#ifndef RASTERIZERSCENEGLES3_H
#define RASTERIZERSCENEGLES3_H

#include "rasterizer_storage_gles3.h"
#include "drivers/gles3/shaders/scene.glsl.h"
#include "drivers/gles3/shaders/cube_to_dp.glsl.h"
#include "drivers/gles3/shaders/resolve.glsl.h"
#include "drivers/gles3/shaders/screen_space_reflection.glsl.h"
#include "drivers/gles3/shaders/effect_blur.glsl.h"
#include "drivers/gles3/shaders/subsurf_scattering.glsl.h"
#include "drivers/gles3/shaders/ssao_minify.glsl.h"
#include "drivers/gles3/shaders/ssao.glsl.h"
#include "drivers/gles3/shaders/ssao_blur.glsl.h"
#include "drivers/gles3/shaders/exposure.glsl.h"
#include "drivers/gles3/shaders/tonemap.glsl.h"

class RasterizerSceneGLES3 : public RasterizerScene {
public:

	enum ShadowFilterMode {
		SHADOW_FILTER_NEAREST,
		SHADOW_FILTER_PCF5,
		SHADOW_FILTER_PCF13,
	};


	ShadowFilterMode shadow_filter_mode;

	uint64_t shadow_atlas_realloc_tolerance_msec;

	enum SubSurfaceScatterQuality {
		SSS_QUALITY_LOW,
		SSS_QUALITY_MEDIUM,
		SSS_QUALITY_HIGH,
	};

	SubSurfaceScatterQuality subsurface_scatter_quality;
	float subsurface_scatter_size;
	bool subsurface_scatter_follow_surface;

	uint64_t render_pass;
	uint64_t scene_pass;
	uint32_t current_material_index;
	uint32_t current_geometry_index;

	RID default_material;
	RID default_material_twosided;
	RID default_shader;
	RID default_shader_twosided;

	RasterizerStorageGLES3 *storage;

	Vector<RasterizerStorageGLES3::RenderTarget::Exposure> exposure_shrink;
	int exposure_shrink_size;


	struct State {



		bool texscreen_copied;
		int current_blend_mode;
		float current_line_width;
		int current_depth_draw;
		GLuint current_main_tex;

		SceneShaderGLES3 scene_shader;
		CubeToDpShaderGLES3 cube_to_dp_shader;
		ResolveShaderGLES3 resolve_shader;
		ScreenSpaceReflectionShaderGLES3 ssr_shader;
		EffectBlurShaderGLES3 effect_blur_shader;
		SubsurfScatteringShaderGLES3 sss_shader;
		SsaoMinifyShaderGLES3 ssao_minify_shader;
		SsaoShaderGLES3 ssao_shader;
		SsaoBlurShaderGLES3 ssao_blur_shader;
		ExposureShaderGLES3 exposure_shader;
		TonemapShaderGLES3 tonemap_shader;


		struct SceneDataUBO {

			float projection_matrix[16];
			float camera_inverse_matrix[16];
			float camera_matrix[16];
			float time[4];
			float ambient_light_color[4];
			float bg_color[4];
			float ambient_energy;
			float bg_energy;
			float shadow_z_offset;
			float shadow_slope_scale;
			float shadow_dual_paraboloid_render_zfar;
			float shadow_dual_paraboloid_render_side;
			float shadow_atlas_pixel_size[2];
			float shadow_directional_pixel_size[2];
			float reflection_multiplier;
			float subsurface_scatter_width;
			float ambient_occlusion_affect_light;

		} ubo_data;

		GLuint scene_ubo;

		struct EnvironmentRadianceUBO {

			float transform[16];
			float box_min[4]; //unused for now
			float box_max[4];
			float ambient_contribution;

		} env_radiance_data;

		GLuint env_radiance_ubo;

		GLuint brdf_texture;

		GLuint skybox_verts;
		GLuint skybox_array;

		GLuint directional_ubo;

		GLuint spot_array_ubo;
		GLuint omni_array_ubo;
		GLuint reflection_array_ubo;

