nuclear@0: #include <stdlib.h>
nuclear@0: #include "mouse.h"
nuclear@0: #include "inttypes.h"
nuclear@0: 
nuclear@0: 
nuclear@0: #define REG_BASE_ADDR	0xdff000
nuclear@0: #define REGNO_JOY0DAT	0x00a
nuclear@0: #define REG_JOY0DAT *(volatile uint16_t*)(REG_BASE_ADDR | REGNO_JOY0DAT)
nuclear@0: #define REG_CIAA_PORTA	*(volatile uint8_t*)0xbfe001
nuclear@0: 
nuclear@0: #define CIAA_PA_FIR0	0x40
nuclear@0: #define CIAA_PA_FIR1	0x80
nuclear@0: 
nuclear@0: static int xrng[2] = {0, 320};
nuclear@0: static int yrng[2] = {0, 240};
nuclear@0: 
nuclear@0: void set_mouse_bounds(int x0, int y0, int x1, int y1)
nuclear@0: {
nuclear@0: 	xrng[0] = x0;
nuclear@0: 	xrng[1] = x1;
nuclear@0: 	yrng[0] = y0;
nuclear@0: 	yrng[1] = y1;
nuclear@0: }
nuclear@0: 
nuclear@0: int mouse_state(int *x, int *y)
nuclear@0: {
nuclear@0: 	mouse_pos(x, y);
nuclear@0: 	return mouse_bnstate();
nuclear@0: }
nuclear@0: 
nuclear@0: int mouse_bnstate(void)
nuclear@0: {
nuclear@0: 	/* TODO: handle right mouse button */
nuclear@0: 	return (REG_CIAA_PORTA & CIAA_PA_FIR0) ? 0 : 1;
nuclear@0: }
nuclear@0: 
nuclear@0: /* TODO: for when I feel like making a proper mouse handler
nuclear@0:  * use vblank interrupt vector to read the mouse register once
nuclear@0:  * and have mouse_pos (and friends) simply access the global data
nuclear@0:  */
nuclear@0: void mouse_pos(int *x, int *y)
nuclear@0: {
nuclear@0: 	static int xpos, ypos;
nuclear@0: 	static int prev_xcount, prev_ycount;
nuclear@0: 	int xcount, ycount, dx, dy;
nuclear@0: 	uint16_t raw = REG_JOY0DAT;
nuclear@0: 
nuclear@0: 	xcount = raw & 0xff;
nuclear@0: 	ycount = raw >> 8;
nuclear@0: 
nuclear@0: 	dx = xcount - prev_xcount;
nuclear@0: 	dy = ycount - prev_ycount;
nuclear@0: 
nuclear@0: 	if(abs(dx) > 127) dx = 255 - (xcount - prev_xcount);
nuclear@0: 	if(abs(dy) > 127) dy = 255 - (ycount - prev_ycount);
nuclear@0: 	prev_xcount = xcount;
nuclear@0: 	prev_ycount = ycount;
nuclear@0: 
nuclear@0: 	xpos += dx;
nuclear@0: 	ypos += dy;
nuclear@0: 
nuclear@0: 	if(xpos < xrng[0]) xpos = xrng[0];
nuclear@0: 	if(ypos < yrng[0]) ypos = yrng[0];
nuclear@0: 	if(xpos >= xrng[1]) xpos = xrng[1] - 1;
nuclear@0: 	if(ypos >= yrng[1]) ypos = yrng[1] - 1;
nuclear@0: 
nuclear@0: 	*x = xpos;
nuclear@0: 	*y = ypos;
nuclear@0: }