mesa: add new pixel format unpacking code

This will be used instead of the texel fetch code to unpack images
in various formats.

2 files changed, 1543 insertions, 0 deletions

diff --git a/src/mesa/main/format_unpack.c b/src/mesa/main/format_unpack.c
new file mode 100644
index 00000000000..c5146f72da0
--- /dev/null
+++ b/src/mesa/main/format_unpack.c
@@ -0,0 +1,1494 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (c) 2011 VMware, Inc.
+ *
+ * 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
+ * THE AUTHORS 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 "colormac.h"
+#include "format_unpack.h"
+#include "macros.h"
+#include "../../gallium/auxiliary/util/u_format_rgb9e5.h"
+#include "../../gallium/auxiliary/util/u_format_r11g11b10f.h"
+
+
+/**
+ * Convert an 8-bit sRGB value from non-linear space to a
+ * linear RGB value in [0, 1].
+ * Implemented with a 256-entry lookup table.
+ */
+static INLINE GLfloat
+nonlinear_to_linear(GLubyte cs8)
+{
+   static GLfloat table[256];
+   static GLboolean tableReady = GL_FALSE;
+   if (!tableReady) {
+      /* compute lookup table now */
+      GLuint i;
+      for (i = 0; i < 256; i++) {
+         const GLfloat cs = UBYTE_TO_FLOAT(i);
+         if (cs <= 0.04045) {
+            table[i] = cs / 12.92f;
+         }
+         else {
+            table[i] = (GLfloat) pow((cs + 0.055) / 1.055, 2.4);
+         }
+      }
+      tableReady = GL_TRUE;
+   }
+   return table[cs8];
+}
+
+
+typedef void (*unpack_rgba_func)(const void *src, GLfloat dst[4]);
+
+
+static void
+unpack_RGBA8888(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s >> 24)        );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff );
+}
+
+static void
+unpack_RGBA8888_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s >> 24)        );
+}
+
+static void
+unpack_ARGB8888(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s >> 24)        );
+}
+
+static void
+unpack_ARGB8888_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s >> 24)        );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff );
+}
+
+static void
+unpack_XRGB8888(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff );
+   dst[ACOMP] = 1.0f;
+}
+
+static void
+unpack_XRGB8888_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( (s >>  8) & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( (s >> 16) & 0xff );
+   dst[BCOMP] = UBYTE_TO_FLOAT( (s >> 24)        );
+   dst[ACOMP] = 1.0f;
+}
+
+static void
+unpack_RGB888(const void *src, GLfloat dst[4])
+{
+   const GLubyte *s = (const GLubyte *) src;
+   dst[RCOMP] = UBYTE_TO_FLOAT( s[2] );
+   dst[GCOMP] = UBYTE_TO_FLOAT( s[1] );
+   dst[BCOMP] = UBYTE_TO_FLOAT( s[0] );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_BGR888(const void *src, GLfloat dst[4])
+{
+   const GLubyte *s = (const GLubyte *) src;
+   dst[RCOMP] = UBYTE_TO_FLOAT( s[0] );
+   dst[GCOMP] = UBYTE_TO_FLOAT( s[1] );
+   dst[BCOMP] = UBYTE_TO_FLOAT( s[2] );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_RGB565(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = ((s >> 11) & 0x1f) * (1.0F / 31.0F);
+   dst[GCOMP] = ((s >> 5 ) & 0x3f) * (1.0F / 63.0F);
+   dst[BCOMP] = ((s      ) & 0x1f) * (1.0F / 31.0F);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_RGB565_REV(const void *src, GLfloat dst[4])
+{
+   GLushort s = *((const GLushort *) src);
+   s = (s >> 8) | (s << 8); /* byte swap */
+   dst[RCOMP] = UBYTE_TO_FLOAT( ((s >> 8) & 0xf8) | ((s >> 13) & 0x7) );
+   dst[GCOMP] = UBYTE_TO_FLOAT( ((s >> 3) & 0xfc) | ((s >>  9) & 0x3) );
+   dst[BCOMP] = UBYTE_TO_FLOAT( ((s << 3) & 0xf8) | ((s >>  2) & 0x7) );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_ARGB4444(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = ((s >>  8) & 0xf) * (1.0F / 15.0F);
+   dst[GCOMP] = ((s >>  4) & 0xf) * (1.0F / 15.0F);
+   dst[BCOMP] = ((s      ) & 0xf) * (1.0F / 15.0F);
+   dst[ACOMP] = ((s >> 12) & 0xf) * (1.0F / 15.0F);
+}
+
+static void
+unpack_ARGB4444_REV(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = ((s      ) & 0xf) * (1.0F / 15.0F);
+   dst[GCOMP] = ((s >> 12) & 0xf) * (1.0F / 15.0F);
+   dst[BCOMP] = ((s >>  8) & 0xf) * (1.0F / 15.0F);
+   dst[ACOMP] = ((s >>  4) & 0xf) * (1.0F / 15.0F);
+}
+
+static void
+unpack_RGBA5551(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = ((s >> 11) & 0x1f) * (1.0F / 31.0F);
+   dst[GCOMP] = ((s >>  6) & 0x1f) * (1.0F / 31.0F);
+   dst[BCOMP] = ((s >>  1) & 0x1f) * (1.0F / 31.0F);
+   dst[ACOMP] = ((s      ) & 0x01) * 1.0F;
+}
+
+static void
+unpack_ARGB1555(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = ((s >> 10) & 0x1f) * (1.0F / 31.0F);
