/*
 * Copyright © 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.
 *
 * Authors:
 *    Neil Roberts <neil@linux.intel.com>
 *
 */

/** @file bptc-modes.c
 *
 * Tests BPTC-compressed RGBA_UNORM textures that with a block for
 * each of the possible 8 modes. The texture is both rendered and
 * retrieved with glGetTexImage and verified that it has the expected
 * values.
 */

#include "piglit-util-gl.h"

PIGLIT_GL_TEST_CONFIG_BEGIN

	config.supports_gl_compat_version = 10;

	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
	config.khr_no_error_support = PIGLIT_NO_ERRORS;

PIGLIT_GL_TEST_CONFIG_END

#define BLOCK_SIZE 4
#define BLOCK_BYTES 16
#define N_PARTITIONS 64

struct bptc_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;
};

static const struct bptc_mode
bptc_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 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
   }
};

struct bptc_block {
	int mode;
	int partition;
	int rotation;
	int index_selection;
	uint8_t endpoints[2 * 3][4];
	uint8_t pbits[3 * 2];
	uint8_t primary_indices[BLOCK_SIZE * BLOCK_SIZE];
	uint8_t secondary_indices[BLOCK_SIZE * BLOCK_SIZE];
	uint8_t expected_values[BLOCK_SIZE * BLOCK_SIZE * 4];
};

