module primitives; // -*-C-*-ish

import Image;
import CGI;
import Time;
import Logger;

public data DrawColour(Int r, Int g, Int b);

public data Shape = Rectangle(DrawColour rcol, Int rx, Int ry)
    | Ellipse(DrawColour ecol, Int ex, Int ey)
    | Triangle(DrawColour tcol, Int base, Int height);

public data Primitive(Shape shape, Int x, Int y);

public data Drawing(Int x, Int y, DrawColour bg,[Primitive] ps);

public [String] validCols = ["Red","Green","Blue","Yellow","White"];

public DrawColour mkColour(String s) {
    if (s=="Red") {
	return DrawColour(255,0,0);
    }
    else if (s=="Green") {
	return DrawColour(0,255,0);
    }
    else if (s=="Blue") {
	return DrawColour(0,0,255);
    }
    else if (s=="Yellow") {
	return DrawColour(255,255,0);
    }
    else if (s=="White") {
	return DrawColour(255,255,255);
    }
    else {
	srand(now);
	return DrawColour(rand()%255,rand()%255,rand()%255);
    }
}

public Void draw(Drawing d) {
    header("Content-type: image/png");

    i = create(d.x,d.y);
    bg = makeColour(i,d.bg.r,d.bg.g,d.bg.b);
//    DrawColour col = DrawColour(0,0,0);
    for p in d.ps {
	case p.shape of {
	  Rectangle(col,x,y) ->
	      c = makeColour(i,col.r,col.g,col.b);
	      rectangle(i, p.x, p.y, p.shape.rx+p.x, p.shape.ry+p.y, c, true);
	| Ellipse(col,x,y) ->
	      c = makeColour(i,col.r,col.g,col.b);
	      ellipse(i, p.x, p.y, p.shape.ex, p.shape.ey, c, true);
        | Triangle(col,base,height) ->
	      c = makeColour(i,col.r,col.g,col.b);
	      poly(i,[(p.x,p.y),(p.x+base/2,p.y-height),(p.x+base,p.y)],c,true);
	}
    }

    CGI::flushAll();
    makePNG(i);
}