1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-12-13 00:29:14 +00:00
CLK/Outputs/OpenGL/ScanTarget.hpp
2024-12-04 22:29:08 -05:00

160 lines
5.0 KiB
C++

//
// ScanTarget.hpp
// Clock Signal
//
// Created by Thomas Harte on 05/11/2018.
// Copyright © 2018 Thomas Harte. All rights reserved.
//
#pragma once
#include "../Log.hpp"
#include "../DisplayMetrics.hpp"
#include "../ScanTargets/BufferingScanTarget.hpp"
#include "OpenGL.hpp"
#include "Primitives/TextureTarget.hpp"
#include "Primitives/Rectangle.hpp"
#include "../../SignalProcessing/FIRFilter.hpp"
#include <array>
#include <atomic>
#include <cstdint>
#include <chrono>
#include <list>
#include <memory>
#include <string>
#include <vector>
namespace Outputs::Display::OpenGL {
/*!
Provides a ScanTarget that uses OpenGL to render its output;
this uses various internal buffers so that the only geometry
drawn to the target framebuffer is a quad.
*/
class ScanTarget: public Outputs::Display::BufferingScanTarget { // TODO: use private inheritance and expose only display_metrics() and a custom cast?
public:
ScanTarget(GLuint target_framebuffer = 0, float output_gamma = 2.2f);
~ScanTarget();
void set_target_framebuffer(GLuint);
/*! Pushes the current state of output to the target framebuffer. */
void draw(int output_width, int output_height);
/*! Processes all the latest input, at a resolution suitable for later output to a framebuffer of the specified size. */
void update(int output_width, int output_height);
private:
static constexpr int LineBufferWidth = 2048;
static constexpr int LineBufferHeight = 2048;
#ifndef NDEBUG
struct OpenGLVersionDumper {
OpenGLVersionDumper() {
// Note the OpenGL version, as the first thing this class does prior to construction.
Log::Logger<Log::Source::OpenGL>().info().append(
"Constructing scan target with OpenGL %s; shading language version %s",
glGetString(GL_VERSION),
glGetString(GL_SHADING_LANGUAGE_VERSION));
}
} dumper_;
#endif
GLuint target_framebuffer_;
const float output_gamma_;
int resolution_reduction_level_ = 1;
int output_height_ = 0;
size_t lines_submitted_ = 0;
std::chrono::high_resolution_clock::time_point line_submission_begin_time_;
// Contains the first composition of scans into lines;
// they're accumulated prior to output to allow for continuous
// application of any necessary conversions — e.g. composite processing.
TextureTarget unprocessed_line_texture_;
// Contains pre-lowpass-filtered chrominance information that is
// part-QAM-demoduled, if dealing with a QAM data source.
std::unique_ptr<TextureTarget> qam_chroma_texture_;
// Scans are accumulated to the accumulation texture; the full-display
// rectangle is used to ensure untouched pixels properly decay.
std::unique_ptr<TextureTarget> accumulation_texture_;
Rectangle full_display_rectangle_;
bool stencil_is_valid_ = false;
// OpenGL storage handles for buffer data.
GLuint scan_buffer_name_ = 0, scan_vertex_array_ = 0;
GLuint line_buffer_name_ = 0, line_vertex_array_ = 0;
template <typename T> void allocate_buffer(const T &array, GLuint &buffer_name, GLuint &vertex_array_name);
template <typename T> void patch_buffer(const T &array, GLuint target, uint16_t submit_pointer, uint16_t read_pointer);
GLuint write_area_texture_name_ = 0;
bool texture_exists_ = false;
// Receives scan target modals.
void setup_pipeline();
enum class ShaderType {
Composition,
Conversion,
QAMSeparation
};
/*!
Calls @c taret.enable_vertex_attribute_with_pointer to attach all
globals for shaders of @c type to @c target.
*/
static void enable_vertex_attributes(ShaderType type, Shader &target);
void set_uniforms(ShaderType type, Shader &target) const;
std::vector<std::string> bindings(ShaderType type) const;
GLsync fence_ = nullptr;
std::atomic_flag is_drawing_to_accumulation_buffer_;
std::unique_ptr<Shader> input_shader_;
std::unique_ptr<Shader> output_shader_;
std::unique_ptr<Shader> qam_separation_shader_;
/*!
Produces a shader that composes fragment of the input stream to a single buffer,
normalising the data into one of four forms: RGB, 8-bit luminance,
phase-linked luminance or luminance+phase offset.
*/
std::unique_ptr<Shader> composition_shader() const;
/*!
Produces a shader that reads from a composition buffer and converts to host
output RGB, decoding composite or S-Video as necessary.
*/
std::unique_ptr<Shader> conversion_shader() const;
/*!
Produces a shader that writes separated but not-yet filtered QAM components
from the unprocessed line texture to the QAM chroma texture, at a fixed
size of four samples per colour clock, point sampled.
*/
std::unique_ptr<Shader> qam_separation_shader() const;
void set_sampling_window(int output_Width, int output_height, Shader &target);
std::string sampling_function() const;
/*!
@returns true if the current display type is a 'soft' one, i.e. one in which
contrast tends to be low, such as a composite colour display.
*/
bool is_soft_display_type();
// Storage for the various buffers.
std::vector<uint8_t> write_area_texture_;
std::array<Scan, LineBufferHeight*5> scan_buffer_;
std::array<Line, LineBufferHeight> line_buffer_;
std::array<LineMetadata, LineBufferHeight> line_metadata_buffer_;
};
}