skia2/tests/TextureCompressionTest.cpp

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/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkAutoPixmapStorage.h"
#include "SkBitmap.h"
#include "SkData.h"
#include "SkEndian.h"
#include "SkImageInfo.h"
#include "SkTemplates.h"
#include "SkTextureCompressor.h"
#include "Test.h"
// TODO: Create separate tests for RGB and RGBA data once
// ASTC and ETC1 decompression is implemented.
static bool decompresses_a8(SkTextureCompressor::Format fmt) {
switch (fmt) {
case SkTextureCompressor::kLATC_Format:
case SkTextureCompressor::kR11_EAC_Format:
return true;
default:
return false;
}
}
static bool compresses_a8(SkTextureCompressor::Format fmt) {
switch (fmt) {
case SkTextureCompressor::kLATC_Format:
case SkTextureCompressor::kR11_EAC_Format:
case SkTextureCompressor::kASTC_12x12_Format:
return true;
default:
return false;
}
}
/**
* Make sure that we properly fail when we don't have multiple of four image dimensions.
*/
DEF_TEST(CompressAlphaFailDimensions, reporter) {
static const int kWidth = 17;
static const int kHeight = 17;
// R11_EAC and LATC are both dimensions of 4, so we need to make sure that we
// are violating those assumptions. And if we are, then we're also violating the
// assumptions of ASTC, which is 12x12 since any number not divisible by 4 is
// also not divisible by 12. Our dimensions are prime, so any block dimension
// larger than 1 should fail.
REPORTER_ASSERT(reporter, kWidth % 4 != 0);
REPORTER_ASSERT(reporter, kHeight % 4 != 0);
SkAutoPixmapStorage pixmap;
pixmap.alloc(SkImageInfo::MakeA8(kWidth, kHeight));
// leaving the pixels uninitialized, as they don't affect the test...
for (int i = 0; i < SkTextureCompressor::kFormatCnt; ++i) {
const SkTextureCompressor::Format fmt = static_cast<SkTextureCompressor::Format>(i);
if (!compresses_a8(fmt)) {
continue;
}
sk_sp<SkData> data(SkTextureCompressor::CompressBitmapToFormat(pixmap, fmt));
REPORTER_ASSERT(reporter, nullptr == data);
}
}
/**
* Make sure that we properly fail when we don't have the correct bitmap type.
* compressed textures can (currently) only be created from A8 bitmaps.
*/
DEF_TEST(CompressAlphaFailColorType, reporter) {
static const int kWidth = 12;
static const int kHeight = 12;
// ASTC is at most 12x12, and any dimension divisible by 12 is also divisible
// by 4, which is the dimensions of R11_EAC and LATC. In the future, we might
// support additional variants of ASTC, such as 5x6 and 8x8, in which case this would
// need to be updated.
REPORTER_ASSERT(reporter, kWidth % 12 == 0);
REPORTER_ASSERT(reporter, kHeight % 12 == 0);
SkAutoPixmapStorage pixmap;
pixmap.alloc(SkImageInfo::MakeN32Premul(kWidth, kHeight));
// leaving the pixels uninitialized, as they don't affect the test...
for (int i = 0; i < SkTextureCompressor::kFormatCnt; ++i) {
const SkTextureCompressor::Format fmt = static_cast<SkTextureCompressor::Format>(i);
if (!compresses_a8(fmt)) {
continue;
}
sk_sp<SkData> data(SkTextureCompressor::CompressBitmapToFormat(pixmap, fmt));
REPORTER_ASSERT(reporter, nullptr == data);
}
}
/**
* Make sure that if you compress a texture with alternating black/white pixels, and
* then decompress it, you get what you started with.
*/
DEF_TEST(CompressCheckerboard, reporter) {
static const int kWidth = 48; // We need the number to be divisible by both
static const int kHeight = 48; // 12 (ASTC) and 16 (ARM NEON R11 EAC).
// ASTC is at most 12x12, and any dimension divisible by 12 is also divisible
// by 4, which is the dimensions of R11_EAC and LATC. In the future, we might
// support additional variants of ASTC, such as 5x6 and 8x8, in which case this would
// need to be updated. Additionally, ARM NEON and SSE code paths support up to
// four blocks of R11 EAC at once, so they operate on 16-wide blocks. Hence, the
// valid width and height is going to be the LCM of 12 and 16 which is 4*4*3 = 48
REPORTER_ASSERT(reporter, kWidth % 48 == 0);
REPORTER_ASSERT(reporter, kHeight % 48 == 0);
SkAutoPixmapStorage pixmap;
pixmap.alloc(SkImageInfo::MakeA8(kWidth, kHeight));
// Populate the pixels
{
uint8_t* pixels = reinterpret_cast<uint8_t*>(pixmap.writable_addr());
REPORTER_ASSERT(reporter, pixels);
if (nullptr == pixels) {
return;
}
for (int y = 0; y < kHeight; ++y) {
for (int x = 0; x < kWidth; ++x) {
if ((x ^ y) & 1) {
pixels[x] = 0xFF;
} else {
pixels[x] = 0;
}
}
pixels += pixmap.rowBytes();
}
}
SkAutoTMalloc<uint8_t> decompMemory(kWidth*kHeight);
uint8_t* decompBuffer = decompMemory.get();
REPORTER_ASSERT(reporter, decompBuffer);
if (nullptr == decompBuffer) {
return;
}
for (int i = 0; i < SkTextureCompressor::kFormatCnt; ++i) {
const SkTextureCompressor::Format fmt = static_cast<SkTextureCompressor::Format>(i);
// Ignore formats for RGBA data, since the decompressed buffer
// won't match the size and contents of the original.
