Oscar64ShadowedNESExample.c

//	compile with OSCAR64
//
// 	oscar64.exe -tm=nes -n boot.c -O2 -o=bin\boot.nes 
// 	https://github.com/drmortalwombat/oscar64

#include <nes/nes.h>
#include <nes/neslib.h>

extern char PAL_BUF[32];
extern char PAL_UPDATE;

#pragma section( tiles, 0 )
#pragma region( tbank, 0x0000, 0x2000, , 0, { tiles } )

#pragma data(tiles)
__export char tiles[] = {
	#embed "data/rogue.chr"
};

#pragma data(data)
const char PaletteData[] = {
	#embed "data/rogue_bg.pal"
};

#pragma data(data)
const char SprPaletteData[4][16] = {
	{
		//	blue player palette
		#embed "data/rogue_spr.pal"
	}
	,
	{
		//	red player palette
		#embed "data/rogue_spr2.pal"
	}
};

#pragma data(data)
const char NamData[] = {
	#embed "data/rogue.nam"
};

#pragma data(data)
const char PropData[] = {
	#embed "data/rogue.tprop"
};

typedef struct 
{
	char x,y;
	char direction;
	char frame;
} _ent_t_;

__striped __zeropage _ent_t_ ents[2];
__zeropage char ticker;
__zeropage unsigned char controller;
__zeropage unsigned char xx,yy,sprid;
__zeropage char *c;
__zeropage char animspeed,displayframe;
__zeropage unsigned char overchar;
__zeropage char lastX;
__zeropage char lastY;


//	y step lookup table
__striped unsigned char *ycollision[30];

//	pass the pointer to the nametable 
void generateCollisionLookup(unsigned char *ptr)
{
	for (char y=0;y<30;y++)
	{
		ycollision[y]=ptr;
		ptr+=32;
	}
}
//	get the tile from the map via the ycollision lookup table
inline unsigned char getMapChar(char p)
{
	xx = (ents[p].x+4)>>3;
	yy = (ents[p].y+6)>>3;
	c = ycollision[yy];
	return (c[xx]);
}
//	get the property
unsigned char getPropertyChar(char p)
{
	return (PropData[getMapChar(p)]);
}

//	set partial palette
void SetSpritePalette(char spr,char *pal)
{
	spr<<=2;
	PAL_BUF[spr + 17] = pal[1];
	PAL_BUF[spr + 18] = pal[2];
	PAL_BUF[spr + 19] = pal[3];
	PAL_UPDATE++;	
}

//	player input and control
void Player(char p)
{
	lastX = ents[p].x;
	lastY = ents[p].y;
	controller = pad_poll(p);
	animspeed = 0;
	if(controller & PAD_LEFT)
	{
		ents[p].direction=3;
		ents[p].x-=1;
		animspeed= 1;
	}
	if(controller & PAD_RIGHT)
	{
		ents[p].direction=2;
		ents[p].x+=1;
		animspeed = 1;
	}
	//	check for blocking char X movement
	overchar = getPropertyChar(p);
	if ((overchar&0x80)!=0)
	{
		animspeed=0;
		ents[p].x=lastX;
	}

	if(controller & PAD_UP)
	{
		ents[p].direction=1;
		ents[p].y-=1;
		animspeed = 1;
	}
	if(controller & PAD_DOWN)
	{
		ents[p].direction=0;
		ents[p].y+=1;
		animspeed = 1;
	}
	//	check for blocking char Y movement
	overchar = getPropertyChar(p);
	if ((overchar&0x80)!=0)
	{
		animspeed=0;
		ents[p].y=lastY;
	}
	ents[p].frame+=animspeed;

	overchar = getPropertyChar(p)&3;
	SetSpritePalette(p,(char*)&SprPaletteData[p][overchar<<2]);
	displayframe = (ents[p].direction<<4) + 1 + ((ents[p].frame>>2)&7);
	sprid=oam_spr(ents[p].x,ents[p].y,displayframe,p,sprid);
}

void nes_game(void)
{
	ppu_wait_nmi();
	ppu_off();
	pal_bg(PaletteData);
	oam_clear();
	generateCollisionLookup((unsigned char*)&NamData[0]);
	//	copy screen map, lazy 
	vram_adr(0x2000);
	for(char i=0; i<32; i++)
	{
		ppu_wait_nmi();
		vram_write(NamData + 32 * i, 32);
	}
	ticker =0;
	//	set up
	ents[0].x = 48;
	ents[0].y = 64;
	ents[0].frame = 0;
	ents[0].direction = 0;
	ents[1].x = 192;
	ents[1].y = 32;
	ents[1].frame = 0;
	ents[1].direction = 0;

	ppu_on_all();
	ppu.mask=0x1f;
	for(;;)
	{
		ppu_wait_nmi();

		sprid = (ticker&1)<<2;

		Player(ticker&1);

		sprid=8;	//	8 bytes on after the two player sprites

		ticker++;
	}
}