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-rw-r--r--src/mesa/main/txc_fetch_dxtn.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/src/mesa/main/txc_fetch_dxtn.c b/src/mesa/main/txc_fetch_dxtn.c
new file mode 100644
index 00000000000..7f0db56a155
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+++ b/src/mesa/main/txc_fetch_dxtn.c
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+/*
+ * libtxc_dxtn
+ * Version: 1.0
+ *
+ * Copyright (C) 2004 Roland Scheidegger 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.
+ */
+
+#include <stdio.h>
+#include "txc_dxtn.h"
+
+#define EXP5TO8R(packedcol) \
+ ((((packedcol) >> 8) & 0xf8) | (((packedcol) >> 13) & 0x7))
+
+#define EXP6TO8G(packedcol) \
+ ((((packedcol) >> 3) & 0xfc) | (((packedcol) >> 9) & 0x3))
+
+#define EXP5TO8B(packedcol) \
+ ((((packedcol) << 3) & 0xf8) | (((packedcol) >> 2) & 0x7))
+
+#define EXP4TO8(col) \
+ ((col) | ((col) << 4))
+
+/* inefficient. To be efficient, it would be necessary to decode 16 pixels at once */
+
+static void dxt135_decode_imageblock ( const GLubyte *img_block_src,
+ GLint i, GLint j, GLuint dxt_type, GLvoid *texel ) {
+ GLchan *rgba = (GLchan *) texel;
+ const GLushort color0 = img_block_src[0] | (img_block_src[1] << 8);
+ const GLushort color1 = img_block_src[2] | (img_block_src[3] << 8);
+ const GLuint bits = img_block_src[4] | (img_block_src[5] << 8) |
+ (img_block_src[6] << 16) | (img_block_src[7] << 24);
+ /* What about big/little endian? */
+ GLubyte bit_pos = 2 * (j * 4 + i) ;
+ GLubyte code = (GLubyte) ((bits >> bit_pos) & 3);
+
+ rgba[ACOMP] = CHAN_MAX;
+ switch (code) {
+ case 0:
+ rgba[RCOMP] = UBYTE_TO_CHAN( EXP5TO8R(color0) );
+ rgba[GCOMP] = UBYTE_TO_CHAN( EXP6TO8G(color0) );
+ rgba[BCOMP] = UBYTE_TO_CHAN( EXP5TO8B(color0) );
+ break;
+ case 1:
+ rgba[RCOMP] = UBYTE_TO_CHAN( EXP5TO8R(color1) );
+ rgba[GCOMP] = UBYTE_TO_CHAN( EXP6TO8G(color1) );
+ rgba[BCOMP] = UBYTE_TO_CHAN( EXP5TO8B(color1) );
+ break;
+ case 2:
+ if ((dxt_type > 1) || (color0 > color1)) {
+ rgba[RCOMP] = UBYTE_TO_CHAN( ((EXP5TO8R(color0) * 2 + EXP5TO8R(color1)) / 3) );
+ rgba[GCOMP] = UBYTE_TO_CHAN( ((EXP6TO8G(color0) * 2 + EXP6TO8G(color1)) / 3) );
+ rgba[BCOMP] = UBYTE_TO_CHAN( ((EXP5TO8B(color0) * 2 + EXP5TO8B(color1)) / 3) );
+ }
+ else {
+ rgba[RCOMP] = UBYTE_TO_CHAN( ((EXP5TO8R(color0) + EXP5TO8R(color1)) / 2) );
+ rgba[GCOMP] = UBYTE_TO_CHAN( ((EXP6TO8G(color0) + EXP6TO8G(color1)) / 2) );
+ rgba[BCOMP] = UBYTE_TO_CHAN( ((EXP5TO8B(color0) + EXP5TO8B(color1)) / 2) );
+ }
+ break;
+ case 3:
+ if ((dxt_type > 1) || (color0 > color1)) {
+ rgba[RCOMP] = UBYTE_TO_CHAN( ((EXP5TO8R(color0) + EXP5TO8R(color1) * 2) / 3) );
+ rgba[GCOMP] = UBYTE_TO_CHAN( ((EXP6TO8G(color0) + EXP6TO8G(color1) * 2) / 3) );
+ rgba[BCOMP] = UBYTE_TO_CHAN( ((EXP5TO8B(color0) + EXP5TO8B(color1) * 2) / 3) );
+ }
+ else {
+ rgba[RCOMP] = 0;
+ rgba[GCOMP] = 0;
+ rgba[BCOMP] = 0;
+ if (dxt_type == 1) rgba[ACOMP] = UBYTE_TO_CHAN(0);
+ }
+ break;
+ default:
+ /* CANNOT happen (I hope) */
+ break;
+ }
+}
+
+
+void fetch_2d_texel_rgb_dxt1(GLint srcRowStride, const GLubyte *pixdata,
+ GLint i, GLint j, GLvoid *texel)
+{
+ /* Extract the (i,j) pixel from pixdata and return it
+ * in texel[RCOMP], texel[GCOMP], texel[BCOMP], texel[ACOMP].
+ */
+
+ const GLubyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 8);
+ dxt135_decode_imageblock(blksrc, (i&3), (j&3), 0, texel);
+}
+
+
+void fetch_2d_texel_rgba_dxt1(GLint srcRowStride, const GLubyte *pixdata,
+ GLint i, GLint j, GLvoid *texel)
+{
+ /* Extract the (i,j) pixel from pixdata and return it
+ * in texel[RCOMP], texel[GCOMP], texel[BCOMP], texel[ACOMP].
