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81 lines
1.7 KiB
C++
81 lines
1.7 KiB
C++
//
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// Nick.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 14/06/2021.
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// Copyright © 2021 Thomas Harte. All rights reserved.
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//
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#ifndef Nick_hpp
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#define Nick_hpp
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#include <cstdint>
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#include "../../ClockReceiver/ClockReceiver.hpp"
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#include "../../Outputs/CRT/CRT.hpp"
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namespace Enterprise {
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class Nick {
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public:
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Nick(const uint8_t *ram);
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void write(uint16_t address, uint8_t value);
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uint8_t read(uint16_t address);
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void run_for(HalfCycles);
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void set_scan_target(Outputs::Display::ScanTarget *scan_target);
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Outputs::Display::ScanStatus get_scaled_scan_status() const;
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private:
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Outputs::CRT::CRT crt_;
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const uint8_t *const ram_;
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// CPU-provided state.
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uint8_t line_parameter_control_ = 0xc0;
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uint16_t line_parameter_base_ = 0x0000;
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uint16_t border_colour_ = 0;
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// Ephemerals, related to current video position.
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int horizontal_counter_ = 0;
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uint16_t line_parameter_pointer_ = 0x0000;
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uint8_t line_parameters_[16];
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bool should_reload_line_parameters_ = false;
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uint16_t line_data_pointer_[2];
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// Current mode line parameters.
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uint8_t lines_remaining_ = 0x00;
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int left_margin_ = 0, right_margin_ = 0;
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enum class Mode {
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Vsync,
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Pixel,
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Attr,
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CH256,
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CH128,
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CH64,
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Unused,
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LPixel,
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} mode_ = Mode::Vsync;
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enum class State {
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Sync,
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Border,
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Pixels,
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Blank,
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} state_ = State::Sync;
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// An accumulator for border output regions.
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int border_duration_ = 0;
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void flush_border();
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// The destination for new pixels.
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static constexpr int allocation_size = 800; // TODO: pick an appropriate length once the serialiser is working correctly.
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uint16_t *pixel_pointer_ = nullptr, *allocated_pointer_ = nullptr;
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int pixel_duration_ = 0;
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void flush_pixels();
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};
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}
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#endif /* Nick_hpp */
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