if (!decompresses_a8(fmt) || !compresses_a8(fmt)) {
continue;
}
sk_sp<SkData> data(SkTextureCompressor::CompressBitmapToFormat(pixmap, fmt));
REPORTER_ASSERT(reporter, data);
if (nullptr == data) {
continue;
}
bool decompResult =
SkTextureCompressor::DecompressBufferFromFormat(
decompBuffer, kWidth,
data->bytes(),
kWidth, kHeight, fmt);
REPORTER_ASSERT(reporter, decompResult);
const uint8_t* pixels = reinterpret_cast<const uint8_t*>(pixmap.addr());
REPORTER_ASSERT(reporter, pixels);
if (nullptr == pixels) {
continue;
}
for (int y = 0; y < kHeight; ++y) {
for (int x = 0; x < kWidth; ++x) {
bool ok = pixels[y*pixmap.rowBytes() + x] == decompBuffer[y*kWidth + x];
REPORTER_ASSERT(reporter, ok);
}
}
}
}
/**
* Make sure that if we pass in a solid color bitmap that we get the appropriate results
*/
DEF_TEST(CompressLATC, reporter) {
const SkTextureCompressor::Format kLATCFormat = SkTextureCompressor::kLATC_Format;
static const int kLATCEncodedBlockSize = 8;
static const int kWidth = 8;
static const int kHeight = 8;
SkAutoPixmapStorage pixmap;
pixmap.alloc(SkImageInfo::MakeA8(kWidth, kHeight));
int latcDimX, latcDimY;
SkTextureCompressor::GetBlockDimensions(kLATCFormat, &latcDimX, &latcDimY);
REPORTER_ASSERT(reporter, kWidth % latcDimX == 0);
REPORTER_ASSERT(reporter, kHeight % latcDimY == 0);
const size_t kSizeToBe =
SkTextureCompressor::GetCompressedDataSize(kLATCFormat, kWidth, kHeight);
REPORTER_ASSERT(reporter, kSizeToBe == ((kWidth*kHeight*kLATCEncodedBlockSize)/16));
REPORTER_ASSERT(reporter, (kSizeToBe % kLATCEncodedBlockSize) == 0);
for (int lum = 0; lum < 256; ++lum) {
uint8_t* pixels = reinterpret_cast<uint8_t*>(pixmap.writable_addr());
for (int i = 0; i < kWidth*kHeight; ++i) {
pixels[i] = lum;
}
sk_sp<SkData> latcData(
SkTextureCompressor::CompressBitmapToFormat(pixmap, kLATCFormat));
REPORTER_ASSERT(reporter, latcData);
if (nullptr == latcData) {
continue;
}
REPORTER_ASSERT(reporter, kSizeToBe == latcData->size());
// Make sure that it all matches a given block encoding. Since we have
// COMPRESS_LATC_FAST defined in SkTextureCompressor_LATC.cpp, we are using
// an approximation scheme that optimizes for speed against coverage maps.
// That means that each palette in the encoded block is exactly the same,
// and that the three bits saved per pixel are computed from the top three
// bits of the luminance value.
const uint64_t kIndexEncodingMap[8] = { 1, 7, 6, 5, 4, 3, 2, 0 };
// Quantize to three bits in the same way that we do our LATC compression:
// 1. Divide by two
// 2. Add 9
// 3. Divide by two
// 4. Approximate division by three twice
uint32_t quant = static_cast<uint32_t>(lum);
quant >>= 1; // 1
quant += 9; // 2
quant >>= 1; // 3
uint32_t a, b, c, ar, br, cr;
// First division by three
a = quant >> 2;
ar = (quant & 0x3) << 4;
b = quant >> 4;
br = (quant & 0xF) << 2;
c = quant >> 6;
cr = (quant & 0x3F);
quant = (a + b + c) + ((ar + br + cr) >> 6);
// Second division by three
a = quant >> 2;
ar = (quant & 0x3) << 4;
b = quant >> 4;
br = (quant & 0xF) << 2;
c = quant >> 6;
cr = (quant & 0x3F);
quant = (a + b + c) + ((ar + br + cr) >> 6);
const uint64_t kIndex = kIndexEncodingMap[quant];
const uint64_t kConstColorEncoding =
SkEndian_SwapLE64(
255 |
(kIndex << 16) | (kIndex << 19) | (kIndex << 22) | (kIndex << 25) |
(kIndex << 28) | (kIndex << 31) | (kIndex << 34) | (kIndex << 37) |
(kIndex << 40) | (kIndex << 43) | (kIndex << 46) | (kIndex << 49) |
(kIndex << 52) | (kIndex << 55) | (kIndex << 58) | (kIndex << 61));
const uint64_t* blockPtr = reinterpret_cast<const uint64_t*>(latcData->data());
for (size_t i = 0; i < (kSizeToBe/8); ++i) {
REPORTER_ASSERT(reporter, blockPtr[i] == kConstColorEncoding);
}
}
}