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-rw-r--r--src/mesa/main/texcompress_fxt1.c675
1 files changed, 640 insertions, 35 deletions
diff --git a/src/mesa/main/texcompress_fxt1.c b/src/mesa/main/texcompress_fxt1.c
index 5a37a259c73..cd5b0c3d603 100644
--- a/src/mesa/main/texcompress_fxt1.c
+++ b/src/mesa/main/texcompress_fxt1.c
@@ -26,6 +26,7 @@
/**
* \file texcompress_fxt1.c
* GL_EXT_texture_compression_fxt1 support.
+ * \author Daniel Borca
*/
@@ -40,15 +41,15 @@
#include "texstore.h"
-static GLuint
-compress_fxt1 (GLcontext *ctx,
- GLsizei srcWidth,
- GLsizei srcHeight,
- GLenum srcFormat,
- const GLchan *source,
- GLint srcRowStride,
- GLubyte *dest,
- GLint dstRowStride);
+int
+fxt1_encode (GLcontext *ctx,
+ unsigned int width, unsigned int height,
+ int srcFormat,
+ const void *source, int srcRowStride,
+ void *dest, int destRowStride);
+void
+fxt1_decode_1 (const void *texture, int width,
+ int i, int j, unsigned char *rgba);
/**
@@ -77,17 +78,14 @@ texstore_rgb_fxt1(STORE_PARAMS)
ASSERT(dstYoffset % 4 == 0);
ASSERT(dstZoffset == 0);
- /* [dBorca]
- * we still need to pass 4byte/texel to the codec
- */
- if (1 || srcFormat != GL_RGB ||
+ 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*/GL_RGBA,
+ dstFormat->BaseFormat,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType, srcAddr,
srcPacking);
@@ -95,7 +93,7 @@ texstore_rgb_fxt1(STORE_PARAMS)
return GL_FALSE; /* out of memory */
_mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
pixels = tempImage;
- srcRowStride = /*3*/4 * srcWidth;
+ srcRowStride = 3 * srcWidth;
srcFormat = GL_RGB;
}
else {
@@ -108,11 +106,11 @@ texstore_rgb_fxt1(STORE_PARAMS)
GL_COMPRESSED_RGB_FXT1_3DFX,
texWidth, (GLubyte *) dstAddr);
- compress_fxt1(ctx, srcWidth, srcHeight, srcFormat, pixels, srcRowStride,
- dst, dstRowStride);
+ fxt1_encode(ctx, srcWidth, srcHeight, srcFormat, pixels, srcRowStride,
+ dst, dstRowStride);
if (tempImage)
- _mesa_free((void *) tempImage);
+ _mesa_free((void*) tempImage);
return GL_TRUE;
}
@@ -163,8 +161,8 @@ texstore_rgba_fxt1(STORE_PARAMS)
GL_COMPRESSED_RGBA_FXT1_3DFX,
texWidth, (GLubyte *) dstAddr);
- compress_fxt1(ctx, srcWidth, srcHeight, srcFormat, pixels, srcRowStride,
- dst, dstRowStride);
+ fxt1_encode(ctx, srcWidth, srcHeight, srcFormat, pixels, srcRowStride,
+ dst, dstRowStride);
if (tempImage)
_mesa_free((void*) tempImage);
@@ -177,7 +175,7 @@ static void
fetch_texel_2d_rgba_fxt1( const struct gl_texture_image *texImage,
GLint i, GLint j, GLint k, GLchan *texel )
{
- /* XXX to do */
+ fxt1_decode_1(texImage->Data, texImage->Width, i, j, texel);
}
@@ -187,7 +185,7 @@ fetch_texel_2d_f_rgba_fxt1( const struct gl_texture_image *texImage,
{
/* just sample as GLchan and convert to float here */
GLchan rgba[4];
- fetch_texel_2d_rgba_fxt1(texImage, i, j, k, rgba);
+ fxt1_decode_1(texImage->Data, texImage->Width, i, j, rgba);
texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
@@ -199,7 +197,8 @@ static void
fetch_texel_2d_rgb_fxt1( const struct gl_texture_image *texImage,
GLint i, GLint j, GLint k, GLchan *texel )
{
- /* XXX to do */
+ fxt1_decode_1(texImage->Data, texImage->Width, i, j, texel);
+ texel[ACOMP] = 255;
}
@@ -209,11 +208,11 @@ fetch_texel_2d_f_rgb_fxt1( const struct gl_texture_image *texImage,
{
/* just sample as GLchan and convert to float here */
GLchan rgba[4];
- fetch_texel_2d_rgb_fxt1(texImage, i, j, k, rgba);
+ fxt1_decode_1(texImage->Data, texImage->Width, 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]);
+ texel[ACOMP] = 1.0;
}
@@ -263,16 +262,622 @@ const struct gl_texture_format _mesa_texformat_rgba_fxt1 = {
};
-static GLuint
-compress_fxt1 (GLcontext *ctx,
- GLsizei srcWidth,
- GLsizei srcHeight,
- GLenum srcFormat,
- const GLchan *source,
- GLint srcRowStride,
- GLubyte *dest,
- GLint dstRowStride)
+/***************************************************************************\
+ * 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 higly UNoptimized;
+ * moreover it is sub-optimal due to Lloyd's algorithm.
