/*************************************************************************/
/*  light_storage.cpp                                                    */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifdef GLES3_ENABLED

#include "light_storage.h"
#include "config.h"
#include "texture_storage.h"

using namespace GLES3;

LightStorage *LightStorage::singleton = nullptr;

LightStorage *LightStorage::get_singleton() {
	return singleton;
}

LightStorage::LightStorage() {
	singleton = this;
}

LightStorage::~LightStorage() {
	singleton = nullptr;
}

/* Light API */

void LightStorage::_light_initialize(RID p_light, RS::LightType p_type) {
	Light light;
	light.type = p_type;

	light.param[RS::LIGHT_PARAM_ENERGY] = 1.0;
	light.param[RS::LIGHT_PARAM_INDIRECT_ENERGY] = 1.0;
	light.param[RS::LIGHT_PARAM_SPECULAR] = 0.5;
	light.param[RS::LIGHT_PARAM_RANGE] = 1.0;
	light.param[RS::LIGHT_PARAM_SIZE] = 0.0;
	light.param[RS::LIGHT_PARAM_ATTENUATION] = 1.0;
	light.param[RS::LIGHT_PARAM_SPOT_ANGLE] = 45;
	light.param[RS::LIGHT_PARAM_SPOT_ATTENUATION] = 1.0;
	light.param[RS::LIGHT_PARAM_SHADOW_MAX_DISTANCE] = 0;
	light.param[RS::LIGHT_PARAM_SHADOW_SPLIT_1_OFFSET] = 0.1;
	light.param[RS::LIGHT_PARAM_SHADOW_SPLIT_2_OFFSET] = 0.3;
	light.param[RS::LIGHT_PARAM_SHADOW_SPLIT_3_OFFSET] = 0.6;
	light.param[RS::LIGHT_PARAM_SHADOW_FADE_START] = 0.8;
	light.param[RS::LIGHT_PARAM_SHADOW_NORMAL_BIAS] = 1.0;
	light.param[RS::LIGHT_PARAM_SHADOW_OPACITY] = 1.0;
	light.param[RS::LIGHT_PARAM_SHADOW_BIAS] = 0.02;
	light.param[RS::LIGHT_PARAM_SHADOW_BLUR] = 0;
	light.param[RS::LIGHT_PARAM_SHADOW_PANCAKE_SIZE] = 20.0;
	light.param[RS::LIGHT_PARAM_SHADOW_VOLUMETRIC_FOG_FADE] = 0.1;
	light.param[RS::LIGHT_PARAM_TRANSMITTANCE_BIAS] = 0.05;

	light_owner.initialize_rid(p_light, light);
}

RID LightStorage::directional_light_allocate() {
	return light_owner.allocate_rid();
}

void LightStorage::directional_light_initialize(RID p_rid) {
	_light_initialize(p_rid, RS::LIGHT_DIRECTIONAL);
}

RID LightStorage::omni_light_allocate() {
	return light_owner.allocate_rid();
}

void LightStorage::omni_light_initialize(RID p_rid) {
	_light_initialize(p_rid, RS::LIGHT_OMNI);
}

RID LightStorage::spot_light_allocate() {
	return light_owner.allocate_rid();
}

void LightStorage::spot_light_initialize(RID p_rid) {
	_light_initialize(p_rid, RS::LIGHT_SPOT);
}

void LightStorage::light_free(RID p_rid) {
	light_set_projector(p_rid, RID()); //clear projector

	// delete the texture
	Light *light = light_owner.get_or_null(p_rid);
	light->dependency.deleted_notify(p_rid);
	light_owner.free(p_rid);
}

void LightStorage::light_set_color(RID p_light, const Color &p_color) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->color = p_color;
}

void LightStorage::light_set_param(RID p_light, RS::LightParam p_param, float p_value) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);
	ERR_FAIL_INDEX(p_param, RS::LIGHT_PARAM_MAX);

	if (light->param[p_param] == p_value) {
		return;
	}

	switch (p_param) {
		case RS::LIGHT_PARAM_RANGE:
		case RS::LIGHT_PARAM_SPOT_ANGLE:
		case RS::LIGHT_PARAM_SHADOW_MAX_DISTANCE:
		case RS::LIGHT_PARAM_SHADOW_SPLIT_1_OFFSET:
		case RS::LIGHT_PARAM_SHADOW_SPLIT_2_OFFSET:
		case RS::LIGHT_PARAM_SHADOW_SPLIT_3_OFFSET:
		case RS::LIGHT_PARAM_SHADOW_NORMAL_BIAS:
		case RS::LIGHT_PARAM_SHADOW_PANCAKE_SIZE:
		case RS::LIGHT_PARAM_SHADOW_BIAS: {
			light->version++;
			light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
		} break;
		case RS::LIGHT_PARAM_SIZE: {
			if ((light->param[p_param] > CMP_EPSILON) != (p_value > CMP_EPSILON)) {
				//changing from no size to size and the opposite
				light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT_SOFT_SHADOW_AND_PROJECTOR);
			}
		} break;
		default: {
		}
	}