+   dst[GCOMP] = ((s >>  5) & 0x1f) * (1.0F / 31.0F);
+   dst[BCOMP] = ((s >>  0) & 0x1f) * (1.0F / 31.0F);
+   dst[ACOMP] = ((s >> 15) & 0x01) * 1.0F;
+}
+
+static void
+unpack_ARGB1555_REV(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( ((s >>  7) & 0xf8) | ((s >> 12) & 0x7) );
+   dst[GCOMP] = UBYTE_TO_FLOAT( ((s >>  2) & 0xf8) | ((s >>  7) & 0x7) );
+   dst[BCOMP] = UBYTE_TO_FLOAT( ((s <<  3) & 0xf8) | ((s >>  2) & 0x7) );
+   dst[ACOMP] = UBYTE_TO_FLOAT( ((s >> 15) & 0x01) * 255 );
+}
+
+static void
+unpack_AL44(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = (s & 0xf) * (1.0F / 15.0F);
+   dst[ACOMP] = ((s >> 4) & 0xf) * (1.0F / 15.0F);
+}
+
+static void
+unpack_AL88(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = 
+   dst[GCOMP] = 
+   dst[BCOMP] = UBYTE_TO_FLOAT( s & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( s >> 8 );
+}
+
+static void
+unpack_AL88_REV(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = 
+   dst[GCOMP] = 
+   dst[BCOMP] = UBYTE_TO_FLOAT( s >> 8 );
+   dst[ACOMP] = UBYTE_TO_FLOAT( s & 0xff );
+}
+
+static void
+unpack_AL1616(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = USHORT_TO_FLOAT( s & 0xffff );
+   dst[ACOMP] = USHORT_TO_FLOAT( s >> 16 );
+}
+
+static void
+unpack_AL1616_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = USHORT_TO_FLOAT( s >> 16 );
+   dst[ACOMP] = USHORT_TO_FLOAT( s & 0xffff );
+}
+
+static void
+unpack_RGB332(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] = ((s >> 5) & 0x7) * (1.0F / 7.0F);
+   dst[GCOMP] = ((s >> 2) & 0x7) * (1.0F / 7.0F);
+   dst[BCOMP] = ((s     ) & 0x3) * (1.0F / 3.0F);
+   dst[ACOMP] = 1.0F;
+}
+
+
+static void
+unpack_A8(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = UBYTE_TO_FLOAT(s);
+}
+
+static void
+unpack_A16(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = USHORT_TO_FLOAT(s);
+}
+
+static void
+unpack_L8(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = UBYTE_TO_FLOAT(s);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_L16(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = USHORT_TO_FLOAT(s);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_I8(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = UBYTE_TO_FLOAT(s);
+}
+
+static void
+unpack_I16(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = USHORT_TO_FLOAT(s);
+}
+
+static void
+unpack_YCBCR(const void *src, GLfloat dst[4])
+{
+   const GLuint i = 0;
+   const GLushort *src0 = (const GLushort *) src;
+   const GLushort *src1 = src0 + 1;                               /* odd */
+   const GLubyte y0 = (*src0 >> 8) & 0xff;  /* luminance */
+   const GLubyte cb = *src0 & 0xff;         /* chroma U */
+   const GLubyte y1 = (*src1 >> 8) & 0xff;  /* luminance */
+   const GLubyte cr = *src1 & 0xff;         /* chroma V */
+   const GLubyte y = (i & 1) ? y1 : y0;     /* choose even/odd luminance */
+   GLfloat r = 1.164F * (y - 16) + 1.596F * (cr - 128);
+   GLfloat g = 1.164F * (y - 16) - 0.813F * (cr - 128) - 0.391F * (cb - 128);
+   GLfloat b = 1.164F * (y - 16) + 2.018F * (cb - 128);
+   r *= (1.0F / 255.0F);
+   g *= (1.0F / 255.0F);
+   b *= (1.0F / 255.0F);
+   dst[RCOMP] = CLAMP(r, 0.0F, 1.0F);
+   dst[GCOMP] = CLAMP(g, 0.0F, 1.0F);
+   dst[BCOMP] = CLAMP(b, 0.0F, 1.0F);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_YCBCR_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint i = 0;
+   const GLushort *src0 = (const GLushort *) src;
+   const GLushort *src1 = src0 + 1;                               /* odd */
+   const GLubyte y0 = *src0 & 0xff;         /* luminance */
+   const GLubyte cr = (*src0 >> 8) & 0xff;  /* chroma V */
+   const GLubyte y1 = *src1 & 0xff;         /* luminance */
+   const GLubyte cb = (*src1 >> 8) & 0xff;  /* chroma U */
+   const GLubyte y = (i & 1) ? y1 : y0;     /* choose even/odd luminance */
+   GLfloat r = 1.164F * (y - 16) + 1.596F * (cr - 128);
+   GLfloat g = 1.164F * (y - 16) - 0.813F * (cr - 128) - 0.391F * (cb - 128);
+   GLfloat b = 1.164F * (y - 16) + 2.018F * (cb - 128);
+   r *= (1.0F / 255.0F);
+   g *= (1.0F / 255.0F);
+   b *= (1.0F / 255.0F);
+   dst[RCOMP] = CLAMP(r, 0.0F, 1.0F);
+   dst[GCOMP] = CLAMP(g, 0.0F, 1.0F);
+   dst[BCOMP] = CLAMP(b, 0.0F, 1.0F);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_R8(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[0] = UBYTE_TO_FLOAT(s);
+   dst[1] = dst[2] = 0.0F;
+   dst[3] = 1.0F;
+}
+
+static void
+unpack_RG88(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( s & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( s >> 8 );
+   dst[BCOMP] = 0.0;
+   dst[ACOMP] = 1.0;
+}
+
+static void
