image_data.cpp

Go to the documentation of this file.

// Copyright (c) 2026 Alexander Obzherin � Licensed under the zlib License. See LICENSE.md.
 
#include "image_data.hpp"
#include "image_codec_jpeg.hpp"
#include "image_codec_png.hpp"
#include "logger.hpp"
#include <filesystem>
#include <stdexcept>
 
namespace rendering_engine
{
ImageData::ImageData()
    :
    ImageData::ImageData(0U, 0U)
{
}
 
ImageData::ImageData( unsigned int width, unsigned int height )
    :
    mWidth( width ),
    mHeight( height )
{
    AllocateMemory( mWidth, mHeight );
}
 
ImageData::ImageData(std::string filepath)
    :
    ImageData::ImageData()
{
    auto const pathToTexture = std::filesystem::path(filepath);
    if(std::filesystem::exists(pathToTexture) && std::filesystem::is_regular_file(pathToTexture) )
    {
        size_t const dot = pathToTexture.string().find_last_of(".");
        std::string const fileExtension = pathToTexture.string().substr(dot + 1);
 
        if( std::string{ "jpg" } == fileExtension )
        {
            LoadTextureJpegFile(pathToTexture.string().c_str());
        }
        else
        {
            if( std::string{ "png" } == fileExtension )
            {
                LoadTexturePngFile(pathToTexture.string().c_str());
            }
            else
            {
                throw std::runtime_error("Unsupported texture file format!");
            }
        }
    }
    else
    {
        throw std::runtime_error("Path to texture file is incorrect.");
    }
}
 
ImageData::ImageData(std::vector<uint8_t> const& fileBytes)
{
    if (fileBytes.size() < 4)
        throw std::runtime_error("Invalid image buffer");
 
    // PNG signature
    if (fileBytes[0] == 0x89 &&
        fileBytes[1] == 'P' &&
        fileBytes[2] == 'N' &&
        fileBytes[3] == 'G')
    {
        std::vector<std::uint8_t> pixelsRGBA;
 
        if (!ReadPngFromMemory(fileBytes.data(), fileBytes.size(), mWidth, mHeight, pixelsRGBA))
            throw std::runtime_error("PNG memory decode failed");
 
        AllocateMemory(mWidth, mHeight);
        Fill(Color(0, 0, 0, 255));
        LoadImageDataRGBA(pixelsRGBA);
        return;
    }
 
    // JPEG signature: FF D8 FF
    if (fileBytes[0] == 0xFF &&
        fileBytes[1] == 0xD8 &&
        fileBytes[2] == 0xFF)
    {
        std::vector<std::uint8_t> pixelsRGB;
 
        if (!ReadJpegFromMemory(fileBytes.data(), fileBytes.size(), mWidth, mHeight, pixelsRGB))
            throw std::runtime_error("JPEG memory decode failed");
 
        AllocateMemory(mWidth, mHeight);
        LoadImageDataRGB(pixelsRGB);
 
        return;
    }
 
    throw std::runtime_error("Unsupported image format in memory buffer");
}
 
ImageData::ImageData(unsigned int width, unsigned int height, std::vector<std::uint8_t> const& pixelsRGBA)
    :
ImageData::ImageData(width, height)
{
    Fill(Color(255, 255, 255, 255));
    LoadImageDataRGBA( pixelsRGBA );
}
 
ImageData::~ImageData()
{
    CleanAllocatedMemory();
}
 
ImageData::ImageData( const ImageData & src )
    : 
    mWidth(src.mWidth),
    mHeight(src.mHeight),
    mData(src.mData)
{
}
 
ImageData & ImageData::operator=( const ImageData & rhs )
{
    if (this == &rhs)
    {
        return *this;
    }
 
    mWidth = rhs.mWidth;
    mHeight = rhs.mHeight;
    mData = rhs.mData;
    return *this;
}
 
void ImageData::Fill( Color color )
{
    std::fill(mData.begin(), mData.end(), color);
}
 
void ImageData::SetPixel( unsigned int x, unsigned int y, Color color )
{
    if (x < mWidth && y < mHeight)
    {
        PixelRef(x, y) = color;
    }
}
 
const Color ImageData::GetPixel( unsigned int x, unsigned int y ) const
{
    if (x >= mWidth || y >= mHeight)
    {
        LOG_ERROR("Out of bounds access in GetPixel");
        return Color{};
    }
 
    return PixelRef(x, y);
}
 
void ImageData::DrawImageOnImageAtPos(unsigned int const x, unsigned int const y, ImageData& toImage, ImageData& fromImage)
{
    // If fromImage can not be placed entirely, it will be cropped on right and bottom side
 
    // Source image draw from top left pixel
 
    // At first check if point pos is inside toImage
    if (x >= toImage.GetWidth() || y >= toImage.GetHeight())
    {
        return;
    }
 
    if (toImage.GetWidth() == 0U || toImage.GetHeight() == 0U ||
        fromImage.GetWidth() == 0U || fromImage.GetHeight() == 0U)
    {
        return;
    }
 