+ * Only CHROMA and non-lerp ALPHA is implemented!
+\***************************************************************************/
+
+
+#define MAX_COMP 4 /* ever meeded 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_MAX_E 255 /* fault tolerance (maximum error) */
+
+
+static int
+fxt1_besterr (float vec[][MAX_COMP], int nv,
+ unsigned char input[MAX_COMP], int nc,
+ float *d)
+{
+ int i, j, best = -1;
+ float err = 1e5; /* big enough */
+
+ for (j = 0; j < nv; j++) {
+ float e = 0;
+ for (i = 0; i < nc; i++) {
+ e += (vec[j][i] - input[i]) * (vec[j][i] - input[i]);
+ }
+ if (e < err) {
+ err = e;
+ best = j;
+ }
+ }
+
+ *d = err;
+ return best;
+}
+
+
+static int
+fxt1_worsterr (float vec[MAX_COMP],
+ unsigned char input[N_TEXELS][MAX_COMP], int nc, int n)
+{
+ int i, k, worst = -1;
+ float err = -1; /* small enough */
+
+ for (k = 0; k < n; k++) {
+ float e = 0;
+ 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 void
+fxt1_lloyd (float vec[][MAX_COMP], int nv,
+ unsigned char input[N_TEXELS][MAX_COMP], int nc, int 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] 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
+ */
+
+ int sum[MAX_VECT][MAX_COMP]; /* used to accumulate closest texels */
+ int cnt[MAX_VECT]; /* how many times a certain vector was chosen */
+ float error;
+
+ int i, j, k, rep;
+
+ /* choose the base vectors from input */
+ for (j = 0; j < nv; j++) {
+ int m = j * (n - 1) / (nv - 1);
+ for (i = 0; i < nc; i++) {
+ vec[j][i] = input[m][i];
+ }
+ }
+
+ /* 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++) {
+ float d;
+ int best = fxt1_besterr(vec, nv, input[k], nc, &d);
+ /* 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 += d;
+ }
+
+ /* accumulated distance (error) small enough? */
+ if (error < LL_MAX_E) {
+ break;
+ }
+
+ /* move each vector to the barycenter of its closest colors */
+ for (j = 0; j < nv; j++) {
+ if (cnt[j]) {
+ float div = 1.0 / 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 */
+ int worst = fxt1_worsterr(vec[j], input, nc, n);
+ for (i = 0; i < nc; i++) {
+ vec[j][i] = input[worst][i];
+ }
+ }
+ }
+ }
+}
+
+
+static void
+fxt1_quantize_CHROMA (unsigned long *cc,
+ unsigned char input[N_TEXELS][MAX_COMP])
+{
+ const int n_vect = 4; /* 4 base vectors to find */
+ const int n_comp = 3; /* 3 components: R, G, B */
+ float vec[MAX_VECT][MAX_COMP];
+ int i, j, k;
+ unsigned long long hihi; /* high quadword */
+ unsigned long lohi, lolo; /* low quadword: hi dword, lo dword */
+ float d;
+
+ fxt1_lloyd(vec, n_vect, input, n_comp, N_TEXELS);
+
+ hihi = 4; /* cc-chroma = "010" + unused bit */
+ for (j = 0; j < n_vect; j++) {
+ for (i = 0; i < n_comp; i++) {
+ /* add in colors */
+ hihi <<= 5;
+ hihi |= (unsigned int)vec[n_vect - 1 - j][i] >> 3;
+ }
+ }
+ ((unsigned long long *)cc)[1] = hihi;
+
+ lohi = lolo = 0;
+ /* right microtile */
+ for (k = N_TEXELS - 1; k >= N_TEXELS/2; k--) {
+ lohi <<= 2;
+ lohi |= fxt1_besterr(vec, n_vect, input[k], n_comp, &d);
+ }
+ /* left microtile */
