888
 190    },
 191    {
 192       MESA_FORMAT_RGB565,
 193       fetch_texel_1d_f_rgb565,
 194       fetch_texel_2d_f_rgb565,
 195       fetch_texel_3d_f_rgb565,
 196       store_texel_rgb565
 197    },
 198    {
 199       MESA_FORMAT_RGB565_REV,
 200       fetch_texel_1d_f_rgb565_rev,
 201       fetch_texel_2d_f_rgb565_rev,
 202       fetch_texel_3d_f_rgb565_rev,
 203       store_texel_rgb565_rev
 204    },
 205    {
 206       MESA_FORMAT_ARGB4444,
 207       fetch_texel_1d_f_argb4444,
 208       fetch_texel_2d_f_argb4444,
 209       fetch_texel_3d_f_argb4444,
 210       store_texel_argb4444
 211    },
 212    {
 213       MESA_FORMAT_ARGB4444_REV,
 214       fetch_texel_1d_f_argb4444_rev,
 215       fetch_texel_2d_f_argb4444_rev,
 216       fetch_texel_3d_f_argb4444_rev,
 217       store_texel_argb4444_rev
 218    },
 219    {
 220       MESA_FORMAT_RGBA5551,
 221       fetch_texel_1d_f_rgba5551,
 222       fetch_texel_2d_f_rgba5551,
 223       fetch_texel_3d_f_rgba5551,
 224       store_texel_rgba5551
 225    },
 226    {
 227       MESA_FORMAT_ARGB1555,
 228       fetch_texel_1d_f_argb1555,
 229       fetch_texel_2d_f_argb1555,
 230       fetch_texel_3d_f_argb1555,
 231       store_texel_argb1555
 232    },
 233    {
 234       MESA_FORMAT_ARGB1555_REV,
 235       fetch_texel_1d_f_argb1555_rev,
 236       fetch_texel_2d_f_argb1555_rev,
 237       fetch_texel_3d_f_argb1555_rev,
 238       store_texel_argb1555_rev
 239    },
 240    {
 241       MESA_FORMAT_AL88,
 242       fetch_texel_1d_f_al88,
 243       fetch_texel_2d_f_al88,
 244       fetch_texel_3d_f_al88,
 245       store_texel_al88
 246    },
 247    {
 248       MESA_FORMAT_AL88_REV,
 249       fetch_texel_1d_f_al88_rev,
 250       fetch_texel_2d_f_al88_rev,
 251       fetch_texel_3d_f_al88_rev,
 252       store_texel_al88_rev
 253    },
 254    {
 255       MESA_FORMAT_AL1616,
 256       fetch_texel_1d_f_al1616,
 257       fetch_texel_2d_f_al1616,
 258       fetch_texel_3d_f_al1616,
 259       store_texel_al1616
 260    },
 261    {
 262       MESA_FORMAT_AL1616_REV,
 263       fetch_texel_1d_f_al1616_rev,
 264       fetch_texel_2d_f_al1616_rev,
 265       fetch_texel_3d_f_al1616_rev,
 266       store_texel_al1616_rev
 267    },
 268    {
 269       MESA_FORMAT_RGB332,
 270       fetch_texel_1d_f_rgb332,
 271       fetch_texel_2d_f_rgb332,
 272       fetch_texel_3d_f_rgb332,
 273       store_texel_rgb332
 274    },
 275    {
 276       MESA_FORMAT_A8,
 277       fetch_texel_1d_f_a8,
 278       fetch_texel_2d_f_a8,
 279       fetch_texel_3d_f_a8,
 280       store_texel_a8
 281    },
 282    {
 283       MESA_FORMAT_L8,
 284       fetch_texel_1d_f_l8,
 285       fetch_texel_2d_f_l8,
 286       fetch_texel_3d_f_l8,
 287       store_texel_l8
 288    },
 289    {
 290       MESA_FORMAT_I8,
 291       fetch_texel_1d_f_i8,
 292       fetch_texel_2d_f_i8,
 293       fetch_texel_3d_f_i8,
 294       store_texel_i8
 295    },