	light->param[p_param] = p_value;
}

void LightStorage::light_set_shadow(RID p_light, bool p_enabled) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);
	light->shadow = p_enabled;

	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

void LightStorage::light_set_projector(RID p_light, RID p_texture) {
	GLES3::TextureStorage *texture_storage = GLES3::TextureStorage::get_singleton();
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	if (light->projector == p_texture) {
		return;
	}

	if (light->type != RS::LIGHT_DIRECTIONAL && light->projector.is_valid()) {
		texture_storage->texture_remove_from_decal_atlas(light->projector, light->type == RS::LIGHT_OMNI);
	}

	light->projector = p_texture;

	if (light->type != RS::LIGHT_DIRECTIONAL) {
		if (light->projector.is_valid()) {
			texture_storage->texture_add_to_decal_atlas(light->projector, light->type == RS::LIGHT_OMNI);
		}
		light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT_SOFT_SHADOW_AND_PROJECTOR);
	}
}

void LightStorage::light_set_negative(RID p_light, bool p_enable) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->negative = p_enable;
}

void LightStorage::light_set_cull_mask(RID p_light, uint32_t p_mask) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->cull_mask = p_mask;

	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

void LightStorage::light_set_distance_fade(RID p_light, bool p_enabled, float p_begin, float p_shadow, float p_length) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->distance_fade = p_enabled;
	light->distance_fade_begin = p_begin;
	light->distance_fade_shadow = p_shadow;
	light->distance_fade_length = p_length;
}

void LightStorage::light_set_reverse_cull_face_mode(RID p_light, bool p_enabled) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->reverse_cull = p_enabled;

	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

void LightStorage::light_set_bake_mode(RID p_light, RS::LightBakeMode p_bake_mode) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->bake_mode = p_bake_mode;

	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

void LightStorage::light_omni_set_shadow_mode(RID p_light, RS::LightOmniShadowMode p_mode) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->omni_shadow_mode = p_mode;

	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

RS::LightOmniShadowMode LightStorage::light_omni_get_shadow_mode(RID p_light) {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, RS::LIGHT_OMNI_SHADOW_CUBE);

	return light->omni_shadow_mode;
}

void LightStorage::light_directional_set_shadow_mode(RID p_light, RS::LightDirectionalShadowMode p_mode) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->directional_shadow_mode = p_mode;
	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

void LightStorage::light_directional_set_blend_splits(RID p_light, bool p_enable) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->directional_blend_splits = p_enable;
	light->version++;
	light->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_LIGHT);
}

bool LightStorage::light_directional_get_blend_splits(RID p_light) const {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, false);

	return light->directional_blend_splits;
}

void LightStorage::light_directional_set_sky_mode(RID p_light, RS::LightDirectionalSkyMode p_mode) {
	Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND(!light);

	light->directional_sky_mode = p_mode;
}

RS::LightDirectionalSkyMode LightStorage::light_directional_get_sky_mode(RID p_light) const {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, RS::LIGHT_DIRECTIONAL_SKY_MODE_LIGHT_AND_SKY);

	return light->directional_sky_mode;
}

RS::LightDirectionalShadowMode LightStorage::light_directional_get_shadow_mode(RID p_light) {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, RS::LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL);

	return light->directional_shadow_mode;
}

RS::LightBakeMode LightStorage::light_get_bake_mode(RID p_light) {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, RS::LIGHT_BAKE_DISABLED);

	return light->bake_mode;
}

uint64_t LightStorage::light_get_version(RID p_light) const {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, 0);

	return light->version;
}

AABB LightStorage::light_get_aabb(RID p_light) const {
	const Light *light = light_owner.get_or_null(p_light);
	ERR_FAIL_COND_V(!light, AABB());

	switch (light->type) {
		case RS::LIGHT_SPOT: {
			float len = light->param[RS::LIGHT_PARAM_RANGE];
			float size = Math::tan(Math::deg_to_rad(light->param[RS::LIGHT_PARAM_SPOT_ANGLE])) * len;
			return AABB(Vector3(-size, -size, -len), Vector3(size * 2, size * 2, len));
		};
		case RS::LIGHT_OMNI: {
			float r = light->param[RS::LIGHT_PARAM_RANGE];
			return AABB(-Vector3(r, r, r), Vector3(r, r, r) * 2);
		};
		case RS::LIGHT_DIRECTIONAL: {
			return AABB();
		};
	}

