mesa: Add texel fetch functions for BPTC-compressed textures

Adds functions to fetch from any of the four BPTC-compressed formats.

v2: Set the alpha component to 1.0 when fetching from the half-float formats
    instead of leaving it uninitialised. Don't linearize the alpha component
    when fetching from sRGB.

Reviewed-by: Ian Romanick <[email protected]>

4 files changed, 1001 insertions, 0 deletions

diff --git a/src/mesa/Makefile.sources b/src/mesa/Makefile.sources
index 59456577178..12336c074ab 100644
--- a/src/mesa/Makefile.sources
+++ b/src/mesa/Makefile.sources
@@ -97,6 +97,7 @@ MAIN_FILES = \
 	$(SRCDIR)main/stencil.c \
 	$(SRCDIR)main/syncobj.c \
 	$(SRCDIR)main/texcompress.c \
+	$(SRCDIR)main/texcompress_bptc.c \
 	$(SRCDIR)main/texcompress_cpal.c \
 	$(SRCDIR)main/texcompress_rgtc.c \
 	$(SRCDIR)main/texcompress_s3tc.c \
diff --git a/src/mesa/main/texcompress.c b/src/mesa/main/texcompress.c
index 53c0ea02206..b4efeee3bcc 100644
--- a/src/mesa/main/texcompress.c
+++ b/src/mesa/main/texcompress.c
@@ -42,6 +42,7 @@
 #include "texcompress_rgtc.h"
 #include "texcompress_s3tc.h"
 #include "texcompress_etc.h"
+#include "texcompress_bptc.h"
 
 
 /**
@@ -610,6 +611,11 @@ _mesa_get_compressed_fetch_func(mesa_format format)
       return _mesa_get_compressed_rgtc_func(format);
    case MESA_FORMAT_ETC1_RGB8:
       return _mesa_get_etc_fetch_func(format);
+   case MESA_FORMAT_BPTC_RGBA_UNORM:
+   case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM:
+   case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT:
+   case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT:
+      return _mesa_get_bptc_fetch_func(format);
    default:
       return NULL;
    }
diff --git a/src/mesa/main/texcompress_bptc.c b/src/mesa/main/texcompress_bptc.c
new file mode 100644
index 00000000000..7ec294b56a2
--- /dev/null
+++ b/src/mesa/main/texcompress_bptc.c
@@ -0,0 +1,960 @@
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 OR COPYRIGHT HOLDERS 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_bptc.c
+ * GL_ARB_texture_compression_bptc support.
+ */
+
+#include <stdbool.h>
+#include "texcompress.h"
+#include "texcompress_bptc.h"
+#include "util/format_srgb.h"
+#include "texstore.h"
+#include "macros.h"
+#include "image.h"
+
+#define BLOCK_SIZE 4
+#define N_PARTITIONS 64
+#define BLOCK_BYTES 16
+
+struct bptc_unorm_mode {
+   int n_subsets;
+   int n_partition_bits;
+   bool has_rotation_bits;
+   bool has_index_selection_bit;
+   int n_color_bits;
+   int n_alpha_bits;
+   bool has_endpoint_pbits;
+   bool has_shared_pbits;
+   int n_index_bits;
+   int n_secondary_index_bits;
+};
+
+struct bptc_float_bitfield {
+   int8_t endpoint;
+   uint8_t component;
+   uint8_t offset;
+   uint8_t n_bits;
+   bool reverse;
+};
+
+struct bptc_float_mode {
+   bool reserved;
+   bool transformed_endpoints;
+   int n_partition_bits;
+   int n_endpoint_bits;
+   int n_index_bits;
+   int n_delta_bits[3];
+   struct bptc_float_bitfield bitfields[24];
+};
+
+static const struct bptc_unorm_mode
+bptc_unorm_modes[] = {
+   /* 0 */ { 3, 4, false, false, 4, 0, true,  false, 3, 0 },
+   /* 1 */ { 2, 6, false, false, 6, 0, false, true,  3, 0 },
+   /* 2 */ { 3, 6, false, false, 5, 0, false, false, 2, 0 },
+   /* 3 */ { 2, 6, false, false, 7, 0, true,  false, 2, 0 },
+   /* 4 */ { 1, 0, true,  true,  5, 6, false, false, 2, 3 },
+   /* 5 */ { 1, 0, true,  false, 7, 8, false, false, 2, 2 },
+   /* 6 */ { 1, 0, false, false, 7, 7, true,  false, 4, 0 },
+   /* 7 */ { 2, 6, false, false, 5, 5, true,  false, 2, 0 }
+};
+
+static const struct bptc_float_mode
+bptc_float_modes[] = {
+   /* 00 */
+   { false, true, 5, 10, 3, { 5, 5, 5 },
+     { { 2, 1, 4, 1, false }, { 2, 2, 4, 1, false }, { 3, 2, 4, 1, false },
+       { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
+       { 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