+ for (; k >= 0; k--) {
+ lolo <<= 2;
+ lolo |= fxt1_besterr(vec, n_vect, input[k], n_comp, &d);
+ }
+ cc[1] = lohi;
+ cc[0] = lolo;
+}
+
+
+static void
+fxt1_quantize_ALPHA0 (unsigned long *cc,
+ unsigned char input[N_TEXELS][MAX_COMP],
+ unsigned char reord[N_TEXELS][MAX_COMP], int n)
+{
+ const int n_vect = 3; /* 3 base vectors to find */
+ const int n_comp = 4; /* 4 components: R, G, B, A */
+ float vec[MAX_VECT][MAX_COMP];
+ int i, j, k;
+ unsigned long long hihi; /* high quadword */
+ unsigned long lohi, lolo; /* low quadword: hi dword, lo dword */
+ float d;
+
+ /* 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 */
+ fxt1_lloyd(vec, n_vect, reord, n_comp, n);
+
+ hihi = 6; /* alpha = "011" + lerp = 0 */
+ for (j = 0; j < n_vect; j++) {
+ /* add in alphas */
+ hihi <<= 5;
+ hihi |= (unsigned int)vec[n_vect - 1 - j][n_comp - 1] >> 3;
+ }
+ for (j = 0; j < n_vect; j++) {
+ for (i = 0; i < n_comp - 1; i++) {
+ /* add in colors */
+ hihi <<= 5;
+ hihi |= (unsigned int)vec[n_vect - 1 - j][i] >> 3;
+ }
+ }
+ ((unsigned long long *)cc)[1] = hihi;
+
+ lohi = lolo = 0;
+ /* right microtile */
+ for (k = N_TEXELS - 1; k >= N_TEXELS/2; k--) {
+ lohi <<= 2;
+ lohi |= fxt1_besterr(vec, n_vect + 1, input[k], n_comp, &d);
+ }
+ /* left microtile */
+ for (; k >= 0; k--) {
+ lolo <<= 2;
+ lolo |= fxt1_besterr(vec, n_vect + 1, input[k], n_comp, &d);
+ }
+ cc[1] = lohi;
+ cc[0] = lolo;
+}
+
+
+static void
+fxt1_quantize (unsigned long *cc, const unsigned char *lines[], int comps)
{
- /* here be dragons */
+ int trualpha = 0;
+ unsigned char reord[N_TEXELS][MAX_COMP];
+
+ unsigned char input[N_TEXELS][MAX_COMP];
+ int i, k, l;
+
+ /* 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 (; i < MAX_COMP; i++) {
+ input[k + l * 4][i] = 255;
+ }
+ }
+ for (k = 0; k < 4; k++) {
+ for (i = 0; i < comps; i++) {
+ input[k + l * 4 + 16][i] = *lines[l]++;
+ }
+ for (; i < MAX_COMP; i++) {
+ input[k + l * 4 + 16][i] = 255;
+ }
+ }
+ }
+
+ /* [dBorca]
+ * stupidity flows forth from this
+ */
+
+ if (comps == 4) {
+ /* skip all transparent black texels */
+ l = 0;
+ for (k = 0; k < N_TEXELS; k++) {
+ int t = 0;
+ /* test all components against 0 */
+ for (i = 0; i < comps; i++) {
+ reord[l][i] = input[k][i];
+ t += input[k][i];
+ }
+ if (t) {
+ /* texel is not transparent black */
+ if (reord[l][comps - 1] < 255) {
+ /* non-opaque texel */
+ trualpha = !0;
+ }
+ l++;
+ } else {
+ /* transparent black texel */
+ trualpha = !0;
+ }
+ }
+ }
+
+ if (trualpha) {
+ fxt1_quantize_ALPHA0(cc, input, reord, l);
+ } else {
+ fxt1_quantize_CHROMA(cc, input);
+ }
+}
+
+
+int
+fxt1_encode (GLcontext *ctx,
+ unsigned int width, unsigned int height,
+ int srcFormat,
+ const void *source, int srcRowStride,
+ void *dest, int destRowStride)
+{
+ const int comps = (srcFormat == GL_RGB) ? 3 : 4;
+ unsigned int x, y;
+ const unsigned char *data = source;
+ unsigned long *encoded = dest;
+ GLubyte *newSource = NULL;
+
+ /*
+ * Rescale image if width is less than 8 or height is less than 4.