+unpack_RG88_REV(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = UBYTE_TO_FLOAT( s & 0xff );
+   dst[GCOMP] = UBYTE_TO_FLOAT( s >> 8 );
+   dst[BCOMP] = 0.0;
+   dst[ACOMP] = 1.0;
+}
+
+static void
+unpack_R16(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = USHORT_TO_FLOAT(s);
+   dst[GCOMP] = 0.0;
+   dst[BCOMP] = 0.0;
+   dst[ACOMP] = 1.0;
+}
+
+static void
+unpack_RG1616(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = USHORT_TO_FLOAT( s & 0xffff );
+   dst[GCOMP] = USHORT_TO_FLOAT( s >> 16 );
+   dst[BCOMP] = 0.0;
+   dst[ACOMP] = 1.0;
+}
+
+static void
+unpack_RG1616_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = USHORT_TO_FLOAT( s >> 16 );
+   dst[GCOMP] = USHORT_TO_FLOAT( s & 0xffff );
+   dst[BCOMP] = 0.0;
+   dst[ACOMP] = 1.0;
+}
+
+static void
+unpack_ARGB2101010(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = ((s >> 20) & 0x3ff) * (1.0F / 1023.0F);
+   dst[GCOMP] = ((s >> 10) & 0x3ff) * (1.0F / 1023.0F);
+   dst[BCOMP] = ((s >>  0) & 0x3ff) * (1.0F / 1023.0F);
+   dst[ACOMP] = ((s >> 30) & 0x03) * (1.0F / 3.0F);
+}
+
+
+static void
+unpack_Z24_S8(const void *src, GLfloat dst[4])
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   const GLfloat scale = 1.0F / (GLfloat) 0xffffff;
+   dst[0] = dst[1] = dst[2] = (s >> 8) * scale;
+   dst[3] = 1.0F;
+   ASSERT(dst[0] >= 0.0F);
+   ASSERT(dst[0] <= 1.0F);
+}
+
+static void
+unpack_S8_Z24(const void *src, GLfloat dst[4])
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   const GLfloat scale = 1.0F / (GLfloat) 0xffffff;
+   dst[0] = dst[1] = dst[2] = (s & 0x00ffffff) * scale;
+   dst[3] = 1.0F;
+   ASSERT(dst[0] >= 0.0F);
+   ASSERT(dst[0] <= 1.0F);
+}
+
+static void
+unpack_Z16(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[0] = dst[1] = dst[2] = s * (1.0F / 65535.0F);
+   dst[3] = 1.0F;
+}
+
+static void
+unpack_X8_Z24(const void *src, GLfloat dst[4])
+{
+   unpack_S8_Z24(src, dst);
+}
+
+static void
+unpack_Z24_X8(const void *src, GLfloat dst[4])
+{
+   unpack_Z24_S8(src, dst);
+}
+
+static void
+unpack_Z32(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[0] = dst[1] = dst[2] = s * (1.0F / 0xffffffff);
+   dst[3] = 1.0F;
+}
+
+static void
+unpack_Z32_FLOAT(const void *src, GLfloat dst[4])
+{
+   const GLfloat s = *((const GLfloat *) src);
+   dst[0] = dst[1] = dst[2] = s;
+   dst[3] = 1.0F;
+}
+
+static void
+unpack_Z32_FLOAT_X24S8(const void *src, GLfloat dst[4])
+{
+   const GLfloat s = *((const GLfloat *) src);
+   dst[0] = dst[1] = dst[2] = s;
+   dst[3] = 1.0F;
+}
+
+
+static void
+unpack_S8(const void *src, GLfloat dst[4])
+{
+   /* should never be used */
+   dst[0] = dst[1] = dst[2] = 0.0F;
+   dst[3] = 1.0F;
+}
+
+
+static void
+unpack_SRGB8(const void *src, GLfloat dst[4])
+{
+   const GLubyte *s = (const GLubyte *) src;
+   dst[RCOMP] = nonlinear_to_linear(s[2]);
+   dst[GCOMP] = nonlinear_to_linear(s[1]);
+   dst[BCOMP] = nonlinear_to_linear(s[0]);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SRGBA8(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = nonlinear_to_linear( (s >> 24) );
+   dst[GCOMP] = nonlinear_to_linear( (s >> 16) & 0xff );
+   dst[BCOMP] = nonlinear_to_linear( (s >>  8) & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s      ) & 0xff ); /* linear! */
+}
+
+static void
+unpack_SARGB8(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = nonlinear_to_linear( (s >> 16) & 0xff );
+   dst[GCOMP] = nonlinear_to_linear( (s >>  8) & 0xff );
+   dst[BCOMP] = nonlinear_to_linear( (s      ) & 0xff );
+   dst[ACOMP] = UBYTE_TO_FLOAT( (s >> 24) ); /* linear! */
+}
+
+static void
+unpack_SL8(const void *src, GLfloat dst[4])
+{
+   const GLubyte s = *((const GLubyte *) src);
+   dst[RCOMP] = 
+   dst[GCOMP] = 
+   dst[BCOMP] = nonlinear_to_linear(s);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SLA8(const void *src, GLfloat dst[4])
+{
+   const GLubyte *s = (const GLubyte *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = nonlinear_to_linear(s[0]);
+   dst[ACOMP] = UBYTE_TO_FLOAT(s[1]); /* linear */
+}
+
+static void
+unpack_SRGB_DXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_SRGBA_DXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_SRGBA_DXT3(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_SRGBA_DXT5(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGB_FXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGBA_FXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGB_DXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGBA_DXT1(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGBA_DXT3(const void *src, GLfloat dst[4])
+{
+}
+
+static void