 296    {
 297       MESA_FORMAT_CI8,
 298       fetch_texel_1d_f_ci8,
 299       fetch_texel_2d_f_ci8,
 300       fetch_texel_3d_f_ci8,
 301       store_texel_ci8
 302    },
 303    {
 304       MESA_FORMAT_YCBCR,
 305       fetch_texel_1d_f_ycbcr,
 306       fetch_texel_2d_f_ycbcr,
 307       fetch_texel_3d_f_ycbcr,
 308       store_texel_ycbcr
 309    },
 310    {
 311       MESA_FORMAT_YCBCR_REV,
 312       fetch_texel_1d_f_ycbcr_rev,
 313       fetch_texel_2d_f_ycbcr_rev,
 314       fetch_texel_3d_f_ycbcr_rev,
 315       store_texel_ycbcr_rev
 316    },
 317    {
 318       MESA_FORMAT_Z24_S8,
 319       fetch_texel_1d_f_z24_s8,
 320       fetch_texel_2d_f_z24_s8,
 321       fetch_texel_3d_f_z24_s8,
 322       store_texel_z24_s8
 323    },
 324    {
 325       MESA_FORMAT_S8_Z24,
 326       fetch_texel_1d_f_s8_z24,
 327       fetch_texel_2d_f_s8_z24,
 328       fetch_texel_3d_f_s8_z24,
 329       store_texel_s8_z24
 330    },
 331    {
 332       MESA_FORMAT_Z16,
 333       fetch_texel_1d_f_z16,
 334       fetch_texel_2d_f_z16,
 335       fetch_texel_3d_f_z16,
 336       store_texel_z16
 337    },
 338    {
 339       MESA_FORMAT_X8_Z24,
 340       fetch_texel_1d_f_s8_z24,
 341       fetch_texel_2d_f_s8_z24,
 342       fetch_texel_3d_f_s8_z24,
 343       store_texel_s8_z24
 344    },
 345    {
 346       MESA_FORMAT_Z24_X8,
 347       fetch_texel_1d_f_z24_s8,
 348       fetch_texel_2d_f_z24_s8,
 349       fetch_texel_3d_f_z24_s8,
 350       store_texel_z24_s8
 351    },
 352    {
 353       MESA_FORMAT_Z32,
 354       fetch_texel_1d_f_z32,
 355       fetch_texel_2d_f_z32,
 356       fetch_texel_3d_f_z32,
 357       store_texel_z32
 358    },
 359    {
 360       MESA_FORMAT_S8,
 361       NULL,
 362       NULL,
 363       NULL,
 364       NULL
 365    },
 366    {
 367       MESA_FORMAT_SRGB8,
 368       fetch_texel_1d_srgb8,
 369       fetch_texel_2d_srgb8,
 370       fetch_texel_3d_srgb8,
 371       store_texel_srgb8
 372    },
 373    {
 374       MESA_FORMAT_SRGBA8,
 375       fetch_texel_1d_srgba8,
 376       fetch_texel_2d_srgba8,
 377       fetch_texel_3d_srgba8,
 378       store_texel_srgba8
 379    },
 380    {
 381       MESA_FORMAT_SARGB8,
 382       fetch_texel_1d_sargb8,
 383       fetch_texel_2d_sargb8,
 384       fetch_texel_3d_sargb8,
 385       store_texel_sargb8
 386    },
 387    {
 388       MESA_FORMAT_SL8,
 389       fetch_texel_1d_sl8,
 390       fetch_texel_2d_sl8,
 391       fetch_texel_3d_sl8,
 392       store_texel_sl8
 393    },
 394    {
 395       MESA_FORMAT_SLA8,
 396       fetch_texel_1d_sla8,
 397       fetch_texel_2d_sla8,
 398       fetch_texel_3d_sla8,
 399       store_texel_sla8
 400    },
 401    {
 402       MESA_FORMAT_SRGB_DXT1,
 403       NULL,
 404       _mesa_fetch_texel_2d_f_srgb_dxt1,
 405       NULL,
 406       NULL
 407    },
 408    {
 409       MESA_FORMAT_SRGBA_DXT1,
 410       NULL,
 411       _mesa_fetch_texel_2d_f_srgba_dxt1,
