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CLK/Components/9918/Implementation/9918Base.hpp

102 lines
2.3 KiB
C++

//
// 9918Base.hpp
// Clock Signal
//
// Created by Thomas Harte on 14/12/2017.
// Copyright © 2017 Thomas Harte. All rights reserved.
//
#ifndef TMS9918Base_hpp
#define TMS9918Base_hpp
#include "../../../Outputs/CRT/CRT.hpp"
#include "../../../ClockReceiver/ClockReceiver.hpp"
#include <cstdint>
#include <memory>
namespace TI {
class TMS9918Base {
protected:
TMS9918Base();
std::unique_ptr<Outputs::CRT::CRT> crt_;
uint8_t ram_[16384];
uint16_t ram_pointer_ = 0;
uint8_t read_ahead_buffer_ = 0;
enum class MemoryAccess {
Read, Write, None
} queued_access_ = MemoryAccess::None;
uint8_t status_ = 0;
bool write_phase_ = false;
uint8_t low_write_ = 0;
// The various register flags.
int next_screen_mode_ = 0, screen_mode_ = 0;
bool next_blank_screen_ = true, blank_screen_ = true;
bool sprites_16x16_ = false;
bool sprites_magnified_ = false;
bool generate_interrupts_ = false;
int sprite_height_ = 8;
uint16_t pattern_name_address_ = 0;
uint16_t colour_table_address_ = 0;
uint16_t pattern_generator_table_address_ = 0;
uint16_t sprite_attribute_table_address_ = 0;
uint16_t sprite_generator_table_address_ = 0;
uint8_t text_colour_ = 0;
uint8_t background_colour_ = 0;
HalfCycles half_cycles_into_frame_;
int column_ = 0, row_ = 0, output_column_ = 0;
int cycles_error_ = 0;
uint32_t *pixel_target_ = nullptr, *pixel_base_ = nullptr;
void output_border(int cycles);
// Vertical timing details.
int frame_lines_ = 262;
int first_vsync_line_ = 227;
// Horizontal selections.
enum class LineMode {
Text = 0,
Character = 1,
Refresh = 2
} line_mode_ = LineMode::Text;
int first_pixel_column_, first_right_border_column_;
uint8_t pattern_names_[40];
uint8_t pattern_buffer_[40];
uint8_t colour_buffer_[40];
struct SpriteSet {
struct ActiveSprite {
int index = 0;
int row = 0;
uint8_t info[4];
uint8_t image[2];
int shift_position = 0;
} active_sprites[4];
int active_sprite_slot = 0;
} sprite_sets_[2];
int active_sprite_set_ = 0;
bool sprites_stopped_ = false;
int access_pointer_ = 0;
inline void test_sprite(int sprite_number, int screen_row);
inline void get_sprite_contents(int start, int cycles, int screen_row);
};
}
#endif /* TMS9918Base_hpp */