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			690 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			690 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
//
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//  ScanTargetVertexArrayAttributs.cpp
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//  Clock Signal
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//
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//  Created by Thomas Harte on 11/11/2018.
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//  Copyright © 2018 Thomas Harte. All rights reserved.
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//
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#include "ScanTarget.hpp"
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#include <cmath>
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#include <numbers>
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using namespace Outputs::Display::OpenGL;
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// MARK: - State setup for compiled shaders.
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void ScanTarget::set_uniforms(ShaderType type, Shader &target) const {
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	// Slightly over-amping rowHeight here is a cheap way to make sure that lines
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	// converge even allowing for the fact that they may not be spaced by exactly
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	// the expected distance. Cf. the stencil-powered logic for making sure all
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	// pixels are painted only exactly once per field.
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	const auto modals = BufferingScanTarget::modals();
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	switch(type) {
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		case ShaderType::Composition: break;
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		default:
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			target.set_uniform("rowHeight", GLfloat(1.05f / modals.expected_vertical_lines));
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			target.set_uniform("scale", GLfloat(modals.output_scale.x), GLfloat(modals.output_scale.y));
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			target.set_uniform("phaseOffset", GLfloat(modals.input_data_tweaks.phase_linked_luminance_offset));
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			const float clocks_per_angle = float(modals.cycles_per_line) * float(modals.colour_cycle_denominator) / float(modals.colour_cycle_numerator);
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			GLfloat texture_offsets[4];
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			GLfloat angles[4];
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			for(int c = 0; c < 4; ++c) {
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				GLfloat angle = (GLfloat(c) - 1.5f) / 4.0f;
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				texture_offsets[c] = angle * clocks_per_angle;
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				angles[c] = GLfloat(angle * 2.0f * std::numbers::pi_v<float>);
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			}
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			target.set_uniform("textureCoordinateOffsets", 1, 4, texture_offsets);
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			target.set_uniform("compositeAngleOffsets", 4, 1, angles);
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			switch(modals.composite_colour_space) {
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				case ColourSpace::YIQ: {
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					const GLfloat rgbToYIQ[] = {0.299f, 0.596f, 0.211f, 0.587f, -0.274f, -0.523f, 0.114f, -0.322f, 0.312f};
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					const GLfloat yiqToRGB[] = {1.0f, 1.0f, 1.0f, 0.956f, -0.272f, -1.106f, 0.621f, -0.647f, 1.703f};
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					target.set_uniform_matrix("lumaChromaToRGB", 3, false, yiqToRGB);
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					target.set_uniform_matrix("rgbToLumaChroma", 3, false, rgbToYIQ);
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				} break;
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				case ColourSpace::YUV: {
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					const GLfloat rgbToYUV[] = {0.299f, -0.14713f, 0.615f, 0.587f, -0.28886f, -0.51499f, 0.114f, 0.436f, -0.10001f};
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					const GLfloat yuvToRGB[] = {1.0f, 1.0f, 1.0f, 0.0f, -0.39465f, 2.03211f, 1.13983f, -0.58060f, 0.0f};
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					target.set_uniform_matrix("lumaChromaToRGB", 3, false, yuvToRGB);
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					target.set_uniform_matrix("rgbToLumaChroma", 3, false, rgbToYUV);
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				} break;
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			}
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		break;
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	}
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}
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void ScanTarget::set_sampling_window(int output_width, int, Shader &target) {
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	const auto modals = BufferingScanTarget::modals();
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	if(modals.display_type != DisplayType::CompositeColour) {
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		const float one_pixel_width = float(modals.cycles_per_line) * modals.visible_area.size.width / float(output_width);
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		const float clocks_per_angle = float(modals.cycles_per_line) * float(modals.colour_cycle_denominator) / float(modals.colour_cycle_numerator);
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		GLfloat texture_offsets[4];
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		GLfloat angles[4];
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		for(int c = 0; c < 4; ++c) {
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			texture_offsets[c] = 1.0f * (((one_pixel_width * float(c)) / 3.0f) - (one_pixel_width * 0.5f));
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			angles[c] = GLfloat((texture_offsets[c] / clocks_per_angle) * 2.0f * std::numbers::pi_v<float>);
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		}
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		target.set_uniform("textureCoordinateOffsets", 1, 4, texture_offsets);
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		target.set_uniform("compositeAngleOffsets", 4, 1, angles);
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	}
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}
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void ScanTarget::enable_vertex_attributes(ShaderType type, Shader &target) {
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#define rt_offset_of(field, source) (reinterpret_cast<uint8_t *>(&source.field) - reinterpret_cast<uint8_t *>(&source))
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	// test_scan and test_line are here so that the byte offsets that need to be
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	// calculated inside a loop can be done so validly; offsetof requires constant arguments.
