KlassischeKeplerKriege/game/renderer_polygon_3d/particle_batch.hpp

#pragma once

#include <vector>

#include <glm/vec2.hpp>
#include <glm/vec3.hpp>

#include "glclasses.hpp"

//class VertexAttribute {
//    std::string nameInShader;
//    Guint attributeIndex;
//    Type type;
//    modifictaion
//    void *dataSource;
//};

namespace endofthejedi {
    class ParticleBatch {
        public:
            ParticleBatch(size_t id, size_t numParticles, float particleRadius, float halfAge);

            // deallocate opengl stuff on destroy
            ~ParticleBatch();

            size_t numParticles() const { return m_numParticles; }

            void setParticle(size_t index, const glm::vec3 &p, const glm::vec3 &v, float maxDistance);

            void setCenter(const glm::vec3 &center);
            void setMaxVelocity(float maxVelocity);

            void setup(Shader *shader);
            void bind();
            void upload();
            void render(Shader *shader);

            void tick(float dt);
            float ageNormalized() const { return m_age / (m_maxNumHalfAges*m_halfAge); }
            float age() const { return m_age; }
            bool done() const;

            size_t id() const { return m_id; }


            const glm::vec3 &explosionCenter() const { return m_center; }

        private:
            size_t dataSizeForIndex(size_t index);
            void  *dataSourceForIndex(size_t index);

        private:
            // id of explosion
            size_t                 m_id;

            // uniforms for the shader
            size_t                 m_numParticles;
            float                  m_particleRadius;
            float                  m_age;
            const float            m_halfAge;
            const float            m_maxNumHalfAges;
            float                  m_maxVelocity;
            glm::vec3              m_center;

            // meta data
            size_t                 m_num_vertex_buffers;
            std::vector<GLuint>    m_data_vbos;
            std::vector<GLuint>    m_attr_locations;

            // vertex attributes
            std::vector<float>     m_data_geometry;
            std::vector<glm::vec3> m_data_position;
            std::vector<glm::vec3> m_data_velocity;
            std::vector<float>     m_data_max_distance;
    };
}