/*                    24-384a  Computational Geometry 
 *                        Mechanical Engineering  
 *                      Carnegie Mellon University 
 *
 *                            Eric Paulsen
 *                         Programming Project
 *                           DrawBrickWall.c
 *
 *This Program was written to Interactively Draw Brick Walls using flexible 
 *and versatile code.
 *
 */

#include	<stdio.h>
#include	<math.h>

typedef double Point[3]; /* type double 3D point */
typedef double Dim[3]; /* type double Dimensions array */

void BeginFile( Point StartRow, FILE *vrmlfile, char *filename );
void DrawBrickWall( Point StartWall, Dim WallDim, Dim BrickDim, double OffSet, int UseCornerBrick[2], FILE *vrmlfile );
void DrawBrickRow( int i, Point StartRow, Dim WallDim, Dim BrickDim, double OSDist, int UseCornerBrick[2], FILE *vrmlfile );
void DrawBrick( Dim BrickDim, FILE *vrmlfile );
double GetRandomNumber();
void CopyPoint( Point A, Point B );
void EndFile( FILE *vrmlfile );

void main()
{
	Dim     WallDim;  /* ( Length, Height, Width ) */
	Dim     BrickDim; /* ( Length, Height, Width ) */
	double  OffSet;   /* spacing offset from one row to the next */
	int     UseCornerBrick[2]; /* ( off/on, off/on ). 0 or 1 specifies the placement*/
	                           /* of a corner brick at ( beginning, end ) */
	Point   StartWall; /* coordinates to start Wall at:( x, y, z )*/
	char    vrmlfname[256] = "BrickWall3.wrl";
	FILE    *vrmlfile;

	vrmlfile = fopen(vrmlfname, "w");
	/*sets dimensions of brick*/
	BrickDim[0] = 4; BrickDim[1] = 1; BrickDim[2] = 2;
	/*sets dimensions of wall*/	
	WallDim[0] = 5*BrickDim[0]; WallDim[1] = 5*BrickDim[1]; WallDim[2] = BrickDim[2];
	OffSet = .5*BrickDim[0];/*defines the offset spaceing between rows*/
	UseCornerBrick[0] = 1; UseCornerBrick[1] = 1;
	StartWall[0] = 0; StartWall[1] = 0; StartWall[2] = 0;

	BeginFile( StartWall, vrmlfile, vrmlfname );
	DrawBrickWall( StartWall, WallDim, BrickDim, OffSet, UseCornerBrick, vrmlfile );
	EndFile( vrmlfile );
}

void BeginFile( Point StartPoint, FILE *vrmlfile, char *filename )
/*
Writes beginning of vrml file.
*/
{
	fprintf(vrmlfile, "#VRML V1.0 ascii\n\n");
    	fprintf(vrmlfile, "DEF BackgroundColor Info { string \"1.0 1.0 1.0\" }");
	fprintf(vrmlfile, "\t# White\n\n");
	fprintf(vrmlfile, "Separator {\n");
	fprintf(vrmlfile, "\t# %s \n", filename);
	fprintf(vrmlfile, "\tTranslation {translation %f", StartPoint[0]);
	fprintf(vrmlfile, " %f %f}\n",StartPoint[1],StartPoint[2]);
}

void DrawBrickWall( Point StartWall, Dim WallDim, Dim BrickDim, double OffSet, int UseCornerBrick[2], FILE *vrmlfile )
/*
draws a wall at specified location of specified dimensions.
*/
{      /*row counter, number of rows, 0 <-> 1 switch indicates*/
        int row, Rows, OddEven; /*odd or even row*/
	double  OSDist;   /* cumulative offset distance */
	Point StartRow;   /* coordinates to start Row at: (x, y, z) */

	CopyPoint( StartRow, StartWall );
	OddEven = 1;
	OSDist = BrickDim[0];
	Rows = floor( (WallDim[1]/BrickDim[1]) );

	for(row = 0; row < Rows; row++) {
	  fprintf(vrmlfile, "\tSeparator { #row %d\n", row);
	  DrawBrickRow( OddEven, StartRow, WallDim, BrickDim, OSDist, UseCornerBrick, vrmlfile );
	  StartRow[1] += BrickDim[1];
	  if(OddEven == 1){OddEven = 0;}
	  else{OddEven = 1;}
	  OSDist += OffSet;
	}
}

