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534 lines
21 KiB
C++
534 lines
21 KiB
C++
// CRTOpenGL.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 03/02/2016.
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// Copyright 2016 Thomas Harte. All rights reserved.
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//
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#include "../CRT.hpp"
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#include <cassert>
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#include <cmath>
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#include <cstdlib>
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#include "CRTOpenGL.hpp"
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#include "../../../SignalProcessing/FIRFilter.hpp"
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#include "Shaders/OutputShader.hpp"
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using namespace Outputs::CRT;
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namespace {
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static const GLenum source_data_texture_unit = GL_TEXTURE0;
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static const GLenum pixel_accumulation_texture_unit = GL_TEXTURE1;
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static const GLenum composite_texture_unit = GL_TEXTURE2;
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static const GLenum separated_texture_unit = GL_TEXTURE3;
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static const GLenum filtered_texture_unit = GL_TEXTURE4;
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static const GLenum work_texture_unit = GL_TEXTURE2;
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}
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OpenGLOutputBuilder::OpenGLOutputBuilder(std::size_t bytes_per_pixel) :
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visible_area_(Rect(0, 0, 1, 1)),
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composite_src_output_y_(0),
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last_output_width_(0),
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last_output_height_(0),
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fence_(nullptr),
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texture_builder(bytes_per_pixel, source_data_texture_unit),
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array_builder(SourceVertexBufferDataSize, OutputVertexBufferDataSize) {
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glBlendFunc(GL_SRC_ALPHA, GL_CONSTANT_COLOR);
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glBlendColor(0.4f, 0.4f, 0.4f, 1.0f);
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// create the output vertex array
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glGenVertexArrays(1, &output_vertex_array_);
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// create the source vertex array
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glGenVertexArrays(1, &source_vertex_array_);
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// bool supports_texture_barrier = false;
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#ifdef GL_NV_texture_barrier
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// GLint number_of_extensions;
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// glGetIntegerv(GL_NUM_EXTENSIONS, &number_of_extensions);
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//
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// for(GLuint c = 0; c < (GLuint)number_of_extensions; c++) {
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// const char *extension_name = (const char *)glGetStringi(GL_EXTENSIONS, c);
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// if(!std::strcmp(extension_name, "GL_NV_texture_barrier")) {
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// supports_texture_barrier = true;
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// }
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// }
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#endif
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// if(supports_texture_barrier) {
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// work_texture_.reset(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight*2, work_texture_unit));
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// } else {
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composite_texture_.reset(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight, composite_texture_unit, GL_NEAREST));
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separated_texture_.reset(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight, separated_texture_unit, GL_NEAREST));
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filtered_texture_.reset(new OpenGL::TextureTarget(IntermediateBufferWidth, IntermediateBufferHeight, filtered_texture_unit, GL_LINEAR));
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// }
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}
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OpenGLOutputBuilder::~OpenGLOutputBuilder() {
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glDeleteVertexArrays(1, &output_vertex_array_);
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}
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void OpenGLOutputBuilder::set_target_framebuffer(GLint target_framebuffer) {
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target_framebuffer_ = target_framebuffer;
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}
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void OpenGLOutputBuilder::draw_frame(unsigned int output_width, unsigned int output_height, bool only_if_dirty) {
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// lock down any other draw_frames
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draw_mutex_.lock();
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// establish essentials
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if(!output_shader_program_) {
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prepare_composite_input_shaders();
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prepare_svideo_input_shaders();
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prepare_rgb_input_shaders();
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prepare_source_vertex_array();
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prepare_output_shader();
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prepare_output_vertex_array();
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set_timing_uniforms();
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set_colour_space_uniforms();
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set_gamma();
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}
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if(fence_ != nullptr) {
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// if the GPU is still busy, don't wait; we'll catch it next time
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if(glClientWaitSync(fence_, GL_SYNC_FLUSH_COMMANDS_BIT, only_if_dirty ? 0 : GL_TIMEOUT_IGNORED) == GL_TIMEOUT_EXPIRED) {
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draw_mutex_.unlock();
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return;
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}
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glDeleteSync(fence_);
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}
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// make sure everything is bound
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composite_texture_->bind_texture();
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separated_texture_->bind_texture();
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filtered_texture_->bind_texture();
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if(work_texture_) work_texture_->bind_texture();
