Builds texture atlases from collections of images. More...

#include <texture_atlas_maker.hpp>

Public Member Functions
	TextureAtlasMaker (std::map< char, ImageData > images)
	Constructs an atlas maker from a collection of images. More...

	~TextureAtlasMaker ()=default

bool	CreateTextureAtlas (std::map< char, std::pair< unsigned int, unsigned int > > &texAtlasData, ImageData &texAtlasImage)
	Creates a texture atlas from the stored image collection. More...

Static Public Member Functions
static ImageData	CreateTextureAtlas (std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > &ioFontAtlas)
	Creates a texture atlas from glyph images and updates glyph metrics. More...

Protected Member Functions
void	FindCellDimensions (unsigned int &outputWidth, unsigned int &outputHeight)
	Computes maximum cell dimensions for the stored images. More...

void	CalculateGridDimensions (unsigned int &outputNumberOfColumns, unsigned int &outputNumberOfRows)
	Calculates grid dimensions for the stored images. More...

Static Protected Member Functions
static void	FindCellDimensions (unsigned int &outputWidth, unsigned int &outputHeight, std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > &fontAtlas)
	Computes maximum cell dimensions for glyph images. More...

static void	CalculateGridDimensions (unsigned int &outputNumberOfColumns, unsigned int &outputNumberOfRows, std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > &fontAtlas)
	Calculates grid dimensions for glyph images. More...

Protected Attributes
std::map< char, ImageData >	mImageCollection

Static Protected Attributes
static const Color	sDefaultPaletteBackgroundColor

Detailed Description

Builds texture atlases from collections of images.

Arranges input images into a grid-based atlas, aiming for a compact, near-square layout. Supports generic image atlases and font glyph atlases.

Definition at line 28 of file texture_atlas_maker.hpp.

Constructor & Destructor Documentation

◆ TextureAtlasMaker()

rendering_engine::TextureAtlasMaker::TextureAtlasMaker ( std::map< char, ImageData > images )

Constructs an atlas maker from a collection of images.

Parameters

images Map of identifiers to image data.

Definition at line 10 of file texture_atlas_maker.cpp.

{
    mImageCollection = images;
}

◆ ~TextureAtlasMaker()

rendering_engine::TextureAtlasMaker::~TextureAtlasMaker ( )

default

Member Function Documentation

◆ CalculateGridDimensions() [1/2]

void rendering_engine::TextureAtlasMaker::CalculateGridDimensions	(	unsigned int &	outputNumberOfColumns,
		unsigned int &	outputNumberOfRows
	)

protected

Calculates grid dimensions for the stored images.

Parameters

outputNumberOfColumns	Output number of columns.
outputNumberOfRows	Output number of rows.

Definition at line 144 of file texture_atlas_maker.cpp.

{
    unsigned int cellWidth;
    unsigned int cellHeight;
    FindCellDimensions(cellWidth, cellHeight);
 
    unsigned int cellsNum = mImageCollection.size();
    int totalSquare = cellWidth * cellHeight * cellsNum;
    float rootSq = sqrtf(totalSquare);
 
    outputNumberOfColumns = std::ceil(rootSq / cellWidth);
    outputNumberOfRows = std::ceil((float)(cellsNum) / (float)(outputNumberOfColumns));
}

◆ CalculateGridDimensions() [2/2]

void rendering_engine::TextureAtlasMaker::CalculateGridDimensions	(	unsigned int &	outputNumberOfColumns,
		unsigned int &	outputNumberOfRows,
		std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > &	fontAtlas
	)

staticprotected

Calculates grid dimensions for glyph images.

Parameters

outputNumberOfColumns	Output number of columns.
outputNumberOfRows	Output number of rows.
fontAtlas	Glyph image collection.

Definition at line 158 of file texture_atlas_maker.cpp.

{
    unsigned int cellWidth;
    unsigned int cellHeight;
    FindCellDimensions(cellWidth, cellHeight, fontAtlas);
 
    unsigned int cellsNum = fontAtlas.size();
    int totalSquare = cellWidth * cellHeight * cellsNum;
    float rootSq = sqrtf(totalSquare);
 
    outputNumberOfColumns = std::ceil(rootSq / cellWidth);
    outputNumberOfRows = std::ceil((float)(cellsNum) / (float)(outputNumberOfColumns));
}

◆ CreateTextureAtlas() [1/2]

bool rendering_engine::TextureAtlasMaker::CreateTextureAtlas	(	std::map< char, std::pair< unsigned int, unsigned int > > &	texAtlasData,
		ImageData &	texAtlasImage
	)

Creates a texture atlas from the stored image collection.

Parameters

texAtlasData	Output map of image identifiers to atlas positions.
texAtlasImage	Output atlas image.

Returns: True if the atlas was created successfully.

Definition at line 15 of file texture_atlas_maker.cpp.