		GLuint immediate_buffer;
		GLuint immediate_array;

		uint32_t ubo_light_size;
		uint8_t *spot_array_tmp;
		uint8_t *omni_array_tmp;
		uint8_t *reflection_array_tmp;

		int max_ubo_lights;
		int max_forward_lights_per_object;
		int max_ubo_reflections;
		int max_skeleton_bones;



		int spot_light_count;
		int omni_light_count;
		int directional_light_count;
		int reflection_probe_count;

		bool cull_front;
		bool used_sss;

	} state;

	/* SHADOW ATLAS API */

	struct ShadowAtlas : public RID_Data {

		enum {
			QUADRANT_SHIFT=27,
			SHADOW_INDEX_MASK=(1<<QUADRANT_SHIFT)-1,
			SHADOW_INVALID=0xFFFFFFFF
		};

		struct Quadrant {

			uint32_t subdivision;

			struct Shadow {
				RID owner;
				uint64_t version;
				uint64_t alloc_tick;

				Shadow() {
					version=0;
					alloc_tick=0;
				}
			};

			Vector<Shadow> shadows;

			Quadrant() {
				subdivision=0; //not in use
			}

		} quadrants[4];

		int size_order[4];
		uint32_t smallest_subdiv;

		int size;

		GLuint fbo;
		GLuint depth;

		Map<RID,uint32_t> shadow_owners;
	};

	struct ShadowCubeMap {

		GLuint fbo_id[6];
		GLuint cubemap;
		int size;
	};

	Vector<ShadowCubeMap> shadow_cubemaps;

	RID_Owner<ShadowAtlas> shadow_atlas_owner;

	RID shadow_atlas_create();
	void shadow_atlas_set_size(RID p_atlas,int p_size);
	void shadow_atlas_set_quadrant_subdivision(RID p_atlas,int p_quadrant,int p_subdivision);
	bool _shadow_atlas_find_shadow(ShadowAtlas *shadow_atlas, int *p_in_quadrants, int p_quadrant_count, int p_current_subdiv, uint64_t p_tick, int &r_quadrant, int &r_shadow);
	bool shadow_atlas_update_light(RID p_atlas,RID p_light_intance,float p_coverage,uint64_t p_light_version);


	struct DirectionalShadow {
		GLuint fbo;
		GLuint depth;
		int light_count;
		int size;
		int current_light;
	} directional_shadow;

	virtual int get_directional_light_shadow_size(RID p_light_intance);
	virtual void set_directional_shadow_count(int p_count);

	/* REFLECTION PROBE ATLAS API */

	struct ReflectionAtlas : public RID_Data {

		int subdiv;
		int size;

		struct Reflection {
			RID owner;
			uint64_t last_frame;
		};

		GLuint fbo[6];
		GLuint color;

		Vector<Reflection> reflections;
	};

	mutable RID_Owner<ReflectionAtlas> reflection_atlas_owner;

	virtual RID reflection_atlas_create();
	virtual void reflection_atlas_set_size(RID p_ref_atlas,int p_size);
	virtual void reflection_atlas_set_subdivision(RID p_ref_atlas,int p_subdiv);

	/* REFLECTION CUBEMAPS */

	struct ReflectionCubeMap {

		GLuint fbo_id[6];
		GLuint cubemap;
		GLuint depth;
		int size;
	};

	Vector<ReflectionCubeMap> reflection_cubemaps;

	/* REFLECTION PROBE INSTANCE */

	struct ReflectionProbeInstance : public RID_Data {

		RasterizerStorageGLES3::ReflectionProbe *probe_ptr;
		RID probe;
		RID self;
		RID atlas;

		int reflection_atlas_index;

		int render_step;



		uint64_t last_pass;
		int reflection_index;

