void main(void)
{
ppu_on_all();//enable rendering
//set initial coords
cat_x[0]=52;
cat_y[0]=100;
cat_x[1]=180;
cat_y[1]=100;
//init other vars
touch=0;//collision flag
frame=0;//frame counter
//now the main loop
while(1)
{
ppu_waitnmi();//wait for next TV frame
//flashing color for touch
i=frame&1?0x30:0x2a;
pal_col(17,touch?i:0x21);//set first sprite color
pal_col(21,touch?i:0x26);//set second sprite color
//process players
spr=0;
for(i=0;i<2;++i)
{
//display metasprite
spr=oam_meta_spr(cat_x[i],cat_y[i],spr,!i?metaCat1:metaCat2);
//poll pad and change coordinates
pad=pad_poll(i);
if(pad&PAD_LEFT &&cat_x[i]> 0) cat_x[i]-=2;
if(pad&PAD_RIGHT&&cat_x[i]<232) cat_x[i]+=2;
if(pad&PAD_UP &&cat_y[i]> 0) cat_y[i]-=2;
if(pad&PAD_DOWN &&cat_y[i]<212) cat_y[i]+=2;
}
//check for collision for a smaller bounding box
//metasprite is 24x24, collision box is 20x20
if(!(cat_x[0]+22< cat_x[1]+2 ||
cat_x[0]+ 2>=cat_x[1]+22||
cat_y[0]+22< cat_y[1]+2 ||
cat_y[0]+ 2>=cat_y[1]+22)) touch=1; else touch=0;
frame++;
}
}
void main(void) {
//set palette for sprites
pal_spr(palSprites);
// set background color to black
pal_col(0, 0x0f);
//enable rendering
ppu_on_all();
//initialize invader parameters
for(i=0;i<INVADERS_MAX;++i) {
//starting coordinates
invader_x[i]=rand8();
invader_y[i]=rand8();
//direction bits
j=rand8();
//horizontal speed -3..-3, excluding 0
spr=1+(rand8()%3);
invader_dx[i]=j&1?-spr:spr;
//vertical speed
spr=1+(rand8()%3);
invader_dy[i]=j&2?-spr:spr;
}
//the main loop
while(1) {
//wait for next TV frame
ppu_wait_frame();
spr=0;
for(i=0;i<INVADERS_MAX;++i) {
//set a sprite for current invader
spr=oam_spr(invader_x[i],invader_y[i],0x40,i&3,spr);//0x40 is tile number, i&3 is palette
//move the invader
invader_x[i]+=invader_dx[i];
invader_y[i]+=invader_dy[i];
//bounce the invader off the edges
if(invader_x[i]>=(256-8)) invader_dx[i]=-invader_dx[i];
if(invader_y[i]>=(240-8)) invader_dy[i]=-invader_dy[i];
}
}
}
void main(void)
{
static unsigned char i,row;
static int y;
static unsigned int adr;
pal_col(1,0x30);//set while color
y=0;
update_list[0]=0x20|NT_UPD_HORZ;//horizontal update sequence, dummy address
update_list[1]=0x00;
update_list[2]=32;//update sequence is 32 tiles wide
update_list[3+32]=NT_UPD_EOF;
set_vram_update(update_list);
ppu_on_all();//enable rendering
while(1)
{
scroll(0,y);//scroll value will be applied on the next nmi
if(!(y&7))//put new row every 8 pixels
{
row=(y>>3)+59;//get row number for update, it is shifted just above the visible part of the screen
if(row>=60) row-=60;//keep the row number within the limits
adr=row<<5;//convert Y from pixels to tiles (row=y/8), then to nametable offset (offset=row*32)
if(adr<960) adr=adr|NAMETABLE_A; else adr=(adr-960)|NAMETABLE_C;//add base address of one of two nametables
update_list[0]=MSB(adr)|NT_UPD_HORZ;//set the address
update_list[1]=LSB(adr);
for(i=0;i<32;++i) update_list[3+i]=0x10+(rand8()&7);//fill row buffer with random tiles
}
--y;//next pixel
if(y<0) y=240*2-1;//keep Y within the total height of two nametables
ppu_wait_nmi();
}
void title_screen(void)
{
scroll(-8,240);//title is aligned to the color attributes, so shift it a bit to the right
unrle_vram(title_nam,0x2000);
vram_adr(0x2800);//clear second nametable, as it is visible in the jumping effect
vram_fill(0,1024);
pal_bg(palTitle);
pal_bright(4);
ppu_on_bg();
delay(20);//delay just to make it look better
iy=240<<FP_BITS;
dy=-8<<FP_BITS;
frame_cnt=0;
wait=160;
bright=4;
while(1)
{
ppu_waitnmi();
scroll(-8,iy>>FP_BITS);
if(pad_trigger(0)&PAD_START) break;
iy+=dy;
if(iy<0)
{
iy=0;
dy=-dy>>1;
}
if(dy>(-8<<FP_BITS)) dy-=2;
if(wait)
{
--wait;
}
else
{
pal_col(2,(frame_cnt&32)?0x0f:0x20);//blinking press start text
++frame_cnt;
}
}
