//////////////////////////////////////////////////////////////////////
// Simple ARM9 demo (touch screen controls the colors)
// -- joat
//////////////////////////////////////////////////////////////////////

#include <NDS/NDS.h>
#include <NDS/ARM9/rand.h>

#include "ball.h"

//////////////////////////////////////////////////////////////////////
#define NUM_SPRITES 128	

sSpriteEntry OAMCopySub[128];

//////////////////////////////////////////////////////////////////////

//simple sprite struct
typedef struct
{
   int x,y;	//location 
   int dx, dy;	//speed
   sSpriteEntry* oam;	
   int gfxID; //graphics lovation
}Sprite;

///////////////////////////////////////////////////////////////////////

void MoveSprite(Sprite* sp)
{
	int x = sp->x >> 8;
	int y = sp->y >> 8;

   sp->oam->attribute[1] &= 0xFE00;
   sp->oam->attribute[1] |= (x & 0x01FF);
 
   sp->oam->attribute[0] &= 0xFF00;
   sp->oam->attribute[0] |= (y & 0x00FF);

} 
///////////////////////////////////////////////////////////////////////
void initOAM(void)
{
	int i;

	for(i = 0; i < 128; i++)
	{
		OAMCopySub[i].attribute[0] = ATTR0_DISABLED;
	}	
}

//////////////////////////////////////////////////////////////////////
void updateOAM(void)
{
	int i;
	
	for(i = 0; i < 128 * sizeof(sSpriteEntry) / 4 ; i++)
	{
		((uint32*)OAM_SUB)[i] = ((uint32*)OAMCopySub)[i];
	}
}

///////////////// C code entry (main())/////////////////////
int main(void) 
{
	
	/////////variables
	uint16* back = VRAM_A;
	uint16* front = VRAM_B;

	Sprite sprites[NUM_SPRITES];

	int i, delta = 0;
	int ix = 0;
	int iy = 0;
	int screen = 1;
	uint16* map0 = (uint16*)SCREEN_BASE_BLOCK_SUB(1);
	uint16* map1 = (uint16*)SCREEN_BASE_BLOCK_SUB(2);
	uint16 red;
	
	
	///////////////set up/////////////
	//set main display to render directly from the frame buffer
	videoSetMode(MODE_FB1);
	
	//set up the sub display
	videoSetModeSub(MODE_0_2D | 
					DISPLAY_SPR_1D_LAYOUT | 
					DISPLAY_SPR_ACTIVE | 
					DISPLAY_BG0_ACTIVE |
					DISPLAY_BG1_ACTIVE );
	
	//vram banks are somewhat complex
	vramSetMainBanks(VRAM_A_LCD, VRAM_B_LCD, VRAM_C_SUB_BG, VRAM_D_SUB_SPRITE);
	
	//irqs are nice..ndslib comes with a very unoptomized default handler
//	irqInitHandler(irqDefaultHandler);
//	irqSet(IRQ_VBLANK, 0);
  
	/////////////Init the sprites ///////////
	for(i = 0; i < 256; i++)
		SPRITE_PALETTE_SUB[i] = ballpalette_bin[i];

	for(i = 0; i< 32*16; i++)
		SPRITE_GFX_SUB[i] = balldata_bin[i];
	
	//turn of sprites
	initOAM();

	for(i = 0; i < NUM_SPRITES; i++)
	{
		//random place and speed
		sprites[i].x = rand() & 0xFFFF;
		sprites[i].y = rand() & 0x7FFF;
		sprites[i].dx = (rand() & 0xFF) + 0x100;
		sprites[i].dy = (rand() & 0xFF) + 0x100;
	
		if(rand() & 1)
			sprites[i].dx = -sprites[i].dx;
		if(rand() & 1)
			sprites[i].dy = -sprites[i].dy;
	
		sprites[i].oam = &OAMCopySub[i];
		sprites[i].gfxID = 0;
	
