97 lines
2.3 KiB
C
97 lines
2.3 KiB
C
//
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// Created by william on 12/30/23.
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//
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#include <stdbool.h>
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#include <stddef.h>
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#include "types.h"
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#ifndef NESEMULATOR_PPU_H
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#define NESEMULATOR_PPU_H
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#define PPU_REGISTER_SIZE 0x8
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#define PPU_VRAM_SIZE 0x4000
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#define PPU_OAM_SIZE 0xff
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#define PPU_REGISTER_CTRL 0x00
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#define PPU_REGISTER_MASK 0x01
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#define PPU_REGISTER_STATUS 0x02
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#define PPU_REGISTER_OAM_ADDR 0x03
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#define PPU_REGISTER_OAM_DATA 0x04
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#define PPU_REGISTER_SCROLL 0x05
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#define PPU_REGISTER_ADDR 0x06
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#define PPU_REGISTER_DATA 0x07
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#define PPU_CTRL_BASE_NAMETABLE_ADDR 0x3
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#define PPU_CTRL_VRAM_ADDR_INCREMENT 0x4
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#define PPU_CTRL_SP_PATTERN_TABLE_ADDR 0x8
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#define PPU_CTRL_BG_PATTERN_TABLE_ADDR 0x10
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#define PPU_CTRL_SP_SIZE 0x20
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#define PPU_CTRL_MODE_SELECT 0x40
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#define PPU_CTRL_GEN_VBLANK_NMI 0x80
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#define PPU_MASK_GREYSCALE 0x1
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#define PPU_MASK_SHOW_BG_LEFT 0x2
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#define PPU_MASK_SHOW_SP_LEFT 0x4
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#define PPU_MASK_SHOW_BG 0x8
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#define PPU_MASK_SHOW_SP 0x10
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#define PPU_MASK_EMP_RED 0x20
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#define PPU_MASK_EMP_GREEN 0x40
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#define PPU_MASK_EMP_BLUE 0x80
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#define PPU_STATUS_OPEN_BUS 0x1f
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#define PPU_STATUS_SP_OVERFLOW 0x20
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#define PPU_STATUS_SP_0_HIT 0x40
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#define PPU_STATUS_VBLANK 0x80
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#define PPU_MASK_NONE 0xff
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typedef struct ppu {
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byte* registers;
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byte* oam_dma_register;
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byte vram[PPU_VRAM_SIZE];
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byte oam[PPU_OAM_SIZE];
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bool odd_frame;
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address v;
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address t;
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byte x;
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bool w;
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} PPU;
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/**
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* Initializes the PPU, according to the power up state.
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* https://www.nesdev.org/wiki/PPU_power_up_state
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*
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* @param ppu
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*/
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void ppu_init(PPU *ppu, byte *registers_ram, byte *oam_dma_register);
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/**
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* Cycles the PPU.
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*
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* @param ppu
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* @param ram
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*/
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void ppu_cycle(PPU *ppu);
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/**
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* Read a flag from the PPU registers.
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*
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* @param reg The register index
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* @param mask The flag mask
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*/
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bool ppu_read_flag(PPU *ppu, size_t reg, byte mask);
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/**
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* Read a value from the PPU registers. Does not apply any offset to the value, a mask of 0x20 will either result in 0x20 (true) or 0x0 (false).
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* Read a value from the PPU registers. Does not apply any offset to the value, a mask of 0x20 will either result in 0x20 (true) or 0x0 (false).
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*
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* @param reg The register index
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* @param mask The value mask
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*/
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void ppu_read_register(PPU *ppu, byte reg);
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void ppu_write_register(PPU *ppu, byte reg);
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#endif //NESEMULATOR_PPU_H
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