text: /*************************************************************************/
  /*  renderer_compositor_rd.cpp                                           */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
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  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "renderer_compositor_rd.h"
  
  #include "core/config/project_settings.h"
  
  void RendererCompositorRD::prepare_for_blitting_render_targets() {
  	RD::get_singleton()->prepare_screen_for_drawing();
  }
  
  void RendererCompositorRD::blit_render_targets_to_screen(DisplayServer::WindowID p_screen, const BlitToScreen *p_render_targets, int p_amount) {
  	RD::DrawListID draw_list = RD::get_singleton()->draw_list_begin_for_screen(p_screen);
  
  	for (int i = 0; i < p_amount; i++) {
  		RID texture = storage->render_target_get_texture(p_render_targets[i].render_target);
  		ERR_CONTINUE(texture.is_null());
  		RID rd_texture = storage->texture_get_rd_texture(texture);
  		ERR_CONTINUE(rd_texture.is_null());
  		if (!render_target_descriptors.has(rd_texture) || !RD::get_singleton()->uniform_set_is_valid(render_target_descriptors[rd_texture])) {
  			Vector<RD::Uniform> uniforms;
  			RD::Uniform u;
  			u.uniform_type = RD::UNIFORM_TYPE_SAMPLER_WITH_TEXTURE;
  			u.binding = 0;
  			u.ids.push_back(copy_viewports_sampler);
  			u.ids.push_back(rd_texture);
  			uniforms.push_back(u);
  			RID uniform_set = RD::get_singleton()->uniform_set_create(uniforms, copy_viewports_rd_shader, 0);
  
  			render_target_descriptors[rd_texture] = uniform_set;
  		}
  
  		Size2 screen_size(RD::get_singleton()->screen_get_width(p_screen), RD::get_singleton()->screen_get_height(p_screen));
  
  		RD::get_singleton()->draw_list_bind_render_pipeline(draw_list, copy_viewports_rd_pipeline);
  		RD::get_singleton()->draw_list_bind_index_array(draw_list, copy_viewports_rd_array);
  		RD::get_singleton()->draw_list_bind_uniform_set(draw_list, render_target_descriptors[rd_texture], 0);
  
  		float push_constant[4] = {
  			p_render_targets[i].rect.position.x / screen_size.width,
  			p_render_targets[i].rect.position.y / screen_size.height,
  			p_render_targets[i].rect.size.width / screen_size.width,
  			p_render_targets[i].rect.size.height / screen_size.height,
  		};
  		RD::get_singleton()->draw_list_set_push_constant(draw_list, push_constant, 4 * sizeof(float));
  		RD::get_singleton()->draw_list_draw(draw_list, true);
  	}
  
  	RD::get_singleton()->draw_list_end();
  }
  
  void RendererCompositorRD::begin_frame(double frame_step) {
  	frame++;
  	delta = frame_step;
  	time += frame_step;
  
  	double time_roll_over = GLOBAL_GET("rendering/limits/time/time_rollover_secs");
  	time = Math::fmod(time, time_roll_over);
  
  	canvas->set_time(time);
  	scene->set_time(time, frame_step);
  }
  
  void RendererCompositorRD::end_frame(bool p_swap_buffers) {
  #ifndef _MSC_VER
  #warning TODO: likely pass a bool to swap buffers to avoid display?
  #endif
  	RD::get_singleton()->swap_buffers(); //probably should pass some bool to avoid display?
  }
  
  void RendererCompositorRD::initialize() {
  	{ //create framebuffer copy shader
  		RenderingDevice::ShaderStageData vert;
  		vert.shader_stage = RenderingDevice::SHADER_STAGE_VERTEX;
  		vert.spir_v = RenderingDevice::get_singleton()->shader_compile_from_source(RenderingDevice::SHADER_STAGE_VERTEX,
  				"#version 450\n"
  				"layout(push_constant, binding = 0, std140) uniform Pos { vec4 dst_rect; } pos;\n"
  				"layout(location =0) out vec2 uv;\n"
  				"void main() { \n"
  				" vec2 base_arr[4] = vec2[](vec2(0.0,0.0),vec2(0.0,1.0),vec2(1.0,1.0),vec2(1.0,0.0));\n"
  				" uv = base_arr[gl_VertexIndex];\n"
  				" vec2 vtx = pos.dst_rect.xy+uv*pos.dst_rect.zw;\n"
  				" gl_Position = vec4(vtx * 2.0 - 1.0,0.0,1.0);\n"
  				"}\n");
  
  		RenderingDevice::ShaderStageData frag;
  		frag.shader_stage = RenderingDevice::SHADER_STAGE_FRAGMENT;
  		frag.spir_v = RenderingDevice::get_singleton()->shader_compile_from_source(RenderingDevice::SHADER_STAGE_FRAGMENT,
  				"#version 450\n"
  				"layout (location = 0) in vec2 uv;\n"
  				"layout (location = 0) out vec4 color;\n"
  				"layout (binding = 0) uniform sampler2D src_rt;\n"
  				"void main() { color=texture(src_rt,uv); }\n");
  
  		Vector<RenderingDevice::ShaderStageData> source;
  		source.push_back(vert);
  		source.push_back(frag);
  		String error;
  		copy_viewports_rd_shader = RD::get_singleton()->shader_create(source);
  		if (!copy_viewports_rd_shader.is_valid()) {
  			print_line("Failed compilation: " + error);
  		}
  	}
  
  	{ //create index array for copy shader
  		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;
  		}
  		copy_viewports_rd_index_buffer = RD::get_singleton()->index_buffer_create(6, RenderingDevice::INDEX_BUFFER_FORMAT_UINT32, pv);
  		copy_viewports_rd_array = RD::get_singleton()->index_array_create(copy_viewports_rd_index_buffer, 0, 6);
  	}
  
  	{ //pipeline
  		copy_viewports_rd_pipeline = RD::get_singleton()->render_pipeline_create(copy_viewports_rd_shader, RD::get_singleton()->screen_get_framebuffer_format(), RD::INVALID_ID, RD::RENDER_PRIMITIVE_TRIANGLES, RD::PipelineRasterizationState(), RD::PipelineMultisampleState(), RD::PipelineDepthStencilState(), RenderingDevice::PipelineColorBlendState::create_disabled(), 0);
  	}
  	{ // sampler
  		copy_viewports_sampler = RD::get_singleton()->sampler_create(RD::SamplerState());
  	}
  }
  
  uint64_t RendererCompositorRD::frame = 1;
  
  void RendererCompositorRD::finalize() {
  	memdelete(scene);
  	memdelete(canvas);
  	memdelete(storage);
  
  	//only need to erase these, the rest are erased by cascade
  	RD::get_singleton()->free(copy_viewports_rd_index_buffer);
  	RD::get_singleton()->free(copy_viewports_rd_shader);
  	RD::get_singleton()->free(copy_viewports_sampler);
  }
  
  RendererCompositorRD *RendererCompositorRD::singleton = nullptr;
  
  RendererCompositorRD::RendererCompositorRD() {
  	singleton = this;
  	time = 0;
  
  	storage = memnew(RendererStorageRD);
  	canvas = memnew(RendererCanvasRenderRD(storage));
  	scene = memnew(RendererSceneRenderForward(storage));
  }
  