// Program name: cube3d - Game-Editor Version
// Description: Draws a 3D wireframe cube from a database of 3d coordinates
// Based on C code from Lee Adams book -
// 1988 - High Performance Graphics in C Animation and Simulation


// Conversion by: Christopher Hill - TrajectoryLabs.com
// First release: 04/30/2006
// Revised: 00/00/0000


// GAME-EDITOR GLOBAL CODE PORTION


// D E C L A R A T I O N S ----------------------------------------------------
// Declare Variables and Arrays -----------------------------------------------


float xw=0.0,yw=0.0,zw=0.0;				// world coordinates
float sx=0.0,sy=0.0;					// 3D perspective formulas output
float xa=0.0,ya=0.0,za=0.0;				// temp 3D formula values
float sxa=0.0,sya=0.0,sxb=0.0,syb=0.0;	// 2D line endpoints
float sxs=0.0,sys=0.0;					// temp 2D line startpoints
float temp_swap=0.0;					// swap variable holder
float d=500.0;							// angular perspective factor - startval 1200
double r1=5.68319;						// yaw angle in radians - startval 5.68319
double r2=6.48319;						// roll angle in radians - startval 6.28319
double r3=5.59778;						// pitch angle in radians - startval 5.79778
double sr1=0.0,sr2=0.0,sr3=0.0;			// sine rotation factors
double cr1=0.0,cr2=0.0,cr3=0.0;			// cosine rotation factors
float mx=-70.0,my=-90.0,mz=-275.0;			// viewpoint position - startvals 0.0,0.0,350.0
int maxx=160,minx=-160,maxy=120,miny=-120;	// clipping viewport - startvals 638,1,198,1
float screen_x=638,screen_y=199;		// screen dimensions - startvals 638, 199
float c=0.0;							// line clipping variable
float rx=0.0,ry=0.0;					// mapping routine scaling values
int t1=0,t2=0;							// loop counters
int p1=0;                               // array indexer


int c0=0,c1=1,c2=2,c3=3,c4=4,c5=5,c6=6,c7=7,c8=8,c9=9,c10=10,
	c11=11,c12=12,c13=13,c14=14,c15=15;
float sx1,sy1,sx2,sy2;
float x_res,y_res;




// database of xyz cartesian world coordinates for the cube


int array1[][3]={
 30,-30, 30,  30,-30,-30, -30,-30,-30, -30,-30, 30,  30,-30, 30,
 30, 30,-30, -30, 30,-30, -30,-30,-30,  30,-30,-30,  30, 30,-30,
-30, 30,-30, -30, 30, 30, -30,-30, 30, -30,-30,-30, -30, 30,-30,
-30, 30, 30,  30, 30, 30,  30,-30, 30, -30,-30, 30, -30, 30, 30,
 30, 30, 30,  30, 30,-30,  30,-30,-30,  30,-30, 30,  30, 30, 30,
-30, 30,-30,  30, 30,-30,  30, 30, 30, -30, 30, 30, -30, 30, 30,
-30, 30,-30,  30, 30,-30,  30, 30, 30, -30, 30, 30, -30, 30,-30};




// F U N C T I O N S ------------------------------------------------------------
// Define Functions -------------------------------------------------------------




// Calculate SIN, COS Factors
// Enter with r1,r2,r3 viewing angles of yaw, pitch and roll expressed in
// radians (0.0 through 6.28319
// Returns sine and cosine factors


void rotation(double r1, double r2, double r3)
{
sr1=sin(r1);
sr2=sin(r2);
sr3=sin(r3);
cr1=cos(r1);
cr2=cos(r2);
cr3=cos(r3);
}




// Standard 3D Formulas
// Enter with x,y,z cartesian world coordinates
// Returns sx,sy cartesian display coordinates
// Returns x,y,z cartesian view coordinates


void calc_3d (float xw, float yx, float zw)
{
xw=(-1)*xw;
xa=cr1*xw-sr1*zw;
za=sr1*xw+cr1*zw;
xw=cr2*xa+sr2*yw;
ya=cr2*yw-sr2*xa;
zw=cr3*za-sr3*ya;
yw=sr3*za+cr3*ya;
xw=xw+mx;
yw=yw+my;
zw=zw+mz;
sx=d*xw/zw;
sy=d*yw/zw;
}




// Map Cartesian Coordinates to Physical Screen Coords.
// Enter with sx,sy cartesian display coordinates.

// returns sx,sy unclipped physical display coordinates.


void window (float sx, float sy)
{
sx=sx+399;  //startval +399
sy=sy+299;  //startval +299
rx=screen_x/799;   //startval 799
ry=screen_y/599;   //startval 599
sx=sx*rx;
sx=sy*ry;
}


// 2D Line Clipping
// Enter with sxa,sya and sxb, syb line endpoints to be clipped.

// Returns line endpoints clipped to screen.

void viewport ( float sxa, float sya, float sxb, float syb)
{
	if (sxa>sxb) {temp_swap=sxa;sxa=sxb;sxb=temp_swap;
				  temp_swap=sya;sya=syb;syb=temp_swap;};

    if (sxa<minx) if (sxb<minx) return;
    if (sxa>minx) if (sxb>maxx) return;
	if (sya<miny) if (syb<miny) return;
	if (sya>maxy) if (syb>maxy) return;

	if (sxa<minx) {{c=(syb-sya)/(sxb-sxa)*(sxb-minx);
					sxa=minx; sya=syb-c;};
					if (sya<miny) if (syb<miny) return;
					if (sya>maxy) if (syb>maxy) return;
	               };

	if (sxb>maxx) {{c=(syb-sya)/(sxb-sxa)*(maxx-sxa);
	                sxb=maxx;syb=sya+c;};
	                if (sya<miny) if (syb<miny) return;
	                if (sya>maxy) if (syb>maxy) return;
	               };

	if (sya>syb) {temp_swap=sya;sya=syb;syb=temp_swap;
	              temp_swap=sxa;sxa=sxb;sxb=temp_swap;};

    if (sya<miny) {c=(sxb-sxa)/(syb-sya)*(syb-miny);
	               sxa=sxb-c;sya=miny;};
    if (syb>maxy) {c=(sxb-sxa)/(syb-sya)*(maxy-sya);
	               sxb=sxa+c;syb=maxy;};
	}





// Accepts sx,sy display coordinates and returns scaled sy,sy coordinates


void coords(float sx, float sy)
{
sx=sx*(x_res/640); //Pocket PC screenheight = 320
sy=sy*(y_res/480); //Pocket PC screenwidth = 240
}