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	Scan test_scan;
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	Line test_line;
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	// Some GPUs require alignment and will need to copy vertex data to a
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	// shadow buffer otherwise
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	static_assert(sizeof(Scan) % 4 == 0);
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	static_assert(sizeof(Line) % 4 == 0);
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	switch(type) {
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		case ShaderType::Composition:
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			for(int c = 0; c < 2; ++c) {
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				const std::string prefix = c ? "end" : "start";
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				target.enable_vertex_attribute_with_pointer(
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					prefix + "DataX",
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					1, GL_UNSIGNED_SHORT, GL_FALSE,
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					sizeof(Scan),
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					reinterpret_cast<void *>(rt_offset_of(scan.end_points[c].data_offset, test_scan)),
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					1);
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				target.enable_vertex_attribute_with_pointer(
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					prefix + "Clock",
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					1, GL_UNSIGNED_SHORT, GL_FALSE,
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					sizeof(Scan),
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					reinterpret_cast<void *>(rt_offset_of(scan.end_points[c].cycles_since_end_of_horizontal_retrace, test_scan)),
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					1);
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			}
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			target.enable_vertex_attribute_with_pointer(
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				"dataY",
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				1, GL_UNSIGNED_SHORT, GL_FALSE,
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				sizeof(Scan),
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				reinterpret_cast<void *>(offsetof(Scan, data_y)),
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				1);
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			target.enable_vertex_attribute_with_pointer(
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				"lineY",
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				1, GL_UNSIGNED_SHORT, GL_FALSE,
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				sizeof(Scan),
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				reinterpret_cast<void *>(offsetof(Scan, line)),
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				1);
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		break;
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		default:
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			for(int c = 0; c < 2; ++c) {
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				const std::string prefix = c ? "end" : "start";
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				if(type == ShaderType::Conversion) {
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					target.enable_vertex_attribute_with_pointer(
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						prefix + "Point",
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						2, GL_UNSIGNED_SHORT, GL_FALSE,
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						sizeof(Line),
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						reinterpret_cast<void *>(rt_offset_of(end_points[c].x, test_line)),
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						1);
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				}
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				target.enable_vertex_attribute_with_pointer(
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					prefix + "Clock",
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					1, GL_UNSIGNED_SHORT, GL_FALSE,
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					sizeof(Line),
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					reinterpret_cast<void *>(rt_offset_of(end_points[c].cycles_since_end_of_horizontal_retrace, test_line)),
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					1);
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				target.enable_vertex_attribute_with_pointer(
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					prefix + "CompositeAngle",
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					1, GL_SHORT, GL_FALSE,
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					sizeof(Line),
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					reinterpret_cast<void *>(rt_offset_of(end_points[c].composite_angle, test_line)),
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					1);
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			}
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			target.enable_vertex_attribute_with_pointer(
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				"lineY",
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				1, GL_UNSIGNED_SHORT, GL_FALSE,
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				sizeof(Line),
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				reinterpret_cast<void *>(offsetof(Line, line)),
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				1);
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			target.enable_vertex_attribute_with_pointer(
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				"lineCompositeAmplitude",
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				1, GL_UNSIGNED_BYTE, GL_FALSE,
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				sizeof(Line),
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				reinterpret_cast<void *>(offsetof(Line, composite_amplitude)),
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				1);
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		break;
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	}
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#undef rt_offset_of
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}
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std::vector<std::string> ScanTarget::bindings(ShaderType type) const {
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	switch(type) {
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		case ShaderType::Composition: return {
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			"startDataX",
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			"startClock",
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			"endDataX",
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			"endClock",
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			"dataY",
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			"lineY"
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		};
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		default: return {
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			"startPoint",
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			"endPoint",
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			"startClock",
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			"endClock",
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			"lineY",
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			"lineCompositeAmplitude",
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			"startCompositeAngle",
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			"endCompositeAngle"
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		};
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	}
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}
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// MARK: - Shader code.