+       { 1, 2, 0, 5, false }, { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false },
+       { 2, 0, 0, 5, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false },
+       { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 01 */
+   { false, true, 5, 7, 3, { 6, 6, 6 },
+     { { 2, 1, 5, 1, false }, { 3, 1, 4, 1, false }, { 3, 1, 5, 1, false },
+       { 0, 0, 0, 7, false }, { 3, 2, 0, 1, false }, { 3, 2, 1, 1, false },
+       { 2, 2, 4, 1, false }, { 0, 1, 0, 7, false }, { 2, 2, 5, 1, false },
+       { 3, 2, 2, 1, false }, { 2, 1, 4, 1, false }, { 0, 2, 0, 7, false },
+       { 3, 2, 3, 1, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 6, false },
+       { 3, 1, 0, 4, false }, { 1, 2, 0, 6, false }, { 2, 2, 0, 4, false },
+       { 2, 0, 0, 6, false },
+       { 3, 0, 0, 6, false },
+       { -1 } }
+   },
+   /* 00010 */
+   { false, true, 5, 11, 3, { 5, 4, 4 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 5, false }, { 0, 0, 10, 1, false }, { 2, 1, 0, 4, false },
+       { 1, 1, 0, 4, false }, { 0, 1, 10, 1, false }, { 3, 2, 0, 1, false },
+       { 3, 1, 0, 4, false }, { 1, 2, 0, 4, false }, { 0, 2, 10, 1, false },
+       { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
+       { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 00011 */
+   { false, false, 0, 10, 4, { 10, 10, 10 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 10, false }, { 1, 1, 0, 10, false }, { 1, 2, 0, 10, false },
+       { -1 } }
+   },
+   /* 00110 */
+   { false, true, 5, 11, 3, { 4, 5, 4 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 4, false }, { 0, 0, 10, 1, false }, { 3, 1, 4, 1, false },
+       { 2, 1, 0, 4, false }, { 1, 1, 0, 5, false }, { 0, 1, 10, 1, false },
+       { 3, 1, 0, 4, false }, { 1, 2, 0, 4, false }, { 0, 2, 10, 1, false },
+       { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 4, false },
+       { 3, 2, 0, 1, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 4, false },
+       { 2, 1, 4, 1, false }, { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 00111 */
+   { false, true, 0, 11, 4, { 9, 9, 9 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 9, false }, { 0, 0, 10, 1, false }, { 1, 1, 0, 9, false },
+       { 0, 1, 10, 1, false }, { 1, 2, 0, 9, false }, { 0, 2, 10, 1, false },
+       { -1 } }
+   },
+   /* 01010 */
+   { false, true, 5, 11, 3, { 4, 4, 5 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 4, false }, { 0, 0, 10, 1, false }, { 2, 2, 4, 1, false },
+       { 2, 1, 0, 4, false }, { 1, 1, 0, 4, false }, { 0, 1, 10, 1, false },
+       { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
+       { 0, 2, 10, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 4, false },
+       { 3, 2, 1, 1, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 4, false },
+       { 3, 2, 4, 1, false }, { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 01011 */
+   { false, true, 0, 12, 4, { 8, 8, 8 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 8, false }, { 0, 0, 10, 2, true }, { 1, 1, 0, 8, false },
+       { 0, 1, 10, 2, true }, { 1, 2, 0, 8, false }, { 0, 2, 10, 2, true },
+       { -1 } }
+   },
+   /* 01110 */
+   { false, true, 5, 9, 3, { 5, 5, 5 },
+     { { 0, 0, 0, 9, false }, { 2, 2, 4, 1, false }, { 0, 1, 0, 9, false },
+       { 2, 1, 4, 1, false }, { 0, 2, 0, 9, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
+       { 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
+       { 1, 2, 0, 5, false }, { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false },
+       { 2, 0, 0, 5, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false },
+       { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 01111 */
+   { false, true, 0, 16, 4, { 4, 4, 4 },
+     { { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