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// make sure there's a target to draw to
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if(!framebuffer_ || static_cast<unsigned int>(framebuffer_->get_height()) != output_height || static_cast<unsigned int>(framebuffer_->get_width()) != output_width) {
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std::unique_ptr<OpenGL::TextureTarget> new_framebuffer(new OpenGL::TextureTarget((GLsizei)output_width, (GLsizei)output_height, pixel_accumulation_texture_unit, GL_LINEAR));
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if(framebuffer_) {
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new_framebuffer->bind_framebuffer();
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glClear(GL_COLOR_BUFFER_BIT);
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glActiveTexture(pixel_accumulation_texture_unit);
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framebuffer_->bind_texture();
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framebuffer_->draw(static_cast<float>(output_width) / static_cast<float>(output_height));
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new_framebuffer->bind_texture();
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}
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framebuffer_ = std::move(new_framebuffer);
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}
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// lock out the machine emulation until data is copied
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output_mutex_.lock();
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// release the mapping, giving up on trying to draw if data has been lost
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ArrayBuilder::Submission array_submission = array_builder.submit();
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// upload new source pixels, if any
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glActiveTexture(source_data_texture_unit);
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texture_builder.bind();
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texture_builder.submit();
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// buffer usage restart from 0 for the next time around
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composite_src_output_y_ = 0;
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// data having been grabbed, allow the machine to continue
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output_mutex_.unlock();
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struct RenderStage {
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OpenGL::Shader *const shader;
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OpenGL::TextureTarget *const target;
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float clear_colour[3];
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};
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// for composite video, go through four steps to get to something that can be painted to the output
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const RenderStage composite_render_stages[] = {
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{composite_input_shader_program_.get(), composite_texture_.get(), {0.0, 0.0, 0.0}},
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{composite_separation_filter_program_.get(), separated_texture_.get(), {0.0, 0.5, 0.5}},
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{composite_chrominance_filter_shader_program_.get(), filtered_texture_.get(), {0.0, 0.0, 0.0}},
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{nullptr, nullptr}
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};
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// for s-video, there are two steps: it's like composite but skips separation
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const RenderStage svideo_render_stages[] = {
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{svideo_input_shader_program_.get(), separated_texture_.get(), {0.0, 0.5, 0.5}},
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{composite_chrominance_filter_shader_program_.get(), filtered_texture_.get(), {0.0, 0.0, 0.0}},
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{nullptr, nullptr}
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};
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// for RGB video, there's also only two steps; a lowpass filter is still applied per physical reality
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const RenderStage rgb_render_stages[] = {
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{rgb_input_shader_program_.get(), composite_texture_.get(), {0.0, 0.0, 0.0}},
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{rgb_filter_shader_program_.get(), filtered_texture_.get(), {0.0, 0.0, 0.0}},
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{nullptr, nullptr}
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};
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const RenderStage *active_pipeline;
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switch(video_signal_) {
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default:
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case VideoSignal::Composite: active_pipeline = composite_render_stages; break;
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case VideoSignal::SVideo: active_pipeline = svideo_render_stages; break;
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case VideoSignal::RGB: active_pipeline = rgb_render_stages; break;
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}
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if(array_submission.input_size || array_submission.output_size) {
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// all drawing will be from the source vertex array and without blending
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glBindVertexArray(source_vertex_array_);
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glDisable(GL_BLEND);
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#ifdef GL_NV_texture_barrier
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// if(work_texture_) {
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// work_texture_->bind_framebuffer();
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// glClear(GL_COLOR_BUFFER_BIT);
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// }
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#endif
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while(active_pipeline->shader) {
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// switch to the framebuffer and shader associated with this stage
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active_pipeline->shader->bind();
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if(!work_texture_) {
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active_pipeline->target->bind_framebuffer();
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// if this is the final stage before painting to the CRT, clear the framebuffer before drawing in order to blank out
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// those portions for which no input was provided
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// if(!active_pipeline[1].shader) {
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glClearColor(active_pipeline->clear_colour[0], active_pipeline->clear_colour[1], active_pipeline->clear_colour[2], 1.0f);
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glClear(GL_COLOR_BUFFER_BIT);
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// }
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}
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// draw
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glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, (GLsizei)array_submission.input_size / SourceVertexSize);
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active_pipeline++;
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#ifdef GL_NV_texture_barrier
