tests/KtxTest.cpp

/*
 * 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 "Resources.h"
#include "SkBitmap.h"
#include "SkData.h"
#include "SkImageGenerator.h"
#include "SkForceLinking.h"
#include "SkImageDecoder.h"
#include "SkOSFile.h"
#include "SkRandom.h"
#include "SkStream.h"
#include "Test.h"

__SK_FORCE_IMAGE_DECODER_LINKING;

/**
 * First, make sure that writing an 8-bit RGBA KTX file and then
 * reading it produces the same bitmap.
 */
DEF_TEST(KtxReadWrite, reporter) {

    // Random number generator with explicit seed for reproducibility
    SkRandom rand(0x1005cbad);

    SkBitmap bm8888;
    bm8888.allocN32Pixels(128, 128);

    uint8_t *pixels = reinterpret_cast<uint8_t*>(bm8888.getPixels());
    REPORTER_ASSERT(reporter, pixels);

    if (nullptr == pixels) {
        return;
    }
    
    uint8_t *row = pixels;
    for (int y = 0; y < bm8888.height(); ++y) {        
        for (int x = 0; x < bm8888.width(); ++x) {
            uint8_t a = rand.nextRangeU(0, 255);
            uint8_t r = rand.nextRangeU(0, 255);
            uint8_t g = rand.nextRangeU(0, 255);
            uint8_t b = rand.nextRangeU(0, 255);

            SkPMColor &pixel = *(reinterpret_cast<SkPMColor*>(row + x*sizeof(SkPMColor)));
            pixel = SkPreMultiplyARGB(a, r, g, b);
        }
        row += bm8888.rowBytes();
    }
    REPORTER_ASSERT(reporter, !(bm8888.empty()));

    SkAutoDataUnref encodedData(SkImageEncoder::EncodeData(bm8888, SkImageEncoder::kKTX_Type, 0));
    if (nullptr == encodedData.get()) {
        ERRORF(reporter, "failed to encode the bitmap to KTX");
        return;
    }


    SkAutoTDelete<SkMemoryStream> stream(new SkMemoryStream(encodedData));
    REPORTER_ASSERT(reporter, stream);

    SkBitmap decodedBitmap;
    bool imageDecodeSuccess = SkImageDecoder::DecodeStream(stream, &decodedBitmap);
    if (!imageDecodeSuccess) {
        ERRORF(reporter, "failed to decode the KTX stream");
        return;
    }

    REPORTER_ASSERT(reporter, decodedBitmap.colorType() == bm8888.colorType());
    REPORTER_ASSERT(reporter, decodedBitmap.alphaType() == bm8888.alphaType());
    REPORTER_ASSERT(reporter, decodedBitmap.width() == bm8888.width());
    REPORTER_ASSERT(reporter, decodedBitmap.height() == bm8888.height());
    REPORTER_ASSERT(reporter, !(decodedBitmap.empty()));

    uint8_t *decodedPixels = reinterpret_cast<uint8_t*>(decodedBitmap.getPixels());
    REPORTER_ASSERT(reporter, decodedPixels);
    REPORTER_ASSERT(reporter, decodedBitmap.getSize() == bm8888.getSize());

    if (nullptr == decodedPixels) {
        return;
    }

    REPORTER_ASSERT(reporter, memcmp(decodedPixels, pixels, decodedBitmap.getSize()) == 0);
}

/**
 * Next test is to see whether or not reading an unpremultiplied KTX file accurately
 * creates a premultiplied buffer...
 */
DEF_TEST(KtxReadUnpremul, reporter) {

    static const uint8_t kHalfWhiteKTX[] = {
        0xAB, 0x4B, 0x54, 0x58, 0x20, 0x31, // First twelve bytes is magic
        0x31, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A, // KTX identifier string
        0x01, 0x02, 0x03, 0x04, // Then magic endian specifier
        0x01, 0x14, 0x00, 0x00, // uint32_t fGLType;
        0x01, 0x00, 0x00, 0x00, // uint32_t fGLTypeSize;
        0x08, 0x19, 0x00, 0x00, // uint32_t fGLFormat;
        0x58, 0x80, 0x00, 0x00, // uint32_t fGLInternalFormat;
        0x08, 0x19, 0x00, 0x00, // uint32_t fGLBaseInternalFormat;
        0x02, 0x00, 0x00, 0x00, // uint32_t fPixelWidth;
        0x02, 0x00, 0x00, 0x00, // uint32_t fPixelHeight;
        0x00, 0x00, 0x00, 0x00, // uint32_t fPixelDepth;
        0x00, 0x00, 0x00, 0x00, // uint32_t fNumberOfArrayElements;
        0x01, 0x00, 0x00, 0x00, // uint32_t fNumberOfFaces;
        0x01, 0x00, 0x00, 0x00, // uint32_t fNumberOfMipmapLevels;
        0x00, 0x00, 0x00, 0x00, // uint32_t fBytesOfKeyValueData;
        0x10, 0x00, 0x00, 0x00, // image size: 2x2 image of RGBA = 4 * 4 = 16 bytes
        0xFF, 0xFF, 0xFF, 0x80, // Pixel 1
        0xFF, 0xFF, 0xFF, 0x80, // Pixel 2
        0xFF, 0xFF, 0xFF, 0x80, // Pixel 3
        0xFF, 0xFF, 0xFF, 0x80};// Pixel 4

    SkAutoTDelete<SkMemoryStream> stream(new SkMemoryStream(kHalfWhiteKTX, sizeof(kHalfWhiteKTX)));
    REPORTER_ASSERT(reporter, stream);

    SkBitmap decodedBitmap;
    bool imageDecodeSuccess = SkImageDecoder::DecodeStream(stream, &decodedBitmap);
    if (!imageDecodeSuccess) {
        ERRORF(reporter, "failed to decode the KTX stream");
        return;
    }

    REPORTER_ASSERT(reporter, decodedBitmap.colorType() == kN32_SkColorType);
    REPORTER_ASSERT(reporter, decodedBitmap.alphaType() == kPremul_SkAlphaType);
    REPORTER_ASSERT(reporter, decodedBitmap.width() == 2);
    REPORTER_ASSERT(reporter, decodedBitmap.height() == 2);
    REPORTER_ASSERT(reporter, !(decodedBitmap.empty()));

    uint8_t *decodedPixels = reinterpret_cast<uint8_t*>(decodedBitmap.getPixels());
    REPORTER_ASSERT(reporter, decodedPixels);

    uint8_t *row = decodedPixels;
    for (int j = 0; j < decodedBitmap.height(); ++j) {
        for (int i = 0; i < decodedBitmap.width(); ++i) {
            SkPMColor pixel = *(reinterpret_cast<SkPMColor*>(row + i*sizeof(SkPMColor)));
            REPORTER_ASSERT(reporter, SkPreMultiplyARGB(0x80, 0xFF, 0xFF, 0xFF) == pixel);
        }
        row += decodedBitmap.rowBytes();
    }
}