		Transform transform;
	};

	struct ReflectionProbeDataUBO {

		float box_extents[4];
		float box_ofs[4];
		float params[4]; // intensity, 0, 0, boxproject
		float ambient[4]; //color, probe contrib
		float atlas_clamp[4];
		float local_matrix[16]; //up to here for spot and omni, rest is for directional
		//notes: for ambientblend, use distance to edge to blend between already existing global environment
	};


	mutable RID_Owner<ReflectionProbeInstance> reflection_probe_instance_owner;

	virtual RID reflection_probe_instance_create(RID p_probe);
	virtual void reflection_probe_instance_set_transform(RID p_instance,const Transform& p_transform);
	virtual void reflection_probe_release_atlas_index(RID p_instance);
	virtual bool reflection_probe_instance_needs_redraw(RID p_instance);
	virtual bool reflection_probe_instance_has_reflection(RID p_instance);
	virtual bool reflection_probe_instance_begin_render(RID p_instance, RID p_reflection_atlas);
	virtual bool reflection_probe_instance_postprocess_step(RID p_instance);




	/* ENVIRONMENT API */

	struct Environment : public RID_Data {

		VS::EnvironmentBG bg_mode;

		RID skybox;
		float skybox_scale;

		Color bg_color;
		float bg_energy;
		float skybox_ambient;

		Color ambient_color;
		float ambient_energy;
		float ambient_skybox_contribution;

		int canvas_max_layer;

		bool ssr_enabled;
		int ssr_max_steps;
		float ssr_accel;
		float ssr_fade;
		float ssr_depth_tolerance;
		bool ssr_smooth;
		bool ssr_roughness;


		bool ssao_enabled;
		float ssao_intensity;
		float ssao_radius;
		float ssao_intensity2;
		float ssao_radius2;
		float ssao_bias;
		float ssao_light_affect;
		Color ssao_color;
		bool ssao_filter;

		bool glow_enabled;
		int glow_levels;
		float glow_intensity;
		float glow_strength;
		float glow_bloom;
		VS::EnvironmentGlowBlendMode glow_blend_mode;
		float glow_hdr_bleed_treshold;
		float glow_hdr_bleed_scale;
		bool glow_bicubic_upscale;

		VS::EnvironmentToneMapper tone_mapper;
		float tone_mapper_exposure;
		float tone_mapper_exposure_white;
		bool auto_exposure;
		float auto_exposure_speed;
		float auto_exposure_min;
		float auto_exposure_max;
		float auto_exposure_grey;

		bool dof_blur_far_enabled;
		float dof_blur_far_distance;
		float dof_blur_far_transition;
		float dof_blur_far_amount;
		VS::EnvironmentDOFBlurQuality dof_blur_far_quality;

		bool dof_blur_near_enabled;
		float dof_blur_near_distance;
		float dof_blur_near_transition;
		float dof_blur_near_amount;
		VS::EnvironmentDOFBlurQuality dof_blur_near_quality;

		Environment() {
			bg_mode=VS::ENV_BG_CLEAR_COLOR;
			skybox_scale=1.0;
			bg_energy=1.0;
			skybox_ambient=0;
			ambient_energy=1.0;
			ambient_skybox_contribution=0.0;
			canvas_max_layer=0;

			ssr_enabled=false;
			ssr_max_steps=64;
			ssr_accel=0.04;
			ssr_fade=2.0;
			ssr_depth_tolerance=0.2;
			ssr_smooth=true;
			ssr_roughness=true;

			ssao_enabled=false;
			ssao_intensity=1.0;
			ssao_radius=1.0;
			ssao_intensity2=1.0;
			ssao_radius2=0.0;
			ssao_bias=0.01;
			ssao_light_affect=0;
			ssao_filter=true;

			tone_mapper=VS::ENV_TONE_MAPPER_LINEAR;
			tone_mapper_exposure=1.0;
			tone_mapper_exposure_white=1.0;
			auto_exposure=false;
			auto_exposure_speed=0.5;
			auto_exposure_min=0.05;
			auto_exposure_max=8;
			auto_exposure_grey=0.4;