		//set up our sprites OAM entry attributes
		sprites[i].oam->attribute[0] = ATTR0_COLOR_256 | ATTR0_SQUARE;  
		sprites[i].oam->attribute[1] = ATTR1_SIZE_32;
		sprites[i].oam->attribute[2] = sprites[i].gfxID;
		}

	//set up two backgrounds to scroll around
	SUB_BG0_CR = BG_COLOR_256 | (1 << SCREEN_SHIFT);
	SUB_BG1_CR = BG_COLOR_256 | (2 << SCREEN_SHIFT);

	BG_PALETTE_SUB[0] = RGB15(10,10,10);
	BG_PALETTE_SUB[1] = RGB15(0,16,0);
	BG_PALETTE_SUB[2] = RGB15(0,0,31);
	
	//load the maps with alternating tiles (0,1 for bg0 and 0,2 for bg1)
	for(iy = 0; iy < 32; iy++)
	for(ix = 0; ix <32; ix++)
	{
		map0[iy * 32 + ix] = (ix ^ iy) & 1;
		map1[iy * 32 + ix] = ((ix ^ iy) & 1)<<1;
	}    
	//fill 2 tiles with different colors
	for(i = 0; i < 64 / 2; i++)
	{
		BG_GFX_SUB[i+32] = 0x0101;
		BG_GFX_SUB[i+32+32] = 0x0202;
	}	
        
	while (1) 
	{
		//scroll the background
		SUB_BG0_X0 = delta ;
		SUB_BG0_Y0 = delta++ ;
		
		//move the sprites
		for(i = 0; i < NUM_SPRITES; i++)
		{
			sprites[i].x += sprites[i].dx;
			sprites[i].y += sprites[i].dy;
			
			//check for collision with the screen boundries
			if(sprites[i].x < (1<<8) || sprites[i].x > (247 << 8))
				sprites[i].dx = -sprites[i].dx;
			if(sprites[i].y < (1<<8) || sprites[i].y > (182 << 8))
				sprites[i].dy = -sprites[i].dy;
			
			//reposition the sprites
			MoveSprite(&sprites[i]);
		}
		
#define KEY_TOUCH (((~IPC->buttons) << 6) & (1<<12))
                if(KEY_TOUCH)
                {
                    int tx=0;
                    int ty=0;
                    const int divx = 14;
                    const int divy = 18;
                    const int subx = 00;
                    const int suby = 12;

                    tx = IPC->touchX / divx - subx;
                    ty = IPC->touchY / divy - suby;
                    for(int y=-3;y<=3; y++)
                    {
                        for(int x=-3;x<=3; x++)
                        {
                            front[(ty+y)*256 + (tx+x)] = 0xFFFF;
                        }
                    }
                }

	
		//do the plasma/fire
		for(ix = 0; ix < SCREEN_WIDTH; ix++)
		{
			back[ix + SCREEN_WIDTH * (SCREEN_HEIGHT - 1)] = rand()& 0xFFFF;
			back[ix + SCREEN_WIDTH * (SCREEN_HEIGHT - 2)] = rand()& 0xFFFF;
		}

		back++;
		
		for(iy = 1; iy < SCREEN_HEIGHT - 2 ; iy++)
		{
			for(ix = 1; ix < SCREEN_WIDTH - 1; ix++) 
			{
				red = 0;

				red += front[0];
				red += front[2];
				
				
				front += SCREEN_WIDTH;

				red += front[0];
				red += front[1];
				red += front[2];
				
				front += SCREEN_WIDTH;

				red += front[0];
				red += front[1];
				red += front[2];

				
				front -= (2 * SCREEN_WIDTH) - 1;	
			
				back[0] =  (red >> 3);	
				back++;
			}
			back += 2;
			front += 2;
		
		}

		swiWaitForVBlank();
		
		updateOAM();

		if(screen)
		{
			videoSetMode(MODE_FB1);
			front = VRAM_B;
			back = VRAM_A;
			screen = 0;
		}
		else
		{
			videoSetMode(MODE_FB0);	
			front = VRAM_A;
			back = VRAM_B;
			screen = 1;
		}
	}    
	return 0;
}

//////////////////////////////////////////////////////////////////////