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std::string ScanTarget::sampling_function() const {
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	std::string fragment_shader;
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	const auto modals = BufferingScanTarget::modals();
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	const bool is_svideo = modals.display_type == DisplayType::SVideo;
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	if(is_svideo) {
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		fragment_shader +=
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			"vec2 svideo_sample(vec2 coordinate, float angle) {";
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	} else {
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		fragment_shader +=
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			"float composite_sample(vec2 coordinate, float angle) {";
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	}
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	switch(modals.input_data_type) {
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		case InputDataType::Luminance1:
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		case InputDataType::Luminance8:
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			// Easy, just copy across.
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			fragment_shader +=
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				is_svideo ?
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					"return vec2(textureLod(textureName, coordinate, 0).r, 0.0);" :
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					"return textureLod(textureName, coordinate, 0).r;";
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		break;
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		case InputDataType::PhaseLinkedLuminance8:
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			fragment_shader +=
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				"uint iPhase = uint(step(sign(angle), 0.0) * 3) ^ uint(abs(angle * 2.0 / 3.141592654) ) & 3u;";
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			fragment_shader +=
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				is_svideo ?
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					"return vec2(textureLod(textureName, coordinate, 0)[iPhase], 0.0);" :
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					"return textureLod(textureName, coordinate, 0)[iPhase];";
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		break;
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		case InputDataType::Luminance8Phase8:
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			fragment_shader +=
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				"vec2 yc = textureLod(textureName, coordinate, 0).rg;"
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				"float phaseOffset = 3.141592654 * 2.0 * 2.0 * yc.y;"
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				"float rawChroma = step(yc.y, 0.75) * cos(angle + phaseOffset);";
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			fragment_shader +=
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				is_svideo ?
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					"return vec2(yc.x, rawChroma);" :
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					"return mix(yc.x, rawChroma, compositeAmplitude);";
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		break;
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		case InputDataType::Red1Green1Blue1:
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		case InputDataType::Red2Green2Blue2:
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		case InputDataType::Red4Green4Blue4:
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		case InputDataType::Red8Green8Blue8:
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			fragment_shader +=
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				"vec3 colour = rgbToLumaChroma * textureLod(textureName, coordinate, 0).rgb;"
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				"vec2 quadrature = vec2(cos(angle), sin(angle));";
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			fragment_shader +=
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				is_svideo ?
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					"return vec2(colour.r, dot(quadrature, colour.gb));" :
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					"return mix(colour.r, dot(quadrature, colour.gb), compositeAmplitude);";
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		break;
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	}
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	fragment_shader += "}";
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	return fragment_shader;
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}
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std::unique_ptr<Shader> ScanTarget::conversion_shader() const {
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	const auto modals = BufferingScanTarget::modals();
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	// Compose a vertex shader. If the display type is RGB, generate just the proper
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	// geometry position, plus a solitary textureCoordinate.
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	//
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	// If the display type is anything other than RGB, also produce composite
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	// angle and 1/composite amplitude as outputs.
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	//
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	// If the display type is composite colour, generate four textureCoordinates,
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	// spanning a range of -135, -45, +45, +135 degrees.
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	//
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	// If the display type is S-Video, generate three textureCoordinates, at
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	// -45, 0, +45.
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	std::string vertex_shader = R"glsl(
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		#version 150
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		uniform vec2 scale;
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		uniform float rowHeight;
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		in vec2 startPoint;
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		in vec2 endPoint;
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		in float startClock;
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		in float startCompositeAngle;
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		in float endClock;
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		in float endCompositeAngle;
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		in float lineY;
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		in float lineCompositeAmplitude;
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		uniform sampler2D textureName;
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		uniform sampler2D qamTextureName;
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		uniform vec2 origin;
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		uniform vec2 size;
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		uniform float textureCoordinateOffsets[4];
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		out vec2 textureCoordinates[4];
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	)glsl";
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	std::string fragment_shader = R"glsl(
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		#version 150
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		uniform sampler2D textureName;
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		uniform sampler2D qamTextureName;
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		in vec2 textureCoordinates[4];
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		out vec4 fragColour;
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	)glsl";
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	if(modals.display_type != DisplayType::RGB) {
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		vertex_shader += R"glsl(
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			out float compositeAngle;
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			out float compositeAmplitude;
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			out float oneOverCompositeAmplitude;
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			uniform float angleOffsets[4];
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		)glsl";
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		fragment_shader += R"glsl(
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			in float compositeAngle;
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			in float compositeAmplitude;
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			in float oneOverCompositeAmplitude;
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			uniform vec4 compositeAngleOffsets;
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		)glsl";
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	}
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	if(modals.display_type == DisplayType::SVideo || modals.display_type == DisplayType::CompositeColour) {
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		vertex_shader += "out vec2 qamTextureCoordinates[4];";
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		fragment_shader += "in vec2 qamTextureCoordinates[4];";
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	}
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	// Add the code to generate a proper output position; this applies to all display types.