    // Crop
    unsigned int left;
    if ((toImage.GetWidth() - x) < fromImage.GetWidth())
    {
        left = toImage.GetWidth() - x;
    }
    else
    {
        left = fromImage.GetWidth();
    }
 
    unsigned int bottom;
    if ((toImage.GetHeight() - y) < fromImage.GetHeight())
    {
        bottom = toImage.GetHeight() - y;
    }
    else
    {
        bottom = fromImage.GetHeight();
    }
 
    if (left == 0U || bottom == 0U)
    {
        return;
    }
 
    for (unsigned int deltaY = 0; deltaY < bottom; ++deltaY)
    {
        const size_t srcRowOffset =
            static_cast<size_t>(deltaY) * static_cast<size_t>(fromImage.GetWidth());
 
        const size_t dstRowOffset =
            static_cast<size_t>(y + deltaY) * static_cast<size_t>(toImage.GetWidth()) +
            static_cast<size_t>(x);
 
        std::memcpy(
            toImage.mData.data() + dstRowOffset,
            fromImage.mData.data() + srcRowOffset,
            static_cast<size_t>(left) * sizeof(Color));
    }
}
 
std::vector<uint8_t> ImageData::GetImageDataRGBA() const
{
    if (mWidth == 0 || mHeight == 0)
    {
        return {};
    }
 
    const size_t totalBytes =
        static_cast<size_t>(mWidth) * static_cast<size_t>(mHeight) * 4;
 
    std::vector<uint8_t> result(totalBytes);
    std::memcpy(result.data(), mData.data(), totalBytes);
 
    return result;
}
 
std::vector<uint8_t> ImageData::GetImageDataRGB() const
{
    if (mWidth == 0 || mHeight == 0)
    {
        return {};
    }
 
    const size_t pixelCount =
        static_cast<size_t>(mWidth) * static_cast<size_t>(mHeight);
 
    std::vector<uint8_t> result(pixelCount * 3);
 
    const Color* src = mData.data();
    uint8_t* dst = result.data();
 
    for (size_t i = 0; i < pixelCount; ++i)
    {
        dst[i * 3 + 0] = src[i].r;
        dst[i * 3 + 1] = src[i].g;
        dst[i * 3 + 2] = src[i].b;
    }
 
    return result;
}
 
void ImageData::WriteJpegFile(char const* filename)
{
    SaveTextureFileJpeg(*this, filename);
}
 
bool ImageData::LoadTextureJpegFile(char const* filename)
{
    CleanAllocatedMemory();
    unsigned int width = 0;
    unsigned int height = 0;
    std::vector<std::uint8_t> rgbImageDataVector;
 
    bool result = ReadJpegFile(filename, width, height, rgbImageDataVector);
    const size_t expectedSize =
        static_cast<size_t>(width) * static_cast<size_t>(height) * 3U;
 
    if (result && rgbImageDataVector.size() == expectedSize)
    {
        mWidth = width;
        mHeight = height;
        AllocateMemory(width, height);
        LoadImageDataRGB(rgbImageDataVector);
    }
 
    return result;
}
 
void ImageData::WritePngFile(char const* filename)
{
    SaveTextureFilePng(*this, filename);
}
 
bool ImageData::LoadTexturePngFile(char const* filename)
{
    CleanAllocatedMemory();
    unsigned int width = 0;
    unsigned int height = 0;
    std::vector<std::uint8_t> rgbaImageDataVector;
 
    bool result = ReadPngFile(filename, width, height, rgbaImageDataVector);
 
    const size_t expectedSize = static_cast<size_t>(width) * static_cast<size_t>(height) * 4U;
 
    if (result && rgbaImageDataVector.size() == expectedSize)
    {
        mWidth = width;
        mHeight = height;
        AllocateMemory(width, height);
        LoadImageDataRGBA(rgbaImageDataVector);
    }
    return true;
}
 
void ImageData::AllocateMemory( unsigned int width, unsigned int height )
{
    mWidth = width;
    mHeight = height;
    mData.resize(static_cast<size_t>(mWidth) * static_cast<size_t>(mHeight));
}
 
void ImageData::CleanAllocatedMemory()
{
    mData.clear();
 
    mWidth = 0;
    mHeight = 0;
}
 
void ImageData::LoadImageDataRGBA(const std::vector<uint8_t>& pixels)
{
    const size_t pixelCount = static_cast<size_t>(mWidth) * static_cast<size_t>(mHeight);
 
    const size_t expectedSize = pixelCount * 4U;
 
    if (pixels.size() != expectedSize)
    {
        throw std::runtime_error("Array data size doesn't match image dimension.");
    }
 
    mData.resize(pixelCount);
 
    std::memcpy(mData.data(), pixels.data(), expectedSize);
}
 
void ImageData::LoadImageDataRGB(std::vector<std::uint8_t> const& pixels)
{
    const size_t pixelCount =
        static_cast<size_t>(mWidth) * static_cast<size_t>(mHeight);
 
    const size_t expectedSize = pixelCount * 3;
    if (pixels.size() != expectedSize)
    {
        throw std::runtime_error("Array data size doesn't match image dimension.");
    }
 
    mData.resize(pixelCount);
 
    const uint8_t* src = pixels.data();
    Color* dst = mData.data();
 
    for (size_t i = 0; i < pixelCount; ++i)
    {
        dst[i].r = src[i * 3 + 0];
        dst[i].g = src[i * 3 + 1];
        dst[i].b = src[i * 3 + 2];
        dst[i].a = 255;
    }
}
 
 
} //namespace rendering_engine