			glow_enabled=false;
			glow_levels=(1<<2)|(1<<4);
			glow_intensity=0.8;
			glow_strength=1.0;
			glow_bloom=0.0;
			glow_blend_mode=VS::GLOW_BLEND_MODE_SOFTLIGHT;
			glow_hdr_bleed_treshold=1.0;
			glow_hdr_bleed_scale=2.0;
			glow_bicubic_upscale=false;

			dof_blur_far_enabled=false;
			dof_blur_far_distance=10;
			dof_blur_far_transition=5;
			dof_blur_far_amount=0.1;
			dof_blur_far_quality=VS::ENV_DOF_BLUR_QUALITY_MEDIUM;

			dof_blur_near_enabled=false;
			dof_blur_near_distance=2;
			dof_blur_near_transition=1;
			dof_blur_near_amount=0.1;
			dof_blur_near_quality=VS::ENV_DOF_BLUR_QUALITY_MEDIUM;

		}
	};

	RID_Owner<Environment> environment_owner;

	virtual RID environment_create();

	virtual void environment_set_background(RID p_env,VS::EnvironmentBG p_bg);
	virtual void environment_set_skybox(RID p_env,RID p_skybox);
	virtual void environment_set_skybox_scale(RID p_env,float p_scale);
	virtual void environment_set_bg_color(RID p_env,const Color& p_color);
	virtual void environment_set_bg_energy(RID p_env,float p_energy);
	virtual void environment_set_canvas_max_layer(RID p_env,int p_max_layer);
	virtual void environment_set_ambient_light(RID p_env,const Color& p_color,float p_energy=1.0,float p_skybox_contribution=0.0);

	virtual void environment_set_dof_blur_near(RID p_env,bool p_enable,float p_distance,float p_transition,float p_far_amount,VS::EnvironmentDOFBlurQuality p_quality);
	virtual void environment_set_dof_blur_far(RID p_env,bool p_enable,float p_distance,float p_transition,float p_far_amount,VS::EnvironmentDOFBlurQuality p_quality);
	virtual void environment_set_glow(RID p_env,bool p_enable,int p_level_flags,float p_intensity,float p_strength,float p_bloom_treshold,VS::EnvironmentGlowBlendMode p_blend_mode,float p_hdr_bleed_treshold,float p_hdr_bleed_scale,bool p_bicubic_upscale);
	virtual void environment_set_fog(RID p_env,bool p_enable,float p_begin,float p_end,RID p_gradient_texture);

	virtual void environment_set_ssr(RID p_env,bool p_enable, int p_max_steps,float p_accel,float p_fade,float p_depth_tolerance,bool p_smooth,bool p_roughness);
	virtual void environment_set_ssao(RID p_env,bool p_enable, float p_radius, float p_radius2, float p_intensity2, float p_intensity, float p_bias, float p_light_affect,const Color &p_color,bool p_blur);


	virtual void environment_set_tonemap(RID p_env,VS::EnvironmentToneMapper p_tone_mapper,float p_exposure,float p_white,bool p_auto_exposure,float p_min_luminance,float p_max_luminance,float p_auto_exp_speed,float p_auto_exp_scale);

	virtual void environment_set_adjustment(RID p_env,bool p_enable,float p_brightness,float p_contrast,float p_saturation,RID p_ramp);


	/* LIGHT INSTANCE */

	struct LightDataUBO {

		float light_pos_inv_radius[4];
		float light_direction_attenuation[4];
		float light_color_energy[4];
		float light_params[4]; //spot attenuation, spot angle, specular, shadow enabled
		float light_clamp[4];
		float light_shadow_color[4];
		float shadow_matrix1[16]; //up to here for spot and omni, rest is for directional
		float shadow_matrix2[16];
		float shadow_matrix3[16];
		float shadow_matrix4[16];
		float shadow_split_offsets[4];

	};

	struct LightInstance : public RID_Data {

		struct ShadowTransform {

			CameraMatrix camera;
			Transform transform;
			float far;
			float split;
		};



		ShadowTransform shadow_transform[4];