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	vertex_shader += R"glsl(
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		void main(void) {
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			float lateral = float(gl_VertexID & 1);
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			float longitudinal = float((gl_VertexID & 2) >> 1);
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			vec2 centrePoint = mix(startPoint, vec2(endPoint.x, startPoint.y), lateral) / scale;
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			vec2 height = normalize(vec2(endPoint.x, startPoint.y) - startPoint).yx * (longitudinal - 0.5) * rowHeight;
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			vec2 eyePosition = vec2(-1.0, 1.0) + vec2(2.0, -2.0) * ((centrePoint + height) - origin) * size;
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			gl_Position = vec4(eyePosition, 0.0, 1.0);
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	)glsl";
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	// For everything other than RGB, calculate the two composite outputs.
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	if(modals.display_type != DisplayType::RGB) {
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		vertex_shader += R"glsl(
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			compositeAngle = (mix(startCompositeAngle, endCompositeAngle, lateral) / 32.0) * 3.141592654;
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			compositeAmplitude = lineCompositeAmplitude / 255.0;
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			oneOverCompositeAmplitude = mix(0.0, 255.0 / lineCompositeAmplitude, step(0.95, lineCompositeAmplitude));
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		)glsl";
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	}
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	vertex_shader += R"glsl(
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		float centreClock = mix(startClock, endClock, lateral);
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		textureCoordinates[0] = vec2(centreClock + textureCoordinateOffsets[0], lineY + 0.5) / textureSize(textureName, 0);
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		textureCoordinates[1] = vec2(centreClock + textureCoordinateOffsets[1], lineY + 0.5) / textureSize(textureName, 0);
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		textureCoordinates[2] = vec2(centreClock + textureCoordinateOffsets[2], lineY + 0.5) / textureSize(textureName, 0);
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		textureCoordinates[3] = vec2(centreClock + textureCoordinateOffsets[3], lineY + 0.5) / textureSize(textureName, 0);
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	)glsl";
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	if((modals.display_type == DisplayType::SVideo) || (modals.display_type == DisplayType::CompositeColour)) {
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		vertex_shader += R"glsl(
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			float centreCompositeAngle = abs(mix(startCompositeAngle, endCompositeAngle, lateral)) * 4.0 / 64.0;
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			centreCompositeAngle = floor(centreCompositeAngle);
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			qamTextureCoordinates[0] = vec2(centreCompositeAngle - 1.5, lineY + 0.5) / textureSize(textureName, 0);
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			qamTextureCoordinates[1] = vec2(centreCompositeAngle - 0.5, lineY + 0.5) / textureSize(textureName, 0);
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			qamTextureCoordinates[2] = vec2(centreCompositeAngle + 0.5, lineY + 0.5) / textureSize(textureName, 0);
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			qamTextureCoordinates[3] = vec2(centreCompositeAngle + 1.5, lineY + 0.5) / textureSize(textureName, 0);
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		)glsl";
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	}
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						|
	vertex_shader += "}";
 | 
						|
 | 
						|
	// Compose a fragment shader.
 | 
						|
 | 
						|
	if(modals.display_type != DisplayType::RGB) {
 | 
						|
		fragment_shader +=
 | 
						|
			"uniform mat3 lumaChromaToRGB;"
 | 
						|
			"uniform mat3 rgbToLumaChroma;";
 | 
						|
 | 
						|
		fragment_shader += sampling_function();
 | 
						|
	}
 | 
						|
 | 
						|
	fragment_shader +=
 | 
						|
		"void main(void) {"
 | 
						|
			"vec3 fragColour3;";
 | 
						|
 | 
						|
	switch(modals.display_type) {
 | 
						|
		case DisplayType::CompositeColour:
 | 
						|
			fragment_shader += R"glsl(
 | 
						|
				vec4 angles = compositeAngle + compositeAngleOffsets;
 | 
						|
 | 
						|
				// Sample four times over, at proper angle offsets.