+       { 1, 0, 0, 4, false }, { 0, 0, 10, 6, true }, { 1, 1, 0, 4, false },
+       { 0, 1, 10, 6, true }, { 1, 2, 0, 4, false }, { 0, 2, 10, 6, true },
+       { -1 } }
+   },
+   /* 10010 */
+   { false, true, 5, 8, 3, { 6, 5, 5 },
+     { { 0, 0, 0, 8, false }, { 3, 1, 4, 1, false }, { 2, 2, 4, 1, false },
+       { 0, 1, 0, 8, false }, { 3, 2, 2, 1, false }, { 2, 1, 4, 1, false },
+       { 0, 2, 0, 8, false }, { 3, 2, 3, 1, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 5, false },
+       { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
+       { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 6, false },
+       { 3, 0, 0, 6, false },
+       { -1 } }
+   },
+   /* 10011 */
+   { true /* reserved */ },
+   /* 10110 */
+   { false, true, 5, 8, 3, { 5, 6, 5 },
+     { { 0, 0, 0, 8, false }, { 3, 2, 0, 1, false }, { 2, 2, 4, 1, false },
+       { 0, 1, 0, 8, false }, { 2, 1, 5, 1, false }, { 2, 1, 4, 1, false },
+       { 0, 2, 0, 8, false }, { 3, 1, 5, 1, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
+       { 1, 1, 0, 6, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
+       { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
+       { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 10111 */
+   { true /* reserved */ },
+   /* 11010 */
+   { false, true, 5, 8, 3, { 5, 5, 6 },
+     { { 0, 0, 0, 8, false }, { 3, 2, 1, 1, false }, { 2, 2, 4, 1, false },
+       { 0, 1, 0, 8, false }, { 2, 2, 5, 1, false }, { 2, 1, 4, 1, false },
+       { 0, 2, 0, 8, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
+       { 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
+       { 1, 2, 0, 6, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
+       { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
+       { -1 } }
+   },
+   /* 11011 */
+   { true /* reserved */ },
+   /* 11110 */
+   { false, false, 5, 6, 3, { 6, 6, 6 },
+     { { 0, 0, 0, 6, false }, { 3, 1, 4, 1, false }, { 3, 2, 0, 1, false },
+       { 3, 2, 1, 1, false }, { 2, 2, 4, 1, false }, { 0, 1, 0, 6, false },
+       { 2, 1, 5, 1, false }, { 2, 2, 5, 1, false }, { 3, 2, 2, 1, false },
+       { 2, 1, 4, 1, false }, { 0, 2, 0, 6, false }, { 3, 1, 5, 1, false },
+       { 3, 2, 3, 1, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
+       { 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 6, false },
+       { 3, 1, 0, 4, false }, { 1, 2, 0, 6, false }, { 2, 2, 0, 4, false },
+       { 2, 0, 0, 6, false }, { 3, 0, 0, 6, false },
+       { -1 } }
+   },
+   /* 11111 */
+   { true /* reserved */ },
+};
+
+/* This partition table is used when the mode has two subsets. Each
+ * partition is represented by a 32-bit value which gives 2 bits per texel
+ * within the block. The value of the two bits represents which subset to use
+ * (0 or 1).
+ */
+static const uint32_t
+partition_table1[N_PARTITIONS] = {
+   0x50505050U, 0x40404040U, 0x54545454U, 0x54505040U,
+   0x50404000U, 0x55545450U, 0x55545040U, 0x54504000U,
+   0x50400000U, 0x55555450U, 0x55544000U, 0x54400000U,
+   0x55555440U, 0x55550000U, 0x55555500U, 0x55000000U,
+   0x55150100U, 0x00004054U, 0x15010000U, 0x00405054U,
+   0x00004050U, 0x15050100U, 0x05010000U, 0x40505054U,
+   0x00404050U, 0x05010100U, 0x14141414U, 0x05141450U,
+   0x01155440U, 0x00555500U, 0x15014054U, 0x05414150U,
+   0x44444444U, 0x55005500U, 0x11441144U, 0x05055050U,
+   0x05500550U, 0x11114444U, 0x41144114U, 0x44111144U,
+   0x15055054U, 0x01055040U, 0x05041050U, 0x05455150U,
+   0x14414114U, 0x50050550U, 0x41411414U, 0x00141400U,
+   0x00041504U, 0x00105410U, 0x10541000U, 0x04150400U,
+   0x50410514U, 0x41051450U, 0x05415014U, 0x14054150U,
+   0x41050514U, 0x41505014U, 0x40011554U, 0x54150140U,
+   0x50505500U, 0x00555050U, 0x15151010U, 0x54540404U,
+};
+
+/* This partition table is used when the mode has three subsets. In this case
+ * the values can be 0, 1 or 2.