+unpack_RGBA_DXT5(const void *src, GLfloat dst[4])
+{
+}
+
+
+static void
+unpack_RGBA_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] = s[0];
+   dst[GCOMP] = s[1];
+   dst[BCOMP] = s[2];
+   dst[ACOMP] = s[3];
+}
+
+static void
+unpack_RGBA_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] = _mesa_half_to_float(s[0]);
+   dst[GCOMP] = _mesa_half_to_float(s[1]);
+   dst[BCOMP] = _mesa_half_to_float(s[2]);
+   dst[ACOMP] = _mesa_half_to_float(s[3]);
+}
+
+static void
+unpack_RGB_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] = s[0];
+   dst[GCOMP] = s[1];
+   dst[BCOMP] = s[2];
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_RGB_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] = _mesa_half_to_float(s[0]);
+   dst[GCOMP] = _mesa_half_to_float(s[1]);
+   dst[BCOMP] = _mesa_half_to_float(s[2]);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_ALPHA_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = s[0];
+}
+
+static void
+unpack_ALPHA_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = _mesa_half_to_float(s[0]);
+}
+
+static void
+unpack_LUMINANCE_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = s[0];
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_LUMINANCE_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = _mesa_half_to_float(s[0]);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_LUMINANCE_ALPHA_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = s[0];
+   dst[ACOMP] = s[1];
+}
+
+static void
+unpack_LUMINANCE_ALPHA_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = _mesa_half_to_float(s[0]);
+   dst[ACOMP] = _mesa_half_to_float(s[1]);
+}
+
+static void
+unpack_INTENSITY_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = s[0];
+}
+
+static void
+unpack_INTENSITY_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = s[0];
+}
+
+static void
+unpack_R_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] = s[0];
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_R_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] = _mesa_half_to_float(s[0]);
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_RG_FLOAT32(const void *src, GLfloat dst[4])
+{
+   const GLfloat *s = (const GLfloat *) src;
+   dst[RCOMP] = s[0];
+   dst[GCOMP] = s[1];
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_RG_FLOAT16(const void *src, GLfloat dst[4])
+{
+   const GLhalfARB *s = (const GLhalfARB *) src;
+   dst[RCOMP] = _mesa_half_to_float(s[0]);
+   dst[GCOMP] = _mesa_half_to_float(s[1]);
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+
+static void
+unpack_RGBA_INT8(const void *src, GLfloat dst[4])
+{
+   const GLbyte *s = (const GLbyte *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_RGBA_INT16(const void *src, GLfloat dst[4])
+{
+   const GLshort *s = (const GLshort *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_RGBA_INT32(const void *src, GLfloat dst[4])
+{
+   const GLint *s = (const GLint *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_RGBA_UINT8(const void *src, GLfloat dst[4])
+{
+   const GLubyte *s = (const GLubyte *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_RGBA_UINT16(const void *src, GLfloat dst[4])
+{
+   const GLushort *s = (const GLushort *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_RGBA_UINT32(const void *src, GLfloat dst[4])
+{
+   const GLuint *s = (const GLuint *) src;
+   dst[RCOMP] = (GLfloat) s[0];
+   dst[GCOMP] = (GLfloat) s[1];
+   dst[BCOMP] = (GLfloat) s[2];
+   dst[ACOMP] = (GLfloat) s[3];
+}
+
+static void
+unpack_DUDV8(const void *src, GLfloat dst[4])
+{
+   const GLbyte *s = (const GLbyte *) src;
+   dst[RCOMP] = BYTE_TO_FLOAT(s[0]);
+   dst[GCOMP] = BYTE_TO_FLOAT(s[1]);
+   dst[BCOMP] = 0;
+   dst[ACOMP] = 0;
+}
+
+static void
+unpack_SIGNED_R8(const void *src, GLfloat dst[4])
+{
+   const GLbyte s = *((const GLbyte *) src);
+   dst[RCOMP] = BYTE_TO_FLOAT_TEX( s );
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_RG88_REV(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLushort *) src);
+   dst[RCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s & 0xff) );
+   dst[GCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 8) );
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_RGBX8888(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 24) );
+   dst[GCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 16) );
+   dst[BCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >>  8) );
+   dst[ACOMP] = 1.0f;
+}
+
+static void
+unpack_SIGNED_RGBA8888(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 24) );
+   dst[GCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 16) );