 412       NULL,
 413       NULL
 414    },
 415    {
 416       MESA_FORMAT_SRGBA_DXT3,
 417       NULL,
 418       _mesa_fetch_texel_2d_f_srgba_dxt3,
 419       NULL,
 420       NULL
 421    },
 422    {
 423       MESA_FORMAT_SRGBA_DXT5,
 424       NULL,
 425       _mesa_fetch_texel_2d_f_srgba_dxt5,
 426       NULL,
 427       NULL
 428    },
 429
 430    {
 431       MESA_FORMAT_RGB_FXT1,
 432       NULL,
 433       _mesa_fetch_texel_2d_f_rgb_fxt1,
 434       NULL,
 435       NULL
 436    },
 437    {
 438       MESA_FORMAT_RGBA_FXT1,
 439       NULL,
 440       _mesa_fetch_texel_2d_f_rgba_fxt1,
 441       NULL,
 442       NULL
 443    },
 444    {
 445       MESA_FORMAT_RGB_DXT1,
 446       NULL,
 447       _mesa_fetch_texel_2d_f_rgb_dxt1,
 448       NULL,
 449       NULL
 450    },
 451    {
 452       MESA_FORMAT_RGBA_DXT1,
 453       NULL,
 454       _mesa_fetch_texel_2d_f_rgba_dxt1,
 455       NULL,
 456       NULL
 457    },
 458    {
 459       MESA_FORMAT_RGBA_DXT3,
 460       NULL,
 461       _mesa_fetch_texel_2d_f_rgba_dxt3,
 462       NULL,
 463       NULL
 464    },
 465    {
 466       MESA_FORMAT_RGBA_DXT5,
 467       NULL,
 468       _mesa_fetch_texel_2d_f_rgba_dxt5,
 469       NULL,
 470       NULL
 471    },
 472    {
 473       MESA_FORMAT_RGBA_FLOAT32,
 474       fetch_texel_1d_f_rgba_f32,
 475       fetch_texel_2d_f_rgba_f32,
 476       fetch_texel_3d_f_rgba_f32,
 477       store_texel_rgba_f32
 478    },
 479    {
 480       MESA_FORMAT_RGBA_FLOAT16,
 481       fetch_texel_1d_f_rgba_f16,
 482       fetch_texel_2d_f_rgba_f16,
 483       fetch_texel_3d_f_rgba_f16,
 484       store_texel_rgba_f16
 485    },
 486    {
 487       MESA_FORMAT_RGB_FLOAT32,
 488       fetch_texel_1d_f_rgb_f32,
 489       fetch_texel_2d_f_rgb_f32,
 490       fetch_texel_3d_f_rgb_f32,
 491       store_texel_rgb_f32
 492    },
 493    {
 494       MESA_FORMAT_RGB_FLOAT16,
 495       fetch_texel_1d_f_rgb_f16,
 496       fetch_texel_2d_f_rgb_f16,
 497       fetch_texel_3d_f_rgb_f16,
 498       store_texel_rgb_f16
 499    },
 500    {
 501       MESA_FORMAT_ALPHA_FLOAT32,
 502       fetch_texel_1d_f_alpha_f32,
 503       fetch_texel_2d_f_alpha_f32,
 504       fetch_texel_3d_f_alpha_f32,
 505       store_texel_alpha_f32
 506    },
 507    {
 508       MESA_FORMAT_ALPHA_FLOAT16,
 509       fetch_texel_1d_f_alpha_f16,
 510       fetch_texel_2d_f_alpha_f16,
 511       fetch_texel_3d_f_alpha_f16,
 512       store_texel_alpha_f16
 513    },
 514    {
 515       MESA_FORMAT_LUMINANCE_FLOAT32,
 516       fetch_texel_1d_f_luminance_f32,
 517       fetch_texel_2d_f_luminance_f32,
 518       fetch_texel_3d_f_luminance_f32,
 519       store_texel_luminance_f32
 520    },
 521    {
 522       MESA_FORMAT_LUMINANCE_FLOAT16,
 523       fetch_texel_1d_f_luminance_f16,
 524       fetch_texel_2d_f_luminance_f16,
 525       fetch_texel_3d_f_luminance_f16,
 526       store_texel_luminance_f16