 | 
						|
				vec4 samples = vec4(
 | 
						|
					composite_sample(textureCoordinates[0], angles.x),
 | 
						|
					composite_sample(textureCoordinates[1], angles.y),
 | 
						|
					composite_sample(textureCoordinates[2], angles.z),
 | 
						|
					composite_sample(textureCoordinates[3], angles.w)
 | 
						|
				);
 | 
						|
 | 
						|
				// The outer structure of the OpenGL scan target means in practice that
 | 
						|
				// compositeAmplitude will be the same value across a piece of
 | 
						|
				// geometry. I am therefore optimistic that this conditional will not
 | 
						|
				// cause a divergence in fragment execution.
 | 
						|
				if(compositeAmplitude < 0.01) {
 | 
						|
					// Compute only a luminance for use if there's no colour information.
 | 
						|
					fragColour3 = vec3(dot(samples, vec4(0.15, 0.35, 0.35, 0.15)));
 | 
						|
				} else {
 | 
						|
					// Take the average to calculate luminance, then subtract that from all four samples to
 | 
						|
					// give chrominance.
 | 
						|
					float luminance = dot(samples, vec4(0.25));
 | 
						|
 | 
						|
					// Split and average chrominance.
 | 
						|
					vec2 chrominances[4] = vec2[4](
 | 
						|
						textureLod(qamTextureName, qamTextureCoordinates[0], 0).gb,
 | 
						|
						textureLod(qamTextureName, qamTextureCoordinates[1], 0).gb,
 | 
						|
						textureLod(qamTextureName, qamTextureCoordinates[2], 0).gb,
 | 
						|
						textureLod(qamTextureName, qamTextureCoordinates[3], 0).gb
 | 
						|
					);
 | 
						|
					vec2 channels = (chrominances[0] + chrominances[1] + chrominances[2] + chrominances[3])*0.5 - vec2(1.0);
 | 
						|
 | 
						|
					// Apply a colour space conversion to get RGB.
 | 
						|
					fragColour3 = lumaChromaToRGB * vec3(luminance / (1.0 - compositeAmplitude), channels);
 | 
						|
				}
 | 
						|
			)glsl";
 | 
						|
		break;
 | 
						|
 | 
						|
		case DisplayType::CompositeMonochrome:
 | 
						|
			fragment_shader +=
 | 
						|
				"vec4 angles = compositeAngle + compositeAngleOffsets;"
 | 
						|
				"vec4 samples = vec4("
 | 
						|
					"composite_sample(textureCoordinates[0], angles.x),"
 | 
						|
					"composite_sample(textureCoordinates[1], angles.y),"
 | 
						|
					"composite_sample(textureCoordinates[2], angles.z),"
 | 
						|
					"composite_sample(textureCoordinates[3], angles.w)"
 | 
						|
				");"
 | 
						|
				"fragColour3 = vec3(dot(samples, vec4(0.15, 0.35, 0.35, 0.25)));";
 | 
						|
		break;
 | 
						|
 | 
						|
		case DisplayType::RGB:
 | 
						|
			fragment_shader +=
 | 
						|
				"vec3 samples[4] = vec3[4]("
 | 
						|
					"textureLod(textureName, textureCoordinates[0], 0).rgb,"
 | 
						|
					"textureLod(textureName, textureCoordinates[1], 0).rgb,"
 | 
						|
					"textureLod(textureName, textureCoordinates[2], 0).rgb,"
 | 
						|
					"textureLod(textureName, textureCoordinates[3], 0).rgb"
 | 
						|
				");"
 | 
						|
				"fragColour3 = samples[0]*0.15 + samples[1]*0.35 + samples[2]*0.35 + samples[2]*0.15;";
 | 
						|
		break;
 | 
						|
 | 
						|
		case DisplayType::SVideo:
 | 
						|
			fragment_shader +=
 | 
						|
				// Sample the S-Video stream to obtain luminance.
 | 
						|
				"vec4 angles = compositeAngle + compositeAngleOffsets;"
 | 
						|
				"vec4 samples = vec4("
 | 
						|
					"svideo_sample(textureCoordinates[0], angles.x).x,"
 | 
						|
					"svideo_sample(textureCoordinates[1], angles.y).x,"
 | 
						|
					"svideo_sample(textureCoordinates[2], angles.z).x,"
 | 
						|
					"svideo_sample(textureCoordinates[3], angles.w).x"
 | 
						|
				");"
 | 
						|
				"float luminance = dot(samples, vec4(0.15, 0.35, 0.35, 0.25));"
 | 
						|
 | 
						|
				// Split and average chrominance.
