BC7TextureWriter.cpp

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#include <tdme/engine/fileio/textures/BC7TextureWriter.h>
 
#include <ext/bc7enc_rdo/bc7enc.h>
 
#include <string>
#include <vector>
 
#include <tdme/tdme.h>
#include <tdme/engine/Texture.h>
#include <tdme/math/Math.h>
#include <tdme/utilities/ByteBuffer.h>
#include <tdme/utilities/Console.h>
 
using std::string;
using std::to_string;
using std::vector;
 
using tdme::engine::fileio::textures::BC7TextureWriter;
 
using tdme::engine::Texture;
using tdme::math::Math;
using tdme::utilities::ByteBuffer;
using tdme::utilities::Console;
 
bool BC7TextureWriter::write(int width, int height, int bytesPerPixel, const ByteBuffer& textureByteBuffer, vector<uint8_t>& bc7Data) {
    //
    bc7enc_compress_block_params bc7encParameters;
    bc7encParameters.m_uber_level = BC7ENC_MAX_UBER_LEVEL;
    bc7enc_compress_block_params_init(&bc7encParameters);
    bc7enc_compress_block_params_init_linear_weights(&bc7encParameters);
 
    //
    auto xBlocks = static_cast<int>(Math::ceil(width / 4.0f));
    auto yBlocks = static_cast<int>(Math::ceil(height / 4.0f));
    bc7Data.resize(xBlocks * yBlocks * 16);
 
    //
    for (auto yBlock = 0; yBlock < yBlocks; yBlock++) {
        for (auto xBlock = 0; xBlock < xBlocks; xBlock++) {
            //
            array<uint8_t, 4 * 4 * 4> rgbaBlockPixels { 0 };
            auto blockPixelIdx = 0;
            auto xBlockOffset = xBlock * 4;
            auto yBlockOffset = yBlock * 4;
            for (int y = 0; y < 4; y++) {
                for (int x = 0; x < 4; x++) {
                    auto offset = (yBlockOffset + y) * width * bytesPerPixel + (xBlockOffset + x) * bytesPerPixel;
                    auto red = 0xff;
                    auto green = 0;
                    auto blue = 0;
                    auto alpha = 0;
                    if (offset < textureByteBuffer.getCapacity()) {
                        red = textureByteBuffer.get(offset + 0);
                        green = textureByteBuffer.get(offset + 1);
                        blue = textureByteBuffer.get(offset + 2);
                        alpha = bytesPerPixel == 4?textureByteBuffer.get(offset + 3):0xff;
                    }
                    rgbaBlockPixels[blockPixelIdx * 4 + 0] = red;
                    rgbaBlockPixels[blockPixelIdx * 4 + 1] = green;
                    rgbaBlockPixels[blockPixelIdx * 4 + 2] = blue;
                    rgbaBlockPixels[blockPixelIdx * 4 + 3] = alpha;
                    blockPixelIdx++;
                }
            }
            //
            bc7enc_compress_block_init();
            bc7enc_compress_block(&bc7Data.data()[yBlock * xBlocks * 16 + xBlock * 16], rgbaBlockPixels.data(), &bc7encParameters);
        }
    }
 
    //
    return true;
}