/************************************************
 *												*
 *	   	MULTIPLE SPRITES DISPLAY PROGRAM		*
 *	   ================================== 		*
 *												*
 *		    Written by Steven Lewis				*
 *												*
 *			    Downloaded from:				*
 *	 http://www.netyaroze-europe.com/~slewis/	*
 *												*
 *					E-mail:						*
 *	stevenlewis@birminghamhome.freeserve.co.uk  *
 *												*
 ************************************************/


// --------------
// HEADER FILES
// --------------

#include <libps.h>
#include <pad.h>


// -------------
// DEFINITIONS
// -------------

#define SCREEN_WIDTH	(320)		// Width of the screen display
#define SCREEN_HEIGHT	(256)		// Height of the screen display

#define SPRITE_COUNT	(2)			// Number of sprites on screen at a time

#define SPRITE1_ADDRESS	(0x80094000)	// Memory address of sprite 1
#define SPRITE2_ADDRESS	(0x800a4000)	// Memory address of sprite 2


// -------------------------
// SPRITE STRUCTURE POINTER
// -------------------------

GsSPRITE	sprite1,sprite2;	// Two sprite structures declared, one for each sprite


// --------------------------
// ORDERING TABLE VARIABLES
// --------------------------

#define OT_LENGTH	(1)		// Sets the length of the Ordering Table

GsOT		WorldOT[2];		// Declares two Ordering Table headers, one for each graphics buffer
GsOT_TAG	OTTags[2][1<<OT_LENGTH];	// Declares two Ordering Table bodies
PACKET		GpuPacketArea[2][SPRITE_COUNT*sizeof(GsSPRITE)];	/*  Sets space for drawing the
																	OTs	*/																	
int	activeBuffer;	// Sets a variable for storing the value of the active buffer


// ------------------------------
// CONTROLLER RELATED VARIABLES
// ------------------------------

//volatile u_char *pad1Buffer, *pad2Buffer;	// Two pointers to buffers where pad info is stored

#define PORT_ONE	(0)		// Defines the value of joypad port 1
#define PORT_TWO	(1)		// Defines the value of joypad port 2

volatile u_char	*padBuffer[2];	// Variable for storing whether the pads are in use

u_long pad1Check, pad2Check;	// Variable used for checking whether either pad is being used



// ---------------------
// PROTOTYPE FUNCTIONS
// ---------------------

void InitSprite1();		// Loads sprite 1

void InitSprite2();		// Loads sprite 2

static u_long ReadPads(u_char port);	// Function for reading what is entered on the joypads

static long InitPads();		// Function for setting up the joypads

void Joypad1();	// Provides joypad 1 movement 

void Joypad2();	// Provides joypad 2 movement



// ----------------
// MAIN FUNCTION
// ----------------

void main()
{
	int i;		// Working variable
	
	SetVideoMode(MODE_PAL);		// Sets up PAL display mode
	
	GsInitGraph(SCREEN_WIDTH,SCREEN_HEIGHT,4,0,0);	// Initialises the PSX graphics mode

	GsDefDispBuff(0,0,SCREEN_WIDTH,SCREEN_HEIGHT);	// Sets up the double buffering display mode
	
	// 'if' loop to slightly correct the PAL display problem which produces a 'letterboxed' view
	if(SCREEN_HEIGHT==256)
		GsDISPENV.screen.h = SCREEN_HEIGHT;
		
	// 'for' loop to initialise the Ordering Tables
	for(i=0;i<2;i++)
	{
		WorldOT[i].length = OT_LENGTH;
		WorldOT[i].org = OTTags[i];
	}
	
	InitSprite1();		// Load sprite 1 into memory by calling the InitSprite1() function
	InitSprite2();		// Load sprite 2 into memory
	
	
	GetPadBuf(&padBuffer[0],&padBuffer[1]);	// Sets the address of the joypad buffers
	
	//Main program loop
	while((InitPads()) != 99)
	{
		
		Joypad1();	// Calls joypad one function
			
		Joypad2();	// Calls joypad two function
		
		activeBuffer = GsGetActiveBuff();	// Finds out which buffer is active
		
		GsSetWorkBase((PACKET *)GpuPacketArea[activeBuffer]);	/*  Initialises the space for
																	drawing the OT	*/
		