 | 
						|
				"vec2 chrominances[4] = vec2[4]("
 | 
						|
					"textureLod(qamTextureName, qamTextureCoordinates[0], 0).gb,"
 | 
						|
					"textureLod(qamTextureName, qamTextureCoordinates[1], 0).gb,"
 | 
						|
					"textureLod(qamTextureName, qamTextureCoordinates[2], 0).gb,"
 | 
						|
					"textureLod(qamTextureName, qamTextureCoordinates[3], 0).gb"
 | 
						|
				");"
 | 
						|
				"vec2 channels = (chrominances[0] + chrominances[1] + chrominances[2] + chrominances[3])*0.5 - vec2(1.0);"
 | 
						|
 | 
						|
				// Apply a colour space conversion to get RGB.
 | 
						|
				"fragColour3 = lumaChromaToRGB * vec3(luminance, channels);";
 | 
						|
		break;
 | 
						|
	}
 | 
						|
 | 
						|
	// Apply a brightness adjustment if requested.
 | 
						|
	if(fabs(modals.brightness - 1.0f) > 0.05f) {
 | 
						|
		fragment_shader += "fragColour3 = fragColour3 * " + std::to_string(modals.brightness) + ";";
 | 
						|
	}
 | 
						|
 | 
						|
	// Apply a gamma correction if required.
 | 
						|
	if(fabs(output_gamma_ - modals.intended_gamma) > 0.05f) {
 | 
						|
		const float gamma_ratio = output_gamma_ / modals.intended_gamma;
 | 
						|
		fragment_shader += "fragColour3 = pow(fragColour3, vec3(" + std::to_string(gamma_ratio) + "));";
 | 
						|
	}
 | 
						|
 | 
						|
	fragment_shader +=
 | 
						|
			"fragColour = vec4(fragColour3, 0.64);"
 | 
						|
		"}";
 | 
						|
 | 
						|
	return std::make_unique<Shader>(
 | 
						|
		vertex_shader,
 | 
						|
		fragment_shader,
 | 
						|
		bindings(ShaderType::Conversion)
 | 
						|
	);
 | 
						|
}
 | 
						|
 | 
						|
std::unique_ptr<Shader> ScanTarget::composition_shader() const {
 | 
						|
	const auto modals = BufferingScanTarget::modals();
 | 
						|
	const std::string vertex_shader = R"glsl(
 | 
						|
		#version 150
 | 
						|
 | 
						|
		in float startDataX;
 | 
						|
		in float startClock;
 | 
						|
 | 
						|
		in float endDataX;
 | 
						|
		in float endClock;
 | 
						|
 | 
						|
		in float dataY;
 | 
						|
		in float lineY;
 | 
						|
 | 
						|
		out vec2 textureCoordinate;
 | 
						|
		uniform usampler2D textureName;
 | 
						|
 | 
						|
		void main(void) {
 | 
						|
			float lateral = float(gl_VertexID & 1);
 | 
						|
			float longitudinal = float((gl_VertexID & 2) >> 1);
 | 
						|
 | 
						|
			textureCoordinate = vec2(mix(startDataX, endDataX, lateral), dataY + 0.5) / textureSize(textureName, 0);
 | 
						|
			vec2 eyePosition = vec2(mix(startClock, endClock, lateral), lineY + longitudinal) / vec2(2048.0, 2048.0);
 | 
						|
			gl_Position = vec4(eyePosition*2.0 - vec2(1.0), 0.0, 1.0);
 | 
						|
		}
 | 
						|
	)glsl";
 | 
						|
 | 
						|
	std::string fragment_shader =
 | 
						|
	R"x(#version 150
 | 
						|
 | 
						|
		out vec4 fragColour;
 | 
						|
		in vec2 textureCoordinate;
 | 
						|
 | 
						|
		uniform usampler2D textureName;
 | 
						|
 | 
						|
		void main(void) {
 | 
						|
	)x";
 | 
						|
 | 
						|
	switch(modals.input_data_type) {
 | 
						|
		case InputDataType::Luminance1:
 | 
						|
			fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0).rrrr;";
 | 
						|
		break;
 | 
						|
 | 
						|
		case InputDataType::Luminance8:
 | 
						|
			fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0).rrrr / vec4(255.0);";
 | 
						|
		break;
 | 
						|
 | 