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// glTextureBarrierNV();
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#endif
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}
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// prepare to transfer to framebuffer
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framebuffer_->bind_framebuffer();
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// draw from the output array buffer, with blending
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glBindVertexArray(output_vertex_array_);
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glEnable(GL_BLEND);
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// update uniforms, then bind the target
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if(last_output_width_ != output_width || last_output_height_ != output_height) {
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output_shader_program_->set_output_size(output_width, output_height, visible_area_);
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last_output_width_ = output_width;
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last_output_height_ = output_height;
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// Configure a right gutter to crop the right-hand 2% of the display.
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right_overlay_.reset(new OpenGL::Rectangle(output_shader_program_->get_right_extent() * 0.98f, -1.0f, 1.0f, 2.0f));
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}
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output_shader_program_->bind();
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// draw
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glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, (GLsizei)array_submission.output_size / OutputVertexSize);
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// mask off the gutter
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glDisable(GL_BLEND);
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right_overlay_->draw(0.0, 0.0, 0.0);
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}
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#ifdef GL_NV_texture_barrier
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// glTextureBarrierNV();
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#endif
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// Copy framebuffer to the intended place; apply a threshold so that any persistent errors in
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// the lower part of the colour channels are invisible.
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glDisable(GL_BLEND);
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glBindFramebuffer(GL_FRAMEBUFFER, static_cast<GLuint>(target_framebuffer_));
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glViewport(0, 0, (GLsizei)output_width, (GLsizei)output_height);
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glActiveTexture(pixel_accumulation_texture_unit);
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framebuffer_->bind_texture();
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framebuffer_->draw(static_cast<float>(output_width) / static_cast<float>(output_height), 4.0f / 255.0f);
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fence_ = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
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draw_mutex_.unlock();
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}
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void OpenGLOutputBuilder::reset_all_OpenGL_state() {
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composite_input_shader_program_ = nullptr;
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composite_separation_filter_program_ = nullptr;
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composite_chrominance_filter_shader_program_ = nullptr;
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svideo_input_shader_program_ = nullptr;
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rgb_input_shader_program_ = nullptr;
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rgb_filter_shader_program_ = nullptr;
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output_shader_program_ = nullptr;
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framebuffer_ = nullptr;
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last_output_width_ = last_output_height_ = 0;
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}
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void OpenGLOutputBuilder::set_openGL_context_will_change(bool should_delete_resources) {
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output_mutex_.lock();
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reset_all_OpenGL_state();
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output_mutex_.unlock();
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}
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void OpenGLOutputBuilder::set_composite_sampling_function(const std::string &shader) {
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std::lock_guard<std::mutex> lock_guard(output_mutex_);
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composite_shader_ = shader;
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reset_all_OpenGL_state();
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}
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void OpenGLOutputBuilder::set_svideo_sampling_function(const std::string &shader) {
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std::lock_guard<std::mutex> lock_guard(output_mutex_);
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svideo_shader_ = shader;
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reset_all_OpenGL_state();
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}
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void OpenGLOutputBuilder::set_rgb_sampling_function(const std::string &shader) {
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std::lock_guard<std::mutex> lock_guard(output_mutex_);
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rgb_shader_ = shader;
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reset_all_OpenGL_state();
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}
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// MARK: - Program compilation
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void OpenGLOutputBuilder::prepare_composite_input_shaders() {
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composite_input_shader_program_ = OpenGL::IntermediateShader::make_composite_source_shader(composite_shader_, svideo_shader_, rgb_shader_);
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composite_input_shader_program_->set_source_texture_unit(source_data_texture_unit);
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composite_input_shader_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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composite_separation_filter_program_ = OpenGL::IntermediateShader::make_chroma_luma_separation_shader();
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composite_separation_filter_program_->set_source_texture_unit(work_texture_ ? work_texture_unit : composite_texture_unit);
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composite_separation_filter_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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composite_chrominance_filter_shader_program_ = OpenGL::IntermediateShader::make_chroma_filter_shader();
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composite_chrominance_filter_shader_program_->set_source_texture_unit(work_texture_ ? work_texture_unit : separated_texture_unit);
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composite_chrominance_filter_shader_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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// TODO: the below is related to texture fencing, which is not yet implemented correctly, so not yet enabled.
