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gem5 / public / gem5-resources / 8ccd059d5dcaaeffe15cd93c17f1e76e92907662 / . / src / parsec / disk-image / parsec / parsec-benchmark / pkgs / libs / mesa / src / src / mesa / main / texcompress_fxt1.c
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/*
* 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 "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;
}
/**
* Called via TexFormat->StoreImage to store an RGB_FXT1 texture.
*/
static GLboolean
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_texformat_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,
dstFormat->BaseFormat,
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->MesaFormat,
texWidth, (GLubyte *) dstAddr);
fxt1_encode(srcWidth, srcHeight, 3, pixels, srcRowStride,
dst, dstRowStride);
if (tempImage)
_mesa_free((void*) tempImage);
return GL_TRUE;
}
/**
* Called via TexFormat->StoreImage to store an RGBA_FXT1 texture.
*/
static GLboolean
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_texformat_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,
dstFormat->BaseFormat,
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->MesaFormat,
texWidth, (GLubyte *) dstAddr);
fxt1_encode(srcWidth, srcHeight, 4, pixels, srcRowStride,
dst, dstRowStride);
if (tempImage)
_mesa_free((void*) tempImage);
return GL_TRUE;
}
static void
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);
}
static void
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]);
}
static void
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;
}
static void
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 */
texstore_rgb_fxt1, /* StoreTexImageFunc */
NULL, /*impossible*/ /* FetchTexel1D */
fetch_texel_2d_rgb_fxt1, /* FetchTexel2D */
NULL, /*impossible*/ /* FetchTexel3D */
NULL, /*impossible*/ /* FetchTexel1Df */
fetch_texel_2d_f_rgb_fxt1, /* FetchTexel2Df */
NULL, /*impossible*/ /* FetchTexel3Df */
NULL /* StoreTexel */
};
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 */
texstore_rgba_fxt1, /* StoreTexImageFunc */
NULL, /*impossible*/ /* FetchTexel1D */
fetch_texel_2d_rgba_fxt1, /* FetchTexel2D */
NULL, /*impossible*/ /* FetchTexel3D */
NULL, /*impossible*/ /* FetchTexel1Df */
fetch_texel_2d_f_rgba_fxt1, /* FetchTexel2Df */
NULL, /*impossible*/ /* FetchTexel3Df */
NULL /* StoreTexel */
};
/***************************************************************************\
* 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
*/
#ifdef GL_EXT_timer_query /* this extensions defines the GLuint64EXT type */
#define FX64_NATIVE 1
typedef GLuint64EXT Fx64;
#define FX64_MOV32(a, b) a = b
#define FX64_OR32(a, b) a |= b
#define FX64_SHL(a, c) a <<= c
#else /* !GL_EXT_timer_query */
#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 /* !GL_EXT_timer_query */
#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);
}