/*
surface shader:
	shiny_building

creator:
	Nick Meshes, DePaul University

description:
	Based on loosely screen.sl and shiny.sl
	Makes a surface that looks like an office building with reflective windows. Walls
	look plastic-like though.
	
parameters:
	Ka, Kd, Ks, roughness, specularcolor - work just like the plastic shader
	wallcolor and windowcolor
	window width and height set
	parts between windows set as well.
	up - x=0, y=1, z=2, building is square in this algorithm
	widthoffset will be between 0 and (windowwidth + wallwidth)
	heightoffset will be between 0 and (windowheight + wallheight)  
	ceiling - top where no more windows exist
	floor - bottom where no more windows exist

 */

#include "rayserver.h"
#include "raytrace.h"

surface
linewind_building (float Ka = .8, Kd = 0.75, Ks = 0.2, roughness = 0.2;
	   color specularcolor = 1;
	   color wallcolor = Cs;
	   color windowcolor = color(1, .75, 0);
	   float up = 2;
         float ceiling = 100, floor = -100;
	   float windowwidth = 1, wallwidth = 1;
	   float windowheight = 1, wallheight = 1;
	   float widthoffset = 0, heightoffset = 0;
	   float windowlines = 2;
	   float linewidth = .2;
	   color linecolor = color(0, 0, 0);
	   float Kr = 0.5, blur = 0;
	   float samples = 1; 
 )
{
	normal Nf = faceforward(normalize(N),I);
	vector IN = normalize(I);;
	float xpart, ypart, zpart;
	float sum = 0;
	color ev = 0;

	if (up == 0){
		xpart = abs(ycomp(P));
		ypart = abs(zcomp(P));
		zpart = abs(xcomp(P));
	}
	else if (up == 1){
		xpart = abs(zcomp(P));
		ypart = abs(xcomp(P));
		zpart = abs(ycomp(P));
	}
	else{
		xpart = abs(xcomp(P));
		ypart = abs(ycomp(P));
		zpart = abs(zcomp(P));
	}

	Cs = wallcolor;
	xpart = mod((xpart + widthoffset), (windowwidth + wallwidth));
	ypart = mod((ypart + widthoffset), (windowwidth + wallwidth));
	zpart = mod((zpart + heightoffset), (windowheight + wallheight));
	
	if (zpart <= floor)
		sum = 1;
	if (zpart >= ceiling)
		sum = 1;
	
	if (xpart > (windowwidth/2))
		if (xpart < (wallwidth + (windowwidth/2))) sum = sum + .5;
	if (ypart > (windowwidth/2))
		if (ypart < (wallwidth + (windowwidth/2))) sum = sum + .5;
	if (zpart > (windowheight/2))
		if (zpart < (wallheight + (windowheight/2))) sum = sum + 1;
	
	if (sum < 1){
		if (Kr > 0.001) {
			vector Rdir = normalize (reflect (IN, Nf));
			ev = Kr * RayTrace (P, Rdir, blur, 1, samples);
			Cs = windowcolor;
		linewidth = linewidth/2;
		windowwidth = windowwidth/(windowlines + 1);
	    	xpart = mod(xpart, windowwidth);
	    	ypart = mod(ypart, windowwidth);
		if (xpart > (windowwidth - linewidth)) Cs = linecolor;
		else if (xpart < linewidth) Cs = linecolor;
		else if (ypart > (windowwidth - linewidth)) Cs = linecolor;
		else if (ypart > linewidth) Cs = linecolor;
/*		else if (Kr > 0.001) {
	*		vector Rdir = normalize (reflect (IN, Nf));
	*		ev = Kr * RayTrace (P, Rdir, blur, 1, samples);
	*		Cs = windowcolor;
 */
  	    	}
	} 

	Ci = Cs * (Ka*ambient() + Kd*diffuse(Nf)) + specularcolor * (ev + Ks*specular(Nf,-IN,roughness));
	Oi = Os;
	Ci *= Oi;
}