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if(work_texture_) {
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composite_input_shader_program_->set_is_double_height(true, 0.0f, 0.0f);
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composite_separation_filter_program_->set_is_double_height(true, 0.0f, 0.5f);
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composite_chrominance_filter_shader_program_->set_is_double_height(true, 0.5f, 0.0f);
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} else {
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composite_input_shader_program_->set_is_double_height(false);
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composite_separation_filter_program_->set_is_double_height(false);
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composite_chrominance_filter_shader_program_->set_is_double_height(false);
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}
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}
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void OpenGLOutputBuilder::prepare_svideo_input_shaders() {
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if(!svideo_shader_.empty() || !rgb_shader_.empty()) {
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svideo_input_shader_program_ = OpenGL::IntermediateShader::make_svideo_source_shader(svideo_shader_, rgb_shader_);
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svideo_input_shader_program_->set_source_texture_unit(source_data_texture_unit);
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svideo_input_shader_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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// TODO: the below is related to texture fencing, which is not yet implemented correctly, so not yet enabled.
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if(work_texture_) {
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svideo_input_shader_program_->set_is_double_height(true, 0.0f, 0.0f);
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} else {
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svideo_input_shader_program_->set_is_double_height(false);
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}
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}
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}
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void OpenGLOutputBuilder::prepare_rgb_input_shaders() {
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if(!rgb_shader_.empty()) {
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rgb_input_shader_program_ = OpenGL::IntermediateShader::make_rgb_source_shader(rgb_shader_);
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rgb_input_shader_program_->set_source_texture_unit(source_data_texture_unit);
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rgb_input_shader_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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rgb_filter_shader_program_ = OpenGL::IntermediateShader::make_rgb_filter_shader();
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rgb_filter_shader_program_->set_source_texture_unit(composite_texture_unit);
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rgb_filter_shader_program_->set_output_size(IntermediateBufferWidth, IntermediateBufferHeight);
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}
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}
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void OpenGLOutputBuilder::prepare_source_vertex_array() {
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if(composite_input_shader_program_ || svideo_input_shader_program_) {
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glBindVertexArray(source_vertex_array_);
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array_builder.bind_input();
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}
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using Shader = OpenGL::IntermediateShader;
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OpenGL::IntermediateShader *const shaders[] = {
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composite_input_shader_program_.get(),
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svideo_input_shader_program_.get()
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};
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for(int c = 0; c < 2; ++c) {
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if(!shaders[c]) continue;
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shaders[c]->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::InputStart),
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2, GL_UNSIGNED_SHORT, GL_FALSE, SourceVertexSize,
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(void *)SourceVertexOffsetOfInputStart, 1);
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shaders[c]->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::OutputStart),
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2, GL_UNSIGNED_SHORT, GL_FALSE, SourceVertexSize,
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(void *)SourceVertexOffsetOfOutputStart, 1);
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shaders[c]->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::Ends),
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2, GL_UNSIGNED_SHORT, GL_FALSE, SourceVertexSize,
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(void *)SourceVertexOffsetOfEnds, 1);
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shaders[c]->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::PhaseTimeAndAmplitude),
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3, GL_UNSIGNED_BYTE, GL_FALSE, SourceVertexSize,
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(void *)SourceVertexOffsetOfPhaseTimeAndAmplitude, 1);
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}
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}
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void OpenGLOutputBuilder::prepare_output_shader() {
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output_shader_program_ = OpenGL::OutputShader::make_shader("", "texture(texID, srcCoordinatesVarying).rgb", false);
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output_shader_program_->set_source_texture_unit(work_texture_ ? work_texture_unit : filtered_texture_unit);