						|
		case InputDataType::PhaseLinkedLuminance8:
 | 
						|
		case InputDataType::Luminance8Phase8:
 | 
						|
		case InputDataType::Red8Green8Blue8:
 | 
						|
			fragment_shader += "fragColour = textureLod(textureName, textureCoordinate, 0) / vec4(255.0);";
 | 
						|
		break;
 | 
						|
 | 
						|
		case InputDataType::Red1Green1Blue1:
 | 
						|
			fragment_shader += "fragColour = vec4(textureLod(textureName, textureCoordinate, 0).rrr & uvec3(4u, 2u, 1u), 1.0);";
 | 
						|
		break;
 | 
						|
 | 
						|
		case InputDataType::Red2Green2Blue2:
 | 
						|
			fragment_shader +=
 | 
						|
				"uint textureValue = textureLod(textureName, textureCoordinate, 0).r;"
 | 
						|
				"fragColour = vec4(float((textureValue >> 4) & 3u), float((textureValue >> 2) & 3u), float(textureValue & 3u), 3.0) / 3.0;";
 | 
						|
		break;
 | 
						|
 | 
						|
		case InputDataType::Red4Green4Blue4:
 | 
						|
			fragment_shader +=
 | 
						|
				"uvec2 textureValue = textureLod(textureName, textureCoordinate, 0).rg;"
 | 
						|
				"fragColour = vec4(float(textureValue.r) / 15.0, float(textureValue.g & 240u) / 240.0, float(textureValue.g & 15u) / 15.0, 1.0);";
 | 
						|
		break;
 | 
						|
	}
 | 
						|
 | 
						|
	return std::make_unique<Shader>(
 | 
						|
		vertex_shader,
 | 
						|
		fragment_shader + "}",
 | 
						|
		bindings(ShaderType::Composition)
 | 
						|
	);
 | 
						|
}
 | 
						|
 | 
						|
std::unique_ptr<Shader> ScanTarget::qam_separation_shader() const {
 | 
						|
	const auto modals = BufferingScanTarget::modals();
 | 
						|
	const bool is_svideo = modals.display_type == DisplayType::SVideo;
 | 
						|
 | 
						|
	// Sets up texture coordinates to run between startClock and endClock, mapping to
 | 
						|
	// coordinates that correlate with four times the absolute value of the composite angle.
 | 
						|
	std::string vertex_shader =
 | 
						|
		"#version 150\n"
 | 
						|
 | 
						|
		"in float startClock;"
 | 
						|
		"in float startCompositeAngle;"
 | 
						|
		"in float endClock;"
 | 
						|
		"in float endCompositeAngle;"
 | 
						|
 | 
						|
		"in float lineY;"
 | 
						|
		"in float lineCompositeAmplitude;"
 | 
						|
 | 
						|
		"uniform sampler2D textureName;"
 | 
						|
		"uniform float textureCoordinateOffsets[4];"
 | 
						|
 | 
						|
		"out float compositeAngle;"
 | 
						|
		"out float compositeAmplitude;"
 | 
						|
		"out float oneOverCompositeAmplitude;";
 | 
						|
 | 
						|
	std::string fragment_shader =
 | 
						|
		"#version 150\n"
 | 
						|
 | 
						|
		"uniform sampler2D textureName;"
 | 
						|
		"uniform mat3 rgbToLumaChroma;"
 | 
						|
 | 
						|
		"in float compositeAngle;"
 | 
						|
		"in float compositeAmplitude;"
 | 
						|
		"in float oneOverCompositeAmplitude;"
 | 
						|
 | 
						|
		"out vec4 fragColour;"
 | 
						|
		"uniform vec4 compositeAngleOffsets;";
 | 
						|
 | 
						|
	if(is_svideo) {
 | 
						|
		vertex_shader += "out vec2 textureCoordinate;";
 | 
						|
		fragment_shader += "in vec2 textureCoordinate;";
 | 
						|
	} else {
 | 
						|
		vertex_shader += "out vec2 textureCoordinates[4];";
 | 
						|
		fragment_shader += "in vec2 textureCoordinates[4];";
 | 
						|
	}
 | 
						|
 | 
						|
	vertex_shader +=
 | 
						|
		"void main(void) {"
 | 
						|
			"float lateral = float(gl_VertexID & 1);"
