/*************************************************************************/
/*  utilities.cpp                                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
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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 "utilities.h"
#include "config.h"
#include "light_storage.h"
#include "material_storage.h"
#include "mesh_storage.h"
#include "particles_storage.h"
#include "texture_storage.h"

#include "servers/rendering/rendering_server_globals.h"

using namespace GLES3;

Utilities *Utilities::singleton = nullptr;

Utilities::Utilities() {
	singleton = this;
	frame = 0;
	for (int i = 0; i < FRAME_COUNT; i++) {
		frames[i].index = 0;
		glGenQueries(max_timestamp_query_elements, frames[i].queries);

		frames[i].timestamp_names.resize(max_timestamp_query_elements);
		frames[i].timestamp_cpu_values.resize(max_timestamp_query_elements);
		frames[i].timestamp_count = 0;

		frames[i].timestamp_result_names.resize(max_timestamp_query_elements);
		frames[i].timestamp_cpu_result_values.resize(max_timestamp_query_elements);
		frames[i].timestamp_result_values.resize(max_timestamp_query_elements);
		frames[i].timestamp_result_count = 0;
	}
}

Utilities::~Utilities() {
	singleton = nullptr;
	for (int i = 0; i < FRAME_COUNT; i++) {
		glDeleteQueries(max_timestamp_query_elements, frames[i].queries);
	}
}

Vector<uint8_t> Utilities::buffer_get_data(GLenum p_target, GLuint p_buffer, uint32_t p_buffer_size) {
	Vector<uint8_t> ret;

	if (p_buffer_size == 0) {
		return ret;
	}

	ret.resize(p_buffer_size);
	glBindBuffer(p_target, p_buffer);

#if defined(__EMSCRIPTEN__)
	{
		uint8_t *w = ret.ptrw();
		glGetBufferSubData(p_target, 0, p_buffer_size, w);
	}
#else
	void *data = glMapBufferRange(p_target, 0, p_buffer_size, GL_MAP_READ_BIT);
	ERR_FAIL_NULL_V(data, Vector<uint8_t>());
	{
		uint8_t *w = ret.ptrw();
		memcpy(w, data, p_buffer_size);
	}
	glUnmapBuffer(p_target);
#endif
	glBindBuffer(p_target, 0);
	return ret;
}

/* INSTANCES */

RS::InstanceType Utilities::get_base_type(RID p_rid) const {
	if (GLES3::MeshStorage::get_singleton()->owns_mesh(p_rid)) {
		return RS::INSTANCE_MESH;
	} else if (GLES3::MeshStorage::get_singleton()->owns_multimesh(p_rid)) {
		return RS::INSTANCE_MULTIMESH;
	} else if (GLES3::LightStorage::get_singleton()->owns_light(p_rid)) {
		return RS::INSTANCE_LIGHT;
	} else if (GLES3::LightStorage::get_singleton()->owns_lightmap(p_rid)) {
		return RS::INSTANCE_LIGHTMAP;
	}
	return RS::INSTANCE_NONE;
}

bool Utilities::free(RID p_rid) {
	if (GLES3::TextureStorage::get_singleton()->owns_render_target(p_rid)) {
		GLES3::TextureStorage::get_singleton()->render_target_free(p_rid);
		return true;
	} else if (GLES3::TextureStorage::get_singleton()->owns_texture(p_rid)) {
		GLES3::TextureStorage::get_singleton()->texture_free(p_rid);
		return true;
	} else if (GLES3::TextureStorage::get_singleton()->owns_canvas_texture(p_rid)) {
		GLES3::TextureStorage::get_singleton()->canvas_texture_free(p_rid);
		return true;
	} else if (GLES3::MaterialStorage::get_singleton()->owns_shader(p_rid)) {
		GLES3::MaterialStorage::get_singleton()->shader_free(p_rid);
		return true;
	} else if (GLES3::MaterialStorage::get_singleton()->owns_material(p_rid)) {
		GLES3::MaterialStorage::get_singleton()->material_free(p_rid);
		return true;
	} else if (GLES3::MeshStorage::get_singleton()->owns_mesh(p_rid)) {
		GLES3::MeshStorage::get_singleton()->mesh_free(p_rid);
		return true;
	} else if (GLES3::MeshStorage::get_singleton()->owns_multimesh(p_rid)) {
		GLES3::MeshStorage::get_singleton()->multimesh_free(p_rid);
		return true;
	} else if (GLES3::MeshStorage::get_singleton()->owns_mesh_instance(p_rid)) {
		GLES3::MeshStorage::get_singleton()->mesh_instance_free(p_rid);
		return true;
	} else if (GLES3::LightStorage::get_singleton()->owns_light(p_rid)) {
		GLES3::LightStorage::get_singleton()->light_free(p_rid);
		return true;
	} else if (GLES3::LightStorage::get_singleton()->owns_lightmap(p_rid)) {
		GLES3::LightStorage::get_singleton()->lightmap_free(p_rid);
		return true;
	} else {
		return false;
	}
	/*
	else if (reflection_probe_owner.owns(p_rid)) {
		// delete the texture
		ReflectionProbe *reflection_probe = reflection_probe_owner.get_or_null(p_rid);
		reflection_probe->instance_remove_deps();