		GsClearOt( 0, 0, &WorldOT[activeBuffer]);	// Clears the OT
		
		GsSortSprite(&sprite1,&WorldOT[activeBuffer],0);	// Draws sprite 1 into OT
		
		GsSortSprite(&sprite2,&WorldOT[activeBuffer],0);	// Draws sprite 2 into OT
		
		DrawSync(0);	// Waits for all of the above to finish before continuing
		
		VSync(0);		// Waits for the vertical retrace on the TV to finish
		
		GsSwapDispBuff();	// Swaps the display buffers
		
		GsSortClear(0,0,0,&WorldOT[activeBuffer]);	// Sorts the OT
		
		GsDrawOt(&WorldOT[activeBuffer]);	// Draw the OT into the active buffer
	}
}


// ---------------------------
// JOYPAD 1 MOVEMENT FUNCTION
// ---------------------------

void Joypad1()
{
	// Joypad One movement code
		if(pad1Check & PADLleft)	// If left is pressed...
			sprite1.x -= 5;			// 	...move 5 to the left
			
		if(pad1Check & PADLright)	// If right is pressed...
			sprite1.x += 5;			//	...move 5 to the right
			
		if(pad1Check & PADLup)
			sprite1.y -= 5;
		
		if(pad1Check & PADLdown)
			sprite1.y += 5;
}


// ---------------------------
// JOYPAD 2 MOVEMENT FUNCTION
// ---------------------------

void Joypad2()
{
	// Joypad 2 movement code
	if(pad2Check & PADLleft)
		sprite2.x -= 5;
		
	if(pad2Check & PADLright)
		sprite2.x += 5;
			
	if(pad2Check & PADLup)
		sprite2.y -= 5;
		
	if(pad2Check & PADLdown)
		sprite2.y += 5;
}
			

// --------------------------
// SPRITE 1 LOADING FUNCTION
// --------------------------

void InitSprite1()
{
	RECT	rect;	// Creates a retangular structure to put around the sprite
	
	GsIMAGE tim_info;	// Creates a structure for storing all relevant TIM file information
	
	GsGetTimInfo((u_long *)(SPRITE1_ADDRESS+4),&tim_info);	/*	Gets all information required
																about the TIM file and stores
																it at the memory address of
																tim_info	*/
	
	// Load sprite into the frame buffer
	rect.x = tim_info.px;		// x position of sprite
	rect.y = tim_info.py;		// y position of sprite
	rect.w = tim_info.pw;		// width of sprite
	rect.h = tim_info.ph;		// height of sprite
	LoadImage(&rect,tim_info.pixel);	// Load all of the above into the frame buffer
	
	// Load CLUT into the frame buffer, if the TIM file has one
	if((tim_info.pmode>>3) & 0x01)
	{
		rect.x = tim_info.cx;		// x position of CLUT
		rect.y = tim_info.cy;		// y position of CLUT
		rect.w = tim_info.cw;		// width of CLUT
		rect.h = tim_info.ch;		// height of CLUT
		LoadImage(&rect,tim_info.clut);		// Loads all of the above into the frame buffer
	}
	
	// Initialise the sprite structure:'switch' statement enables different TIM types to be used
	switch(tim_info.pmode)
	{
		// If the image is 4-bit
		case 0x08:	sprite1.attribute = 0x00000000;	// Sets the sprite attribute
					sprite1.w = tim_info.pw * 4;	// Sets the width of the sprite
					sprite1.tpage = GetTPage(0,0,tim_info.px,tim_info.py); /* Gets texture page
																			 info	*/
					break;	// Breaks from the switch statement
					
		// If the image is 8-bit
		case 0x09:	sprite1.attribute = 0x01000000;	
					sprite1.w = tim_info.pw * 2;	
					sprite1.tpage = GetTPage(0,0,tim_info.px,tim_info.py);
					break;
					
		// If the image is 16-bit
		default:	sprite1.attribute = 0x02000000;
					sprite1.w = tim_info.pw;
					sprite1.tpage = GetTPage(0,0,tim_info.px,tim_info.py);
					break;
	}
	
	sprite1.x = 50;			// x position on screen of the sprite
	sprite1.y = 100;			// y position on screen of the sprite
	
	sprite1.h = tim_info.ph;	// sprite height
	
	sprite1.u = 0;			// Texture page offset - x axis
	sprite1.v = 0;			// Texture page offset - y axis
	
	sprite1.cx = tim_info.cx;	// CLUT x axis position
	sprite1.cy = tim_info.cy;	// CLUT y axis position
	
	sprite1.r = 128;		// Applies red tint to the sprite - 128 is normal
	sprite1.g = 128;		// Applies green tint to the sprite - 128 is normal
	sprite1.b = 128;		// Applies blue tint to the sprite - 128 is normal
	
	sprite1.mx = (sprite1.w/2);		// Sets the center point of the image - x axis
	sprite1.my = (sprite1.h/2);		// Sets the center point of the image - y axis
	
	sprite1.scalex = ONE;	// Sets scale ratio to 1:1 on the x axis
	sprite1.scaley = ONE;	// Sets scale ratio to 1:1 on the y axis
	
	sprite1.rotate = 0;		// Sets sprite rotation to 'off'
	