+ */
+static const uint32_t
+partition_table2[N_PARTITIONS] = {
+   0xaa685050U, 0x6a5a5040U, 0x5a5a4200U, 0x5450a0a8U,
+   0xa5a50000U, 0xa0a05050U, 0x5555a0a0U, 0x5a5a5050U,
+   0xaa550000U, 0xaa555500U, 0xaaaa5500U, 0x90909090U,
+   0x94949494U, 0xa4a4a4a4U, 0xa9a59450U, 0x2a0a4250U,
+   0xa5945040U, 0x0a425054U, 0xa5a5a500U, 0x55a0a0a0U,
+   0xa8a85454U, 0x6a6a4040U, 0xa4a45000U, 0x1a1a0500U,
+   0x0050a4a4U, 0xaaa59090U, 0x14696914U, 0x69691400U,
+   0xa08585a0U, 0xaa821414U, 0x50a4a450U, 0x6a5a0200U,
+   0xa9a58000U, 0x5090a0a8U, 0xa8a09050U, 0x24242424U,
+   0x00aa5500U, 0x24924924U, 0x24499224U, 0x50a50a50U,
+   0x500aa550U, 0xaaaa4444U, 0x66660000U, 0xa5a0a5a0U,
+   0x50a050a0U, 0x69286928U, 0x44aaaa44U, 0x66666600U,
+   0xaa444444U, 0x54a854a8U, 0x95809580U, 0x96969600U,
+   0xa85454a8U, 0x80959580U, 0xaa141414U, 0x96960000U,
+   0xaaaa1414U, 0xa05050a0U, 0xa0a5a5a0U, 0x96000000U,
+   0x40804080U, 0xa9a8a9a8U, 0xaaaaaa44U, 0x2a4a5254U
+};
+
+static const uint8_t
+anchor_indices[][N_PARTITIONS] = {
+   /* Anchor index values for the second subset of two-subset partitioning */
+   {
+      0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,
+      0xf,0x2,0x8,0x2,0x2,0x8,0x8,0xf,0x2,0x8,0x2,0x2,0x8,0x8,0x2,0x2,
+      0xf,0xf,0x6,0x8,0x2,0x8,0xf,0xf,0x2,0x8,0x2,0x2,0x2,0xf,0xf,0x6,
+      0x6,0x2,0x6,0x8,0xf,0xf,0x2,0x2,0xf,0xf,0xf,0xf,0xf,0x2,0x2,0xf
+   },
+
+   /* Anchor index values for the second subset of three-subset partitioning */
+   {
+      0x3,0x3,0xf,0xf,0x8,0x3,0xf,0xf,0x8,0x8,0x6,0x6,0x6,0x5,0x3,0x3,
+      0x3,0x3,0x8,0xf,0x3,0x3,0x6,0xa,0x5,0x8,0x8,0x6,0x8,0x5,0xf,0xf,
+      0x8,0xf,0x3,0x5,0x6,0xa,0x8,0xf,0xf,0x3,0xf,0x5,0xf,0xf,0xf,0xf,
+      0x3,0xf,0x5,0x5,0x5,0x8,0x5,0xa,0x5,0xa,0x8,0xd,0xf,0xc,0x3,0x3
+   },
+
+   /* Anchor index values for the third subset of three-subset
+    * partitioning
+    */
+   {
+      0xf,0x8,0x8,0x3,0xf,0xf,0x3,0x8,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0x8,
+      0xf,0x8,0xf,0x3,0xf,0x8,0xf,0x8,0x3,0xf,0x6,0xa,0xf,0xf,0xa,0x8,
+      0xf,0x3,0xf,0xa,0xa,0x8,0x9,0xa,0x6,0xf,0x8,0xf,0x3,0x6,0x6,0x8,
+      0xf,0x3,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0x3,0xf,0xf,0x8
+   }
+};
+
+static int
+extract_bits(const uint8_t *block,
+             int offset,
+             int n_bits)
+{
+   int byte_index = offset / 8;
+   int bit_index = offset % 8;
+   int n_bits_in_byte = MIN2(n_bits, 8 - bit_index);
+   int result = 0;
+   int bit = 0;
+
+   while (true) {
+      result |= ((block[byte_index] >> bit_index) &
+                 ((1 << n_bits_in_byte) - 1)) << bit;
+
+      n_bits -= n_bits_in_byte;
+
+      if (n_bits <= 0)
+         return result;
+
+      bit += n_bits_in_byte;
+      byte_index++;
+      bit_index = 0;
+      n_bits_in_byte = MIN2(n_bits, 8);
+   }
+}
+
+static uint8_t
+expand_component(uint8_t byte,
+                 int n_bits)
+{
+   /* Expands a n-bit quantity into a byte by copying the most-significant
+    * bits into the unused least-significant bits.