void DrawBrickRow( int i, Point StartRow, Dim WallDim, Dim BrickDim, double OSDist, int UseCornerBrick[2], FILE *vrmlfile )
/*
 Draws a row of bricks at the specified location. The algorith was designed to allow 
 all configurations to use the same code to minimize duplication of code.
*/
{
       int j;
       double k, l, m;/*dummy variables*/
       Dim PartialBrickDim1, PartialBrickDim2;/* partial(cut) brick dimensions */
       int NB;/*Number of Uncut Bricks*/
       Point StartBrick;/*Point where Brick is drawn*/
       /*Initializes the partial brick dimensions*/
       PartialBrickDim1[0] = BrickDim[0]; PartialBrickDim2[0] = BrickDim[0]; 
       PartialBrickDim1[1] = BrickDim[1]; PartialBrickDim2[1] = BrickDim[1]; 
       PartialBrickDim1[2] = BrickDim[2]; PartialBrickDim2[2] = BrickDim[2];

       if(i==1){/*for even rows*/
	 PartialBrickDim1[0] = ( OSDist - floor( OSDist/BrickDim[0] )*BrickDim[0] );
       }
       else{    /*for odd rows*/
	 k = floor( (OSDist - UseCornerBrick[0]*BrickDim[2])/BrickDim[0] )*BrickDim[0];
	 PartialBrickDim1[0] = ( OSDist - ( UseCornerBrick[0]*BrickDim[2] + k ) );
       }
       l = BrickDim[2]*UseCornerBrick[i];
       NB  = floor( ( WallDim[0] - ( l + PartialBrickDim1[0] ) )/BrickDim[0] );  
       m = UseCornerBrick[1]*BrickDim[2];
       PartialBrickDim2[0] = WallDim[0] - ( PartialBrickDim1[0] + m + NB*BrickDim[0] );
       fprintf(vrmlfile, "\t\tTranslation {translation %f %f", StartRow[0], StartRow[1]);
       fprintf(vrmlfile, " %f}\n", StartRow[2]);
       if( (i == 0) && ( UseCornerBrick[i] == 1) ){/*inserts space for corner brick when*/
	 fprintf(vrmlfile, "\t\tTranslation {translation %f 0.0 0.0}\n", BrickDim[2] );
       }                           /*on an odd row and when beginning brick is specified*/
       if( PartialBrickDim1[0] > 0.01*BrickDim[0] ){/*Draws a partial brick only when*/
	 DrawBrick( PartialBrickDim1, vrmlfile );  /* brick is greater than minimum size*/
	 fprintf(vrmlfile, "\t\tTranslation {translation %f 0.0 0.0}\n", PartialBrickDim1[0]);
       }             /*to avoid wasting file space with very short or zero length bricks*/
       for( j = 0; j < NB; j++){/*draws regular bricks*/
	 DrawBrick( BrickDim, vrmlfile );
	 fprintf(vrmlfile, "\t\tTranslation {translation %f 0.0 0.0}\n", BrickDim[0]);
       }
       if( PartialBrickDim2[0] > 0.01*BrickDim[0] ){
	 DrawBrick( PartialBrickDim2, vrmlfile );
	 fprintf(vrmlfile, "\t\tTranslation {translation %f 0.0 0.0}\n", PartialBrickDim2[0]);
       }
       if( (i == 1) && ( UseCornerBrick[i] == 1) ){/*inserts space for corner brick when*/
	 fprintf(vrmlfile, "\t\tTranslation {translation %f 0.0 0.0}\n", BrickDim[2] );
       }                         /*on an even row and when end corner brick is specified*/
       fprintf(vrmlfile, "\t}\n");
}

void DrawBrick( Dim BrickDim, FILE *vrmlfile )
/*
Draws a Brick of specified dimensions to a specified file in vrml format.
*/
{
       fprintf(vrmlfile, "\t\tSeparator {\n");
       fprintf(vrmlfile, "\t\t\tTranslation {translation %f", .5*BrickDim[0]);
       fprintf(vrmlfile, " %f %f}\n", .5*BrickDim[1], .5*BrickDim[2]);
       fprintf(vrmlfile, "\t\t\tMaterial { diffuseColor %2.1f ", GetRandomNumber() );
       fprintf(vrmlfile, "%2.1f %2.1f }\n", GetRandomNumber(), GetRandomNumber() );
       fprintf(vrmlfile, "\t\t\tCube {\n");
       fprintf(vrmlfile, "\t\t\t\twidth   %f\n",BrickDim[0]);
       fprintf(vrmlfile, "\t\t\t\theight  %f\n",BrickDim[1]);
       fprintf(vrmlfile, "\t\t\t\tdepth   %f\n",BrickDim[2]);
       fprintf(vrmlfile, "\t\t\t}\n\t\t}\n");
}

void CopyPoint( Point A, Point B )
/*
Copies point B to point A
*/
{
        int i;
	for(i=0; i<3; i++) {A[i]=B[i];}
}

double GetRandomNumber()
{
       double i;
       int j;
       
       i = rand();
       i /= 1e4;
       i -= floor(i);
       return i;
}

void EndFile( FILE *vrmlfile )
{
  fprintf(vrmlfile, "}\n");
  fclose(vrmlfile);
}