/**************************************************************************/
/*  effects_rd.cpp                                                        */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#include "effects_rd.h"

#include "core/config/project_settings.h"
#include "core/math/math_defs.h"
#include "core/os/os.h"

#include "servers/rendering/renderer_rd/renderer_compositor_rd.h"
#include "thirdparty/misc/cubemap_coeffs.h"

bool EffectsRD::get_prefer_raster_effects() {
	return prefer_raster_effects;
}

RID EffectsRD::_get_uniform_set_from_image(RID p_image) {
	if (image_to_uniform_set_cache.has(p_image)) {
		RID uniform_set = image_to_uniform_set_cache[p_image];
		if (RD::get_singleton()->uniform_set_is_valid(uniform_set)) {
			return uniform_set;
		}
	}
	Vector<RD::Uniform> uniforms;
	RD::Uniform u;
	u.uniform_type = RD::UNIFORM_TYPE_IMAGE;
	u.binding = 0;
	u.append_id(p_image);
	uniforms.push_back(u);
	//any thing with the same configuration (one texture in binding 0 for set 0), is good
	RID uniform_set = RD::get_singleton()->uniform_set_create(uniforms, roughness_limiter.shader.version_get_shader(roughness_limiter.shader_version, 0), 1);

	image_to_uniform_set_cache[p_image] = uniform_set;

	return uniform_set;
}

RID EffectsRD::_get_compute_uniform_set_from_texture(RID p_texture, bool p_use_mipmaps) {
	if (texture_to_compute_uniform_set_cache.has(p_texture)) {
		RID uniform_set = texture_to_compute_uniform_set_cache[p_texture];
		if (RD::get_singleton()->uniform_set_is_valid(uniform_set)) {
			return uniform_set;
		}
	}

	Vector<RD::Uniform> uniforms;
	RD::Uniform u;
	u.uniform_type = RD::UNIFORM_TYPE_SAMPLER_WITH_TEXTURE;
	u.binding = 0;
	u.append_id(p_use_mipmaps ? default_mipmap_sampler : default_sampler);
	u.append_id(p_texture);
	uniforms.push_back(u);
	//any thing with the same configuration (one texture in binding 0 for set 0), is good
	RID uniform_set = RD::get_singleton()->uniform_set_create(uniforms, roughness_limiter.shader.version_get_shader(roughness_limiter.shader_version, 0), 0);

	texture_to_compute_uniform_set_cache[p_texture] = uniform_set;

	return uniform_set;
}

void EffectsRD::roughness_limit(RID p_source_normal, RID p_roughness, const Size2i &p_size, float p_curve) {
	roughness_limiter.push_constant.screen_size[0] = p_size.x;
	roughness_limiter.push_constant.screen_size[1] = p_size.y;
	roughness_limiter.push_constant.curve = p_curve;

	RD::ComputeListID compute_list = RD::get_singleton()->compute_list_begin();
	RD::get_singleton()->compute_list_bind_compute_pipeline(compute_list, roughness_limiter.pipeline);
	RD::get_singleton()->compute_list_bind_uniform_set(compute_list, _get_compute_uniform_set_from_texture(p_source_normal), 0);
	RD::get_singleton()->compute_list_bind_uniform_set(compute_list, _get_uniform_set_from_image(p_roughness), 1);

	RD::get_singleton()->compute_list_set_push_constant(compute_list, &roughness_limiter.push_constant, sizeof(RoughnessLimiterPushConstant)); //not used but set anyway

	RD::get_singleton()->compute_list_dispatch_threads(compute_list, p_size.x, p_size.y, 1);

	RD::get_singleton()->compute_list_end();
}

void EffectsRD::sort_buffer(RID p_uniform_set, int p_size) {
	Sort::PushConstant push_constant;
	push_constant.total_elements = p_size;

	bool done = true;

	int numThreadGroups = ((p_size - 1) >> 9) + 1;

	if (numThreadGroups > 1) {
		done = false;
	}

	RD::ComputeListID compute_list = RD::get_singleton()->compute_list_begin();