+    */
+   return byte << (8 - n_bits) | (byte >> (2 * n_bits - 8));
+}
+
+static int
+extract_unorm_endpoints(const struct bptc_unorm_mode *mode,
+                        const uint8_t *block,
+                        int bit_offset,
+                        uint8_t endpoints[][4])
+{
+   int component;
+   int subset;
+   int endpoint;
+   int pbit;
+   int n_components;
+
+   /* Extract each color component */
+   for (component = 0; component < 3; component++) {
+      for (subset = 0; subset < mode->n_subsets; subset++) {
+         for (endpoint = 0; endpoint < 2; endpoint++) {
+            endpoints[subset * 2 + endpoint][component] =
+               extract_bits(block, bit_offset, mode->n_color_bits);
+            bit_offset += mode->n_color_bits;
+         }
+      }
+   }
+
+   /* Extract the alpha values */
+   if (mode->n_alpha_bits > 0) {
+      for (subset = 0; subset < mode->n_subsets; subset++) {
+         for (endpoint = 0; endpoint < 2; endpoint++) {
+            endpoints[subset * 2 + endpoint][3] =
+               extract_bits(block, bit_offset, mode->n_alpha_bits);
+            bit_offset += mode->n_alpha_bits;
+         }
+      }
+
+      n_components = 4;
+   } else {
+      for (subset = 0; subset < mode->n_subsets; subset++)
+         for (endpoint = 0; endpoint < 2; endpoint++)
+            endpoints[subset * 2 + endpoint][3] = 255;
+
+      n_components = 3;
+   }
+
+   /* Add in the p-bits */
+   if (mode->has_endpoint_pbits) {
+      for (subset = 0; subset < mode->n_subsets; subset++) {
+         for (endpoint = 0; endpoint < 2; endpoint++) {
+            pbit = extract_bits(block, bit_offset, 1);
+            bit_offset += 1;
+
+            for (component = 0; component < n_components; component++) {
+               endpoints[subset * 2 + endpoint][component] <<= 1;
+               endpoints[subset * 2 + endpoint][component] |= pbit;
+            }
+         }
+      }
+   } else if (mode->has_shared_pbits) {
+      for (subset = 0; subset < mode->n_subsets; subset++) {
+         pbit = extract_bits(block, bit_offset, 1);
+         bit_offset += 1;
+
+         for (endpoint = 0; endpoint < 2; endpoint++) {
+            for (component = 0; component < n_components; component++) {
+               endpoints[subset * 2 + endpoint][component] <<= 1;
+               endpoints[subset * 2 + endpoint][component] |= pbit;
+            }
+         }
+      }
+   }
+
+   /* Expand the n-bit values to a byte */
+   for (subset = 0; subset < mode->n_subsets; subset++) {
+      for (endpoint = 0; endpoint < 2; endpoint++) {
+         for (component = 0; component < 3; component++) {
+            endpoints[subset * 2 + endpoint][component] =
+               expand_component(endpoints[subset * 2 + endpoint][component],
+                                mode->n_color_bits +
+                                mode->has_endpoint_pbits +
+                                mode->has_shared_pbits);
+         }
+
+         if (mode->n_alpha_bits > 0) {
+            endpoints[subset * 2 + endpoint][3] =
+               expand_component(endpoints[subset * 2 + endpoint][3],
+                                mode->n_alpha_bits +
+                                mode->has_endpoint_pbits +
+                                mode->has_shared_pbits);
+         }
+      }
+   }
+
+   return bit_offset;
+}
+
+static bool
+is_anchor(int n_subsets,
+          int partition_num,
+          int texel)
+{
+   if (texel == 0)
+      return true;
+
+   switch (n_subsets) {
+   case 1:
+      return false;
+   case 2:
+      return anchor_indices[0][partition_num] == texel;
+   case 3:
+      return (anchor_indices[1][partition_num] == texel ||
+              anchor_indices[2][partition_num] == texel);
+   default:
+      assert(false);
+      return false;
+   }
+}
+
+static int
+count_anchors_before_texel(int n_subsets,
+                           int partition_num,
+                           int texel)
+{
+   int count = 1;
+
+   if (texel == 0)
+      return 0;
+
+   switch (n_subsets) {
+   case 1:
+      break;
+   case 2:
+      if (texel > anchor_indices[0][partition_num])
+         count++;
+      break;
+   case 3:
+      if (texel > anchor_indices[1][partition_num])
+         count++;
+      if (texel > anchor_indices[2][partition_num])
+         count++;
+      break;
+   default:
+      assert(false);
+      return 0;
+   }
+
+   return count;
+}
+
+static int32_t
+interpolate(int32_t a, int32_t b,
+            int index,
+            int index_bits)
