sprite_animation.h

// © Joseph Cameron - MIT License
 
#ifndef GDK_GRAPHICS_EXT_SPRITE_ANIMATION_H
#define GDK_GRAPHICS_EXT_SPRITE_ANIMATION_H
 
#include <gdk/graphics/data_types.h>
 
#include <cstddef>
#include <span>
#include <vector>
 
namespace gdk::graphics {
    class sprite_animation final {
    public:
        using normalized_texture_coordinate_type = float;
        using time_type = float;
        using texel_coordinate_type = int;

        enum class play_mode {
            loop, 
            once  
        };

        struct frame {
            texel_coordinate_type x;
            texel_coordinate_type y;
            texel_coordinate_type w;
            texel_coordinate_type h;
            time_type length;
        };

        struct normalized_frame {
            normalized_texture_coordinate_type u;
            normalized_texture_coordinate_type v;
            normalized_texture_coordinate_type w;
            normalized_texture_coordinate_type h;
        };

        [[nodiscard]] normalized_frame at(time_type aTime) const;

        [[nodiscard]] bool has_finished(time_type aTime) const;

        [[nodiscard]] time_type length() const;

        [[nodiscard]] std::size_t frame_count() const;

        sprite_animation(std::span<const frame> aFrameData,
            texel_coordinate_type aTextureWidth,
            texel_coordinate_type aTextureHeight,
            play_mode aPlayMode = play_mode::loop);
 
    private:
        std::vector<double> m_Starts;

        std::vector<normalized_frame> m_Frames;
 
        double m_Length = 0;
 
        play_mode m_PlayMode = play_mode::loop;
    };
}
 
#endif