+ */
+
+ const GLubyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 8);
+ dxt135_decode_imageblock(blksrc, (i&3), (j&3), 1, texel);
+}
+
+void fetch_2d_texel_rgba_dxt3(GLint srcRowStride, const GLubyte *pixdata,
+ GLint i, GLint j, GLvoid *texel) {
+
+ /* Extract the (i,j) pixel from pixdata and return it
+ * in texel[RCOMP], texel[GCOMP], texel[BCOMP], texel[ACOMP].
+ */
+
+ GLchan *rgba = (GLchan *) texel;
+ const GLubyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 16);
+#if 0
+ /* Simple 32bit version. */
+/* that's pretty brain-dead for a single pixel, isn't it? */
+ const GLubyte bit_pos = 4 * ((j&3) * 4 + (i&3));
+ const GLuint alpha_low = blksrc[0] | (blksrc[1] << 8) | (blksrc[2] << 16) | (blksrc[3] << 24);
+ const GLuint alpha_high = blksrc[4] | (blksrc[5] << 8) | (blksrc[6] << 16) | (blksrc[7] << 24);
+
+ dxt135_decode_imageblock(blksrc + 8, (i&3), (j&3), 2, texel);
+ if (bit_pos < 32)
+ rgba[ACOMP] = UBYTE_TO_CHAN( (GLubyte)(EXP4TO8((alpha_low >> bit_pos) & 15)) );
+ else
+ rgba[ACOMP] = UBYTE_TO_CHAN( (GLubyte)(EXP4TO8((alpha_high >> (bit_pos - 32)) & 15)) );
+#endif
+#if 1
+/* TODO test this! */
+ const GLubyte anibble = (blksrc[((j&3) * 4 + (i&3)) / 2] >> (4 * (i&1))) & 0xf;
+ dxt135_decode_imageblock(blksrc + 8, (i&3), (j&3), 2, texel);
+ rgba[ACOMP] = UBYTE_TO_CHAN( (GLubyte)(EXP4TO8(anibble)) );
+#endif
+
+}
+
+void fetch_2d_texel_rgba_dxt5(GLint srcRowStride, const GLubyte *pixdata,
+ GLint i, GLint j, GLvoid *texel) {
+
+ /* Extract the (i,j) pixel from pixdata and return it
+ * in texel[RCOMP], texel[GCOMP], texel[BCOMP], texel[ACOMP].
+ */
+
+ GLchan *rgba = (GLchan *) texel;
+ const GLubyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 16);
+ const GLubyte alpha0 = blksrc[0];
+ const GLubyte alpha1 = blksrc[1];
+#if 0
+ const GLubyte bit_pos = 3 * ((j&3) * 4 + (i&3));
+ /* simple 32bit version */
+ const GLuint bits_low = blksrc[2] | (blksrc[3] << 8) | (blksrc[4] << 16) | (blksrc[5] << 24);
+ const GLuint bits_high = blksrc[6] | (blksrc[7] << 8);
+ GLubyte code;
+
+ if (bit_pos < 30)
+ code = (GLubyte) ((bits_low >> bit_pos) & 7);
+ else if (bit_pos == 30)
+ code = (GLubyte) ((bits_low >> 30) & 3) | ((bits_high << 2) & 4);
+ else
+ code = (GLubyte) ((bits_high >> (bit_pos - 32)) & 7);
+#endif
+#if 1
+/* TODO test this! */
+ const GLubyte bit_pos = ((j&3) * 4 + (i&3)) * 3;
+ const GLubyte acodelow = blksrc[2 + bit_pos / 8];
+ const GLubyte acodehigh = blksrc[3 + bit_pos / 8];
+ const GLubyte code = (acodelow >> (bit_pos & 0x7) |
+ (acodehigh << (8 - (bit_pos & 0x7)))) & 0x7;
+#endif
+ dxt135_decode_imageblock(blksrc + 8, (i&3), (j&3), 2, texel);
+#if 0
+ if (alpha0 > alpha1) {
+ switch (code) {
+ case 0:
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha0 );
+ break;
+ case 1:
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha1 );
+ break;
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ rgba[ACOMP] = UBYTE_TO_CHAN( ((alpha0 * (8 - code) + (alpha1 * (code - 1))) / 7) );
+ break;
+ }
+ }
+ else {
+ switch (code) {
+ case 0:
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha0 );
+ break;
+ case 1:
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha1 );
+ break;
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ rgba[ACOMP] = UBYTE_TO_CHAN( ((alpha0 * (6 - code) + (alpha1 * (code - 1))) / 5) );
+ break;
+ case 6:
+ rgba[ACOMP] = 0;
+ break;
+ case 7:
+ rgba[ACOMP] = CHAN_MAX;
+ break;
+ }
+ }
+#endif
+/* not sure. Which version is faster? */
+#if 1
+/* TODO test this */
+ if (code == 0)
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha0 );
+ else if (code == 1)
+ rgba[ACOMP] = UBYTE_TO_CHAN( alpha1 );
+ else if (alpha0 > alpha1)
+ rgba[ACOMP] = UBYTE_TO_CHAN( ((alpha0 * (8 - code) + (alpha1 * (code - 1))) / 7) );
+ else if (code < 6)
+ rgba[ACOMP] = UBYTE_TO_CHAN( ((alpha0 * (6 - code) + (alpha1 * (code - 1))) / 5) );
+ else if (code == 6)
+ rgba[ACOMP] = 0;
+ else
+ rgba[ACOMP] = CHAN_MAX;
+#endif
+}
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