	RD::get_singleton()->compute_list_bind_compute_pipeline(compute_list, sort.pipelines[SORT_MODE_BLOCK]);
	RD::get_singleton()->compute_list_bind_uniform_set(compute_list, p_uniform_set, 1);
	RD::get_singleton()->compute_list_set_push_constant(compute_list, &push_constant, sizeof(Sort::PushConstant));
	RD::get_singleton()->compute_list_dispatch(compute_list, numThreadGroups, 1, 1);

	int presorted = 512;

	while (!done) {
		RD::get_singleton()->compute_list_add_barrier(compute_list);

		done = true;
		RD::get_singleton()->compute_list_bind_compute_pipeline(compute_list, sort.pipelines[SORT_MODE_STEP]);

		numThreadGroups = 0;

		if (p_size > presorted) {
			if (p_size > presorted * 2) {
				done = false;
			}

			int pow2 = presorted;
			while (pow2 < p_size) {
				pow2 *= 2;
			}
			numThreadGroups = pow2 >> 9;
		}

		unsigned int nMergeSize = presorted * 2;

		for (unsigned int nMergeSubSize = nMergeSize >> 1; nMergeSubSize > 256; nMergeSubSize = nMergeSubSize >> 1) {
			push_constant.job_params[0] = nMergeSubSize;
			if (nMergeSubSize == nMergeSize >> 1) {
				push_constant.job_params[1] = (2 * nMergeSubSize - 1);
				push_constant.job_params[2] = -1;
			} else {
				push_constant.job_params[1] = nMergeSubSize;
				push_constant.job_params[2] = 1;
			}
			push_constant.job_params[3] = 0;

			RD::get_singleton()->compute_list_set_push_constant(compute_list, &push_constant, sizeof(Sort::PushConstant));
			RD::get_singleton()->compute_list_dispatch(compute_list, numThreadGroups, 1, 1);
			RD::get_singleton()->compute_list_add_barrier(compute_list);
		}

		RD::get_singleton()->compute_list_bind_compute_pipeline(compute_list, sort.pipelines[SORT_MODE_INNER]);
		RD::get_singleton()->compute_list_set_push_constant(compute_list, &push_constant, sizeof(Sort::PushConstant));
		RD::get_singleton()->compute_list_dispatch(compute_list, numThreadGroups, 1, 1);

		presorted *= 2;
	}

	RD::get_singleton()->compute_list_end();
}

EffectsRD::EffectsRD(bool p_prefer_raster_effects) {
	prefer_raster_effects = p_prefer_raster_effects;

	if (!prefer_raster_effects) {
		// Initialize roughness limiter
		Vector<String> shader_modes;
		shader_modes.push_back("");

		roughness_limiter.shader.initialize(shader_modes);

		roughness_limiter.shader_version = roughness_limiter.shader.version_create();

		roughness_limiter.pipeline = RD::get_singleton()->compute_pipeline_create(roughness_limiter.shader.version_get_shader(roughness_limiter.shader_version, 0));
	}

	{
		Vector<String> sort_modes;
		sort_modes.push_back("\n#define MODE_SORT_BLOCK\n");
		sort_modes.push_back("\n#define MODE_SORT_STEP\n");
		sort_modes.push_back("\n#define MODE_SORT_INNER\n");

		sort.shader.initialize(sort_modes);

		sort.shader_version = sort.shader.version_create();

		for (int i = 0; i < SORT_MODE_MAX; i++) {
			sort.pipelines[i] = RD::get_singleton()->compute_pipeline_create(sort.shader.version_get_shader(sort.shader_version, i));
		}
	}

	RD::SamplerState sampler;
	sampler.mag_filter = RD::SAMPLER_FILTER_LINEAR;
	sampler.min_filter = RD::SAMPLER_FILTER_LINEAR;
	sampler.max_lod = 0;

	default_sampler = RD::get_singleton()->sampler_create(sampler);
	RD::get_singleton()->set_resource_name(default_sampler, "Default Linear Sampler");

	sampler.min_filter = RD::SAMPLER_FILTER_LINEAR;
	sampler.mip_filter = RD::SAMPLER_FILTER_LINEAR;
	sampler.max_lod = 1e20;

	default_mipmap_sampler = RD::get_singleton()->sampler_create(sampler);
	RD::get_singleton()->set_resource_name(default_mipmap_sampler, "Default MipMap Sampler");

	{ //create index array for copy shaders
		Vector<uint8_t> pv;
		pv.resize(6 * 4);
		{
			uint8_t *w = pv.ptrw();
			int *p32 = (int *)w;
			p32[0] = 0;
			p32[1] = 1;
			p32[2] = 2;
			p32[3] = 0;
			p32[4] = 2;
			p32[5] = 3;
		}
		index_buffer = RD::get_singleton()->index_buffer_create(6, RenderingDevice::INDEX_BUFFER_FORMAT_UINT32, pv);
		index_array = RD::get_singleton()->index_array_create(index_buffer, 0, 6);
	}
}

EffectsRD::~EffectsRD() {
	RD::get_singleton()->free(default_sampler);
	RD::get_singleton()->free(default_mipmap_sampler);
	RD::get_singleton()->free(index_buffer); //array gets freed as dependency

	if (!prefer_raster_effects) {
		roughness_limiter.shader.version_free(roughness_limiter.shader_version);
	}
	sort.shader.version_free(sort.shader_version);
}