/* * Mesa 3-D graphics library * Version: 7.1 * * Copyright (C) 1999-2008 Brian Paul 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, sublicense, * 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 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 NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL 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. */ /** * \file texcompress_fxt1.c * GL_EXT_texture_compression_fxt1 support. */ #include "glheader.h" #include "imports.h" #include "colormac.h" #include "context.h" #include "convolve.h" #include "image.h" #include "mipmap.h" #include "texcompress.h" #include "texcompress_fxt1.h" #include "texformat.h" #include "texstore.h" static void fxt1_encode (GLuint width, GLuint height, GLint comps, const void *source, GLint srcRowStride, void *dest, GLint destRowStride); void fxt1_decode_1 (const void *texture, GLint stride, GLint i, GLint j, GLchan *rgba); /** * Called during context initialization. */ void _mesa_init_texture_fxt1( GLcontext *ctx ) { (void) ctx; } /** * Store user's image in rgb_fxt1 format. */ GLboolean _mesa_texstore_rgb_fxt1(TEXSTORE_PARAMS) { const GLchan *pixels; GLint srcRowStride; GLubyte *dst; const GLint texWidth = dstRowStride * 8 / 16; /* a bit of a hack */ const GLchan *tempImage = NULL; ASSERT(dstFormat == MESA_FORMAT_RGB_FXT1); ASSERT(dstXoffset % 8 == 0); ASSERT(dstYoffset % 4 == 0); ASSERT(dstZoffset == 0); (void) dstZoffset; (void) dstImageOffsets; if (srcFormat != GL_RGB || srcType != CHAN_TYPE || ctx->_ImageTransferState || srcPacking->SwapBytes) { /* convert image to RGB/GLchan */ tempImage = _mesa_make_temp_chan_image(ctx, dims, baseInternalFormat, _mesa_get_format_base_format(dstFormat), srcWidth, srcHeight, srcDepth, srcFormat, srcType, srcAddr, srcPacking); if (!tempImage) return GL_FALSE; /* out of memory */ _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight); pixels = tempImage; srcRowStride = 3 * srcWidth; srcFormat = GL_RGB; } else { pixels = (const GLchan *) srcAddr; srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat, srcType) / sizeof(GLchan); } dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0, dstFormat, texWidth, (GLubyte *) dstAddr); fxt1_encode(srcWidth, srcHeight, 3, pixels, srcRowStride, dst, dstRowStride); if (tempImage) _mesa_free((void*) tempImage); return GL_TRUE; } /** * Store user's image in rgba_fxt1 format. */ GLboolean _mesa_texstore_rgba_fxt1(TEXSTORE_PARAMS) { const GLchan *pixels; GLint srcRowStride; GLubyte *dst; GLint texWidth = dstRowStride * 8 / 16; /* a bit of a hack */ const GLchan *tempImage = NULL; ASSERT(dstFormat == MESA_FORMAT_RGBA_FXT1); ASSERT(dstXoffset % 8 == 0); ASSERT(dstYoffset % 4 == 0); ASSERT(dstZoffset == 0); (void) dstZoffset; (void) dstImageOffsets; if (srcFormat != GL_RGBA || srcType != CHAN_TYPE || ctx->_ImageTransferState || srcPacking->SwapBytes) { /* convert image to RGBA/GLchan */ tempImage = _mesa_make_temp_chan_image(ctx, dims, baseInternalFormat, _mesa_get_format_base_format(dstFormat), srcWidth, srcHeight, srcDepth, srcFormat, srcType, srcAddr, srcPacking); if (!tempImage) return GL_FALSE; /* out of memory */ _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight); pixels = tempImage; srcRowStride = 4 * srcWidth; srcFormat = GL_RGBA; } else { pixels = (const GLchan *) srcAddr; srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat, srcType) / sizeof(GLchan); } dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0, dstFormat, texWidth, (GLubyte *) dstAddr); fxt1_encode(srcWidth, srcHeight, 4, pixels, srcRowStride, dst, dstRowStride); if (tempImage) _mesa_free((void*) tempImage); return GL_TRUE; } void _mesa_fetch_texel_2d_rgba_fxt1( const struct gl_texture_image *texImage, GLint i, GLint j, GLint k, GLchan *texel ) { (void) k; fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, texel); } void _mesa_fetch_texel_2d_f_rgba_fxt1( const struct gl_texture_image *texImage, GLint i, GLint j, GLint k, GLfloat *texel ) { /* just sample as GLchan and convert to float here */ GLchan rgba[4]; (void) k; fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, rgba); texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]); texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]); texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]); texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]); } void _mesa_fetch_texel_2d_rgb_fxt1( const struct gl_texture_image *texImage, GLint i, GLint j, GLint k, GLchan *texel ) { (void) k; fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, texel); texel[ACOMP] = 255; } void _mesa_fetch_texel_2d_f_rgb_fxt1( const