static const struct bptc_block
bptc_blocks[] = {
	{
		0, /* mode */
		2, /* partition */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #000000ff #ffffffff */
			{ 0x0, 0x0, 0x0, 0x0 }, { 0xf, 0xf, 0xf, 0x0 },
			/* #100010ff #ef08efff */
			{ 0x1, 0x0, 0x1, 0x0 }, { 0xe, 0x0, 0xe, 0x0 },
			/* #001010ff #08dedeff */
			{ 0x0, 0x1, 0x1, 0x0 }, { 0x0, 0xd, 0xd, 0x0 }
		},
		/* pbits */
		{ 0, 1, 0, 1, 0, 1 },
		/* primary indices */
		{
			0x0, 0x2, 0x4, 0x7, /* subsets 0(a) 0    0    0    */
			0x0, 0x0, 0x7, 0x7, /* subsets 2    0    0    1    */
			0x0, 0x7, 0x0, 0x7, /* subsets 2(a) 2    1    1    */
			0x4, 0x2, 0x4, 0x2  /* subsets 2    2    1    1(a) */
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x00, 0x00, 0x00, 0xff, 0x48, 0x48, 0x48, 0xff,
			0x93, 0x93, 0x93, 0xff, 0xff, 0xff, 0xff, 0xff,
			0x00, 0x10, 0x10, 0xff, 0x00, 0x00, 0x00, 0xff,
			0xff, 0xff, 0xff, 0xff, 0xef, 0x08, 0xef, 0xff,
			0x00, 0x10, 0x10, 0xff, 0x08, 0xde, 0xde, 0xff,
			0x10, 0x00, 0x10, 0xff, 0xef, 0x08, 0xef, 0xff,
			0x05, 0x87, 0x87, 0xff, 0x02, 0x4a, 0x4a, 0xff,
			0x91, 0x05, 0x91, 0xff, 0x4f, 0x02, 0x4f, 0xff
		},
	},
	{
		1, /* mode */
		63, /* partition */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #000000ff #fdfdfdff */
			{ 0x00, 0x00, 0x00, 0x00 }, { 0x3f, 0x3f, 0x3f, 0x00 },
			/* #060206ff #bb02bbff */
			{ 0x01, 0x00, 0x01, 0x00 }, { 0x2e, 0x00, 0x2e, 0x00 },
		},
		/* pbits */
		{ 0, 1 },
		/* primary indices */
		{
			0x0, 0x2, 0x4, 0x7, /* subsets 0(a) 1    0    0    */
			0x0, 0x0, 0x7, 0x7, /* subsets 0    1    0    0    */
			0x0, 0x7, 0x0, 0x7, /* subsets 0    1    1    1    */
			0x4, 0x2, 0x4, 0x2  /* subsets 0    1    1    1(a) */
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x00, 0x00, 0x00, 0xff, 0x39, 0x02, 0x39, 0xff,
			0x92, 0x92, 0x92, 0xff, 0xfd, 0xfd, 0xfd, 0xff,
			0x00, 0x00, 0x00, 0xff, 0x06, 0x02, 0x06, 0xff,
			0xfd, 0xfd, 0xfd, 0xff, 0xfd, 0xfd, 0xfd, 0xff,
			0x00, 0x00, 0x00, 0xff, 0xbb, 0x02, 0xbb, 0xff,
			0x06, 0x02, 0x06, 0xff, 0xbb, 0x02, 0xbb, 0xff,
			0x92, 0x92, 0x92, 0xff, 0x39, 0x02, 0x39, 0xff,
			0x6f, 0x02, 0x6f, 0xff, 0x39, 0x02, 0x39, 0xff,
		},
	},
	{
		2, /* mode */
		52, /* partition */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #000000ff #ffffffff */
			{ 0x00, 0x00, 0x00, 0x00 }, { 0x1f, 0x1f, 0x1f, 0x00 },
			/* #080008ff #730073ff */
			{ 0x01, 0x00, 0x01, 0x00 }, { 0x0e, 0x00, 0x0e, 0x00 },
			/* #008484ff #006b6bff */
			{ 0x00, 0x10, 0x10, 0x00 }, { 0x00, 0x0d, 0x0d, 0x00 }
		},
		/* pbits */
		{ 0 },
		/* primary indices */
		{
			0x0, 0x0, 0x1, 0x2, /* subsets 0(a) 2    2    2    */
			0x1, 0x0, 0x1, 0x2, /* subsets 0    1(a) 1    1    */