+{
+   static const uint8_t weights2[] = { 0, 21, 43, 64 };
+   static const uint8_t weights3[] = { 0, 9, 18, 27, 37, 46, 55, 64 };
+   static const uint8_t weights4[] =
+      { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
+   static const uint8_t *weights[] = {
+      NULL, NULL, weights2, weights3, weights4
+   };
+   int weight;
+
+   weight = weights[index_bits][index];
+
+   return ((64 - weight) * a + weight * b + 32) >> 6;
+}
+
+static void
+apply_rotation(int rotation,
+               uint8_t *result)
+{
+   uint8_t t;
+
+   if (rotation == 0)
+      return;
+
+   rotation--;
+
+   t = result[rotation];
+   result[rotation] = result[3];
+   result[3] = t;
+}
+
+static void
+fetch_rgba_unorm_from_block(const uint8_t *block,
+                            uint8_t *result,
+                            int texel)
+{
+   int mode_num = ffs(block[0]);
+   const struct bptc_unorm_mode *mode;
+   int bit_offset, secondary_bit_offset;
+   int partition_num;
+   int subset_num;
+   int rotation;
+   int index_selection;
+   int index_bits;
+   int indices[2];
+   int index;
+   int anchors_before_texel;
+   bool anchor;
+   uint8_t endpoints[3 * 2][4];
+   uint32_t subsets;
+   int component;
+
+   if (mode_num == 0) {
+      /* According to the spec this mode is reserved and shouldn't be used. */
+      memset(result, 0, 3);
+      result[3] = 0xff;
+      return;
+   }
+
+   mode = bptc_unorm_modes + mode_num - 1;
+   bit_offset = mode_num;
+
+   partition_num = extract_bits(block, bit_offset, mode->n_partition_bits);
+   bit_offset += mode->n_partition_bits;
+
+   switch (mode->n_subsets) {
+   case 1:
+      subsets = 0;
+      break;
+   case 2:
+      subsets = partition_table1[partition_num];
+      break;
+   case 3:
+      subsets = partition_table2[partition_num];
+      break;
+   default:
+      assert(false);
+      return;
+   }
+
+   if (mode->has_rotation_bits) {
+      rotation = extract_bits(block, bit_offset, 2);
+      bit_offset += 2;
+   } else {
+      rotation = 0;
+   }
+
+   if (mode->has_index_selection_bit) {
+      index_selection = extract_bits(block, bit_offset, 1);
+      bit_offset++;
+   } else {
+      index_selection = 0;
+   }
+
+   bit_offset = extract_unorm_endpoints(mode, block, bit_offset, endpoints);
+
+   anchors_before_texel = count_anchors_before_texel(mode->n_subsets,
+                                                     partition_num, texel);
+
+   /* Calculate the offset to the secondary index */
+   secondary_bit_offset = (bit_offset +
+                           BLOCK_SIZE * BLOCK_SIZE * mode->n_index_bits -
+                           mode->n_subsets +
+                           mode->n_secondary_index_bits * texel -
+                           anchors_before_texel);
+
+   /* Calculate the offset to the primary index for this texel */
+   bit_offset += mode->n_index_bits * texel - anchors_before_texel;
+
+   subset_num = (subsets >> (texel * 2)) & 3;
+
+   anchor = is_anchor(mode->n_subsets, partition_num, texel);
+
+   index_bits = mode->n_index_bits;
+   if (anchor)
+      index_bits--;
+   indices[0] = extract_bits(block, bit_offset, index_bits);
+
+   if (mode->n_secondary_index_bits) {
+      index_bits = mode->n_secondary_index_bits;
+      if (anchor)
+         index_bits--;
+      indices[1] = extract_bits(block, secondary_bit_offset, index_bits);
+   }
+
+   index = indices[index_selection];
+   index_bits = (index_selection ?
+                 mode->n_secondary_index_bits :
+                 mode->n_index_bits);
+
+   for (component = 0; component < 3; component++)
+      result[component] = interpolate(endpoints[subset_num * 2][component],
+                                      endpoints[subset_num * 2 + 1][component],
+                                      index,
+                                      index_bits);
+
+   /* Alpha uses the opposite index from the color components */
+   if (mode->n_secondary_index_bits && !index_selection) {
+      index = indices[1];
+      index_bits = mode->n_secondary_index_bits;
+   } else {
+      index = indices[0];
+      index_bits = mode->n_index_bits;
+   }
+
+   result[3] = interpolate(endpoints[subset_num * 2][3],
+                           endpoints[subset_num * 2 + 1][3],
+                           index,
+                           index_bits);
+
+   apply_rotation(rotation, result);
+}
+
+static void
+fetch_bptc_rgba_unorm_bytes(const GLubyte *map,
+                            GLint rowStride, GLint i, GLint j,