		RID self;
		RID light;
		RasterizerStorageGLES3::Light *light_ptr;
		Transform transform;

		Vector3 light_vector;
		Vector3 spot_vector;
		float linear_att;

		uint64_t shadow_pass;
		uint64_t last_scene_pass;
		uint64_t last_scene_shadow_pass;
		uint64_t last_pass;
		uint16_t light_index;
		uint16_t light_directional_index;

		uint32_t current_shadow_atlas_key;

		Vector2 dp;

		Rect2 directional_rect;


		Set<RID> shadow_atlases; //shadow atlases where this light is registered

		LightInstance() { }

	};

	mutable RID_Owner<LightInstance> light_instance_owner;

	virtual RID light_instance_create(RID p_light);
	virtual void light_instance_set_transform(RID p_light_instance,const Transform& p_transform);
	virtual void light_instance_set_shadow_transform(RID p_light_instance,const CameraMatrix& p_projection,const Transform& p_transform,float p_far,float p_split,int p_pass);
	virtual void light_instance_mark_visible(RID p_light_instance);

	/* RENDER LIST */

	struct RenderList {

		enum {
			DEFAULT_MAX_ELEMENTS=65536,
			SORT_FLAG_SKELETON=1,
			SORT_FLAG_INSTANCING=2,
			MAX_DIRECTIONAL_LIGHTS=16,
			MAX_LIGHTS=4096,


			SORT_KEY_DEPTH_LAYER_SHIFT=60,
			SORT_KEY_UNSHADED_FLAG=uint64_t(1)<<59,
			SORT_KEY_NO_DIRECTIONAL_FLAG=uint64_t(1)<<58,
			SORT_KEY_SHADING_SHIFT=58,
			SORT_KEY_SHADING_MASK=3,
			SORT_KEY_MATERIAL_INDEX_SHIFT=40,
			SORT_KEY_GEOMETRY_INDEX_SHIFT=20,
			SORT_KEY_GEOMETRY_TYPE_SHIFT=15,
			SORT_KEY_SKELETON_FLAG=2,
			SORT_KEY_MIRROR_FLAG=1

		};

		int max_elements;

		struct Element {

			RasterizerScene::InstanceBase *instance;
			RasterizerStorageGLES3::Geometry *geometry;
			RasterizerStorageGLES3::Material *material;
			RasterizerStorageGLES3::GeometryOwner *owner;
			uint64_t sort_key;

		};


		Element *_elements;
		Element **elements;

		int element_count;
		int alpha_element_count;


		void clear() {

			element_count=0;
			alpha_element_count=0;
		}

		//should eventually be replaced by radix

		struct SortByKey {

			_FORCE_INLINE_ bool operator()(const Element* A,  const Element* B ) const {
				return A->sort_key < B->sort_key;
			}
		};

		void sort_by_key(bool p_alpha) {

			SortArray<Element*,SortByKey> sorter;
			if (p_alpha) {
				sorter.sort(&elements[max_elements-alpha_element_count],alpha_element_count);
			} else {
				sorter.sort(elements,element_count);
			}
		}

		struct SortByDepth {

			_FORCE_INLINE_ bool operator()(const Element* A,  const Element* B ) const {
				return A->instance->depth > B->instance->depth;
			}
		};

		void sort_by_depth(bool p_alpha) {

			SortArray<Element*,SortByDepth> sorter;
			if (p_alpha) {
				sorter.sort(&elements[max_elements-alpha_element_count],alpha_element_count);
			} else {
				sorter.sort(elements,element_count);
			}
		}


		_FORCE_INLINE_ Element* add_element() {

			if (element_count+alpha_element_count>=max_elements)
				return NULL;
			elements[element_count]=&_elements[element_count];
			return elements[element_count++];
		}