{
    if( mImageCollection.size() == 0 )
    {
        return false;
    }
 
    //Find palette specification
 
    //Find dimension of each cell
    unsigned int cellWidth;
    unsigned int cellHeight;
    FindCellDimensions(cellWidth, cellHeight);
 
    //Find number of rows and columns
    unsigned int numberOfColumns;
    unsigned int numberOfRows;
    CalculateGridDimensions(numberOfColumns, numberOfRows);
 
    //Create palette
    ImageData textureAtlasPalette(static_cast<unsigned int>(cellWidth * numberOfColumns), static_cast<unsigned int>(cellHeight * numberOfRows));
    textureAtlasPalette.Fill(sDefaultPaletteBackgroundColor);
 
    auto imageIterator = mImageCollection.begin();
 
    for( int y = 0; y < numberOfRows; y++ )
    {
        for( int x = 0; x < numberOfColumns; x++ )
        {
            if( imageIterator != mImageCollection.end() )
            {
                ImageData::DrawImageOnImageAtPos(x * cellWidth, y * cellHeight, textureAtlasPalette, imageIterator->second);
 
                texAtlasData.emplace(imageIterator->first, std::make_pair<unsigned int, unsigned int>(x * cellWidth, y * cellHeight));
 
 
                imageIterator++;
            }
        }
    }
    texAtlasImage = textureAtlasPalette;
 
    return true;
}

◆ CreateTextureAtlas() [2/2]

ImageData rendering_engine::TextureAtlasMaker::CreateTextureAtlas ( std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > & ioFontAtlas )

static

Creates a texture atlas from glyph images and updates glyph metrics.

Modifies glyph metrics in-place to include atlas coordinates.

Parameters

ioFontAtlas Map of glyph identifiers to glyph metrics and images.

Returns: Generated atlas image.

Definition at line 60 of file texture_atlas_maker.cpp.

{
    if (ioFontAtlas.size() == 0)
    {
        return ImageData();
    }
 
    //Find palette specification
 
    //Find dimension of each cell
    unsigned int cellWidth;
    unsigned int cellHeight;
    FindCellDimensions(cellWidth, cellHeight, ioFontAtlas);
 
    //Find number of rows and columns
    unsigned int numberOfColumns;
    unsigned int numberOfRows;
    CalculateGridDimensions(numberOfColumns, numberOfRows, ioFontAtlas);
 
    //Create palette
    ImageData textureAtlasPalette(static_cast<unsigned int>(cellWidth * numberOfColumns), static_cast<unsigned int>(cellHeight * numberOfRows));
    textureAtlasPalette.Fill(sDefaultPaletteBackgroundColor);
 
    auto imageIterator = ioFontAtlas.begin();
 
    for (int y = 0; y < numberOfRows; y++)
    {
        for (int x = 0; x < numberOfColumns; x++)
        {
            if (imageIterator != ioFontAtlas.end())
            {
                ImageData::DrawImageOnImageAtPos(x * cellWidth, y * cellHeight, textureAtlasPalette, imageIterator->second.second);
 
                imageIterator->second.first.atlasX = static_cast<std::uint32_t>(x * cellWidth) + imageIterator->second.first.padding;
                imageIterator->second.first.atlasY = static_cast<std::uint32_t>(y * cellHeight) + imageIterator->second.first.padding;
                
                imageIterator++;
            }
        }
    }
 
    return textureAtlasPalette;
}

◆ FindCellDimensions() [1/2]

void rendering_engine::TextureAtlasMaker::FindCellDimensions	(	unsigned int &	outputWidth,
		unsigned int &	outputHeight
	)

protected

Computes maximum cell dimensions for the stored images.

Parameters

outputWidth	Output cell width in pixels.
outputHeight	Output cell height in pixels.

Definition at line 104 of file texture_atlas_maker.cpp.

{
    unsigned int height = 0U;
    unsigned int width = 0U;
    for( auto& it : mImageCollection )
    {
        if( it.second.GetHeight() >= height )
        {
            height = it.second.GetHeight();
        }
        if( it.second.GetWidth() >= width )
        {
            width = it.second.GetWidth();
        }
    }
 
    outputWidth = width;
    outputHeight = height;
}

◆ FindCellDimensions() [2/2]

void rendering_engine::TextureAtlasMaker::FindCellDimensions	(	unsigned int &	outputWidth,
		unsigned int &	outputHeight,
		std::unordered_map< std::uint32_t, std::pair< GlyphMetrics, ImageData > > &	fontAtlas
	)

staticprotected

Computes maximum cell dimensions for glyph images.

Parameters

outputWidth	Output cell width in pixels.
outputHeight	Output cell height in pixels.
fontAtlas	Glyph image collection.

Definition at line 124 of file texture_atlas_maker.cpp.

{
    unsigned int height = 0U;
    unsigned int width = 0U;
    for (auto& it : fontAtlas)
    {
        if (it.second.second.GetHeight() >= height)
        {
            height = it.second.second.GetHeight();
        }
        if (it.second.second.GetWidth() >= width)
        {
            width = it.second.second.GetWidth();
        }
    }
 
    outputWidth = width;
    outputHeight = height;
}

Member Data Documentation

◆ mImageCollection

std::map<char, ImageData> rendering_engine::TextureAtlasMaker::mImageCollection

protected

Definition at line 93 of file texture_atlas_maker.hpp.

◆ sDefaultPaletteBackgroundColor

const Color rendering_engine::TextureAtlasMaker::sDefaultPaletteBackgroundColor

staticprotected

Definition at line 95 of file texture_atlas_maker.hpp.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ TextureAtlasMaker()

◆ ~TextureAtlasMaker()

Member Function Documentation

◆ CalculateGridDimensions() [1/2]

◆ CalculateGridDimensions() [2/2]

◆ CreateTextureAtlas() [1/2]

◆ CreateTextureAtlas() [2/2]

◆ FindCellDimensions() [1/2]

◆ FindCellDimensions() [2/2]

Member Data Documentation

◆ mImageCollection

◆ sDefaultPaletteBackgroundColor