// 4-bit sprite viewer, just to demonstrate how to get a sprite on screen
// This is an adaption of the 8-bit viewer I did, it just a slight cahnge in 
// the way the sprite is initialised
// I know its all been done before but if you are still stuck this might help
// Author : Paul Bircham [Doodle]
// Date : 3/7/98
// Notice : Please feel free to use this source, or parts in your program
// as long as a thanks in your demos credits are given to me
// Contact : If you have any questions about this program feel free to e-mail me at doodlek@globalnet.co.uk
// with any of your questions and I will try and answer them

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

#define Screen_Width    320				// Screen resolution variables.
#define Screen_Height   240

#define Sprite_Add      0x80090000      // memory address of sprite

#define OT_LENGTH 2						//Ordering Table length

#define MOVESPEED 1		

#define TOP_WALL 15			// collision boundaries for the screen
#define BOTTOM_WALL (Screen_Height-15)
#define LEFT_WALL 15		// so sprite doesnt move off the screen
#define RIGHT_WALL (Screen_Width-15)

// PROTOTYPE FUNCTIONS 
void InitGraphics();	
void InitOTs();		
void InitControllers() ;
void InitSprite();	
void InitBox() ;			
void MoveSprite();			
								
// GLOBALS AND SYSTEM RELATED STUFF 

GsOT            WorldOT[2];
GsOT_TAG        OTTags[2][1<<OT_LENGTH];

int    activeBuff;

u_long PadStatus ;

PACKET          GpuPacketArea[2][10*1024];

GsSPRITE sprite1;

GsBOXF box1;

// MAIN FUNCTION

void main()
{

	InitGraphics();
    InitOTs();
    InitControllers() ;
    InitSprite();
    InitBox();

	PadStatus = PadRead() ;

    while(!(PadStatus&PADselect))
    {
    	activeBuff = GsGetActiveBuff();

        GsSetWorkBase((PACKET *)GpuPacketArea[activeBuff]);

        GsClearOt(0,0,&WorldOT[activeBuff]);
                
        GsSortBoxFill(&box1,&WorldOT[activeBuff],1);	// display box as background
        GsSortSprite(&sprite1,&WorldOT[activeBuff],0);	// display sprite in foreground

        DrawSync(0);

        VSync(0);

        GsSwapDispBuff();

        GsSortClear(0,0,0,&WorldOT[activeBuff]);

        GsDrawOt(&WorldOT[activeBuff]);

		MoveSprite() ;
	}

    ResetGraph(3);
}

// INITIALISE STUFF

void InitGraphics()
{
        SetVideoMode(MODE_PAL);
        GsInitGraph(Screen_Width, Screen_Height, GsOFSGPU, 0, 0);
        GsDefDispBuff(0,0,0,Screen_Height);
}

void InitOTs()
{
        int i;

        for(i=0;i<2;i++)
        {
                WorldOT[i].length = OT_LENGTH;
                WorldOT[i].org = OTTags[i];
        }
}

void InitSprite()
{
        RECT rect;
        GsIMAGE timData ;

        // Setup Sprite

        GsGetTimInfo((u_long*)(Sprite_Add+4),&timData);

        rect.x=timData.px;
        rect.y=timData.py;
        rect.w=timData.pw;
        rect.h=timData.ph;
        LoadImage(&rect, timData.pixel);

        rect.x=timData.cx;
        rect.y=timData.cy;
        rect.w=timData.cw;
        rect.h=timData.ch;
        LoadImage(&rect, timData.clut);

        sprite1.attribute = (0<<24);
        sprite1.x = (Screen_Width/2);
        sprite1.y = (Screen_Height/2);
        sprite1.w = (timData.pw*4);
        sprite1.h = (timData.ph);
        sprite1.tpage = GetTPage(1,0,timData.px,timData.py);
        sprite1.u = 0;
        sprite1.v = 0;
        sprite1.cx = timData.cx;
        sprite1.cy = timData.cy;
        sprite1.r = 128;
        sprite1.g = 128;
        sprite1.b = 128;
        sprite1.mx = sprite1.w/2;
        sprite1.my = sprite1.h/2;
        sprite1.scalex = ONE;
        sprite1.scaley = ONE;
        sprite1.rotate = 0;

    DrawSync(0);
	
}

void InitBox()
{
	box1.attribute = (1<<30) ;
	box1.x = 0 ;
	box1.y = 0 ;
	box1.w = Screen_Width ;
	box1.h = Screen_Height ;
	box1.r = 0 ;
	box1.g = 220 ;
	box1.b = 20 ;
}

//     MAIN FUNCTIONS

void MoveSprite()
{
	PadStatus = PadRead() ;
	
	if (PadStatus&PADLup)
	{
	if ((sprite1.y - MOVESPEED)<TOP_WALL)
	{
		sprite1.y = TOP_WALL ;
	}
	else
		sprite1.y -= MOVESPEED ;
	}
	if (PadStatus&PADLdown)
	{
	if ((sprite1.y + MOVESPEED)>BOTTOM_WALL)
	{
		sprite1.y = BOTTOM_WALL ;
	}
	else
		sprite1.y += MOVESPEED ;
	}
	if (PadStatus&PADLright)
	{
	if ((sprite1.x+MOVESPEED)>RIGHT_WALL)
	{
		sprite1.x = RIGHT_WALL ;
	}
	else
		sprite1.x += MOVESPEED ;
	}
	if (PadStatus&PADLleft)
	{
	if ((sprite1.x-MOVESPEED)<LEFT_WALL)
	{
		sprite1.x = LEFT_WALL ;
	}
	else
		sprite1.x-=MOVESPEED ;
	}

}

void InitControllers()
{
	PadInit() ;
}