struct gl_texture_image *texImage, GLint i, GLint j, GLint k, GLfloat *texel ) { /* just sample as GLchan and convert to float here */ GLchan rgba[4]; (void) k; fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, rgba); texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]); texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]); texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]); texel[ACOMP] = 1.0F; } const struct gl_texture_format _mesa_texformat_rgb_fxt1 = { MESA_FORMAT_RGB_FXT1, /* MesaFormat */ GL_RGB, /* BaseFormat */ GL_UNSIGNED_NORMALIZED_ARB, /* DataType */ 4, /*approx*/ /* RedBits */ 4, /*approx*/ /* GreenBits */ 4, /*approx*/ /* BlueBits */ 0, /* AlphaBits */ 0, /* LuminanceBits */ 0, /* IntensityBits */ 0, /* IndexBits */ 0, /* DepthBits */ 0, /* StencilBits */ 0 /* TexelBytes */ }; const struct gl_texture_format _mesa_texformat_rgba_fxt1 = { MESA_FORMAT_RGBA_FXT1, /* MesaFormat */ GL_RGBA, /* BaseFormat */ GL_UNSIGNED_NORMALIZED_ARB, /* DataType */ 4, /*approx*/ /* RedBits */ 4, /*approx*/ /* GreenBits */ 4, /*approx*/ /* BlueBits */ 1, /*approx*/ /* AlphaBits */ 0, /* LuminanceBits */ 0, /* IntensityBits */ 0, /* IndexBits */ 0, /* DepthBits */ 0, /* StencilBits */ 0 /* TexelBytes */ }; /***************************************************************************\ * FXT1 encoder * * The encoder was built by reversing the decoder, * and is vaguely based on Texus2 by 3dfx. Note that this code * is merely a proof of concept, since it is highly UNoptimized; * moreover, it is sub-optimal due to initial conditions passed * to Lloyd's algorithm (the interpolation modes are even worse). \***************************************************************************/ #define MAX_COMP 4 /* ever needed maximum number of components in texel */ #define MAX_VECT 4 /* ever needed maximum number of base vectors to find */ #define N_TEXELS 32 /* number of texels in a block (always 32) */ #define LL_N_REP 50 /* number of iterations in lloyd's vq */ #define LL_RMS_D 10 /* fault tolerance (maximum delta) */ #define LL_RMS_E 255 /* fault tolerance (maximum error) */ #define ALPHA_TS 2 /* alpha threshold: (255 - ALPHA_TS) deemed opaque */ #define ISTBLACK(v) (*((GLuint *)(v)) == 0) /* * Define a 64-bit unsigned integer type and macros */ #if 1 #define FX64_NATIVE 1 typedef uint64_t Fx64; #define FX64_MOV32(a, b) a = b #define FX64_OR32(a, b) a |= b #define FX64_SHL(a, c) a <<= c #else #define FX64_NATIVE 0 typedef struct { GLuint lo, hi; } Fx64; #define FX64_MOV32(a, b) a.lo = b #define FX64_OR32(a, b) a.lo |= b #define FX64_SHL(a, c) \ do { \ if ((c) >= 32) { \ a.hi = a.lo << ((c) - 32); \ a.lo = 0; \ } else { \ a.hi = (a.hi << (c)) | (a.lo >> (32 - (c))); \ a.lo <<= (c); \ } \ } while (0) #endif #define F(i) (GLfloat)1 /* can be used to obtain an oblong metric: 0.30 / 0.59 / 0.11 */ #define SAFECDOT 1 /* for paranoids */ #define MAKEIVEC(NV, NC, IV, B, V0, V1) \ do { \ /* compute interpolation vector */ \ GLfloat d2 = 0.0F; \ GLfloat rd2; \ \ for (i = 0; i < NC; i++) { \ IV[i] = (V1[i] - V0[i]) * F(i); \ d2 += IV[i] * IV[i]; \ } \ rd2 = (GLfloat)NV / d2; \ B = 0; \ for (i = 0; i < NC; i++) { \ IV[i] *= F(i); \ B -= IV[i] * V0[i]; \ IV[i] *= rd2; \ } \ B = B * rd2 + 0.5f; \ } while (0) #define CALCCDOT(TEXEL, NV, NC, IV, B, V)\ do { \ GLfloat dot = 0.0F; \ for (i = 0; i < NC; i++) { \ dot += V[i] * IV[i]; \ } \ TEXEL = (GLint)(dot + B); \ if (SAFECDOT) { \ if (TEXEL < 0) { \ TEXEL = 0; \ } else if (TEXEL > NV) { \ TEXEL = NV; \ } \ } \ } while (0) static GLint fxt1_bestcol (GLfloat vec[][MAX_COMP], GLint nv, GLubyte input[MAX_COMP], GLint nc) { GLint i, j, best = -1; GLfloat err = 1e9; /* big enough */ for (j = 0; j < nv; j++) { GLfloat e = 0.0F; for (i = 0; i < nc; i++) { e += (vec[j][i] - input[i]) * (vec[j][i] - input[i]); } if (e < err) { err = e; best = j; } } return best; } static GLint fxt1_worst (GLfloat vec[MAX_COMP], GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n) { GLint i, k, worst = -1; GLfloat err = -1.0F; /* small enough */ for (k = 0; k < n; k++) { GLfloat e = 0.0F; for (i = 0; i < nc; i++) { e += (vec[i] - input[k][i]) * (vec[i] - input[k][i]); } if (e > err) { err = e; worst = k; } } return worst; } static GLint fxt1_variance (GLdouble variance[MAX_COMP], GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n) { GLint i, k, best = 0; GLint sx, sx2; GLdouble var, maxvar = -1; /* small enough */ GLdouble teenth = 1.0 / n; for (i = 0; i < nc; i++) { sx = sx2 = 0; for (k = 0; k < n; k++) { GLint t = input[k][i]; sx += t; sx2 += t * t; } var = sx2 * teenth - sx * sx * teenth * teenth; if (maxvar < var) { maxvar = var; best = i; } if (variance) { variance[i] = var; } } return best; } static GLint fxt1_choose (GLfloat vec[][MAX_COMP], GLint nv, GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n) { #if 0 /* Choose colors from a grid. */ GLint i, j; for (j = 0; j < nv; j++) { GLint m = j * (n - 1) / (nv - 1); for (i = 0; i < nc; i++) { vec[j][i] = input[m][i]; } } #else /* Our solution here is to find the darkest and brightest colors in * the 8x4 tile and use those as the two representative colors. * There are probably better algorithms to use (histogram-based). */ GLint i, j, k; GLint minSum = 2000; /* big enough */ GLint maxSum = -1; /* small enough */ GLint minCol = 0; /* phoudoin: silent compiler! */ GLint maxCol = 0; /* phoudoin: silent compiler! */ struct { GLint flag; GLint key; GLint freq; GLint idx; } hist[N_TEXELS]; GLint lenh = 0; _mesa_memset(hist, 0, sizeof(hist)); for (k = 0; k < n; k++) { GLint l; GLint key = 0; GLint sum = 0; for (i = 0; i < nc; i++) { key <<= 8; key |= input[k][i]; sum += input[k][i]; } for (l = 0; l < n; l++) { if (!hist[l].flag) { /* alloc new slot */ hist[l].flag = !0; hist[l].key = key; hist[l].freq = 1; hist[l].idx = k; lenh = l + 1; break; } else if (hist[l].key == key) { hist[l].freq++; break; } } if (minSum > sum) { minSum = sum; minCol = k; } if (maxSum < sum) { maxSum = sum; maxCol = k; } } if (lenh <= nv) { for (j = 0; j < lenh; j++) { for (i = 0; i < nc; i++) { vec[j][i] = (GLfloat)input[hist[j].idx][i]; } } for (; j < nv; j++) { for (i = 0; i < nc; i++) { vec[j][i] = vec[0][i]; } } return 0; } for (j = 0; j < nv; j++) { for (i = 0; i < nc; i++) { vec[j][i] = ((nv - 1 - j) * input[minCol][i] + j * input[maxCol][i] + (nv - 1) / 2) / (GLfloat)(nv - 1); } } #endif return !0; } static GLint fxt1_lloyd (GLfloat vec[][MAX_COMP], GLint nv, GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n) { /* Use the generalized lloyd's algorithm for VQ: * find 4 color vectors. * * for each sample color * sort to nearest vector. * * replace each vector with the centroid of it's matching colors. * * repeat until RMS doesn't improve. * * if a color vector has no samples, or becomes the same as another * vector, replace it with the color which is farthest from a sample. * * vec[][MAX_COMP] initial vectors and resulting colors * nv number of resulting colors required * input[N_TEXELS][MAX_COMP] input texels * nc number of components in input / vec * n number of input samples */ GLint sum[MAX_VECT][MAX_COMP]; /* used to accumulate closest texels */ GLint cnt[MAX_VECT]; /* how many times a certain vector was chosen */ GLfloat error, lasterror = 1e9; GLint i, j, k, rep; /* the quantizer */ for (rep = 0; rep < LL_N_REP; rep++) { /* reset sums & counters */ for (j = 0; j < nv; j++) { for (i = 0; i < nc; i++) { sum[j][i] = 0; } cnt[j] = 0; } error = 0; /* scan whole block */ for (k = 0; k < n; k++) { #if 1 GLint best = -1; GLfloat err = 1e9; /* big enough */ /* determine best vector */ for (j = 0; j < nv; j++) { GLfloat e = (vec[j][0] - input[k][0]) * (vec[j][0] - input[k][0]) + (vec[j][1] - input[k][1]) * (vec[j][1] - input[k][1]) + (vec[j][2] - input[k][2]) * (vec[j][2] - input[k][2]); if (nc == 4) { e += (vec[j][3] - input[k][3]) * (vec[j][3] - input[k][3]); } if (e < err) { err = e; best = j; } } #else GLint best = fxt1_bestcol(vec, nv, input[k], nc, &err); #endif /* add in closest color */ for (i = 0; i < nc; i++) { sum[best][i] += input[k][i]; } /* mark this vector as used */ cnt[best]++; /* accumulate error */ error += err; } /* check RMS */ if ((error < LL_RMS_E) || ((error < lasterror) && ((lasterror - error) < LL_RMS_D))) { return !0; /* good match */ } lasterror = error; /* move each vector to the barycenter of its closest colors */ for (j = 0; j < nv; j++) { if (cnt[j]) { GLfloat div = 1.0F / cnt[j]; for (i = 0; i < nc; i++) { vec[j][i] = div * sum[j][i]; } } else { /* this vec has no samples or is identical with a previous vec */ GLint worst = fxt1_worst(vec[j], input, nc, n); for (i = 0; i < nc; i++) { vec[j][i] = input[worst][i]; } } } } return 0; /* could not converge fast enough */ } static void fxt1_quantize_CHROMA (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP]) { const GLint n_vect = 4; /* 4 base vectors to find */ const GLint n_comp = 3; /* 3 components: R, G, B */ GLfloat vec[MAX_VECT][MAX_COMP]; GLint i, j, k; Fx64 hi; /* high quadword */ GLuint lohi, lolo; /* low quadword: hi dword, lo dword */ if (fxt1_choose(vec, n_vect, input, n_comp, N_TEXELS) != 0) { fxt1_lloyd(vec, n_vect, input, n_comp, N_TEXELS); } FX64_MOV32(hi, 4); /* cc-chroma = "010" + unused bit */ for (j = n_vect - 1; j >= 0; j--) { for (i = 0; i < n_comp; i++) { /* add in colors */ FX64_SHL(hi, 5); FX64_OR32(hi, (GLuint)(vec[j][i] / 8.0F)); } } ((Fx64 *)cc)[1] = hi; lohi = lolo = 0; /* right microtile */ for (k = N_TEXELS - 1; k >= N_TEXELS/2; k--) { lohi <<= 2; lohi |= fxt1_bestcol(vec, n_vect, input[k], n_comp); } /* left microtile */ for (; k >= 0; k--) { lolo <<= 2; lolo |= fxt1_bestcol(vec, n_vect, input[k], n_comp); } cc[1] = lohi; cc[0] = lolo; } static void fxt1_quantize_ALPHA0 (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP], GLubyte reord[N_TEXELS][MAX_COMP], GLint n) { const GLint n_vect = 3; /* 3 base vectors to find */ const GLint n_comp = 4; /* 4 components: R, G, B, A */ GLfloat vec[MAX_VECT][MAX_COMP]; GLint i, j, k; Fx64 hi; /* high quadword */ GLuint lohi, lolo; /* low quadword: hi dword, lo dword */ /* the last vector indicates zero */ for (i = 0; i < n_comp; i++) { vec[n_vect][i] = 0; } /* the first n texels in reord are guaranteed to be non-zero */ if (fxt1_choose(vec, n_vect, reord, n_comp, n) != 0) { fxt1_lloyd(vec, n_vect, reord, n_comp, n); } FX64_MOV32(hi, 6); /* alpha = "011" + lerp = 0 */ for (j = n_vect - 1; j >= 0; j--) { /* add in alphas */ FX64_SHL(hi, 5); FX64_OR32(hi, (GLuint)(vec[j][ACOMP] / 8.0F)); } for (j = n_vect - 1; j >= 0; j--) { for (i = 0; i < n_comp - 1; i++) { /* add in colors */ FX64_SHL(hi, 5); FX64_OR32(hi, (GLuint)(vec[j][i] / 8.0F)); } } ((Fx64 *)cc)[1] = hi; lohi = lolo = 0; /* right microtile */ for (k = N_TEXELS - 1; k >= N_TEXELS/2; k--) { lohi <<= 2; lohi |= fxt1_bestcol(vec, n_vect + 1, input[k], n_comp); } /* left microtile */ for (; k >= 0; k--) { lolo <<= 2; lolo |= fxt1_bestcol(vec, n_vect + 1, input[k], n_comp); } cc[1] = lohi; cc[0] = lolo; } static void fxt1_quantize_ALPHA1 (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP]) { const GLint n_vect = 3; /* highest vector number in each microtile */ const GLint n_comp = 4; /* 4 components: R, G, B, A */ GLfloat vec[1 + 1 + 1][MAX_COMP]; /* 1.5 extrema for each sub-block */ GLfloat b, iv[MAX_COMP]; /* interpolation vector */ GLint i, j, k; Fx64 hi; /* high quadword */ GLuint lohi, lolo; /* low quadword: hi dword, lo dword */ GLint minSum; GLint maxSum; GLint minColL = 0, maxColL = 0; GLint minColR = 0, maxColR = 0; GLint sumL = 0, sumR = 0; GLint nn_comp; /* Our solution here is to find the darkest and brightest colors in * the 4x4 tile and use those as the two representative colors. * There are probably better algorithms to use (histogram-based). */ nn_comp = n_comp; while ((minColL == maxColL) && nn_comp) { minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (k = 0; k < N_TEXELS / 2; k++) { GLint sum = 0; for (i = 0; i < nn_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColL = k; } if (maxSum < sum) { maxSum = sum; maxColL = k; } sumL += sum; } nn_comp--; } nn_comp = n_comp; while ((minColR == maxColR) && nn_comp) { minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (k = N_TEXELS / 2; k < N_TEXELS; k++) { GLint sum = 0; for (i = 0; i < nn_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColR = k; } if (maxSum < sum) { maxSum = sum; maxColR = k; } sumR += sum; } nn_comp--; } /* choose the common vector (yuck!) */ { GLint j1, j2; GLint v1 = 0, v2 = 0; GLfloat err = 1e9; /* big enough */ GLfloat tv[2 * 2][MAX_COMP]; /* 2 extrema for each sub-block */ for (i = 0; i < n_comp; i++) { tv[0][i] = input[minColL][i]; tv[1][i] = input[maxColL][i]; tv[2][i] = input[minColR][i]; tv[3][i] = input[maxColR][i]; } for (j1 = 0; j1 < 2; j1++) { for (j2 = 2; j2 < 4; j2++) { GLfloat e = 0.0F; for (i = 0; i < n_comp; i++) { e += (tv[j1][i] - tv[j2][i]) * (tv[j1][i] - tv[j2][i]); } if (e < err) { err = e; v1 = j1; v2 = j2; } } } for (i = 0; i < n_comp; i++) { vec[0][i] = tv[1 - v1][i]; vec[1][i] = (tv[v1][i] * sumL + tv[v2][i] * sumR) / (sumL + sumR); vec[2][i] = tv[5 - v2][i]; } } /* left microtile */ cc[0] = 0; if (minColL != maxColL) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[0], vec[1]); /* add in texels */ lolo = 0; for (k = N_TEXELS / 2 - 1; k >= 0; k--) { GLint texel; /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); /* add in texel */ lolo <<= 2; lolo |= texel; } cc[0] = lolo; } /* right microtile */ cc[1] = 0; if (minColR != maxColR) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[2], vec[1]); /* add in texels */ lohi = 0; for (k = N_TEXELS - 1; k >= N_TEXELS / 2; k--) { GLint texel; /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); /* add in texel */ lohi <<= 2; lohi |= texel; } cc[1] = lohi; } FX64_MOV32(hi, 7); /* alpha = "011" + lerp = 1 */ for (j = n_vect - 1; j >= 0; j--) { /* add in alphas */ FX64_SHL(hi, 5); FX64_OR32(hi, (GLuint)(vec[j][ACOMP] / 8.0F)); } for (j = n_vect - 1; j >= 0; j--) { for (i = 0; i < n_comp - 1; i++) { /* add in colors */ FX64_SHL(hi, 5); FX64_OR32(hi, (GLuint)(vec[j][i] / 8.0F)); } } ((Fx64 *)cc)[1] = hi; } static void fxt1_quantize_HI (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP], GLubyte reord[N_TEXELS][MAX_COMP], GLint n) { const GLint n_vect = 6; /* highest vector number */ const GLint n_comp = 3; /* 3 components: R, G, B */ GLfloat b = 0.0F; /* phoudoin: silent compiler! */ GLfloat iv[MAX_COMP]; /* interpolation vector */ GLint i, k; GLuint hihi; /* high quadword: hi dword */ GLint minSum = 2000; /* big enough */ GLint maxSum = -1; /* small enough */ GLint minCol = 0; /* phoudoin: silent compiler! */ GLint maxCol = 0; /* phoudoin: silent compiler! */ /* Our solution here is to find the darkest and brightest colors in * the 8x4 tile and use those as the two representative colors. * There are probably better algorithms to use (histogram-based). */ for (k = 0; k < n; k++) { GLint sum = 0; for (i = 0; i < n_comp; i++) { sum += reord[k][i]; } if (minSum > sum) { minSum = sum; minCol = k; } if (maxSum < sum) { maxSum = sum; maxCol = k; } } hihi = 0; /* cc-hi = "00" */ for (i = 0; i < n_comp; i++) { /* add in colors */ hihi <<= 5; hihi |= reord[maxCol][i] >> 3; } for (i = 0; i < n_comp; i++) { /* add in colors */ hihi <<= 5; hihi |= reord[minCol][i] >> 3; } cc[3] = hihi; cc[0] = cc[1] = cc[2] = 0; /* compute interpolation vector */ if (minCol != maxCol) { MAKEIVEC(n_vect, n_comp, iv, b, reord[minCol], reord[maxCol]); } /* add in texels */ for (k = N_TEXELS - 1; k >= 0; k--) { GLint t = k * 3; GLuint *kk = (GLuint *)((char *)cc + t / 8); GLint texel = n_vect + 1; /* transparent black */ if (!ISTBLACK(input[k])) { if (minCol != maxCol) { /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); /* add in texel */ kk[0] |= texel << (t & 7); } } else { /* add in texel */ kk[0] |= texel << (t & 7); } } } static void fxt1_quantize_MIXED1 (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP]) { const GLint n_vect = 2; /* highest vector number in each microtile */ const GLint n_comp = 3; /* 3 components: R, G, B */ GLubyte vec[2 * 2][MAX_COMP]; /* 2 extrema for each sub-block */ GLfloat b, iv[MAX_COMP]; /* interpolation vector */ GLint i, j, k; Fx64 hi; /* high quadword */ GLuint lohi, lolo; /* low quadword: hi dword, lo dword */ GLint minSum; GLint maxSum; GLint minColL = 0, maxColL = -1; GLint minColR = 0, maxColR = -1; /* Our solution here is to find the darkest and brightest colors in * the 4x4 tile and use those as the two representative colors. * There are probably better algorithms to use (histogram-based). */ minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (k = 0; k < N_TEXELS / 2; k++) { if (!ISTBLACK(input[k])) { GLint sum = 0; for (i = 0; i < n_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColL = k; } if (maxSum < sum) { maxSum = sum; maxColL = k; } } } minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (; k < N_TEXELS; k++) { if (!ISTBLACK(input[k])) { GLint sum = 0; for (i = 0; i < n_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColR = k; } if (maxSum < sum) { maxSum = sum; maxColR = k; } } } /* left microtile */ if (maxColL == -1) { /* all transparent black */ cc[0] = ~0u; for (i = 0; i < n_comp; i++) { vec[0][i] = 0; vec[1][i] = 0; } } else { cc[0] = 0; for (i = 0; i < n_comp; i++) { vec[0][i] = input[minColL][i]; vec[1][i] = input[maxColL][i]; } if (minColL != maxColL) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[0], vec[1]); /* add in texels */ lolo = 0; for (k = N_TEXELS / 2 - 1; k >= 0; k--) { GLint texel = n_vect + 1; /* transparent black */ if (!ISTBLACK(input[k])) { /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); } /* add in texel */ lolo <<= 2; lolo |= texel; } cc[0] = lolo; } } /* right microtile */ if (maxColR == -1) { /* all transparent black */ cc[1] = ~0u; for (i = 0; i < n_comp; i++) { vec[2][i] = 0; vec[3][i] = 0; } } else { cc[1] = 0; for (i = 0; i < n_comp; i++) { vec[2][i] = input[minColR][i]; vec[3][i] = input[maxColR][i]; } if (minColR != maxColR) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[2], vec[3]); /* add in texels */ lohi = 0; for (k = N_TEXELS - 1; k >= N_TEXELS / 2; k--) { GLint texel = n_vect + 1; /* transparent black */ if (!ISTBLACK(input[k])) { /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); } /* add in texel */ lohi <<= 2; lohi |= texel; } cc[1] = lohi; } } FX64_MOV32(hi, 9 | (vec[3][GCOMP] & 4) | ((vec[1][GCOMP] >> 