 527    },
 528    {
 529       MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32,
 530       fetch_texel_1d_f_luminance_alpha_f32,
 531       fetch_texel_2d_f_luminance_alpha_f32,
 532       fetch_texel_3d_f_luminance_alpha_f32,
 533       store_texel_luminance_alpha_f32
 534    },
 535    {
 536       MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16,
 537       fetch_texel_1d_f_luminance_alpha_f16,
 538       fetch_texel_2d_f_luminance_alpha_f16,
 539       fetch_texel_3d_f_luminance_alpha_f16,
 540       store_texel_luminance_alpha_f16
 541    },
 542    {
 543       MESA_FORMAT_INTENSITY_FLOAT32,
 544       fetch_texel_1d_f_intensity_f32,
 545       fetch_texel_2d_f_intensity_f32,
 546       fetch_texel_3d_f_intensity_f32,
 547       store_texel_intensity_f32
 548    },
 549    {
 550       MESA_FORMAT_INTENSITY_FLOAT16,
 551       fetch_texel_1d_f_intensity_f16,
 552       fetch_texel_2d_f_intensity_f16,
 553       fetch_texel_3d_f_intensity_f16,
 554       store_texel_intensity_f16
 555    },
 556
 557    /* non-normalized, signed int */
 558    {
 559       MESA_FORMAT_RGBA_INT8,
 560       fetch_texel_1d_rgba_int8,
 561       fetch_texel_2d_rgba_int8,
 562       fetch_texel_3d_rgba_int8,
 563       store_texel_rgba_int8
 564    },
 565    {
 566       MESA_FORMAT_RGBA_INT16,
 567       fetch_texel_1d_rgba_int16,
 568       fetch_texel_2d_rgba_int16,
 569       fetch_texel_3d_rgba_int16,
 570       store_texel_rgba_int16
 571    },
 572    {
 573       MESA_FORMAT_RGBA_INT32,
 574       fetch_texel_1d_rgba_int32,
 575       fetch_texel_2d_rgba_int32,
 576       fetch_texel_3d_rgba_int32,
 577       store_texel_rgba_int32
 578    },
 579
 580    /* non-normalized, unsigned int */
 581    {
 582       MESA_FORMAT_RGBA_UINT8,
 583       fetch_texel_1d_rgba_uint8,
 584       fetch_texel_2d_rgba_uint8,
 585       fetch_texel_3d_rgba_uint8,
 586       store_texel_rgba_uint8
 587    },
 588    {
 589       MESA_FORMAT_RGBA_UINT16,
 590       fetch_texel_1d_rgba_uint16,
 591       fetch_texel_2d_rgba_uint16,
 592       fetch_texel_3d_rgba_uint16,
 593       store_texel_rgba_uint16
 594    },
 595    {
 596       MESA_FORMAT_RGBA_UINT32,
 597       fetch_texel_1d_rgba_uint32,
 598       fetch_texel_2d_rgba_uint32,
 599       fetch_texel_3d_rgba_uint32,
 600       store_texel_rgba_uint32
 601    },
 602
 603    /* dudv */
 604    {
 605       MESA_FORMAT_DUDV8,
 606       fetch_texel_1d_dudv8,
 607       fetch_texel_2d_dudv8,
 608       fetch_texel_3d_dudv8,
 609       NULL
 610    },
 611
 612    /* signed, normalized */
 613    {
 614       MESA_FORMAT_SIGNED_R8,
 615       fetch_texel_1d_signed_r8,
 616       fetch_texel_2d_signed_r8,
 617       fetch_texel_3d_signed_r8,
 618       store_texel_signed_r8
 619    },
 620    {
 621       MESA_FORMAT_SIGNED_RG88,
 622       fetch_texel_1d_signed_rg88,
 623       fetch_texel_2d_signed_rg88,
 624       fetch_texel_3d_signed_rg88,