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// output_shader_program_->set_source_texture_unit(composite_texture_unit);
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output_shader_program_->set_origin_is_double_height(!!work_texture_);
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}
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void OpenGLOutputBuilder::prepare_output_vertex_array() {
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if(output_shader_program_) {
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glBindVertexArray(output_vertex_array_);
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array_builder.bind_output();
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using Shader = OpenGL::OutputShader;
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output_shader_program_->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::Horizontal),
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2, GL_UNSIGNED_SHORT, GL_FALSE, OutputVertexSize,
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(void *)OutputVertexOffsetOfHorizontal, 1);
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output_shader_program_->enable_vertex_attribute_with_pointer(
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Shader::get_input_name(Shader::Input::Vertical),
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2, GL_UNSIGNED_SHORT, GL_FALSE, OutputVertexSize,
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(void *)OutputVertexOffsetOfVertical, 1);
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}
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}
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// MARK: - Public Configuration
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void OpenGLOutputBuilder::set_video_signal(VideoSignal video_signal) {
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if(video_signal_ != video_signal) {
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video_signal_ = video_signal;
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composite_src_output_y_ = 0;
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last_output_width_ = 0;
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last_output_height_ = 0;
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set_output_shader_width();
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}
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}
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void OpenGLOutputBuilder::set_timing(unsigned int input_frequency, unsigned int cycles_per_line, unsigned int height_of_display, unsigned int horizontal_scan_period, unsigned int vertical_scan_period, unsigned int vertical_period_divider) {
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std::lock_guard<std::mutex> lock_guard(output_mutex_);
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input_frequency_ = input_frequency;
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cycles_per_line_ = cycles_per_line;
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height_of_display_ = height_of_display;
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horizontal_scan_period_ = horizontal_scan_period;
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vertical_scan_period_ = vertical_scan_period;
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vertical_period_divider_ = vertical_period_divider;
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set_timing_uniforms();
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}
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// MARK: - Internal Configuration
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void OpenGLOutputBuilder::set_colour_space_uniforms() {
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GLfloat rgbToYUV[] = {0.299f, -0.14713f, 0.615f, 0.587f, -0.28886f, -0.51499f, 0.114f, 0.436f, -0.10001f};
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GLfloat yuvToRGB[] = {1.0f, 1.0f, 1.0f, 0.0f, -0.39465f, 2.03211f, 1.13983f, -0.58060f, 0.0f};
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GLfloat rgbToYIQ[] = {0.299f, 0.596f, 0.211f, 0.587f, -0.274f, -0.523f, 0.114f, -0.322f, 0.312f};
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GLfloat yiqToRGB[] = {1.0f, 1.0f, 1.0f, 0.956f, -0.272f, -1.106f, 0.621f, -0.647f, 1.703f};
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GLfloat *fromRGB = nullptr, *toRGB = nullptr;
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switch(colour_space_) {
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case ColourSpace::YIQ:
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fromRGB = rgbToYIQ;
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toRGB = yiqToRGB;
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break;
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case ColourSpace::YUV:
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fromRGB = rgbToYUV;
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toRGB = yuvToRGB;
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break;
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default: assert(false); break;
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}
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if(composite_input_shader_program_) composite_input_shader_program_->set_colour_conversion_matrices(fromRGB, toRGB);
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if(composite_separation_filter_program_) composite_separation_filter_program_->set_colour_conversion_matrices(fromRGB, toRGB);
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if(composite_chrominance_filter_shader_program_) composite_chrominance_filter_shader_program_->set_colour_conversion_matrices(fromRGB, toRGB);
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if(svideo_input_shader_program_) svideo_input_shader_program_->set_colour_conversion_matrices(fromRGB, toRGB);
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}
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void OpenGLOutputBuilder::set_gamma() {
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if(output_shader_program_) output_shader_program_->set_gamma_ratio(gamma_);
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}
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/*!
