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8bitworkshop/presets/c64/common.h
2024-10-26 10:54:17 -05:00

145 lines
4.2 KiB
C

#ifndef _COMMON_H
#define _COMMON_H
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <peekpoke.h>
#include <string.h>
#include <c64.h>
#ifdef __CC65__
#include <conio.h>
#include <joystick.h>
#endif
typedef uint8_t byte; // 8-bit unsigned
typedef int8_t sbyte; // 8-bit signed
typedef uint16_t word; // 16-bit unsigned
typedef enum { false, true } bool; // boolean
#define COLS 40 // total # of columns
#define ROWS 25 // total # of rows
///// MACROS /////
// VIC Control Register 1 Flags
#define VIC_CTRL1_RST8 0x80 // Bit 8 of RASTER (read) or raster line interrupt set (write)
#define VIC_CTRL1_ECM 0x40 // Extended Color Mode
#define VIC_CTRL1_BMM 0x20 // Bitmap Mode
#define VIC_CTRL1_DEN 0x10 // Display Enable
#define VIC_CTRL1_RSEL 0x08 // Row Select (25 or 24 rows)
#define VIC_CTRL1_YSCROLL_MASK 0x07 // Vertical Fine Scrolling
// VIC Control Register 2 Flags
#define VIC_CTRL2_RES 0x20 // Chip reset
#define VIC_CTRL2_MCM 0x10 // Multicolor Mode Enable
#define VIC_CTRL2_CSEL 0x08 // Column Select (40 or 38 columns)
#define VIC_CTRL2_XSCROLL_MASK 0x07 // Horizontal Fine Scrolling
// VIC Memory Control Register Flags
#define VIC_ADDR_VM_MASK 0xf0 // Video Matrix Base Address Mask (character data)
#define VIC_ADDR_CB_MASK 0x0e // Character Bank Base Address Mask (screen memory)
// VIC Interrupt Register Flags
#define VIC_IRR_IRQ 0x80 // Interrupt Request
#define VIC_IRR_ILP 0x08 // Light Pen Interrupt
#define VIC_IRR_IMMC 0x04 // Sprite-Sprite Collision Interrupt
#define VIC_IRR_IMBC 0x02 // Sprite-Background Collision Interrupt
#define VIC_IRR_IRST 0x01 // Raster Line Interrupt
// VIC Interrupt Mask Register Flags
#define VIC_IMR_ELP 0x08 // Enable Light Pen Interrupt
#define VIC_IMR_EMMC 0x04 // Enable Sprite-Sprite Collision Interrupt
#define VIC_IMR_EMBC 0x02 // Enable Sprite-Background Collision Interrupt
#define VIC_IMR_ERST 0x01 // Enable Raster Interrupt
// lookup screen address macro
#define SCRNADR(base,col,row) ((base)+(col)+(row)*40)
// default screen base address on startup
#define DEFAULT_SCREEN ((void*)0x400)
// is raster line > 255?
#define RASTER_HIBIT (VIC.ctrl1 & 0x80)
// set VIC Bank (given the start address)
#define SET_VIC_BANK(_addr) \
CIA2.pra = (CIA2.pra & ~3) | (((((_addr)>>8)&0xc0)>>6)^3);
// set VIC character memory (given the start address)
#define SET_VIC_BITMAP(_addr) \
VIC.addr = (VIC.addr & 0b11110001) | ((((_addr)>>8)&0x38)>>2);
// set VIC screen memory (given the start address)
#define SET_VIC_SCREEN(_addr) \
VIC.addr = (VIC.addr & 0b00001111) | ((((_addr)>>8)&0x3c)<<2);
// set scrolling registers
#define SET_SCROLL_Y(_y) \
VIC.ctrl1 = (VIC.ctrl1 & 0xf8) | (_y & 7);
#define SET_SCROLL_X(_x) \
VIC.ctrl2 = (VIC.ctrl2 & 0xf8) | (_x & 7);
// enable RAM from 0xa000-0xffff, disable interrupts
#define ENABLE_HIMEM() \
asm("php"); \
asm("sei"); \
POKE(1, PEEK(1) & ~0b111);
// enable ROM and interrupts
#define DISABLE_HIMEM() \
POKE(1, PEEK(1) | 0b110); \
asm("plp");
// are we on a PAL system?
#define IS_PAL() (PEEK(0x2a6) != 0)
///// FUNCTIONS /////
// wait until specific raster line
void raster_wait(byte line);
// wait until end of frame
void wait_vblank();
// get current VIC bank start address
char* get_vic_bank_start();
// get current screen memory address
char* get_screen_memory();
// read joystick fast
#define READ_STICK(index) ~PEEK(0xdc01-(index))
#define STICK_UP(joy) ((joy & 0x1) != 0)
#define STICK_DOWN(joy) ((joy & 0x2) != 0)
#define STICK_LEFT(joy) ((joy & 0x4) != 0)
#define STICK_RIGHT(joy) ((joy & 0x8) != 0)
#define STICK_BUTTON(joy) ((joy & 0x10) != 0)
#define STICK_MOVED(joy) ((joy & 0x1f) != 0)
#ifdef __CC65__
// return key in buffer, or 0 if none (BIOS call)
char __fastcall__ poll_keyboard();
#endif
#ifndef __CC65__
inline void clrscr() {
__asm__ volatile ("jsr $E544" : : : "a","x","y"); // regs clobbered
}
inline void waitvsync() {
raster_wait(255);
}
#endif
// for use with set_irq()
// sets up the VIC to send raster interrupts
// and disables CIA interrupts
void set_raster_irq(char scanline);
#endif