			0x2, 0x3, 0x0, 0x0, /* subsets 0    1    1    1    */
			0x3, 0x3, 0x0, 0x0  /* subsets 0    2    2    2(a) */
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x00, 0x00, 0x00, 0xff, 0x00, 0x84, 0x84, 0xff,
			0x00, 0x7c, 0x7c, 0xff, 0x00, 0x73, 0x73, 0xff,
			0x54, 0x54, 0x54, 0xff, 0x08, 0x00, 0x08, 0xff,
			0x2b, 0x00, 0x2b, 0xff, 0x50, 0x00, 0x50, 0xff,
			0xab, 0xab, 0xab, 0xff, 0x73, 0x00, 0x73, 0xff,
			0x08, 0x00, 0x08, 0xff, 0x08, 0x00, 0x08, 0xff,
			0xff, 0xff, 0xff, 0xff, 0x00, 0x6b, 0x6b, 0xff,
			0x00, 0x84, 0x84, 0xff, 0x00, 0x84, 0x84, 0xff,
		},
	},
	{
		3, /* mode */
		1, /* partition */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #000000ff #ffffffff */
			{ 0x00, 0x00, 0x00, 0x00 }, { 0x7f, 0x7f, 0x7f, 0x00 },
			/* #840084ff #e101e1ff */
			{ 0x42, 0x00, 0x42, 0x00 }, { 0x70, 0x00, 0x70, 0x00 },
		},
		/* pbits */
		{ 0, 1, 0, 1 },
		/* primary indices */
		{
			0x0, 0x0, 0x0, 0x3, /* subsets 0(a) 0    0    1    */
			0x1, 0x1, 0x1, 0x2, /* subsets 0    0    0    1    */
			0x2, 0x2, 0x2, 0x1, /* subsets 0    0    0    1    */
			0x3, 0x3, 0x3, 0x0  /* subsets 0    0    0    1(a) */
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
			0x00, 0x00, 0x00, 0xff, 0xe1, 0x01, 0xe1, 0xff,
			0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff,
			0x54, 0x54, 0x54, 0xff, 0xc2, 0x01, 0xc2, 0xff,
			0xab, 0xab, 0xab, 0xff, 0xab, 0xab, 0xab, 0xff,
			0xab, 0xab, 0xab, 0xff, 0xa3, 0x00, 0xa3, 0xff,
			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
			0xff, 0xff, 0xff, 0xff, 0x84, 0x00, 0x84, 0xff,
		},
	},
	{
		4, /* mode */
		0, /* partition (not used) */
		1, /* rotation */
		1, /* index selection */
		/* endpoints */
		{
			/* #007bff41 #ff7b00ff */
			{ 0x00, 0x0f, 0x1f, 0x10 }, { 0x1f, 0x0f, 0x00, 0x3f },
		},
		/* pbits */
		{ 0 },
		/* primary indices */
		{
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3
		},
		/* secondary indices */
		{
			0x0, 0x1, 0x2, 0x3,
			0x4, 0x5, 0x6, 0x7,
			0x0, 0x1, 0x2, 0x3,
			0x4, 0x5, 0x6, 0x7
		},
		/* expected results */
		{
			0x41, 0x7b, 0xff, 0x00, 0x7f, 0x7b, 0xdb, 0x24,
			0xc1, 0x7b, 0xb7, 0x48, 0xff, 0x7b, 0x93, 0x6c,
			0x41, 0x7b, 0x6c, 0x93, 0x7f, 0x7b, 0x48, 0xb7,
			0xc1, 0x7b, 0x24, 0xdb, 0xff, 0x7b, 0x00, 0xff,
			0x41, 0x7b, 0xff, 0x00, 0x7f, 0x7b, 0xdb, 0x24,
			0xc1, 0x7b, 0xb7, 0x48, 0xff, 0x7b, 0x93, 0x6c,
			0x41, 0x7b, 0x6c, 0x93, 0x7f, 0x7b, 0x48, 0xb7,
			0xc1, 0x7b, 0x24, 0xdb, 0xff, 0x7b, 0x00, 0xff,
		},
	},
	{
		5, /* mode */
		0, /* partition (not used) */
		3, /* rotation */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #0081ff10 #ff8100ff */