	ERR_FAIL_V(AABB());
}

/* PROBE API */

RID LightStorage::reflection_probe_allocate() {
	return RID();
}

void LightStorage::reflection_probe_initialize(RID p_rid) {
}

void LightStorage::reflection_probe_free(RID p_rid) {
}

void LightStorage::reflection_probe_set_update_mode(RID p_probe, RS::ReflectionProbeUpdateMode p_mode) {
}

void LightStorage::reflection_probe_set_intensity(RID p_probe, float p_intensity) {
}

void LightStorage::reflection_probe_set_ambient_mode(RID p_probe, RS::ReflectionProbeAmbientMode p_mode) {
}

void LightStorage::reflection_probe_set_ambient_color(RID p_probe, const Color &p_color) {
}

void LightStorage::reflection_probe_set_ambient_energy(RID p_probe, float p_energy) {
}

void LightStorage::reflection_probe_set_max_distance(RID p_probe, float p_distance) {
}

void LightStorage::reflection_probe_set_extents(RID p_probe, const Vector3 &p_extents) {
}

void LightStorage::reflection_probe_set_origin_offset(RID p_probe, const Vector3 &p_offset) {
}

void LightStorage::reflection_probe_set_as_interior(RID p_probe, bool p_enable) {
}

void LightStorage::reflection_probe_set_enable_box_projection(RID p_probe, bool p_enable) {
}

void LightStorage::reflection_probe_set_enable_shadows(RID p_probe, bool p_enable) {
}

void LightStorage::reflection_probe_set_cull_mask(RID p_probe, uint32_t p_layers) {
}

void LightStorage::reflection_probe_set_resolution(RID p_probe, int p_resolution) {
}

AABB LightStorage::reflection_probe_get_aabb(RID p_probe) const {
	return AABB();
}

RS::ReflectionProbeUpdateMode LightStorage::reflection_probe_get_update_mode(RID p_probe) const {
	return RenderingServer::REFLECTION_PROBE_UPDATE_ONCE;
}

uint32_t LightStorage::reflection_probe_get_cull_mask(RID p_probe) const {
	return 0;
}

Vector3 LightStorage::reflection_probe_get_extents(RID p_probe) const {
	return Vector3();
}

Vector3 LightStorage::reflection_probe_get_origin_offset(RID p_probe) const {
	return Vector3();
}

float LightStorage::reflection_probe_get_origin_max_distance(RID p_probe) const {
	return 0.0;
}

bool LightStorage::reflection_probe_renders_shadows(RID p_probe) const {
	return false;
}

void LightStorage::reflection_probe_set_mesh_lod_threshold(RID p_probe, float p_ratio) {
}

float LightStorage::reflection_probe_get_mesh_lod_threshold(RID p_probe) const {
	return 0.0;
}

/* LIGHTMAP CAPTURE */

RID LightStorage::lightmap_allocate() {
	return RID();
}

void LightStorage::lightmap_initialize(RID p_rid) {
}

void LightStorage::lightmap_free(RID p_rid) {
}

void LightStorage::lightmap_set_textures(RID p_lightmap, RID p_light, bool p_uses_spherical_haromics) {
}

void LightStorage::lightmap_set_probe_bounds(RID p_lightmap, const AABB &p_bounds) {
}

void LightStorage::lightmap_set_probe_interior(RID p_lightmap, bool p_interior) {
}

void LightStorage::lightmap_set_probe_capture_data(RID p_lightmap, const PackedVector3Array &p_points, const PackedColorArray &p_point_sh, const PackedInt32Array &p_tetrahedra, const PackedInt32Array &p_bsp_tree) {
}

PackedVector3Array LightStorage::lightmap_get_probe_capture_points(RID p_lightmap) const {
	return PackedVector3Array();
}

PackedColorArray LightStorage::lightmap_get_probe_capture_sh(RID p_lightmap) const {
	return PackedColorArray();
}

PackedInt32Array LightStorage::lightmap_get_probe_capture_tetrahedra(RID p_lightmap) const {
	return PackedInt32Array();
}