		reflection_probe_owner.free(p_rid);
		memdelete(reflection_probe);

		return true;
	} else if (lightmap_capture_data_owner.owns(p_rid)) {
		// delete the texture
		LightmapCapture *lightmap_capture = lightmap_capture_data_owner.get_or_null(p_rid);
		lightmap_capture->instance_remove_deps();

		lightmap_capture_data_owner.free(p_rid);
		memdelete(lightmap_capture);
		return true;

	} else if (canvas_occluder_owner.owns(p_rid)) {
		CanvasOccluder *co = canvas_occluder_owner.get_or_null(p_rid);
		if (co->index_id) {
			glDeleteBuffers(1, &co->index_id);
		}
		if (co->vertex_id) {
			glDeleteBuffers(1, &co->vertex_id);
		}

		canvas_occluder_owner.free(p_rid);
		memdelete(co);

		return true;

	} else if (canvas_light_shadow_owner.owns(p_rid)) {
		CanvasLightShadow *cls = canvas_light_shadow_owner.get_or_null(p_rid);
		glDeleteFramebuffers(1, &cls->fbo);
		glDeleteRenderbuffers(1, &cls->depth);
		glDeleteTextures(1, &cls->distance);
		canvas_light_shadow_owner.free(p_rid);
		memdelete(cls);

		return true;
	}
	*/
}

/* DEPENDENCIES */

void Utilities::base_update_dependency(RID p_base, DependencyTracker *p_instance) {
	if (MeshStorage::get_singleton()->owns_mesh(p_base)) {
		Mesh *mesh = MeshStorage::get_singleton()->get_mesh(p_base);
		p_instance->update_dependency(&mesh->dependency);
	} else if (MeshStorage::get_singleton()->owns_multimesh(p_base)) {
		MultiMesh *multimesh = MeshStorage::get_singleton()->get_multimesh(p_base);
		p_instance->update_dependency(&multimesh->dependency);
		if (multimesh->mesh.is_valid()) {
			base_update_dependency(multimesh->mesh, p_instance);
		}
	} else if (LightStorage::get_singleton()->owns_light(p_base)) {
		Light *l = LightStorage::get_singleton()->get_light(p_base);
		p_instance->update_dependency(&l->dependency);
	}
}

/* VISIBILITY NOTIFIER */

RID Utilities::visibility_notifier_allocate() {
	return RID();
}

void Utilities::visibility_notifier_initialize(RID p_notifier) {
}

void Utilities::visibility_notifier_free(RID p_notifier) {
}

void Utilities::visibility_notifier_set_aabb(RID p_notifier, const AABB &p_aabb) {
}

void Utilities::visibility_notifier_set_callbacks(RID p_notifier, const Callable &p_enter_callbable, const Callable &p_exit_callable) {
}

AABB Utilities::visibility_notifier_get_aabb(RID p_notifier) const {
	return AABB();
}

void Utilities::visibility_notifier_call(RID p_notifier, bool p_enter, bool p_deferred) {
}

/* TIMING */

void Utilities::capture_timestamps_begin() {
	capture_timestamp("Frame Begin");
}

void Utilities::capture_timestamp(const String &p_name) {
	ERR_FAIL_COND(frames[frame].timestamp_count >= max_timestamp_query_elements);