			{ 0x00, 0x40, 0x7f, 0x10 }, { 0x7f, 0x40, 0x00, 0xff },
		},
		/* pbits */
		{ 0 },
		/* primary indices */
		{
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3,
			0x0, 0x1, 0x2, 0x3
		},
		/* secondary indices */
		{
			0x0, 0x0, 0x0, 0x0,
			0x1, 0x1, 0x1, 0x1,
			0x2, 0x2, 0x2, 0x2,
			0x3, 0x3, 0x3, 0x3
		},
		/* expected results */
		{
			0x00, 0x81, 0x10, 0xff, 0x54, 0x81, 0x10, 0xab,
			0xab, 0x81, 0x10, 0x54, 0xff, 0x81, 0x10, 0x00,
			0x00, 0x81, 0x5e, 0xff, 0x54, 0x81, 0x5e, 0xab,
			0xab, 0x81, 0x5e, 0x54, 0xff, 0x81, 0x5e, 0x00,
			0x00, 0x81, 0xb1, 0xff, 0x54, 0x81, 0xb1, 0xab,
			0xab, 0x81, 0xb1, 0x54, 0xff, 0x81, 0xb1, 0x00,
			0x00, 0x81, 0xff, 0xff, 0x54, 0x81, 0xff, 0xab,
			0xab, 0x81, 0xff, 0x54, 0xff, 0x81, 0xff, 0x00,
		},
	},
	{
		6, /* mode */
		0, /* partition (not used) */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #0181ff21 #fe8000fe */
			{ 0x00, 0x40, 0x7f, 0x10 }, { 0x7f, 0x40, 0x00, 0x7f },
		},
		/* pbits */
		{ 1, 0 },
		/* primary indices */
		{
			0x0, 0x1, 0x2, 0x3,
			0x4, 0x5, 0x6, 0x7,
			0x8, 0x9, 0xa, 0xb,
			0xc, 0xd, 0xe, 0xf
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x01, 0x81, 0xff, 0x21, 0x11, 0x81, 0xef, 0x2f,
			0x25, 0x81, 0xdb, 0x40, 0x34, 0x81, 0xcb, 0x4e,
			0x44, 0x81, 0xbb, 0x5c, 0x54, 0x81, 0xab, 0x6a,
			0x68, 0x81, 0x97, 0x7b, 0x78, 0x81, 0x87, 0x89,
			0x87, 0x80, 0x78, 0x96, 0x97, 0x80, 0x68, 0xa4,
			0xab, 0x80, 0x54, 0xb5, 0xbb, 0x80, 0x44, 0xc3,
			0xcb, 0x80, 0x34, 0xd1, 0xda, 0x80, 0x24, 0xdf,
			0xee, 0x80, 0x10, 0xf0, 0xfe, 0x80, 0x00, 0xfe,
		},
	},
	{
		7, /* mode */
		8, /* partition */
		0, /* rotation (not used) */
		0, /* index selection (not used) */
		/* endpoints */
		{
			/* #00000000 #ffffffff */
			{ 0x00, 0x00, 0x00, 0x00 }, { 0x1f, 0x1f, 0x1f, 0x1f },
			/* #040c141c #fbf3ebe3 */
			{ 0x00, 0x01, 0x02, 0x03 }, { 0x1f, 0x1e, 0x1d, 0x1c },
		},
		/* pbits */
		{ 0, 1, 1, 0 },
		/* primary indices */
		{
			0x0, 0x1, 0x2, 0x3, /* subsets 0(a) 0    0    0    */
			0x0, 0x1, 0x2, 0x3, /* subsets 0    0    0    0    */
			0x0, 0x1, 0x2, 0x3, /* subsets 0    0    0    1    */
			0x0, 0x1, 0x1, 0x0  /* subsets 0    0    1    1(a) */
		},
		/* secondary indices */
		{ 0 },
		/* expected results */
		{
			0x00, 0x00, 0x00, 0x00, 0x54, 0x54, 0x54, 0x54,
			0xab, 0xab, 0xab, 0xab, 0xff, 0xff, 0xff, 0xff,
			0x00, 0x00, 0x00, 0x00, 0x54, 0x54, 0x54, 0x54,
			0xab, 0xab, 0xab, 0xab, 0xff, 0xff, 0xff, 0xff,
			0x00, 0x00, 0x00, 0x00, 0x54, 0x54, 0x54, 0x54,
			0xab, 0xab, 0xab, 0xab, 0xfb, 0xf3, 0xeb, 0xe3,
			0x00, 0x00, 0x00, 0x00, 0x54, 0x54, 0x54, 0x54,
			0x55, 0x58, 0x5b, 0x5d, 0x04, 0x0c, 0x14, 0x1c,
		},
	},
};

