model_data.h

// © Joseph Cameron - MIT License
 
#ifndef GDK_GRAPHICS_MODEL_DATA_H
#define GDK_GRAPHICS_MODEL_DATA_H
 
#include <cstddef>
#include <gdk/graphics/string_keyed.h>
#include <gdk/graphics/attribute_data.h>
#include <gdk/graphics/data_types.h>
 
#include <array>
#include <functional>
#include <map>
#include <optional>
#include <stdexcept>
#include <string>
#include <string_view>
#include <unordered_map>
#include <vector>
 
namespace gdk::graphics {
    class model_data final {
    public:
        using attribute_collection_type = string_keyed<attribute_data>;
        using index_value_type = unsigned short;
 
        enum class primitive_mode {
            triangles
        };

        primitive_mode get_primitive_mode() const;

        const std::vector<index_value_type> &indexes() const;

        [[nodiscard]] bool indexed() const;

        void set_indexes(std::vector<index_value_type> aIndexes);

        const attribute_collection_type &attributes() const;

        const attribute_data &get_attribute_data(std::string_view aAttributeName) const;
        attribute_data &get_attribute_data(std::string_view aAttributeName);

        void clear();

        void transform(const std::string &aPositionAttributeName, 
            const vector3_type &aPos,
            const quaternion_type &aRot = {},
            const vector3_type &aSca = {1, 1, 1});
        void transform(const std::string &aPositionAttributeName, const matrix4x4_type &aTransform);

        void transform(const std::string &aUVAttributeName,
            const vector2_type &aPos,
            const float aRotation = 0,
            const vector2_type &aSca = {1, 1});

        void sort_by_nearest_triangle(
            const vector3_type &aObserverWorldPosition,
            matrix4x4_type aEntityInstanceWorldMatrix,
            std::string_view aPositionAttributeName = "a_Position");
        
        void sort_by_furthest_triangle(
            const vector3_type &aObserverWorldPosition,
            matrix4x4_type aEntityInstanceWorldMatrix,
            std::string_view aPositionAttributeName = "a_Position");

        void push_back(const model_data &other);

        void overwrite(const std::size_t index, const model_data &other);

        void overwrite(std::string_view aAttributeName, const std::size_t vertexOffset, const model_data &other);

        std::size_t vertex_count() const;

        model_data operator+(const model_data &aData);

        model_data &operator+=(const model_data &other);

        model_data &operator=(model_data &&other) = default;
        model_data(model_data &&) = default;

        model_data(const model_data &) = default;
        model_data &operator=(const model_data &other) = default;

        model_data() = default;

        model_data(attribute_collection_type &&aAttributeData);

        model_data(attribute_collection_type &&aAttributeData,
            std::vector<index_value_type> &&aIndexes);
 
        ~model_data() = default;

        static model_data make_quad();
 
    private:
        std::size_t m_VertexCount{};
 
        std::vector<index_value_type> m_Indexes{};
        attribute_collection_type m_Attributes{};
        primitive_mode m_PrimitiveMode = primitive_mode::triangles; 
    };
}
 
#endif