#ifdef GLES_OVER_GL
	glQueryCounter(frames[frame].queries[frames[frame].timestamp_count], GL_TIMESTAMP);
#endif

	frames[frame].timestamp_names[frames[frame].timestamp_count] = p_name;
	frames[frame].timestamp_cpu_values[frames[frame].timestamp_count] = OS::get_singleton()->get_ticks_usec();
	frames[frame].timestamp_count++;
}

void Utilities::_capture_timestamps_begin() {
	// frame is incremented at the end of the frame so this gives us the queries for frame - 2. By then they should be ready.
	if (frames[frame].timestamp_count) {
#ifdef GLES_OVER_GL
		for (uint32_t i = 0; i < frames[frame].timestamp_count; i++) {
			uint64_t temp = 0;
			glGetQueryObjectui64v(frames[frame].queries[i], GL_QUERY_RESULT, &temp);
			frames[frame].timestamp_result_values[i] = temp;
		}
#endif
		SWAP(frames[frame].timestamp_names, frames[frame].timestamp_result_names);
		SWAP(frames[frame].timestamp_cpu_values, frames[frame].timestamp_cpu_result_values);
	}

	frames[frame].timestamp_result_count = frames[frame].timestamp_count;
	frames[frame].timestamp_count = 0;
	frames[frame].index = Engine::get_singleton()->get_frames_drawn();
	capture_timestamp("Internal Begin");
}

void Utilities::capture_timestamps_end() {
	capture_timestamp("Internal End");
	frame = (frame + 1) % FRAME_COUNT;
}

uint32_t Utilities::get_captured_timestamps_count() const {
	return frames[frame].timestamp_result_count;
}

uint64_t Utilities::get_captured_timestamps_frame() const {
	return frames[frame].index;
}

uint64_t Utilities::get_captured_timestamp_gpu_time(uint32_t p_index) const {
	ERR_FAIL_UNSIGNED_INDEX_V(p_index, frames[frame].timestamp_result_count, 0);
	return frames[frame].timestamp_result_values[p_index];
}

uint64_t Utilities::get_captured_timestamp_cpu_time(uint32_t p_index) const {
	ERR_FAIL_UNSIGNED_INDEX_V(p_index, frames[frame].timestamp_result_count, 0);
	return frames[frame].timestamp_cpu_result_values[p_index];
}

String Utilities::get_captured_timestamp_name(uint32_t p_index) const {
	ERR_FAIL_UNSIGNED_INDEX_V(p_index, frames[frame].timestamp_result_count, String());
	return frames[frame].timestamp_result_names[p_index];
}

/* MISC */

void Utilities::update_dirty_resources() {
	MaterialStorage::get_singleton()->_update_global_shader_uniforms();
	MaterialStorage::get_singleton()->_update_queued_materials();
	//MeshStorage::get_singleton()->_update_dirty_skeletons();
	MeshStorage::get_singleton()->_update_dirty_multimeshes();
	TextureStorage::get_singleton()->update_texture_atlas();
}

void Utilities::set_debug_generate_wireframes(bool p_generate) {
}

bool Utilities::has_os_feature(const String &p_feature) const {
	Config *config = Config::get_singleton();
	if (!config) {
		return false;
	}

	if (p_feature == "rgtc") {
		return config->rgtc_supported;
	}

	if (p_feature == "s3tc") {
		return config->s3tc_supported;
	}

	if (p_feature == "bptc") {
		return config->bptc_supported;
	}

	if (p_feature == "etc" || p_feature == "etc2") {
		return config->etc2_supported;
	}

	return false;
}

void Utilities::update_memory_info() {
}

uint64_t Utilities::get_rendering_info(RS::RenderingInfo p_info) {
	return 0;
}

String Utilities::get_video_adapter_name() const {
	return (const char *)glGetString(GL_RENDERER);
}

String Utilities::get_video_adapter_vendor() const {
	return (const char *)glGetString(GL_VENDOR);
}

RenderingDevice::DeviceType Utilities::get_video_adapter_type() const {
	return RenderingDevice::DeviceType::DEVICE_TYPE_OTHER;
}

String Utilities::get_video_adapter_api_version() const {
	return (const char *)glGetString(GL_VERSION);
}

Size2i Utilities::get_maximum_viewport_size() const {
	Config *config = Config::get_singleton();
	if (!config) {
		return Size2i();
	}

	return Size2i(config->max_viewport_size[0], config->max_viewport_size[1]);
}

#endif // GLES3_ENABLED