+   dst[BCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >>  8) );
+   dst[ACOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s      ) );
+}
+
+static void
+unpack_SIGNED_RGBA8888_REV(const void *src, GLfloat dst[4])
+{
+   const GLuint s = *((const GLuint *) src);
+   dst[RCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s      ) );
+   dst[GCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >>  8) );
+   dst[BCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 16) );
+   dst[ACOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 24) );
+}
+
+static void
+unpack_SIGNED_R16(const void *src, GLfloat dst[4])
+{
+   const GLshort s = *((const GLshort *) src);
+   dst[RCOMP] = SHORT_TO_FLOAT_TEX( s );
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_GR1616(const void *src, GLfloat dst[4])
+{
+   /* XXX TODO */
+}
+
+static void
+unpack_SIGNED_RGB_16(const void *src, GLfloat dst[4])
+{
+   const GLshort *s = (const GLshort *) src;
+   dst[RCOMP] = SHORT_TO_FLOAT_TEX( s[0] );
+   dst[GCOMP] = SHORT_TO_FLOAT_TEX( s[1] );
+   dst[BCOMP] = SHORT_TO_FLOAT_TEX( s[2] );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_RGBA_16(const void *src, GLfloat dst[4])
+{
+   const GLshort *s = (const GLshort *) src;
+   dst[RCOMP] = SHORT_TO_FLOAT_TEX( s[0] );
+   dst[GCOMP] = SHORT_TO_FLOAT_TEX( s[1] );
+   dst[BCOMP] = SHORT_TO_FLOAT_TEX( s[2] );
+   dst[ACOMP] = SHORT_TO_FLOAT_TEX( s[3] );
+}
+
+static void
+unpack_RGBA_16(const void *src, GLfloat dst[4])
+{
+   const GLshort *s = (const GLshort *) src;
+   dst[RCOMP] = USHORT_TO_FLOAT( s[0] );
+   dst[GCOMP] = USHORT_TO_FLOAT( s[1] );
+   dst[BCOMP] = USHORT_TO_FLOAT( s[2] );
+   dst[ACOMP] = USHORT_TO_FLOAT( s[3] );
+}
+
+static void
+unpack_RED_RGTC1(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_SIGNED_RED_RGTC1(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_RG_RGTC2(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_SIGNED_RG_RGTC2(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_L_LATC1(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_SIGNED_L_LATC1(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_LA_LATC2(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_SIGNED_LA_LATC2(const void *src, GLfloat dst[4])
+{
+   /* XXX to do */
+}
+
+static void
+unpack_SIGNED_A8(const void *src, GLfloat dst[4])
+{
+   const GLbyte s = *((const GLbyte *) src);
+   dst[RCOMP] = 0.0F;
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = BYTE_TO_FLOAT_TEX( s );
+}
+
+static void
+unpack_SIGNED_L8(const void *src, GLfloat dst[4])
+{
+   const GLbyte s = *((const GLbyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = BYTE_TO_FLOAT_TEX( s );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_AL88(const void *src, GLfloat dst[4])
+{
+   const GLushort s = *((const GLshort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s & 0xff) );
+   dst[ACOMP] = BYTE_TO_FLOAT_TEX( (GLbyte) (s >> 8) );
+}
+
+static void
+unpack_SIGNED_I8(const void *src, GLfloat dst[4])
+{
+   const GLbyte s = *((const GLbyte *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = BYTE_TO_FLOAT_TEX( s );
+}
+
+static void
+unpack_SIGNED_A16(const void *src, GLfloat dst[4])
+{
+   const GLshort s = *((const GLshort *) src);
+   dst[RCOMP] = 0.0F;
+   dst[GCOMP] = 0.0F;
+   dst[BCOMP] = 0.0F;
+   dst[ACOMP] = SHORT_TO_FLOAT_TEX( s );
+}
+
+static void
+unpack_SIGNED_L16(const void *src, GLfloat dst[4])
+{
+   const GLshort s = *((const GLshort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = SHORT_TO_FLOAT_TEX( s );
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_SIGNED_AL1616(const void *src, GLfloat dst[4])
+{
+   const GLshort *s = (const GLshort *) src;
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] = SHORT_TO_FLOAT_TEX( s[0] );
+   dst[ACOMP] = SHORT_TO_FLOAT_TEX( s[1] );
+}
+
+static void
+unpack_SIGNED_I16(const void *src, GLfloat dst[4])
+{
+   const GLshort s = *((const GLshort *) src);
+   dst[RCOMP] =
+   dst[GCOMP] =
+   dst[BCOMP] =
+   dst[ACOMP] = SHORT_TO_FLOAT_TEX( s );
+}
+
+static void
+unpack_RGB9_E5_FLOAT(const void *src, GLfloat dst[4])
+{
+   const GLuint *s = (const GLuint *) src;
+   rgb9e5_to_float3(*s, dst);
+   dst[ACOMP] = 1.0F;
+}
+
+static void
+unpack_R11_G11_B10_FLOAT(const void *src, GLfloat dst[4])
+{
+   const GLuint *s = (const GLuint *) src;
+   r11g11b10f_to_float3(*s, dst);
+   dst[ACOMP] = 1.0F;
+}
+
+
+/**
+ * Return the unpacker function for the given format.
+ */
+static unpack_rgba_func
+get_unpack_rgba_function(gl_format format)
+{
+   static unpack_rgba_func table[MESA_FORMAT_COUNT];
+   static GLboolean initialized = GL_FALSE;
