TextureAtlas.h

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#pragma once
 
#include <string>
#include <unordered_map>
#include <vector>
 
#include <tdme/tdme.h>
#include <tdme/engine/fwd-tdme.h>
#include <tdme/utilities/fwd-tdme.h>
 
using std::string;
using std::unordered_map;
using std::vector;
 
using tdme::engine::Texture;
 
/**
 * Texture atlas
 * @author Andreas Drewke
 */
class tdme::utilities::TextureAtlas {
public:
    static constexpr bool VERBOSE { false };
    static constexpr int TEXTURE_IDX_NONE { -1 };
 
    /**
     * Texture Atlas Texture
     */
    struct AtlasTexture {
        enum Orientation { ORIENTATION_NONE, ORIENTATION_NORMAL, ORIENTATION_ROTATED };
        Texture* texture { nullptr };
        Orientation orientation { ORIENTATION_NONE };
        int textureIdx { -1 };
        int left { -1 };
        int top { -1 };
        int width { -1 };
        int height { -1 };
        int line { -1 };
    };
 
    // forbid class copy
    FORBID_CLASS_COPY(TextureAtlas)
 
    /**
     * Public constructor
     * @param id texture id
     */
    TextureAtlas(const string& id);
 
    /**
     * Public destructor
     */
    ~TextureAtlas();
 
    /**
     * Returns specific atlas texture index within atlas
     * @param texture texture
     * @return atlas texture id
     */
    inline int getTextureIdx(Texture* texture) {
        auto it = textureToAtlasTextureIdxMapping.find(texture);
        if (it == textureToAtlasTextureIdxMapping.end()) {
            return TEXTURE_IDX_NONE;
        }
        return it->second;
    }
 
    /**
     * Returns specific atlas texture information within atlas
     * @param textureIdx texture index
     * @return atlas texture information
     */
    inline const AtlasTexture* getAtlasTexture(int textureIdx) {
        auto it = atlasTextureIdxToAtlasTextureMapping.find(textureIdx);
        if (it == atlasTextureIdxToAtlasTextureMapping.end()) {
            return nullptr;
        }
        return &it->second;
    }
 
    /**
     * Add texture
     * @param texture texture
     * @return atlas texture id
     */
    int addTexture(Texture* texture);
 
    /**
     * Remove texture
     * @param texture texture
     */
    void removeTexture(Texture* texture);
 
    /**
     * Update texture atlas
     */
    void update();
 
    /**
     * @return is requiring update
     */
    inline bool isRequiringUpdate() {
        return requiresUpdate;
    }
 
    /**
     * @return atlas texture
     */
    inline Texture* getAtlasTexture() {
        return atlasTexture;
    }
 
private:
    bool requiresUpdate { false };
    string atlasTextureId;
    Texture* atlasTexture { nullptr };
    unordered_map<Texture*, int> textureReferenceCounter;
    unordered_map<Texture*, int> textureToAtlasTextureIdxMapping;
    unordered_map<int, AtlasTexture> atlasTextureIdxToAtlasTextureMapping;
    vector<int> freeTextureIds;
};