+ */
+ if (width < 8 || height < 4) {
+ GLint newWidth = (width + 7) & ~7;
+ GLint newHeight = (height + 3) & ~3;
+ newSource = MALLOC(comps * newWidth * newHeight * sizeof(GLchan));
+ _mesa_upscale_teximage2d(width, height, newWidth, newHeight,
+ comps, source, srcRowStride, newSource);
+ source = newSource;
+ width = newWidth;
+ height = newHeight;
+ srcRowStride = comps * newWidth;
+ }
+
+ destRowStride = (destRowStride - width * 2) / 4;
+ for (y = 0; y < height; y += 4) {
+ for (x = 0; x < width; x += 8) {
+ const unsigned char *lines[4];
+ lines[0] = &data[x * comps + (y + 0) * srcRowStride];
+ lines[1] = &data[x * comps + (y + 1) * srcRowStride];
+ lines[2] = &data[x * comps + (y + 2) * srcRowStride];
+ lines[3] = &data[x * comps + (y + 3) * srcRowStride];
+ fxt1_quantize(encoded, lines, comps);
+ /* 128 bits per 8x4 block = 4bpp */
+ encoded += 4;
+ }
+ encoded += destRowStride;
+ }
+
return 0;
}
+
+
+/***************************************************************************\
+ * 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 unsigned char _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 unsigned char _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) ((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)
+#define ZERO_4UBV(v) *((unsigned long *)(v)) = 0
+
+
+static void
+fxt1_decode_1HI (unsigned long code, int t, unsigned char *rgba)
+{
+ const unsigned long *cc;
+
+ t *= 3;
+ cc = (unsigned long *)(code + t / 8);
+ t = (cc[0] >> (t & 7)) & 7;
+
+ if (t == 7) {
+ ZERO_4UBV(rgba);
+ } else {
+ cc = (unsigned long *)(code + 12);
+ if (t == 0) {
+ rgba[BCOMP] = UP5(CC_SEL(cc, 0));
+ rgba[GCOMP] = UP5(CC_SEL(cc, 5));
+ rgba[RCOMP] = UP5(CC_SEL(cc, 10));
+ } else if (t == 6) {
+ rgba[BCOMP] = UP5(CC_SEL(cc, 15));
+ rgba[GCOMP] = UP5(CC_SEL(cc, 20));
+ rgba[RCOMP] = UP5(CC_SEL(cc, 25));
+ } else {
+ rgba[BCOMP] = LERP(6, t, UP5(CC_SEL(cc, 0)), UP5(CC_SEL(cc, 15)));
+ rgba[GCOMP] = LERP(6, t, UP5(CC_SEL(cc, 5)), UP5(CC_SEL(cc, 20)));
+ rgba[RCOMP] = LERP(6, t, UP5(CC_SEL(cc, 10)), UP5(CC_SEL(cc, 25)));
+ }
+ rgba[ACOMP] = 255;
+ }
+}
+
+
+static void
+fxt1_decode_1CHROMA (unsigned long code, int t, unsigned char *rgba)
+{
+ const unsigned long *cc;
+ unsigned long kk;
+
+ cc = (unsigned long *)code;
+ if (t & 16) {
+ cc++;
+ t &= 15;
+ }
+ t = (cc[0] >> (t * 2)) & 3;
+
+ t *= 15;
+ cc = (unsigned long *)(code + 8 + t / 8);
+ kk = cc[0] >> (t & 7);
+ rgba[BCOMP] = UP5(kk);
+ rgba[GCOMP] = UP5(kk >> 5);
+ rgba[RCOMP] = UP5(kk >> 10);
+ rgba[ACOMP] = 255;
+}
+
+
+static void
+fxt1_decode_1MIXED (unsigned long code, int t, unsigned char *rgba)
+{
+ const unsigned long *cc;
+ unsigned int col[2][3];
+ int glsb, selb;
+
+ cc = (unsigned long *)code;
+ if (t & 16) {
+ t &= 15;
+ t = (cc[1] >> (t * 2)) & 3;
+ /* col 2 */
+ col[0][BCOMP] = (*(unsigned long *)(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_4UBV(rgba);