#define N_BLOCKS ARRAY_SIZE(bptc_blocks)

static void
write_bits(uint8_t *out,
	   int *offset,
	   int value,
	   int n_bits)
{
	int bit_index = *offset % 8;
	int byte_index = *offset / 8;
	int n_bits_in_byte = MIN2(n_bits, 8 - bit_index);

	*offset += n_bits;

	while (n_bits > 0) {
		out[byte_index] |= ((value & ((1 << n_bits_in_byte) - 1)) <<
				    bit_index);

		n_bits -= n_bits_in_byte;
		value >>= n_bits_in_byte;
		byte_index++;
		bit_index = 0;
		n_bits_in_byte = MIN2(n_bits, 8);
	}
}

static void
write_component(uint8_t *out,
		int *offset,
		const struct bptc_block *block,
		int component, int subset, int endpoint)
{
	write_bits(out, offset,
		   block->endpoints[subset * 2 + endpoint][component],
		   bptc_modes[block->mode].n_color_bits);
}

static bool
is_anchor(const struct bptc_block *block,
          int texel)
{
	if (texel == 0)
		return true;

	switch (bptc_modes[block->mode].n_subsets) {
	case 1:
		return false;
	case 2:
		return anchor_indices[0][block->partition] == texel;
	case 3:
		return (anchor_indices[1][block->partition] == texel ||
			anchor_indices[2][block->partition] == texel);
	default:
		assert(false);
		return false;
	}
}

static void
make_block(const struct bptc_block *block,
	   uint8_t *out)
{
	const struct bptc_mode *mode = bptc_modes + block->mode;
	int offset = 0;
	int component;
	int subset;
	int endpoint;
	int n_bits;
	int i;

	memset(out, 0, BLOCK_SIZE * BLOCK_SIZE);

	write_bits(out, &offset, 1 << block->mode, block->mode + 1);

	write_bits(out, &offset, block->partition, mode->n_partition_bits);

	write_bits(out, &offset, block->rotation,
		   mode->has_rotation_bits ? 2 : 0);

	write_bits(out, &offset, block->index_selection,
		   mode->has_index_selection_bit);

	for (component = 0; component < 3; component++) {
		for (subset = 0; subset < mode->n_subsets; subset++) {
			for (endpoint = 0; endpoint < 2; endpoint++) {
				write_component(out, &offset, block,
						component, subset, endpoint);
			}
		}
	}

	for (subset = 0; subset < mode->n_subsets; subset++) {
		for (endpoint = 0; endpoint < 2; endpoint++) {
			write_bits(out, &offset,
				   block->endpoints[subset * 2 + endpoint][3],
				   mode->n_alpha_bits);
		}
	}

	for (subset = 0; subset < mode->n_subsets; subset++) {
		for (endpoint = 0; endpoint < 2; endpoint++) {
			write_bits(out, &offset,
				   block->pbits[subset * 2 + endpoint],
				   mode->has_endpoint_pbits);
		}
	}

	for (subset = 0; subset < mode->n_subsets; subset++) {
		write_bits(out, &offset,
			   block->pbits[subset],
			   mode->has_shared_pbits);
	}

	for (i = 0; i < BLOCK_SIZE * BLOCK_SIZE; i++) {
		n_bits = mode->n_index_bits;

		if (is_anchor(block, i))
			n_bits--;

		write_bits(out, &offset, block->primary_indices[i], n_bits);
	}

	if (mode->n_secondary_index_bits) {
		for (i = 0; i < BLOCK_SIZE * BLOCK_SIZE; i++) {
			n_bits = mode->n_secondary_index_bits;

			if (is_anchor(block, i))
				n_bits--;

			write_bits(out, &offset,
				   block->secondary_indices[i], n_bits);
		}
	}

	assert(offset == BLOCK_BYTES * 8);
}

static GLuint
make_tex(void)
{
	GLuint tex;
	uint8_t data[BLOCK_BYTES * N_BLOCKS];
	int i;

	glGenTextures(1, &tex);
	glBindTexture(GL_TEXTURE_2D, tex);

	for (i = 0; i < N_BLOCKS; i++)
		make_block(bptc_blocks + i, data + i * BLOCK_BYTES);

	glCompressedTexImage2D(GL_TEXTURE_2D,
			       0, /* level */
			       GL_COMPRESSED_RGBA_BPTC_UNORM_ARB,
			       BLOCK_SIZE * 2, BLOCK_SIZE * N_BLOCKS / 2,
			       0, /* border */
			       sizeof data,
			       data);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	return tex;
}

