// Filename 		: STOSSPR.C
// Coded by 		: Scott Evans
// Created/Modified : 16/2/98, 19/2/98
// Description		: Contains functions to handle STOS sprites


#include <stosspr.h>


// Function		: Load4bitCLUT()
// Coded by		: Scott Evans
// Created/Modified	: 18/9/97
// Description		: Loads all CLUTs in sprite bank into VRAM

// Parameters		: hdr - address of sprite bank header
//				  x,y - location in frame buffer to load CLUTs

// Returns		: Nothing

// Notes			: Does not wait for loading to finish


void Load4bitCLUT(SprHeader *hdr,u_word x,u_word y)
{
	u_byte i;
	RECT r;
	
	setRECT(&r,x,y,16,1);
	for(i=0;i<hdr->npal;i++)
	{
		LoadImage(&r,(u_long *)((u_byte *)_GetCLUT(hdr)+_4bitCLUTSIZE*i));
		r.y++;
	}
}


// Function		: LoadSprites()
// Coded by		: Scott Evans
// Created/Modified	: 18/9/97
// Description		: Loads all sprite image data into VRAM

// Parameters		: pblk - address of sprite parameter block to start from
//				  n - number of sprites to load
//				  tx,ty - location in frame buffer to load sprites
//				  info - address of buffer to store tpage offsets and width/height
//				  flag - if 1 reset x and y (tpage offsets)

// Returns		: The number of sprites loaded

// Notes			: Does not wait for loading to finish


u_word LoadSprites(SprPblk *pblk,u_word n,u_word tx,u_word ty,SprImgInfo *info,u_byte flag)
{
	static u_word x=0,y=0;
	u_word i;
	u_byte sprw,sprh;
	static u_byte maxh=0;
	RECT r;
	
	if(flag)
		x=y=maxh=0;
	
	// Try and load n sprites into a texture page
	
	for(i=0;i<n;i++,pblk++,info++)
	{
		// Width and height of sprites
		
		sprw=pblk->w;
		maxh=((sprh=pblk->h)>maxh ? sprh : maxh);
		
		info->w=sprw;
		info->h=sprh;
		
		// Fit in as many sprites per row as possible
		
		if(!(x+sprw>TPAGE_WIDTH ? (y+maxh>TPAGE_HEIGHT ? 0 : (x=0,y+=maxh)) : 1))
		{
			maxh=x=y=0;
			break;
		}
			
		// Store offsets
			
		info->u=x;
		info->v=y;
		
		// Image data to frame buffer
		
		setRECT(&r,tx+(x>>2),ty+y,sprw>>2,sprh);
		x+=sprw;
		LoadImage(&r,(u_long *)_GetSprImgData(pblk));
		
		// Save CLUT y position
		
		info->clut_y=pblk->CLUTid;
	}

	// Return number of sprites loaded into texture page
	
	return(i);
}


// Function		: InitSpriteData()
// Coded by		: Scott Evans
// Created/Modified	: 19/2/98
// Description		: Initialise the sprite data

// Parameters		: h - address of sprite bank header
//				  i - pointer to structure to store information
//				  flag - reset texture page offsets

// Returns		: Total number of sprites in bank

// Notes			: None	


u_word InitSpriteData(SprHeader *h,SPRITE_DATA_INFO *i,u_byte flag)
{
	SprPblk *pblock=_GetSprPblks(h);
	u_word nospr=_GetNoSpr(h),n;
	
	// Make sure CLUT x coordinate is on correct boundary
	
	i->cx=((i->cx>>4)<<4);
	
	// Load all the CLUTs
	
	Load4bitCLUT(h,i->cx,i->cy);
	DrawSync(0);
	
	// Make sure texture page is on correct boundary

	i->tx=(i->tx>>6)<<6;
	i->ty=(i->ty>>8)<<8;
	
	// Load sprites
	
	n=LoadSprites(pblock,nospr,i->tx,i->ty,i->offsets,flag);
	DrawSync(0);
	
	// Return the actual number of sprites loaded
	
	i->n=n;
	
	// Calculate texture page ID
	
	i->tpage=GetTPage(TPAGE_4BIT,0,i->tx,i->ty);
	
	// Return number of sprites in sprite bank
	
	#ifdef DEBUG_INFO

	sprintf(fm_string,"Loaded %d sprites out of %d\n",n,nospr);
	PrintFM(fm_string);

	#endif

	return(nospr);
}