 | 
						|
			"float longitudinal = float((gl_VertexID & 2) >> 1);"
 | 
						|
			"float centreClock = mix(startClock, endClock, lateral);"
 | 
						|
 | 
						|
			"compositeAngle = mix(startCompositeAngle, endCompositeAngle, lateral) / 64.0;"
 | 
						|
 | 
						|
			"float snappedCompositeAngle = floor(abs(compositeAngle) * 4.0);"
 | 
						|
			"vec2 eyePosition = vec2(snappedCompositeAngle, lineY + longitudinal) / vec2(2048.0, 2048.0);"
 | 
						|
			"gl_Position = vec4(eyePosition*2.0 - vec2(1.0), 0.0, 1.0);"
 | 
						|
 | 
						|
			"compositeAngle = compositeAngle * 2.0 * 3.141592654;"
 | 
						|
			"compositeAmplitude = lineCompositeAmplitude / 255.0;"
 | 
						|
			"oneOverCompositeAmplitude = mix(0.0, 255.0 / lineCompositeAmplitude, step(0.95, lineCompositeAmplitude));";
 | 
						|
 | 
						|
	if(is_svideo) {
 | 
						|
		vertex_shader +=
 | 
						|
			"textureCoordinate = vec2(centreClock, lineY + 0.5) / textureSize(textureName, 0);";
 | 
						|
	} else {
 | 
						|
		vertex_shader +=
 | 
						|
			"textureCoordinates[0] = vec2(centreClock + textureCoordinateOffsets[0], lineY + 0.5) / textureSize(textureName, 0);"
 | 
						|
			"textureCoordinates[1] = vec2(centreClock + textureCoordinateOffsets[1], lineY + 0.5) / textureSize(textureName, 0);"
 | 
						|
			"textureCoordinates[2] = vec2(centreClock + textureCoordinateOffsets[2], lineY + 0.5) / textureSize(textureName, 0);"
 | 
						|
			"textureCoordinates[3] = vec2(centreClock + textureCoordinateOffsets[3], lineY + 0.5) / textureSize(textureName, 0);";
 | 
						|
	}
 | 
						|
 | 
						|
	vertex_shader += "}";
 | 
						|
 | 
						|
	fragment_shader +=
 | 
						|
		sampling_function() +
 | 
						|
		"void main(void) {";
 | 
						|
 | 
						|
	if(modals.display_type == DisplayType::SVideo) {
 | 
						|
		fragment_shader +=
 | 
						|
			"fragColour = vec4(svideo_sample(textureCoordinate, compositeAngle).rgg * vec3(1.0, cos(compositeAngle), sin(compositeAngle)), 1.0);";
 | 
						|
	} else {
 | 
						|
			fragment_shader +=
 | 
						|
				"vec4 angles = compositeAngle + compositeAngleOffsets;"
 | 
						|
 | 
						|
				// Sample four times over, at proper angle offsets.
 | 
						|
				"vec4 samples = vec4("
 | 
						|
					"composite_sample(textureCoordinates[0], angles.x),"
 | 
						|
					"composite_sample(textureCoordinates[1], angles.y),"
 | 
						|
					"composite_sample(textureCoordinates[2], angles.z),"
 | 
						|
					"composite_sample(textureCoordinates[3], angles.w)"
 | 
						|
				");"
 | 
						|
 | 
						|
				// Take the average to calculate luminance, then subtract that from all four samples to
 | 
						|
				// give chrominance.
 | 
						|
				"float luminance = dot(samples, vec4(0.25));"
 | 
						|
				"float chrominance = (dot(samples.yz, vec2(0.5)) - luminance) * oneOverCompositeAmplitude;"
 | 
						|
 | 
						|
				// Pack that all up and send it on its way.
 | 
						|
				"fragColour = vec4(luminance, vec2(cos(compositeAngle), sin(compositeAngle)) * chrominance, 1.0);";
 | 
						|
	};
 | 
						|
 | 
						|
	fragment_shader +=
 | 
						|
			"fragColour = fragColour*0.5 + vec4(0.5);"
 | 
						|
		"}";
 | 
						|
 | 
						|
	return std::make_unique<Shader>(
 | 
						|
		vertex_shader,
 | 
						|
		fragment_shader,
 | 
						|
		bindings(ShaderType::QAMSeparation)
 | 
						|
	);
 | 
						|
}
 |