1) & 2)); /* chroma = "1" */ for (j = 2 * 2 - 1; j >= 0; j--) { for (i = 0; i < n_comp; i++) { /* add in colors */ FX64_SHL(hi, 5); FX64_OR32(hi, vec[j][i] >> 3); } } ((Fx64 *)cc)[1] = hi; } static void fxt1_quantize_MIXED0 (GLuint *cc, GLubyte input[N_TEXELS][MAX_COMP]) { const GLint n_vect = 3; /* highest vector number in each microtile */ const GLint n_comp = 3; /* 3 components: R, G, B */ GLubyte vec[2 * 2][MAX_COMP]; /* 2 extrema for each sub-block */ GLfloat b, iv[MAX_COMP]; /* interpolation vector */ GLint i, j, k; Fx64 hi; /* high quadword */ GLuint lohi, lolo; /* low quadword: hi dword, lo dword */ GLint minColL = 0, maxColL = 0; GLint minColR = 0, maxColR = 0; #if 0 GLint minSum; GLint maxSum; /* Our solution here is to find the darkest and brightest colors in * the 4x4 tile and use those as the two representative colors. * There are probably better algorithms to use (histogram-based). */ minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (k = 0; k < N_TEXELS / 2; k++) { GLint sum = 0; for (i = 0; i < n_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColL = k; } if (maxSum < sum) { maxSum = sum; maxColL = k; } } minSum = 2000; /* big enough */ maxSum = -1; /* small enough */ for (; k < N_TEXELS; k++) { GLint sum = 0; for (i = 0; i < n_comp; i++) { sum += input[k][i]; } if (minSum > sum) { minSum = sum; minColR = k; } if (maxSum < sum) { maxSum = sum; maxColR = k; } } #else GLint minVal; GLint maxVal; GLint maxVarL = fxt1_variance(NULL, input, n_comp, N_TEXELS / 2); GLint maxVarR = fxt1_variance(NULL, &input[N_TEXELS / 2], n_comp, N_TEXELS / 2); /* Scan the channel with max variance for lo & hi * and use those as the two representative colors. */ minVal = 2000; /* big enough */ maxVal = -1; /* small enough */ for (k = 0; k < N_TEXELS / 2; k++) { GLint t = input[k][maxVarL]; if (minVal > t) { minVal = t; minColL = k; } if (maxVal < t) { maxVal = t; maxColL = k; } } minVal = 2000; /* big enough */ maxVal = -1; /* small enough */ for (; k < N_TEXELS; k++) { GLint t = input[k][maxVarR]; if (minVal > t) { minVal = t; minColR = k; } if (maxVal < t) { maxVal = t; maxColR = k; } } #endif /* left microtile */ cc[0] = 0; for (i = 0; i < n_comp; i++) { vec[0][i] = input[minColL][i]; vec[1][i] = input[maxColL][i]; } if (minColL != maxColL) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[0], vec[1]); /* add in texels */ lolo = 0; for (k = N_TEXELS / 2 - 1; k >= 0; k--) { GLint texel; /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); /* add in texel */ lolo <<= 2; lolo |= texel; } /* funky encoding for LSB of green */ if ((GLint)((lolo >> 1) & 1) != (((vec[1][GCOMP] ^ vec[0][GCOMP]) >> 2) & 1)) { for (i = 0; i < n_comp; i++) { vec[1][i] = input[minColL][i]; vec[0][i] = input[maxColL][i]; } lolo = ~lolo; } cc[0] = lolo; } /* right microtile */ cc[1] = 0; for (i = 0; i < n_comp; i++) { vec[2][i] = input[minColR][i]; vec[3][i] = input[maxColR][i]; } if (minColR != maxColR) { /* compute interpolation vector */ MAKEIVEC(n_vect, n_comp, iv, b, vec[2], vec[3]); /* add in texels */ lohi = 0; for (k = N_TEXELS - 1; k >= N_TEXELS / 2; k--) { GLint texel; /* interpolate color */ CALCCDOT(texel, n_vect, n_comp, iv, b, input[k]); /* add in texel */ lohi <<= 2; lohi |= texel; } /* funky encoding for LSB of green */ if ((GLint)((lohi >> 1) & 1) != (((vec[3][GCOMP] ^ vec[2][GCOMP]) >> 2) & 1)) { for (i = 0; i < n_comp; i++) { vec[3][i] = input[minColR][i]; vec[2][i] = input[maxColR][i]; } lohi = ~lohi; } cc[1] = lohi; } FX64_MOV32(hi, 8 | (vec[3][GCOMP] & 4) | ((vec[1][GCOMP] >> 1) & 2)); /* chroma = "1" */ for (j = 2 * 2 - 1; j >= 0; j--) { for (i = 0; i < n_comp; i++) { /* add in colors */ FX64_SHL(hi, 5); FX64_OR32(hi, vec[j][i] >> 3); } } ((Fx64 *)cc)[1] = hi; } static void fxt1_quantize (GLuint *cc, const GLubyte *lines[], GLint comps) { GLint trualpha; GLubyte reord[N_TEXELS][MAX_COMP]; GLubyte input[N_TEXELS][MAX_COMP]; GLint i, k, l; if (comps == 3) { /* make the whole block opaque */ _mesa_memset(input, -1, sizeof(input)); } /* 8 texels each line */ for (l = 0; l < 4; l++) { for (k = 0; k < 4; k++) { for (i = 0; i < comps; i++) { input[k + l * 4][i] = *lines[l]++; } } for (; k < 8; k++) { for (i = 0; i < comps; i++) { input[k + l * 4 + 12][i] = *lines[l]++; } } } /* block layout: * 00, 01, 02, 03, 08, 09, 0a, 0b * 10, 11, 12, 13, 18, 19, 1a, 1b * 04, 05, 06, 07, 0c, 0d, 0e, 0f * 14, 15, 16, 17, 1c, 1d, 1e, 1f */ /* [dBorca] * stupidity flows forth from this */ l = N_TEXELS; trualpha = 0; if (comps == 4) { /* skip all transparent black texels */ l = 0; for (k = 0; k < N_TEXELS; k++) { /* test all components