	DrawSync(0);	// Waits for all the above to finish before continuing
} 
	
	

// ------------------------------
// INITIALISE SPRITE 2 FUNCTION
// ------------------------------

void InitSprite2()
{
	RECT	rect;	// Creates a retangular structure to put around the sprite
	
	GsIMAGE tim_info;	// Creates a structure for storing all relevant TIM file information
	
	GsGetTimInfo((u_long *)(SPRITE2_ADDRESS+4),&tim_info);	/*	Gets all information required
																about the TIM file and stores
																it at the memory address of
																tim_info	*/
	
	// Load sprite into the frame buffer
	rect.x = tim_info.px;		// x position of sprite
	rect.y = tim_info.py;		// y position of sprite
	rect.w = tim_info.pw;		// width of sprite
	rect.h = tim_info.ph;		// height of sprite
	LoadImage(&rect,tim_info.pixel);	// Load all of the above into the frame buffer
	
	// Load CLUT into the frame buffer, if the TIM file has one
	if((tim_info.pmode>>3) & 0x01)
	{
		rect.x = tim_info.cx;		// x position of CLUT
		rect.y = tim_info.cy;		// y position of CLUT
		rect.w = tim_info.cw;		// width of CLUT
		rect.h = tim_info.ch;		// height of CLUT
		LoadImage(&rect,tim_info.clut);		// Loads all of the above into the frame buffer
	}
	
	// Initialise the sprite structure:'switch' statement enables different TIM types to be used
	switch(tim_info.pmode)
	{
		// If the image is 4-bit
		case 0x08:	sprite2.attribute = 0x00000000;	// Sets the sprite attribute
					sprite2.w = tim_info.pw * 4;	// Sets the width of the sprite
					sprite2.tpage = GetTPage(0,0,tim_info.px,tim_info.py); /* Gets texture page
																			 info	*/
					break;	// Breaks from the switch statement
					
		// If the image is 8-bit
		case 0x09:	sprite2.attribute = 0x01000000;	
					sprite2.w = tim_info.pw * 2;	
					sprite2.tpage = GetTPage(0,0,tim_info.px,tim_info.py);
					break;
					
		// If the image is 16-bit
		default:	sprite2.attribute = 0x02000000;
					sprite2.w = tim_info.pw;
					sprite2.tpage = GetTPage(0,0,tim_info.px,tim_info.py);
					break;
	}
	
	sprite2.x = 225;			// x position on screen of the sprite
	sprite2.y = 85;			// y position on screen of the sprite
	
	sprite2.h = tim_info.ph;	// sprite height
	
	sprite2.u = 0;			// Texture page offset - x axis
	sprite2.v = 0;			// Texture page offset - y axis
	
	sprite2.cx = tim_info.cx;	// CLUT x axis position
	sprite2.cy = tim_info.cy;	// CLUT y axis position
	
	sprite2.r = 128;		// Applies red tint to the sprite - 128 is normal
	sprite2.g = 128;		// Applies green tint to the sprite - 128 is normal
	sprite2.b = 128;		// Applies blue tint to the sprite - 128 is normal
	
	sprite2.mx = (sprite2.w/2);
	sprite2.my = (sprite2.h/2);
	
	sprite2.scalex = ONE;	// Sets scale ratio to 1:1 on the x axis
	sprite2.scaley = ONE;	// Sets scale ratio to 1:1 on the y axis
	
	sprite2.rotate = 0;		// Sets sprite rotation to 'off'
	
	DrawSync(0);	// Waits for all the above to finish before continuing
} 


// ----------------------
// PAD READING FUNCTION
// ----------------------

static u_long ReadPads(u_char port)	// Reads what is being pressed on the joypads
{
	return(~(*(padBuffer[port]+3)|*(padBuffer[port]+2)<<8)); 
}



// -----------------------------
// PAD INITIALISATION FUNCTION
// -----------------------------

static long InitPads()
{
	pad1Check = ReadPads(PORT_ONE);	// Calls the above function for joypad 1
	pad2Check = ReadPads(PORT_TWO);	// Calls the above function for joypad 2
	
	if(pad1Check & PADselect)
		return(99);		// Returns 99 to the main() function if 'select' is pressed
}