+
+   if (!initialized) {
+      table[MESA_FORMAT_NONE] = NULL;
+
+      table[MESA_FORMAT_RGBA8888] = unpack_RGBA8888;
+      table[MESA_FORMAT_RGBA8888_REV] = unpack_RGBA8888_REV;
+      table[MESA_FORMAT_ARGB8888] = unpack_ARGB8888;
+      table[MESA_FORMAT_ARGB8888_REV] = unpack_ARGB8888_REV;
+      table[MESA_FORMAT_XRGB8888] = unpack_XRGB8888;
+      table[MESA_FORMAT_XRGB8888_REV] = unpack_XRGB8888_REV;
+      table[MESA_FORMAT_RGB888] = unpack_RGB888;
+      table[MESA_FORMAT_BGR888] = unpack_BGR888;
+      table[MESA_FORMAT_RGB565] = unpack_RGB565;
+      table[MESA_FORMAT_RGB565_REV] = unpack_RGB565_REV;
+      table[MESA_FORMAT_ARGB4444] = unpack_ARGB4444;
+      table[MESA_FORMAT_ARGB4444_REV] = unpack_ARGB4444_REV;
+      table[MESA_FORMAT_RGBA5551] = unpack_RGBA5551;
+      table[MESA_FORMAT_ARGB1555] = unpack_ARGB1555;
+      table[MESA_FORMAT_ARGB1555_REV] = unpack_ARGB1555_REV;
+      table[MESA_FORMAT_AL44] = unpack_AL44;
+      table[MESA_FORMAT_AL88] = unpack_AL88;
+      table[MESA_FORMAT_AL88_REV] = unpack_AL88_REV;
+      table[MESA_FORMAT_AL1616] = unpack_AL1616;
+      table[MESA_FORMAT_AL1616_REV] = unpack_AL1616_REV;
+      table[MESA_FORMAT_RGB332] = unpack_RGB332;
+      table[MESA_FORMAT_A8] = unpack_A8;
+      table[MESA_FORMAT_A16] = unpack_A16;
+      table[MESA_FORMAT_L8] = unpack_L8;
+      table[MESA_FORMAT_L16] = unpack_L16;
+      table[MESA_FORMAT_I8] = unpack_I8;
+      table[MESA_FORMAT_I16] = unpack_I16;
+      table[MESA_FORMAT_YCBCR] = unpack_YCBCR;
+      table[MESA_FORMAT_YCBCR_REV] = unpack_YCBCR_REV;
+      table[MESA_FORMAT_R8] = unpack_R8;
+      table[MESA_FORMAT_RG88] = unpack_RG88;
+      table[MESA_FORMAT_RG88_REV] = unpack_RG88_REV;
+      table[MESA_FORMAT_R16] = unpack_R16;
+      table[MESA_FORMAT_RG1616] = unpack_RG1616;
+      table[MESA_FORMAT_RG1616_REV] = unpack_RG1616_REV;
+      table[MESA_FORMAT_ARGB2101010] = unpack_ARGB2101010;
+      table[MESA_FORMAT_Z24_S8] = unpack_Z24_S8;
+      table[MESA_FORMAT_S8_Z24] = unpack_S8_Z24;
+      table[MESA_FORMAT_Z16] = unpack_Z16;
+      table[MESA_FORMAT_X8_Z24] = unpack_X8_Z24;
+      table[MESA_FORMAT_Z24_X8] = unpack_Z24_X8;
+      table[MESA_FORMAT_Z32] = unpack_Z32;
+      table[MESA_FORMAT_S8] = unpack_S8;
+      table[MESA_FORMAT_SRGB8] = unpack_SRGB8;
+      table[MESA_FORMAT_SRGBA8] = unpack_SRGBA8;
+      table[MESA_FORMAT_SARGB8] = unpack_SARGB8;
+      table[MESA_FORMAT_SL8] = unpack_SL8;
+      table[MESA_FORMAT_SLA8] = unpack_SLA8;
+      table[MESA_FORMAT_SRGB_DXT1] = unpack_SRGB_DXT1;
+      table[MESA_FORMAT_SRGBA_DXT1] = unpack_SRGBA_DXT1;
+      table[MESA_FORMAT_SRGBA_DXT3] = unpack_SRGBA_DXT3;
+      table[MESA_FORMAT_SRGBA_DXT5] = unpack_SRGBA_DXT5;
+
+      table[MESA_FORMAT_RGB_FXT1] = unpack_RGB_FXT1;
+      table[MESA_FORMAT_RGBA_FXT1] = unpack_RGBA_FXT1;
+      table[MESA_FORMAT_RGB_DXT1] = unpack_RGB_DXT1;
+      table[MESA_FORMAT_RGBA_DXT1] = unpack_RGBA_DXT1;
+      table[MESA_FORMAT_RGBA_DXT3] = unpack_RGBA_DXT3;
+      table[MESA_FORMAT_RGBA_DXT5] = unpack_RGBA_DXT5;
+
+      table[MESA_FORMAT_RGBA_FLOAT32] = unpack_RGBA_FLOAT32;
+      table[MESA_FORMAT_RGBA_FLOAT16] = unpack_RGBA_FLOAT16;
+      table[MESA_FORMAT_RGB_FLOAT32] = unpack_RGB_FLOAT32;
+      table[MESA_FORMAT_RGB_FLOAT16] = unpack_RGB_FLOAT16;
+      table[MESA_FORMAT_ALPHA_FLOAT32] = unpack_ALPHA_FLOAT32;
+      table[MESA_FORMAT_ALPHA_FLOAT16] = unpack_ALPHA_FLOAT16;
+      table[MESA_FORMAT_LUMINANCE_FLOAT32] = unpack_LUMINANCE_FLOAT32;
+      table[MESA_FORMAT_LUMINANCE_FLOAT16] = unpack_LUMINANCE_FLOAT16;
+      table[MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32] = unpack_LUMINANCE_ALPHA_FLOAT32;
+      table[MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16] = unpack_LUMINANCE_ALPHA_FLOAT16;
+      table[MESA_FORMAT_INTENSITY_FLOAT32] = unpack_INTENSITY_FLOAT32;
+      table[MESA_FORMAT_INTENSITY_FLOAT16] = unpack_INTENSITY_FLOAT16;
+      table[MESA_FORMAT_R_FLOAT32] = unpack_R_FLOAT32;
+      table[MESA_FORMAT_R_FLOAT16] = unpack_R_FLOAT16;
+      table[MESA_FORMAT_RG_FLOAT32] = unpack_RG_FLOAT32;
+      table[MESA_FORMAT_RG_FLOAT16] = unpack_RG_FLOAT16;
+
+      table[MESA_FORMAT_RGBA_INT8] = unpack_RGBA_INT8;
+      table[MESA_FORMAT_RGBA_INT16] = unpack_RGBA_INT16;
+      table[MESA_FORMAT_RGBA_INT32] = unpack_RGBA_INT32;
+      table[MESA_FORMAT_RGBA_UINT8] = unpack_RGBA_UINT8;
+      table[MESA_FORMAT_RGBA_UINT16] = unpack_RGBA_UINT16;
+      table[MESA_FORMAT_RGBA_UINT32] = unpack_RGBA_UINT32;
+
+      table[MESA_FORMAT_DUDV8] = unpack_DUDV8;
+      table[MESA_FORMAT_SIGNED_R8] = unpack_SIGNED_R8;