+                            GLubyte *texel)
+{
+   const GLubyte *block;
+
+   block = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
+
+   fetch_rgba_unorm_from_block(block, texel, (i % 4) + (j % 4) * 4);
+}
+
+static void
+fetch_bptc_rgba_unorm(const GLubyte *map,
+                      GLint rowStride, GLint i, GLint j,
+                      GLfloat *texel)
+{
+   GLubyte texel_bytes[4];
+
+   fetch_bptc_rgba_unorm_bytes(map, rowStride, i, j, texel_bytes);
+
+   texel[RCOMP] = UBYTE_TO_FLOAT(texel_bytes[0]);
+   texel[GCOMP] = UBYTE_TO_FLOAT(texel_bytes[1]);
+   texel[BCOMP] = UBYTE_TO_FLOAT(texel_bytes[2]);
+   texel[ACOMP] = UBYTE_TO_FLOAT(texel_bytes[3]);
+}
+
+static void
+fetch_bptc_srgb_alpha_unorm(const GLubyte *map,
+                            GLint rowStride, GLint i, GLint j,
+                            GLfloat *texel)
+{
+   GLubyte texel_bytes[4];
+
+   fetch_bptc_rgba_unorm_bytes(map, rowStride, i, j, texel_bytes);
+
+   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[0]);
+   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[1]);
+   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[2]);
+   texel[ACOMP] = UBYTE_TO_FLOAT(texel_bytes[3]);
+}
+
+static int32_t
+sign_extend(int32_t value,
+            int n_bits)
+{
+   if ((value & (1 << (n_bits - 1)))) {
+      value |= (~(int32_t) 0) << n_bits;
+   }
+
+   return value;
+}
+
+static int
+signed_unquantize(int value, int n_endpoint_bits)
+{
+   bool sign;
+
+   if (n_endpoint_bits >= 16)
+      return value;
+
+   if (value == 0)
+      return 0;
+
+   sign = false;
+
+   if (value < 0) {
+      sign = true;
+      value = -value;
+   }
+
+   if (value >= (1 << (n_endpoint_bits - 1)) - 1)
+      value = 0x7fff;
+   else
+      value = ((value << 15) + 0x4000) >> (n_endpoint_bits - 1);
+
+   if (sign)
+      value = -value;
+
+   return value;
+}
+
+static int
+unsigned_unquantize(int value, int n_endpoint_bits)
+{
+   if (n_endpoint_bits >= 15)
+      return value;
+
+   if (value == 0)
+      return 0;
+
+   if (value == (1 << n_endpoint_bits) - 1)
+      return 0xffff;
+
+   return ((value << 15) + 0x4000) >> (n_endpoint_bits - 1);
+}
+
+static int
+extract_float_endpoints(const struct bptc_float_mode *mode,
+                        const uint8_t *block,
+                        int bit_offset,
+                        int32_t endpoints[][3],
+                        bool is_signed)
+{
+   const struct bptc_float_bitfield *bitfield;
+   int endpoint, component;
+   int n_endpoints;
+   int value;
+   int i;
+
+   if (mode->n_partition_bits)
+      n_endpoints = 4;
+   else
+      n_endpoints = 2;
+
+   memset(endpoints, 0, sizeof endpoints[0][0] * n_endpoints * 3);
+
+   for (bitfield = mode->bitfields; bitfield->endpoint != -1; bitfield++) {
+      value = extract_bits(block, bit_offset, bitfield->n_bits);
+      bit_offset += bitfield->n_bits;
+
+      if (bitfield->reverse) {
+         for (i = 0; i < bitfield->n_bits; i++) {
+            if (value & (1 << i))
+               endpoints[bitfield->endpoint][bitfield->component] |=
+                  1 << ((bitfield->n_bits - 1 - i) + bitfield->offset);
+         }
+      } else {
+         endpoints[bitfield->endpoint][bitfield->component] |=
+            value << bitfield->offset;
+      }
+   }
+
+   if (mode->transformed_endpoints) {
+      /* The endpoints are specified as signed offsets from e0 */
+      for (endpoint = 1; endpoint < n_endpoints; endpoint++) {
+         for (component = 0; component < 3; component++) {
+            value = sign_extend(endpoints[endpoint][component],
+                                mode->n_delta_bits[component]);
+            endpoints[endpoint][component] =
+               ((endpoints[0][component] + value) &
+                ((1 << mode->n_endpoint_bits) - 1));
+         }
+      }
+   }
+
+   if (is_signed) {
+      for (endpoint = 0; endpoint < n_endpoints; endpoint++) {
+         for (component = 0; component < 3; component++) {
+            value = sign_extend(endpoints[endpoint][component],
+                                mode->n_endpoint_bits);
+            endpoints[endpoint][component] =
+               signed_unquantize(value, mode->n_endpoint_bits);
+         }
+      }
+   } else {
+      for (endpoint = 0; endpoint < n_endpoints; endpoint++) {
+         for (component = 0; component < 3; component++) {
+            endpoints[endpoint][component] =
+               unsigned_unquantize(endpoints[endpoint][component],