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@returns The multiplier to apply to x positions received at the shader in order to produce locations in the intermediate
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texture. Intermediate textures are in phase with the composite signal, so this is a function of (i) composite frequency
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(determining how much of the texture adds up to a single line); and (ii) input frequency (determining what the input
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positions mean as a fraction of a line).
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*/
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float OpenGLOutputBuilder::get_composite_output_width() const {
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return
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(static_cast<float>(colour_cycle_numerator_ * 4) / static_cast<float>(colour_cycle_denominator_ * IntermediateBufferWidth)) *
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(static_cast<float>(IntermediateBufferWidth) / static_cast<float>(cycles_per_line_));
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}
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void OpenGLOutputBuilder::set_output_shader_width() {
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if(output_shader_program_) {
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// For anything that isn't RGB, scale so that sampling is in-phase with the colour subcarrier.
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const float width = (video_signal_ == VideoSignal::RGB) ? 1.0f : get_composite_output_width();
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output_shader_program_->set_input_width_scaler(width);
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}
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}
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void OpenGLOutputBuilder::set_timing_uniforms() {
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const float colour_subcarrier_frequency = static_cast<float>(colour_cycle_numerator_) / static_cast<float>(colour_cycle_denominator_);
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const float output_width = get_composite_output_width();
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const float sample_cycles_per_line = cycles_per_line_ / output_width;
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if(composite_separation_filter_program_) {
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composite_separation_filter_program_->set_width_scalers(output_width, output_width);
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composite_separation_filter_program_->set_separation_frequency(sample_cycles_per_line, colour_subcarrier_frequency);
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composite_separation_filter_program_->set_extension(6.0f);
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}
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if(composite_chrominance_filter_shader_program_) {
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composite_chrominance_filter_shader_program_->set_width_scalers(output_width, output_width);
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composite_chrominance_filter_shader_program_->set_extension(5.0f);
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}
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if(rgb_filter_shader_program_) {
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rgb_filter_shader_program_->set_width_scalers(1.0f, 1.0f);
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rgb_filter_shader_program_->set_filter_coefficients(sample_cycles_per_line, static_cast<float>(input_frequency_) * 0.5f);
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}
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if(output_shader_program_) {
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set_output_shader_width();
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output_shader_program_->set_timing(height_of_display_, cycles_per_line_, horizontal_scan_period_, vertical_scan_period_, vertical_period_divider_);
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}
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if(composite_input_shader_program_) {
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composite_input_shader_program_->set_width_scalers(1.0f, output_width);
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composite_input_shader_program_->set_extension(0.0f);
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}
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if(svideo_input_shader_program_) {
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svideo_input_shader_program_->set_width_scalers(1.0f, output_width);
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svideo_input_shader_program_->set_extension(0.0f);
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}
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if(rgb_input_shader_program_) {
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rgb_input_shader_program_->set_width_scalers(1.0f, 1.0f);
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}
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set_integer_coordinate_multiplier(integer_coordinate_multiplier_);
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}
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void OpenGLOutputBuilder::set_integer_coordinate_multiplier(float multiplier) {
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integer_coordinate_multiplier_ = multiplier;
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if(composite_input_shader_program_) composite_input_shader_program_->set_integer_coordinate_multiplier(multiplier);
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if(svideo_input_shader_program_) svideo_input_shader_program_->set_integer_coordinate_multiplier(multiplier);
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if(rgb_input_shader_program_) rgb_input_shader_program_->set_integer_coordinate_multiplier(multiplier);
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}
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