		_FORCE_INLINE_ Element* add_alpha_element() {

			if (element_count+alpha_element_count>=max_elements)
				return NULL;
			int idx = max_elements-alpha_element_count-1;
			elements[idx]=&_elements[idx];
			alpha_element_count++;
			return elements[idx];
		}

		void init() {

			element_count = 0;
			alpha_element_count =0;
			elements=memnew_arr(Element*,max_elements);
			_elements=memnew_arr(Element,max_elements);
			for (int i=0;i<max_elements;i++)
				elements[i]=&_elements[i]; // assign elements

		}


		RenderList() {

			max_elements=DEFAULT_MAX_ELEMENTS;
		}

		~RenderList() {
			memdelete_arr(elements);
			memdelete_arr(_elements);
		}
	};


	LightInstance *directional_light;
	LightInstance *directional_lights[RenderList::MAX_DIRECTIONAL_LIGHTS];



	RenderList render_list;

	_FORCE_INLINE_ void _set_cull(bool p_front,bool p_reverse_cull);

	_FORCE_INLINE_ bool _setup_material(RasterizerStorageGLES3::Material* p_material,bool p_alpha_pass);
	_FORCE_INLINE_ void _setup_transform(InstanceBase *p_instance,const Transform& p_view_transform,const CameraMatrix& p_projection);
	_FORCE_INLINE_ void _setup_geometry(RenderList::Element *e);
	_FORCE_INLINE_ void _render_geometry(RenderList::Element *e);
	_FORCE_INLINE_ void _setup_light(RenderList::Element *e);

	void _render_list(RenderList::Element **p_elements, int p_element_count, const Transform& p_view_transform, const CameraMatrix& p_projection, GLuint p_base_env, bool p_reverse_cull, bool p_alpha_pass, bool p_shadow, bool p_directional_add, bool p_directional_shadows);


	_FORCE_INLINE_ void _add_geometry(  RasterizerStorageGLES3::Geometry* p_geometry,  InstanceBase *p_instance, RasterizerStorageGLES3::GeometryOwner *p_owner,int p_material,bool p_shadow);

	void _draw_skybox(RasterizerStorageGLES3::SkyBox *p_skybox, const CameraMatrix& p_projection, const Transform& p_transform, bool p_vflip, float p_scale);

	void _setup_environment(Environment *env, const CameraMatrix &p_cam_projection, const Transform& p_cam_transform);
	void _setup_directional_light(int p_index, const Transform &p_camera_inverse_transformm, bool p_use_shadows);
	void _setup_lights(RID *p_light_cull_result, int p_light_cull_count, const Transform &p_camera_inverse_transform, const CameraMatrix& p_camera_projection, RID p_shadow_atlas);
	void _setup_reflections(RID *p_reflection_probe_cull_result, int p_reflection_probe_cull_count, const Transform& p_camera_inverse_transform, const CameraMatrix& p_camera_projection, RID p_reflection_atlas, Environment *p_env);

	void _copy_screen();
	void _copy_to_front_buffer(Environment *env);
	void _copy_texture_to_front_buffer(GLuint p_texture); //used for debug

	void _fill_render_list(InstanceBase** p_cull_result,int p_cull_count,bool p_shadow);

	void _render_mrts(Environment *env, const CameraMatrix &p_cam_projection);
	void _post_process(Environment *env, const CameraMatrix &p_cam_projection);

	virtual void render_scene(const Transform& p_cam_transform,const CameraMatrix& p_cam_projection,bool p_cam_ortogonal,InstanceBase** p_cull_result,int p_cull_count,RID* p_light_cull_result,int p_light_cull_count,RID* p_reflection_probe_cull_result,int p_reflection_probe_cull_count,RID p_environment,RID p_shadow_atlas,RID p_reflection_atlas,RID p_reflection_probe,int p_reflection_probe_pass);
	virtual void render_shadow(RID p_light,RID p_shadow_atlas,int p_pass,InstanceBase** p_cull_result,int p_cull_count);
	virtual bool free(RID p_rid);

	void _generate_brdf();

	virtual void set_scene_pass(uint64_t p_pass);

	void iteration();
	void initialize();
	void finalize();
	RasterizerSceneGLES3();
};

#endif // RASTERIZERSCENEGLES3_H