+                                   mode->n_endpoint_bits);
+         }
+      }
+   }
+
+   return bit_offset;
+}
+
+static int32_t
+finish_unsigned_unquantize(int32_t value)
+{
+   return value * 31 / 64;
+}
+
+static int32_t
+finish_signed_unquantize(int32_t value)
+{
+   if (value < 0)
+      return (-value * 31 / 32) | 0x8000;
+   else
+      return value * 31 / 32;
+}
+
+static void
+fetch_rgb_float_from_block(const uint8_t *block,
+                           float *result,
+                           int texel,
+                           bool is_signed)
+{
+   int mode_num;
+   const struct bptc_float_mode *mode;
+   int bit_offset;
+   int partition_num;
+   int subset_num;
+   int index_bits;
+   int index;
+   int anchors_before_texel;
+   int32_t endpoints[2 * 2][3];
+   uint32_t subsets;
+   int n_subsets;
+   int component;
+   int32_t value;
+
+   if (block[0] & 0x2) {
+      mode_num = (((block[0] >> 1) & 0xe) | (block[0] & 1)) + 2;
+      bit_offset = 5;
+   } else {
+      mode_num = block[0] & 3;
+      bit_offset = 2;
+   }
+
+   mode = bptc_float_modes + mode_num;
+
+   if (mode->reserved) {
+      memset(result, 0, sizeof result[0] * 3);
+      result[3] = 1.0f;
+      return;
+   }
+
+   bit_offset = extract_float_endpoints(mode, block, bit_offset,
+                                        endpoints, is_signed);
+
+   if (mode->n_partition_bits) {
+      partition_num = extract_bits(block, bit_offset, mode->n_partition_bits);
+      bit_offset += mode->n_partition_bits;
+
+      subsets = partition_table1[partition_num];
+      n_subsets = 2;
+   } else {
+      partition_num = 0;
+      subsets = 0;
+      n_subsets = 1;
+   }
+
+   anchors_before_texel =
+      count_anchors_before_texel(n_subsets, partition_num, texel);
+
+   /* Calculate the offset to the primary index for this texel */
+   bit_offset += mode->n_index_bits * texel - anchors_before_texel;
+
+   subset_num = (subsets >> (texel * 2)) & 3;
+
+   index_bits = mode->n_index_bits;
+   if (is_anchor(n_subsets, partition_num, texel))
+      index_bits--;
+   index = extract_bits(block, bit_offset, index_bits);
+
+   for (component = 0; component < 3; component++) {
+      value = interpolate(endpoints[subset_num * 2][component],
+                          endpoints[subset_num * 2 + 1][component],
+                          index,
+                          mode->n_index_bits);
+
+      if (is_signed)
+         value = finish_signed_unquantize(value);
+      else
+         value = finish_unsigned_unquantize(value);
+
+      result[component] = _mesa_half_to_float(value);
+   }
+
+   result[3] = 1.0f;
+}
+
+static void
+fetch_bptc_rgb_float(const GLubyte *map,
+                     GLint rowStride, GLint i, GLint j,
+                     GLfloat *texel,
+                     bool is_signed)
+{
+   const GLubyte *block;
+
+   block = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
+
+   fetch_rgb_float_from_block(block, texel, (i % 4) + (j % 4) * 4, is_signed);
+}
+
+static void
+fetch_bptc_rgb_signed_float(const GLubyte *map,
+                            GLint rowStride, GLint i, GLint j,
+                            GLfloat *texel)
+{
+   fetch_bptc_rgb_float(map, rowStride, i, j, texel, true);
+}
+
+static void
+fetch_bptc_rgb_unsigned_float(const GLubyte *map,
+                              GLint rowStride, GLint i, GLint j,
+                              GLfloat *texel)
+{
+   fetch_bptc_rgb_float(map, rowStride, i, j, texel, false);
+}
+
+compressed_fetch_func
+_mesa_get_bptc_fetch_func(mesa_format format)
+{
+   switch (format) {
+   case MESA_FORMAT_BPTC_RGBA_UNORM:
+      return fetch_bptc_rgba_unorm;
+   case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM:
+      return fetch_bptc_srgb_alpha_unorm;
+   case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT:
+      return fetch_bptc_rgb_signed_float;
+   case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT:
+      return fetch_bptc_rgb_unsigned_float;
+   default:
+      return NULL;
+   }
+}
diff --git a/src/mesa/main/texcompress_bptc.h b/src/mesa/main/texcompress_bptc.h
new file mode 100644
index 00000000000..ad5ff50a649
--- /dev/null
+++ b/src/mesa/main/texcompress_bptc.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 OR COPYRIGHT HOLDERS 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 TEXCOMPRESS_BPTC_H
+#define TEXCOMPRESS_BPTC_H
+
+#include <inttypes.h>
+#include "glheader.h"
+#include "texcompress.h"
+
+compressed_fetch_func
+_mesa_get_bptc_fetch_func(mesa_format format);
+
+#endif