 625       store_texel_signed_rg88
 626    },
 627    {
 628       MESA_FORMAT_SIGNED_RGBX8888,
 629       fetch_texel_1d_signed_rgbx8888,
 630       fetch_texel_2d_signed_rgbx8888,
 631       fetch_texel_3d_signed_rgbx8888,
 632       store_texel_signed_rgbx8888
 633    },
 634    {
 635       MESA_FORMAT_SIGNED_RGBA8888,
 636       fetch_texel_1d_signed_rgba8888,
 637       fetch_texel_2d_signed_rgba8888,
 638       fetch_texel_3d_signed_rgba8888,
 639       store_texel_signed_rgba8888
 640    },
 641    {
 642       MESA_FORMAT_SIGNED_RGBA8888_REV,
 643       fetch_texel_1d_signed_rgba8888_rev,
 644       fetch_texel_2d_signed_rgba8888_rev,
 645       fetch_texel_3d_signed_rgba8888_rev,
 646       store_texel_signed_rgba8888_rev
 647    },
 648    {
 649       MESA_FORMAT_SIGNED_R_16,
 650       fetch_texel_1d_signed_r_16,
 651       fetch_texel_2d_signed_r_16,
 652       fetch_texel_3d_signed_r_16,
 653       store_texel_signed_r_16
 654    },
 655    {
 656       MESA_FORMAT_SIGNED_RG_16,
 657       fetch_texel_1d_signed_rg_16,
 658       fetch_texel_2d_signed_rg_16,
 659       fetch_texel_3d_signed_rg_16,
 660       store_texel_signed_rg_16
 661    },
 662    {
 663       MESA_FORMAT_SIGNED_RGB_16,
 664       fetch_texel_1d_signed_rgb_16,
 665       fetch_texel_2d_signed_rgb_16,
 666       fetch_texel_3d_signed_rgb_16,
 667       store_texel_signed_rgb_16
 668    },
 669    {
 670       MESA_FORMAT_SIGNED_RGBA_16,
 671       fetch_texel_1d_signed_rgba_16,
 672       fetch_texel_2d_signed_rgba_16,
 673       fetch_texel_3d_signed_rgba_16,
 674       store_texel_signed_rgba_16
 675    },
 676    {
 677       MESA_FORMAT_RGBA_16,
 678       fetch_texel_1d_rgba_16,
 679       fetch_texel_2d_rgba_16,
 680       fetch_texel_3d_rgba_16,
 681       store_texel_rgba_16
 682    }
 683 };
 684
 685
 686 static FetchTexelFuncF
 687 _mesa_get_texel_fetch_func(gl_format format, GLuint dims)
 688 {
 689 #ifdef DEBUG
 690    /* check that the table entries are sorted by format name */
 691    gl_format fmt;
 692    for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
 693       assert(texfetch_funcs[fmt].Name == fmt);
 694    }
 695 #endif
 696
 697    assert(Elements(texfetch_funcs) == MESA_FORMAT_COUNT);
 698    assert(format < MESA_FORMAT_COUNT);
 699
 700    switch (dims) {
 701    case 1:
 702       return texfetch_funcs[format].Fetch1D;
 703    case 2:
 704       return texfetch_funcs[format].Fetch2D;
 705    case 3:
 706       return texfetch_funcs[format].Fetch3D;
 707    default:
 708       assert(0 && "bad dims in _mesa_get_texel_fetch_func");
 709       return NULL;
 710    }
 711 }
 712
 713
 714 StoreTexelFunc
 715 _mesa_get_texel_store_func(gl_format format)
 716 {
 717    assert(format < MESA_FORMAT_COUNT);
 718    return texfetch_funcs[format].StoreTexel;
 719 }
 720
 721
 722 /**
 723  * Adaptor for fetching a GLchan texel from a float-valued texture.