+      table[MESA_FORMAT_SIGNED_RG88_REV] = unpack_SIGNED_RG88_REV;
+      table[MESA_FORMAT_SIGNED_RGBX8888] = unpack_SIGNED_RGBX8888;
+      table[MESA_FORMAT_SIGNED_RGBA8888] = unpack_SIGNED_RGBA8888;
+      table[MESA_FORMAT_SIGNED_RGBA8888_REV] = unpack_SIGNED_RGBA8888_REV;
+      table[MESA_FORMAT_SIGNED_R16] = unpack_SIGNED_R16;
+      table[MESA_FORMAT_SIGNED_GR1616] = unpack_SIGNED_GR1616;
+      table[MESA_FORMAT_SIGNED_RGB_16] = unpack_SIGNED_RGB_16;
+      table[MESA_FORMAT_SIGNED_RGBA_16] = unpack_SIGNED_RGBA_16;
+      table[MESA_FORMAT_RGBA_16] = unpack_RGBA_16;
+
+      table[MESA_FORMAT_RED_RGTC1] = unpack_RED_RGTC1;
+      table[MESA_FORMAT_SIGNED_RED_RGTC1] = unpack_SIGNED_RED_RGTC1;
+      table[MESA_FORMAT_RG_RGTC2] = unpack_RG_RGTC2;
+      table[MESA_FORMAT_SIGNED_RG_RGTC2] = unpack_SIGNED_RG_RGTC2;
+
+      table[MESA_FORMAT_L_LATC1] = unpack_L_LATC1;
+      table[MESA_FORMAT_SIGNED_L_LATC1] = unpack_SIGNED_L_LATC1;
+      table[MESA_FORMAT_LA_LATC2] = unpack_LA_LATC2;
+      table[MESA_FORMAT_SIGNED_LA_LATC2] = unpack_SIGNED_LA_LATC2;
+
+      table[MESA_FORMAT_SIGNED_A8] = unpack_SIGNED_A8;
+      table[MESA_FORMAT_SIGNED_L8] = unpack_SIGNED_L8;
+      table[MESA_FORMAT_SIGNED_AL88] = unpack_SIGNED_AL88;
+      table[MESA_FORMAT_SIGNED_I8] = unpack_SIGNED_I8;
+      table[MESA_FORMAT_SIGNED_A16] = unpack_SIGNED_A16;
+      table[MESA_FORMAT_SIGNED_L16] = unpack_SIGNED_L16;
+      table[MESA_FORMAT_SIGNED_AL1616] = unpack_SIGNED_AL1616;
+      table[MESA_FORMAT_SIGNED_I16] = unpack_SIGNED_I16;
+
+      table[MESA_FORMAT_RGB9_E5_FLOAT] = unpack_RGB9_E5_FLOAT;
+      table[MESA_FORMAT_R11_G11_B10_FLOAT] = unpack_R11_G11_B10_FLOAT;
+
+      table[MESA_FORMAT_Z32_FLOAT] = unpack_Z32_FLOAT;
+      table[MESA_FORMAT_Z32_FLOAT_X24S8] = unpack_Z32_FLOAT_X24S8;
+
+      initialized = GL_TRUE;
+   }
+
+   return table[format];
+}
+
+
+void
+_mesa_unpack_rgba_row(gl_format format, GLuint n,
+                      const void *src, GLfloat dst[][4])
+{
+   unpack_rgba_func unpack = get_unpack_rgba_function(format);
+   GLuint srcStride = _mesa_get_format_bytes(format);
+   const GLubyte *srcPtr = (GLubyte *) src;
+   GLuint i;
+
+   for (i = 0; i < n; i++) {
+      unpack(srcPtr, dst[i]);
+      srcPtr += srcStride;
+   }
+}
+
+
+
+/**
+ * Unpack a 2D rect of pixels returning float RGBA colors.
+ * \param format  the source image format
+ * \param src  start address of the source image
+ * \param srcRowStride  source image row stride in bytes
+ * \param dst  start address of the dest image
+ * \param dstRowStride  dest image row stride in bytes
+ * \param x  source image start X pos
+ * \param y  source image start Y pos
+ * \param width  width of rect region to convert
+ * \param height  height of rect region to convert
+ */
+void
+_mesa_unpack_rgba_block(gl_format format,
+                        const void *src, GLint srcRowStride,
+                        GLfloat dst[][4], GLint dstRowStride,
+                        GLuint x, GLuint y, GLuint width, GLuint height)
+{
+   unpack_rgba_func unpack = get_unpack_rgba_function(format);
+   const GLuint srcPixStride = _mesa_get_format_bytes(format);
+   const GLuint dstPixStride = 4 * sizeof(GLfloat);
+   const GLubyte *srcRow, *srcPix;
+   GLubyte *dstRow;
+   GLfloat *dstPix;
+   GLuint i, j;
+
+   /* XXX needs to be fixed for compressed formats */
+
+   srcRow = ((const GLubyte *) src) + srcRowStride * y + srcPixStride * x;
+   dstRow = ((GLubyte *) dst) + dstRowStride * y + dstPixStride * x;
+
+   for (i = 0; i < height; i++) {
+      srcPix = srcRow;
+      dstPix = (GLfloat *) dstRow;
+
+      for (j = 0; j < width; j++) {
+         unpack(srcPix, dstPix);
+         srcPix += srcPixStride;
+         dstPix += dstPixStride;
+      }
+
+      dstRow += dstRowStride;
+      srcRow += srcRowStride;
+   }
+}
+
+
+
+
+typedef void (*unpack_float_z_func)(const void *src, GLfloat *dst);
+
+static void
+unpack_float_z_Z24_S8(const void *src, GLfloat *dst)
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   const GLfloat scale = 1.0F / (GLfloat) 0xffffff;
+   *dst = (s >> 8) * scale;
+   ASSERT(*dst >= 0.0F);
+   ASSERT(*dst <= 1.0F);
+}
+
+static void
+unpack_float_z_S8_Z24(const void *src, GLfloat *dst)
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   const GLfloat scale = 1.0F / (GLfloat) 0xffffff;
+   *dst = (s & 0x00ffffff) * scale;
+   ASSERT(*dst >= 0.0F);
+   ASSERT(*dst <= 1.0F);
+}
+
+static void
+unpack_float_z_Z16(const void *src, GLfloat *dst)
+{
+   const GLushort s = *((const GLushort *) src);
+   *dst = s * (1.0F / 65535.0F);
