September 2017 Update

Task/Draw-a-cuboid/Zkl/draw-a-cuboid.zkl

@@ -0,0 +1,21 @@
+var [const] M=50.0;
+fcn cuboid(w,h,z){
+   w*=M; h*=M; z*=M; // relative to abs dimensions
+   bitmap:=PPM(400,400);
+
+   clr:=0xff0000;  // red facing rectangle
+   bitmap.line(0,0, w,0, clr); bitmap.line(0,0, 0,h, clr);
+   bitmap.line(0,h, w,h, clr); bitmap.line(w,0, w,h, clr);
+
+   r,a:=(w+z).toFloat().toPolar(0);  // relative to the origin
+   a,b:=r.toRectangular((30.0).toRad() + a).apply("toInt"); c:=a; d:=b+h;
+   clr=0xff; // blue right side of cuboid
+   bitmap.line(w,0, a,b, clr); bitmap.line(a,b, c,d, clr);
+   bitmap.line(w,h, c,d, clr);
+
+   e:=c-w;
+   clr=0xfff00; // green top of cuboid
+   bitmap.line(0,h, e,d, clr); bitmap.line(c,d, e,d, clr);
+
+   bitmap.write(File("foo.ppm","wb"));
+}(2,3,4);