against 0 */ if (!ISTBLACK(input[k])) { /* texel is not transparent black */ COPY_4UBV(reord[l], input[k]); if (reord[l][ACOMP] < (255 - ALPHA_TS)) { /* non-opaque texel */ trualpha = !0; } l++; } } } #if 0 if (trualpha) { fxt1_quantize_ALPHA0(cc, input, reord, l); } else if (l == 0) { cc[0] = cc[1] = cc[2] = -1; cc[3] = 0; } else if (l < N_TEXELS) { fxt1_quantize_HI(cc, input, reord, l); } else { fxt1_quantize_CHROMA(cc, input); } (void)fxt1_quantize_ALPHA1; (void)fxt1_quantize_MIXED1; (void)fxt1_quantize_MIXED0; #else if (trualpha) { fxt1_quantize_ALPHA1(cc, input); } else if (l == 0) { cc[0] = cc[1] = cc[2] = ~0u; cc[3] = 0; } else if (l < N_TEXELS) { fxt1_quantize_MIXED1(cc, input); } else { fxt1_quantize_MIXED0(cc, input); } (void)fxt1_quantize_ALPHA0; (void)fxt1_quantize_HI; (void)fxt1_quantize_CHROMA; #endif } static void fxt1_encode (GLuint width, GLuint height, GLint comps, const void *source, GLint srcRowStride, void *dest, GLint destRowStride) { GLuint x, y; const GLubyte *data; GLuint *encoded = (GLuint *)dest; void *newSource = NULL; assert(comps == 3 || comps == 4); /* Replicate image if width is not M8 or height is not M4 */ if ((width & 7) | (height & 3)) { GLint newWidth = (width + 7) & ~7; GLint newHeight = (height + 3) & ~3; newSource = _mesa_malloc(comps * newWidth * newHeight * sizeof(GLchan)); if (!newSource) { GET_CURRENT_CONTEXT(ctx); _mesa_error(ctx, GL_OUT_OF_MEMORY, "texture compression"); goto cleanUp; } _mesa_upscale_teximage2d(width, height, newWidth, newHeight, comps, (const GLchan *) source, srcRowStride, (GLchan *) newSource); source = newSource; width = newWidth; height = newHeight; srcRowStride = comps * newWidth; } /* convert from 16/32-bit channels to GLubyte if needed */ if (CHAN_TYPE != GL_UNSIGNED_BYTE) { const GLuint n = width * height * comps; const GLchan *src = (const GLchan *) source; GLubyte *dest = (GLubyte *) _mesa_malloc(n * sizeof(GLubyte)); GLuint i; if (!dest) { GET_CURRENT_CONTEXT(ctx); _mesa_error(ctx, GL_OUT_OF_MEMORY, "texture compression"); goto cleanUp; } for (i = 0; i < n; i++) { dest[i] = CHAN_TO_UBYTE(src[i]); } if (newSource != NULL) { _mesa_free(newSource); } newSource = dest; /* we'll free this buffer before returning */ source = dest; /* the new, GLubyte incoming image */ } data = (const GLubyte *) source; destRowStride = (destRowStride - width * 2) / 4; for (y = 0; y < height; y += 4) { GLuint offs = 0 + (y + 0) * srcRowStride; for (x = 0; x < width; x += 8) { const GLubyte *lines[4]; lines[0] = &data[offs]; lines[1] = lines[0] + srcRowStride; lines[2] = lines[1] + srcRowStride; lines[3] = lines[2] + srcRowStride; offs += 8 * comps; fxt1_quantize(encoded, lines, comps); /* 128 bits per 8x4 block */ encoded += 4; } encoded += destRowStride; } cleanUp: if (newSource != NULL) { _mesa_free(newSource); } } /***************************************************************************\ * FXT1 decoder * * The decoder is based on GL_3DFX_texture_compression_FXT1 * specification and serves as a concept for the encoder. \***************************************************************************/ /* lookup table for scaling 5 bit colors up to 8 bits */ static const GLubyte _rgb_scale_5[] = { 0, 8, 16, 25, 33, 41, 49, 58, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, 197, 206, 214, 222, 230, 239, 247, 255 }; /* lookup table for scaling 6 bit colors up to 8 bits */ static const GLubyte _rgb_scale_6[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142, 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255 }; #define CC_SEL(cc, which) (((GLuint *)(cc))[(which) / 32] >> ((which) & 31)) #define UP5(c) _rgb_scale_5[(c) & 31] #define UP6(c, b) _rgb_scale_6[(((c) & 31) << 1) | ((b) & 1)] #define LERP(n, t, c0, c1) (((n) - (t)) * (c0) + (t) * (c1) + (n) / 2) / (n) static void fxt1_decode_1HI (const GLubyte *code, GLint t, GLchan *rgba) { const GLuint *cc; t *= 3; cc = (const GLuint *)(code + t / 8); t = (cc[0] >> (t & 7)) & 7; if (t == 7) { rgba[RCOMP] = rgba[GCOMP] = rgba[BCOMP] = rgba[ACOMP] = 0; } else { GLubyte r, g, b; cc = (const GLuint *)(code + 12); if (t == 0) { b = UP5(CC_SEL(cc, 0)); g = UP5(CC_SEL(cc, 5)); r = UP5(CC_SEL(cc, 10)); } else if (t == 6) { b = UP5(CC_SEL(cc, 15)); g = UP5(CC_SEL(cc, 20)); r = UP5(CC_SEL(cc, 25)); } else { b = LERP(6, t, UP5(CC_SEL(cc, 0)), UP5(CC_SEL(cc, 15))); g = LERP(6, t, UP5(CC_SEL(cc, 5)), UP5(CC_SEL(cc, 20))); r = LERP(6, t, UP5(CC_SEL(cc, 10)), UP5(CC_SEL(cc, 25))); } rgba[RCOMP] = UBYTE_TO_CHAN(r); rgba[GCOMP] = UBYTE_TO_CHAN(g); rgba[BCOMP] = UBYTE_TO_CHAN(b); rgba[ACOMP] = CHAN_MAX; } } static void fxt1_decode_1CHROMA (const GLubyte *code, GLint t, GLchan *rgba) { const GLuint *cc; GLuint kk; cc = (const GLuint *)code; if (t & 16) { cc++; t &= 15; } t = (cc[0] >> (t * 2)) & 3; t *= 15; cc = (const GLuint *)(code + 8 + t / 8); kk = cc[0] >> (t & 7); rgba[BCOMP] = UBYTE_TO_CHAN( UP5(kk) ); rgba[GCOMP] = UBYTE_TO_CHAN( UP5(kk >> 5) ); rgba[RCOMP] = UBYTE_TO_CHAN( UP5(kk >> 10) ); rgba[ACOMP] = CHAN_MAX; } static void fxt1_decode_1MIXED (const GLubyte *code, GLint t, GLchan *rgba) { const GLuint *cc; GLuint col[2][3]; GLint glsb, selb; cc = (const GLuint *)code; if (t & 16) { t &= 15; t = (cc[1] >> (t * 2)) & 3; /* col 2 */ col[0][BCOMP] = (*(const GLuint *)(code + 11)) >> 6; col[0][GCOMP] = CC_SEL(cc, 99); col[0][RCOMP] = CC_SEL(cc, 104); /* col 3 */ col[1][BCOMP] = CC_SEL(cc, 109); col[1][GCOMP] = CC_SEL(cc, 114); col[1][RCOMP] = CC_SEL(cc, 119); glsb = CC_SEL(cc, 126); selb = CC_SEL(cc, 33); } else { t = (cc[0] >> (t * 2)) & 3; /* col 0 */ col[0][BCOMP] = CC_SEL(cc, 64); col[0][GCOMP] = CC_SEL(cc, 69); col[0][RCOMP] = CC_SEL(cc, 74); /* col 1 */ col[1][BCOMP] = CC_SEL(cc, 79); col[1][GCOMP] = CC_SEL(cc, 84); col[1][RCOMP] = CC_SEL(cc, 89); glsb = CC_SEL(cc, 125); selb = CC_SEL(cc, 1); } if (CC_SEL(cc, 124) & 1) { /* alpha[0] == 1 */ if (t == 3) { /* zero */ rgba[RCOMP] = rgba[BCOMP] = rgba[GCOMP] = rgba[ACOMP] = 0; } else { GLubyte r, g, b; if (t == 0) { b = UP5(col[0][BCOMP]); g = UP5(col[0][GCOMP]); r = UP5(col[0][RCOMP]); } else if (t == 2) { b = UP5(col[1][BCOMP]); g = UP6(col[1][GCOMP], glsb); r = UP5(col[1][RCOMP]); } else { b = (UP5(col[0][BCOMP]) + UP5(col[1][BCOMP])) / 2; g = (UP5(col[0][GCOMP]) + UP6(col[1][GCOMP], glsb)) / 2; r = (UP5(col[0][RCOMP]) + UP5(col[1][RCOMP])) / 2; } rgba[RCOMP] = UBYTE_TO_CHAN(r); rgba[GCOMP] = UBYTE_TO_CHAN(g); rgba[BCOMP] = UBYTE_TO_CHAN(b); rgba[ACOMP] = CHAN_MAX; } } else { /* alpha[0] == 0 */ GLubyte r, g, b; if (t == 0) { b = UP5(col[0][BCOMP]); g = UP6(col[0][GCOMP], glsb ^ selb); r = UP5(col[0][RCOMP]); } else if (t == 3) { b = UP5(col[1][BCOMP]); g = UP6(col[1][GCOMP], glsb); r = UP5(col[1][RCOMP]); } else { b = LERP(3, t, UP5(col[0][BCOMP]), UP5(col[1][BCOMP])); g = LERP(3, t, UP6(col[0][GCOMP], glsb ^ selb), UP6(col[1][GCOMP], glsb)); r = LERP(3, t, UP5(col[0][RCOMP]), UP5(col[1][RCOMP])); } rgba[RCOMP] = UBYTE_TO_CHAN(r); rgba[GCOMP] = UBYTE_TO_CHAN(g); rgba[BCOMP] = UBYTE_TO_CHAN(b); rgba[ACOMP] = CHAN_MAX; } } static void fxt1_decode_1ALPHA (const GLubyte *code, GLint t, GLchan *rgba) { const GLuint *cc; GLubyte r, g, b, a; cc = (const GLuint *)code; if (CC_SEL(cc, 124) & 1) { /* lerp == 1 */ GLuint col0[4]; if (t & 16) { t &= 15; t = (cc[1] >> (t * 2)) & 3; /* col 2 */ col0[BCOMP] = (*(const GLuint *)(code + 11)) >> 6; col0[GCOMP] = CC_SEL(cc, 99); col0[RCOMP] = CC_SEL(cc, 104); col0[ACOMP] = CC_SEL(cc, 119); } else { t = (cc[0] >> (t * 2)) & 3; /* col 0 */ col0[BCOMP] = CC_SEL(cc, 64); col0[GCOMP] = CC_SEL(cc, 69); col0[RCOMP] = CC_SEL(cc, 74); col0[ACOMP] = CC_SEL(cc, 109); } if (t == 0) { b = UP5(col0[BCOMP]); g = UP5(col0[GCOMP]); r = UP5(col0[RCOMP]); a = UP5(col0[ACOMP]); } else if (t == 3) { b = UP5(CC_SEL(cc, 79)); g = UP5(CC_SEL(cc, 84)); r = UP5(CC_SEL(cc, 89)); a = UP5(CC_SEL(cc, 114)); } else { b = LERP(3, t, UP5(col0[BCOMP]), UP5(CC_SEL(cc, 79))); g = LERP(3, t, UP5(col0[GCOMP]), UP5(CC_SEL(cc, 84))); r = LERP(3, t, UP5(col0[RCOMP]), UP5(CC_SEL(cc, 89))); a = LERP(3, t, UP5(col0[ACOMP]), UP5(CC_SEL(cc, 114))); } } else { /* lerp == 0 */ if (t & 16) { cc++; t &= 15; } t = (cc[0] >> (t * 2)) & 3; if (t == 3) { /* zero */ r = g = b = a = 0; } else { GLuint kk; cc = (const GLuint *)code; a = UP5(cc[3] >> (t * 5 + 13)); t *= 15; cc = (const GLuint *)(code + 8 + t / 8); kk = cc[0] >> (t & 7); b = UP5(kk); g = UP5(kk >> 5); r = UP5(kk >> 10); } } rgba[RCOMP] = UBYTE_TO_CHAN(r); rgba[GCOMP] = UBYTE_TO_CHAN(g); rgba[BCOMP] = UBYTE_TO_CHAN(b); rgba[ACOMP] = UBYTE_TO_CHAN(a); } void fxt1_decode_1 (const void *texture, GLint stride, /* in pixels */ GLint i, GLint j, GLchan *rgba) { static void (*decode_1[]) (const GLubyte *, GLint, GLchan *) = { fxt1_decode_1HI, /* cc-high = "00?" */ fxt1_decode_1HI, /* cc-high = "00?" */ fxt1_decode_1CHROMA, /* cc-chroma = "010" */ fxt1_decode_1ALPHA, /* alpha = "011" */ fxt1_decode_1MIXED, /* mixed = "1??" */ fxt1_decode_1MIXED, /* mixed = "1??" */ fxt1_decode_1MIXED, /* mixed = "1??" */ fxt1_decode_1MIXED /* mixed = "1??" */ }; const GLubyte *code = (const GLubyte *)texture + ((j / 4) * (stride / 8) + (i / 8)) * 16; GLint mode = CC_SEL(code, 125); GLint t = i & 7; if (t & 4) { t += 12; } t += (j & 3) * 4; decode_1[mode](code, t, rgba); }