My math is failing somewhere, but when I get it working, you guy can expect a 2D editor first, then a 3D editor when I learn a bit of OpenGL. Cross platform, etc.

Also, someone tell me where my math is wrong:

x1 = env's x position - (env's width /2)
x2 = env's x position + (env's width /2)
y1 = env's y position - (env's height /2)
y2 = env's y position + (env's height /2)


for(y=y1;y>y2 - 1;y++){
	draw(x1,y,black);
	draw(x2,y,black);
}
for(x=x1;x>x2 - 1;x++){
	draw(x,y1,black);
	draw(x,y2,black);
}