static bool
compare_results(const uint8_t *expected,
		const uint8_t *observed,
		int observed_rowstride)
{
	int y, x;

	for (y = 0; y < BLOCK_SIZE; y++) {
		for (x = 0; x < BLOCK_SIZE; x++) {
			if (memcmp(expected, observed, 4)) {
				printf("Unexpected color at %i,%i:\n"
				       "  expected %02x%02x%02x%02x\n"
				       "  observed %02x%02x%02x%02x\n",
				       x, y,
				       expected[0], expected[1],
				       expected[2], expected[3],
				       observed[0], observed[1],
				       observed[2], observed[3]);
				return false;
			}
			expected += 4;
			observed += 4;
		}

		observed += observed_rowstride - 4 * BLOCK_SIZE;
	}

	return true;
}

static void
render_texture(uint8_t *render_data,
	       uint8_t *get_data)
{
	GLuint tex;

	tex = make_tex();

	glBindTexture(GL_TEXTURE_2D, tex);
	glEnable(GL_TEXTURE_2D);

	piglit_draw_rect_tex(0, 0, BLOCK_SIZE * 2, BLOCK_SIZE * N_BLOCKS / 2,
			     0.0f, 0.0f, 1.0f, 1.0f);

	glDisable(GL_TEXTURE_2D);
	glPixelStorei(GL_PACK_ALIGNMENT, 1);
	glReadPixels(0, 0, BLOCK_SIZE * 2, BLOCK_SIZE * N_BLOCKS / 2,
		     GL_RGBA, GL_UNSIGNED_BYTE, render_data);

	glGetTexImage(GL_TEXTURE_2D,
		      0, /* level */
		      GL_RGBA,
		      GL_UNSIGNED_BYTE,
		      get_data);

	glBindTexture(GL_TEXTURE_2D, 0);
	glDeleteTextures(1, &tex);
}

static GLboolean
check_block(const struct bptc_block *block,
	    const uint8_t *render_data,
	    const uint8_t *get_data)
{
	GLboolean overall_result = GL_TRUE;
	GLboolean pass;

	printf("mode %i, partition %i, rotation %i, index %i\n",
	       block->mode,
	       block->partition,
	       block->rotation,
	       block->index_selection);

	pass = compare_results(block->expected_values,
			       render_data,
			       BLOCK_SIZE * 2 * 4);
	printf("render: %s\n", pass ? "pass" : "fail");

	overall_result &= pass;

	pass = compare_results(block->expected_values,
			       get_data,
			       BLOCK_SIZE * 2 * 4);
	printf("glGetTexImage: %s\n", pass ? "pass" : "fail");

	overall_result &= pass;

	return overall_result;
}

enum piglit_result
piglit_display(void)
{
	GLboolean pass = GL_TRUE;
	uint8_t render_data[BLOCK_SIZE * BLOCK_SIZE * N_BLOCKS * 4];
	uint8_t get_data[BLOCK_SIZE * BLOCK_SIZE * N_BLOCKS * 4];
	int offset;
	int i;

	glClearColor(0, 0, 0, 0);
	glClear(GL_COLOR_BUFFER_BIT);

	render_texture(render_data, get_data);

	for (i = 0; i < N_BLOCKS; i++) {
		offset = (i % 2 * BLOCK_SIZE * 4 +
			  i / 2 * BLOCK_SIZE * BLOCK_SIZE * 2 * 4);
		pass &= check_block(bptc_blocks + i,
				    render_data + offset,
				    get_data + offset);
	}

	piglit_present_results();

	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
}

void
piglit_init(int argc, char **argv)
{
	if (piglit_get_gl_version() < 42 &&
	    !piglit_is_extension_supported("GL_ARB_texture_compression_bptc")) {
		printf("OpenGL 4.2 or GL_ARB_texture_compression_bptc "
		       "is required.\n");
		piglit_report_result(PIGLIT_SKIP);
	}

	piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
}