tbx_parallax_backdrop.hpp

#ifndef TurtleBrainsExpress_ParallaxBackdrop_hpp
#define TurtleBrainsExpress_ParallaxBackdrop_hpp

#include <turtle_brains/graphics/tb_graphic.hpp>
#include <turtle_brains/graphics/tb_sprite.hpp>

#include <vector>

namespace TurtleBrainsExpress
{
    namespace Graphics
    {

        class ParallaxBackdrop : public tbGraphics::Graphic
        {
        public:
            enum class ScrollingType
            {
                kNoScrolling,    
                kHorizontal,     
                kVertical,       
                kFullScrolling,  
            };

            explicit ParallaxBackdrop(const ScrollingType& scrollingType = ScrollingType::kNoScrolling);

            virtual ~ParallaxBackdrop(void);

            void AddParallaxLayer(const tbCore::tbString& layerFilepath, const float parallaxMultiplier,
                const tbMath::Vector2& offset = tbMath::Vector2::Zero());

            void AddParallaxLayer(const tbGraphics::Sprite& layerSprite, const float parallaxMultiplier);

            ScrollingType GetScrollingType(void) const { return mScrollingType; }

            void ResetTargetArea(void);

            void ResetTargetArea(float targetWidth, float targetHeight);

        protected:
            virtual void OnRender(void) const override;

        private:
            struct ParallaxLayer
            {
                tbGraphics::Sprite mSprite;
                float mMultiplier;
            };

            std::vector<ParallaxLayer> mParallaxLayers;
            const ScrollingType mScrollingType;
            tbMath::Vector2 mTargetArea;
        };

    }; /* namespace Graphics */
}; /* namespace TurtleBrainsExpress */

namespace tbxGraphics = TurtleBrainsExpress::Graphics;

#endif /* TurtleBrainsExpress_ParallaxBackdrop_hpp */