PackedInt32Array LightStorage::lightmap_get_probe_capture_bsp_tree(RID p_lightmap) const {
	return PackedInt32Array();
}

AABB LightStorage::lightmap_get_aabb(RID p_lightmap) const {
	return AABB();
}

void LightStorage::lightmap_tap_sh_light(RID p_lightmap, const Vector3 &p_point, Color *r_sh) {
}

bool LightStorage::lightmap_is_interior(RID p_lightmap) const {
	return false;
}

void LightStorage::lightmap_set_probe_capture_update_speed(float p_speed) {
}

float LightStorage::lightmap_get_probe_capture_update_speed() const {
	return 0;
}

/* LIGHT SHADOW MAPPING */
/*

RID LightStorage::canvas_light_occluder_create() {
	CanvasOccluder *co = memnew(CanvasOccluder);
	co->index_id = 0;
	co->vertex_id = 0;
	co->len = 0;

	return canvas_occluder_owner.make_rid(co);
}

void LightStorage::canvas_light_occluder_set_polylines(RID p_occluder, const PoolVector<Vector2> &p_lines) {
	CanvasOccluder *co = canvas_occluder_owner.get(p_occluder);
	ERR_FAIL_COND(!co);

	co->lines = p_lines;

	if (p_lines.size() != co->len) {
		if (co->index_id) {
			glDeleteBuffers(1, &co->index_id);
		} if (co->vertex_id) {
			glDeleteBuffers(1, &co->vertex_id);
		}

		co->index_id = 0;
		co->vertex_id = 0;
		co->len = 0;
	}

	if (p_lines.size()) {
		PoolVector<float> geometry;
		PoolVector<uint16_t> indices;
		int lc = p_lines.size();

		geometry.resize(lc * 6);
		indices.resize(lc * 3);

		PoolVector<float>::Write vw = geometry.write();
		PoolVector<uint16_t>::Write iw = indices.write();

		PoolVector<Vector2>::Read lr = p_lines.read();

		const int POLY_HEIGHT = 16384;

		for (int i = 0; i < lc / 2; i++) {
			vw[i * 12 + 0] = lr[i * 2 + 0].x;
			vw[i * 12 + 1] = lr[i * 2 + 0].y;
			vw[i * 12 + 2] = POLY_HEIGHT;

			vw[i * 12 + 3] = lr[i * 2 + 1].x;
			vw[i * 12 + 4] = lr[i * 2 + 1].y;
			vw[i * 12 + 5] = POLY_HEIGHT;

			vw[i * 12 + 6] = lr[i * 2 + 1].x;
			vw[i * 12 + 7] = lr[i * 2 + 1].y;
			vw[i * 12 + 8] = -POLY_HEIGHT;

			vw[i * 12 + 9] = lr[i * 2 + 0].x;
			vw[i * 12 + 10] = lr[i * 2 + 0].y;
			vw[i * 12 + 11] = -POLY_HEIGHT;

			iw[i * 6 + 0] = i * 4 + 0;
			iw[i * 6 + 1] = i * 4 + 1;
			iw[i * 6 + 2] = i * 4 + 2;

			iw[i * 6 + 3] = i * 4 + 2;
			iw[i * 6 + 4] = i * 4 + 3;
			iw[i * 6 + 5] = i * 4 + 0;
		}

		//if same buffer len is being set, just use BufferSubData to avoid a pipeline flush

		if (!co->vertex_id) {
			glGenBuffers(1, &co->vertex_id);
			glBindBuffer(GL_ARRAY_BUFFER, co->vertex_id);
			glBufferData(GL_ARRAY_BUFFER, lc * 6 * sizeof(real_t), vw.ptr(), GL_STATIC_DRAW);
		} else {
			glBindBuffer(GL_ARRAY_BUFFER, co->vertex_id);
			glBufferSubData(GL_ARRAY_BUFFER, 0, lc * 6 * sizeof(real_t), vw.ptr());
		}

		glBindBuffer(GL_ARRAY_BUFFER, 0); //unbind

		if (!co->index_id) {
			glGenBuffers(1, &co->index_id);
			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, co->index_id);
			glBufferData(GL_ELEMENT_ARRAY_BUFFER, lc * 3 * sizeof(uint16_t), iw.ptr(), GL_DYNAMIC_DRAW);
		} else {
			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, co->index_id);
			glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, lc * 3 * sizeof(uint16_t), iw.ptr());
		}

		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); //unbind

		co->len = lc;
	}
}
*/

#endif // !GLES3_ENABLED