+ } else {
+ if (t == 0) {
+ rgba[BCOMP] = UP5(col[0][BCOMP]);
+ rgba[GCOMP] = UP5(col[0][GCOMP]);
+ rgba[RCOMP] = UP5(col[0][RCOMP]);
+ } else if (t == 2) {
+ rgba[BCOMP] = UP5(col[1][BCOMP]);
+ rgba[GCOMP] = UP6(col[1][GCOMP], glsb);
+ rgba[RCOMP] = UP5(col[1][RCOMP]);
+ } else {
+ rgba[BCOMP] = (UP5(col[0][BCOMP]) + UP5(col[1][BCOMP])) / 2;
+ rgba[GCOMP] = (UP5(col[0][GCOMP]) + UP6(col[1][GCOMP], glsb)) / 2;
+ rgba[RCOMP] = (UP5(col[0][RCOMP]) + UP5(col[1][RCOMP])) / 2;
+ }
+ rgba[ACOMP] = 255;
+ }
+ } else {
+ /* alpha[0] == 0 */
+
+ if (t == 0) {
+ rgba[BCOMP] = UP5(col[0][BCOMP]);
+ rgba[GCOMP] = UP6(col[0][GCOMP], glsb ^ selb);
+ rgba[RCOMP] = UP5(col[0][RCOMP]);
+ } else if (t == 3) {
+ rgba[BCOMP] = UP5(col[1][BCOMP]);
+ rgba[GCOMP] = UP6(col[1][GCOMP], glsb);
+ rgba[RCOMP] = UP5(col[1][RCOMP]);
+ } else {
+ rgba[BCOMP] = LERP(3, t, UP5(col[0][BCOMP]), UP5(col[1][BCOMP]));
+ rgba[GCOMP] = LERP(3, t, UP6(col[0][GCOMP], glsb ^ selb),
+ UP6(col[1][GCOMP], glsb));
+ rgba[RCOMP] = LERP(3, t, UP5(col[0][RCOMP]), UP5(col[1][RCOMP]));
+ }
+ rgba[ACOMP] = 255;
+ }
+}
+
+
+static void
+fxt1_decode_1ALPHA (unsigned long code, int t, unsigned char *rgba)
+{
+ const unsigned long *cc;
+
+ cc = (unsigned long *)code;
+ if (CC_SEL(cc, 124) & 1) {
+ /* lerp == 1 */
+ unsigned int col0[4];
+
+ if (t & 16) {
+ t &= 15;
+ t = (cc[1] >> (t * 2)) & 3;
+ /* col 2 */
+ col0[BCOMP] = (*(unsigned long *)(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) {
+ rgba[BCOMP] = UP5(col0[BCOMP]);
+ rgba[GCOMP] = UP5(col0[GCOMP]);
+ rgba[RCOMP] = UP5(col0[RCOMP]);
+ rgba[ACOMP] = UP5(col0[ACOMP]);
+ } else if (t == 3) {
+ rgba[BCOMP] = UP5(CC_SEL(cc, 79));
+ rgba[GCOMP] = UP5(CC_SEL(cc, 84));
+ rgba[RCOMP] = UP5(CC_SEL(cc, 89));
+ rgba[ACOMP] = UP5(CC_SEL(cc, 114));
+ } else {
+ rgba[BCOMP] = LERP(3, t, UP5(col0[BCOMP]), UP5(CC_SEL(cc, 79)));
+ rgba[GCOMP] = LERP(3, t, UP5(col0[GCOMP]), UP5(CC_SEL(cc, 84)));
+ rgba[RCOMP] = LERP(3, t, UP5(col0[RCOMP]), UP5(CC_SEL(cc, 89)));
+ rgba[ACOMP] = 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_4UBV(rgba);
+ } else {
+ unsigned long kk;
+ cc = (unsigned long *)code;
+ rgba[ACOMP] = UP5(cc[3] >> (t * 5 + 13));
+ t *= 15;
+ cc = (unsigned long *)(code + 8 + t / 8);
+ kk = cc[0] >> (t & 7);
+ rgba[BCOMP] = UP5(kk);
+ rgba[GCOMP] = UP5(kk >> 5);
+ rgba[RCOMP] = UP5(kk >> 10);
+ }
+ }
+}
+
+
+void
+fxt1_decode_1 (const void *texture, int width,
+ int i, int j, unsigned char *rgba)
+{
+ static void (*decode_1[]) (unsigned long, int, unsigned char *) = {
+ 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??" */
+ };
+
+ unsigned long code = (unsigned long)texture +
+ ((j / 4) * (width / 8) + (i / 8)) * 16;
+ int mode = CC_SEL((unsigned long *)code, 125);
+ int t = i & 7;
+
+ if (t & 4) {
+ t += 12;
+ }
+ t += (j & 3) * 4;
+
+ decode_1[mode](code, t, rgba);
+}