 724  */
 725 static void
 726 fetch_texel_float_to_chan(const struct gl_texture_image *texImage,
 727                           GLint i, GLint j, GLint k, GLchan *texelOut)
 728 {
 729    GLfloat temp[4];
 730    GLenum baseFormat = _mesa_get_format_base_format(texImage->TexFormat);
 731
 732    ASSERT(texImage->FetchTexelf);
 733    texImage->FetchTexelf(texImage, i, j, k, temp);
 734    if (baseFormat == GL_DEPTH_COMPONENT ||
 735        baseFormat == GL_DEPTH_STENCIL_EXT) {
 736       /* just one channel */
 737       UNCLAMPED_FLOAT_TO_CHAN(texelOut[0], temp[0]);
 738    }
 739    else {
 740       /* four channels */
 741       UNCLAMPED_FLOAT_TO_CHAN(texelOut[0], temp[0]);
 742       UNCLAMPED_FLOAT_TO_CHAN(texelOut[1], temp[1]);
 743       UNCLAMPED_FLOAT_TO_CHAN(texelOut[2], temp[2]);
 744       UNCLAMPED_FLOAT_TO_CHAN(texelOut[3], temp[3]);
 745    }
 746 }
 747
 748
 749 #if 0
 750 /**
 751  * Adaptor for fetching a float texel from a GLchan-valued texture.
 752  */
 753 static void
 754 fetch_texel_chan_to_float(const struct gl_texture_image *texImage,
 755                           GLint i, GLint j, GLint k, GLfloat *texelOut)
 756 {
 757    GLchan temp[4];
 758    GLenum baseFormat = _mesa_get_format_base_format(texImage->TexFormat);
 759
 760    ASSERT(texImage->FetchTexelc);
 761    texImage->FetchTexelc(texImage, i, j, k, temp);
 762    if (baseFormat == GL_DEPTH_COMPONENT ||
 763        baseFormat == GL_DEPTH_STENCIL_EXT) {
 764       /* just one channel */
 765       texelOut[0] = CHAN_TO_FLOAT(temp[0]);
 766    }
 767    else {
 768       /* four channels */
 769       texelOut[0] = CHAN_TO_FLOAT(temp[0]);
 770       texelOut[1] = CHAN_TO_FLOAT(temp[1]);
 771       texelOut[2] = CHAN_TO_FLOAT(temp[2]);
 772       texelOut[3] = CHAN_TO_FLOAT(temp[3]);
 773    }
 774 }
 775 #endif
 776
 777
 778 /**
 779  * Initialize the texture image's FetchTexelc and FetchTexelf methods.
 780  */
 781 void
 782 _mesa_set_fetch_functions(struct gl_texture_image *texImage, GLuint dims)
 783 {
 784    ASSERT(dims == 1 || dims == 2 || dims == 3);
 785    ASSERT(texImage->TexFormat);
 786
 787    if (!texImage->FetchTexelf) {
 788       texImage->FetchTexelf =
 789          _mesa_get_texel_fetch_func(texImage->TexFormat, dims);
 790    }
 791
 792    /* now check if we need to use a float/chan adaptor */
 793    if (!texImage->FetchTexelc) {
 794       texImage->FetchTexelc = fetch_texel_float_to_chan;
 795    }
 796
 797    ASSERT(texImage->FetchTexelc);
 798    ASSERT(texImage->FetchTexelf);
 799 }