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57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
//
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// Video.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 06/06/2017.
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// Copyright 2017 Thomas Harte. All rights reserved.
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//
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#ifndef Machines_ZX8081_Video_hpp
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#define Machines_ZX8081_Video_hpp
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#include "../../Outputs/CRT/CRT.hpp"
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#include "../../ClockReceiver/ClockReceiver.hpp"
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namespace ZX8081 {
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/*!
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Packages a ZX80/81-style video feed into a CRT-compatible waveform.
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While sync is active, this feed will output the sync level.
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While sync is inactive, this feed will output the white level unless it is supplied
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with a byte to output. When a byte is supplied for output, it will be interpreted as
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a 1-bit graphic and output over the next 4 cycles, picking between the white level
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and the black level.
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*/
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class Video {
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public:
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/// Constructs an instance of the video feed; a CRT is also created.
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Video();
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/// @returns The CRT this video feed is feeding.
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Outputs::CRT::CRT *get_crt();
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/// Advances time by @c half-cycles.
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void run_for(const HalfCycles);
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/// Forces output to catch up to the current output position.
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void flush();
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/// Sets the current sync output.
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void set_sync(bool sync);
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/// Causes @c byte to be serialised into pixels and output over the next four cycles.
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void output_byte(uint8_t byte);
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private:
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bool sync_ = false;
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uint8_t *line_data_ = nullptr;
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uint8_t *line_data_pointer_ = nullptr;
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HalfCycles time_since_update_ = 0;
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std::unique_ptr<Outputs::CRT::CRT> crt_;
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void flush(bool next_sync);
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};
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}
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#endif /* Video_hpp */
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