lcdc.c

日本的手持pda源码.wince下使用,完全开源

#include <stdlib.h>

#include "defs.h"
#include "hw.h"
#include "cpu.h"
#include "regs.h"


#define C (cpu.lcdc)

void stat_change(byte b)
{
	R_STAT = 0x80 | ((R_STAT & 0x07) | (b & 0x78));
	if (!hw.cgb && (R_LCDC & 0x80) && (R_STAT & 0x03) == 1 && R_LY != 0)
		hw_interrupt(IF_STAT);
	
	if ((R_LY == 0) && (R_LYC == 0) && (R_STAT & 0x40))
		hw_interrupt(IF_STAT);
}

void lcdc_change(byte b)
{
	if ((b & 0x80) && !(R_LCDC & 0x80)) {
		R_STAT = (R_STAT & 0xFC) | 2;
		R_LY = 0;
		lcd_begin();
	} else if (!(b & 0x80) && (R_LCDC & 0x80)) {
		R_STAT = R_STAT & 0xFC; 
        R_LY = 0;
        lcd_begin();
	}
	R_LCDC = b;
}

void ly_change(byte b)
{
}

INLINE void lyc_compare()
{
	if ((R_STAT & 0x40) && (R_LY == R_LYC))
		hw_interrupt(IF_STAT);
}

INLINE void stat_change0()
{
	R_STAT = (R_STAT & 0xFC);
	if (R_STAT & 0x08)
		hw_interrupt(IF_STAT);
}

INLINE void stat_change1()
{
	R_STAT = (R_STAT & 0xFC) | 1;
	if (R_STAT & 0x10)
		hw_interrupt(IF_STAT);
}

INLINE void stat_change2()
{
	R_STAT = (R_STAT & 0xFC) | 2;
	if (R_STAT & 0x20)
		hw_interrupt(IF_STAT);
}

INLINE void stat_change3()
{
	R_STAT = (R_STAT & 0xFC) | 3;
}

void lcdc_trans()
{
	if (!R_LCDC & 0x80)
	{
		while (C <= 0)
		{
			R_LY++;
			C += 228;

			if (R_LY > 77) //?
				R_STAT = (R_STAT & 0xFC) | 0x02;
			else
				R_STAT = R_STAT & 0xFC;
         
			if (R_LY >= 154)
			{
				R_LY = 0;
				lcd_begin();
				cpu.emulate = 0;
			}
		}
		return;
	}
	while (C <= 0)
	{
		switch ((byte)(R_STAT & 3))
		{
			case 0:
				R_LY++;
				
				lyc_compare();
				if (R_LY == 0x90) {
					stat_change1();
					hw.vblank = 1;
					C += 8;
				}
				else {
					stat_change2();
					C += 40;
				}
				break;
			case 1:
				if (hw.vblank) {
					hw_interrupt(IF_VBLANK);
					hw.vblank = 0;
					C += 228;
					break;
				}
				
				if (R_LY == 0) {
					stat_change2();
					C += 40;

					lcd_begin();
					break;
				}

				if (R_LY < 152)
					C += 228;
				else if (R_LY == 152)
					C += 28;
				else
				{
					R_LY = -1;
					C += 200;
					cpu.emulate = 0;
				}

				R_LY++;
				lyc_compare();
				stat_change1();
				break;
  			case 2:
				stat_change3();
				lcd_refreshline();
				C += 86;
				break;
			case 3:
				stat_change0();
				if (hw.hdma & 0x80)
					hw_hdma();
				C += 102;
				break;
		}
	}
}