+}
+
+static void
+unpack_float_z_X8_Z24(const void *src, GLfloat *dst)
+{
+   unpack_float_z_S8_Z24(src, dst);
+}
+
+static void
+unpack_float_z_Z24_X8(const void *src, GLfloat *dst)
+{
+   unpack_float_z_Z24_S8(src, dst);
+}
+
+static void
+unpack_float_z_Z32(const void *src, GLfloat *dst)
+{
+   const GLuint s = *((const GLuint *) src);
+   *dst = s * (1.0F / 0xffffffff);
+}
+
+static void
+unpack_float_z_Z32X24S8(const void *src, GLfloat *dst)
+{
+   *dst = *((const GLfloat *) src);
+}
+
+
+
+void
+_mesa_unpack_float_z_row(gl_format format, GLuint n,
+                         const void *src, GLfloat *dst)
+{
+   unpack_float_z_func unpack;
+   GLuint srcStride = _mesa_get_format_bytes(format);
+   const GLubyte *srcPtr = (GLubyte *) src;
+   GLuint i;
+
+   switch (format) {
+   case MESA_FORMAT_Z24_S8:
+      unpack = unpack_float_z_Z24_S8;
+      break;
+   case MESA_FORMAT_S8_Z24:
+      unpack = unpack_float_z_S8_Z24;
+      break;
+   case MESA_FORMAT_Z16:
+      unpack = unpack_float_z_Z16;
+      break;
+   case MESA_FORMAT_X8_Z24:
+      unpack = unpack_float_z_X8_Z24;
+      break;
+   case MESA_FORMAT_Z24_X8:
+      unpack = unpack_float_z_Z24_X8;
+      break;
+   case MESA_FORMAT_Z32:
+      unpack = unpack_float_z_Z32;
+      break;
+   case MESA_FORMAT_Z32_FLOAT_X24S8:
+      unpack = unpack_float_z_Z32X24S8;
+      break;
+   default:
+      _mesa_problem(NULL, "bad format %s in _mesa_unpack_float_z_row",
+                    _mesa_get_format_name(format));
+      return;
+   }
+
+   for (i = 0; i < n; i++) {
+      unpack(srcPtr, &dst[i]);
+      srcPtr += srcStride;
+   }
+}
+
+
+
+typedef void (*unpack_uint_z_func)(const void *src, GLuint *dst);
+
+static void
+unpack_uint_z_Z24_S8(const void *src, GLuint *dst)
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   *dst = (s >> 8);
+}
+
+static void
+unpack_uint_z_S8_Z24(const void *src, GLuint *dst)
+{
+   /* only return Z, not stencil data */
+   const GLuint s = *((const GLuint *) src);
+   *dst = s & 0x00ffffff;
+}
+
+static void
+unpack_uint_z_Z16(const void *src, GLuint *dst)
+{
+   *dst = *((const GLushort *) src);
+}
+
+static void
+unpack_uint_z_X8_Z24(const void *src, GLuint *dst)
+{
+   unpack_uint_z_S8_Z24(src, dst);
+}
+
+static void
+unpack_uint_z_Z24_X8(const void *src, GLuint *dst)
+{
+   unpack_uint_z_Z24_S8(src, dst);
+}
+
+static void
+unpack_uint_z_Z32(const void *src, GLuint *dst)
+{
+   *dst = *((const GLuint *) src);
+}
+
+
+void
+_mesa_unpack_uint_z_row(gl_format format, GLuint n,
+                        const void *src, GLuint *dst)
+{
+   unpack_uint_z_func unpack;
+   GLuint srcStride = _mesa_get_format_bytes(format);
+   const GLubyte *srcPtr = (GLubyte *) src;
+   GLuint i;
+
+   switch (format) {
+   case MESA_FORMAT_Z24_S8:
+      unpack = unpack_uint_z_Z24_S8;
+      break;
+   case MESA_FORMAT_S8_Z24:
+      unpack = unpack_uint_z_S8_Z24;
+      break;
+   case MESA_FORMAT_Z16:
+      unpack = unpack_uint_z_Z16;
+      break;
+   case MESA_FORMAT_X8_Z24:
+      unpack = unpack_uint_z_X8_Z24;
+      break;
+   case MESA_FORMAT_Z24_X8:
+      unpack = unpack_uint_z_Z24_X8;
+      break;
+   case MESA_FORMAT_Z32:
+      unpack = unpack_uint_z_Z32;
+      break;
+   default:
+      _mesa_problem(NULL, "bad format %s in _mesa_unpack_uint_z_row",
+                    _mesa_get_format_name(format));
+      return;
+   }
+
+   for (i = 0; i < n; i++) {
+      unpack(srcPtr, &dst[i]);
+      srcPtr += srcStride;
+   }
+}
+
+
diff --git a/src/mesa/main/format_unpack.h b/src/mesa/main/format_unpack.h
new file mode 100644
index 00000000000..c37727d91a0
--- /dev/null
+++ b/src/mesa/main/format_unpack.h
@@ -0,0 +1,49 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (c) 2011 VMware, Inc.
+ *
+ * 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
+ * THE AUTHORS 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.
+ */
+
+#ifndef FORMAT_UNPACK_H
+#define FORMAT_UNPACK_H
+
+extern void
+_mesa_unpack_rgba_row(gl_format format, GLuint n,
+                      const void *src, GLfloat dst[][4]);
+
+
+extern void
+_mesa_unpack_rgba_block(gl_format format,
+                        const void *src, GLint srcRowStride,
+                        GLfloat dst[][4], GLint dstRowStride,
+                        GLuint x, GLuint y, GLuint width, GLuint height);
+
+
+extern void
+_mesa_unpack_float_z_row(gl_format format, GLuint n,
+                         const void *src, GLfloat *dst);
+
+
+void
+_mesa_unpack_uint_z_row(gl_format format, GLuint n,
+                        const void *src, GLuint *dst);
+
+
+#endif /* FORMAT_UNPACK_H */