# CSG rendering.

# Colours to be used:

DEFINE green PLASTIC
{
	PHONG 1
	COLOUR 0 1 0 0.00 0 1.00
}

DEFINE blue PLASTIC
{
	PHONG 1
	COLOUR 1 0 0 0.00 0 1.00
}

DEFINE red PLASTIC
{
	PHONG 1
	COLOUR 0 0 1 0.00 0 1.00
}

DEFINE gold PLASTIC
{
	PHONG 1
	COLOUR 0 1 1 0.25 0 0.75
}

# The three walls.

DEFINE floor OBJECT
{
	PLANE 
	{
		ORIG 0 -1 0
		NORMAL 0 1 0		# note absense of up vector.

		CHECKERBOARD
		{
			PLASTIC PHONG 1

			COLOUR1 1 0 0 0.0 0 1
			COLOUR2 0 1 0 0.0 0 1
			DENSITY 2 2 2
		}
	}
}

DEFINE wall OBJECT
{
	PLANE 
	{
		ORIG 0 0  8
		NORMAL 0 0 -1

		CHECKERBOARD
		{
			PLASTIC PHONG 1

			COLOUR1 1 1 0 0.0 0 1
			COLOUR2 0 1 1 0.0 0 1
			DENSITY 2 2 2
		}
	}
}

DEFINE wall2 OBJECT
{
	PLANE 
	{
		ORIG 2.7 0  0
		NORMAL -1 0 0

		CHECKERBOARD
		{
			PLASTIC PHONG 1

			COLOUR1 0 0 1 0.0 0 1
			COLOUR2 1 0 1 0.0 0 1
			DENSITY 2 2 2
		}
	}
}

# Polygons describing C, S, and G.

DEFINE poly_c POLYGON 8
1 -.5 1   0 -.75 1   -.75 0 1
0 .75 1   1 0.5 1    0 1 1
-1 0 1    0 -1 1

DEFINE poly_s POLYGON 10
1 .3 1    0 1 1    -1 .3 1
.75 -.3 1 0 -.75 1 -1 -.3 1
0 -1 1    1 -.3 1  -.75 .3 1
0 .75 1

DEFINE poly_g POLYGON 11
1 -1 1    1 0 1   0 0 1
1 -.5 1   0 -.75 1   -.75 0 1
0 .75 1   1 0.5 1    0 1 1
-1 0 1    0 -1 1

# The three extruded surfaces based off the polygons

DEFINE g OBJECT
{
	PLANE
	{
		ORIG -1.1 0.5 4
		NORMAL -1 0 0
		VCTUP 0 1 0
		FLIPX TRUE
		poly_g
		green
	}
	PLANE
	{
		ORIG 1.1 .5 4
		NORMAL 1 0 0
		VCTUP 0 1 0
		poly_g
		green
	}
	EXTRUSION 
	{
		START -1.1
		END 1.1
		ORIG 0 .5 4
		NORMAL 1 0 0
		VCTUP 0 1 0
		poly_g
		green
	}
}


DEFINE c OBJECT
{
	PLANE
	{
		ORIG 0 -0.6 4
		NORMAL 0 -1 0
		VCTUP 0 0 1
		FLIPX TRUE
		poly_c
		red
	}
	PLANE
	{
		ORIG 0 1.6 4
		NORMAL 0 1 0
		VCTUP 0 0 1
		poly_c
		red
	}
	EXTRUSION 
	{
		START -1.1
		END 1.1
		ORIG 0 .5 4
		NORMAL 0 1 0
		VCTUP 0 0 1
		poly_c
		red
	}
}
DEFINE s OBJECT
{
	PLANE
	{
		ORIG 0 0.5 2.9
		NORMAL 0 0 -1
		VCTUP 0 1 0
		FLIPX TRUE
		poly_s
		blue
	}
	PLANE
	{
		ORIG 0 0.5 5.1
		NORMAL 0 0 1
		VCTUP 0 1 0
		poly_s
		blue
	}
	EXTRUSION 
	{
		START -1.1
		END 1.1
		ORIG 0 .5 4
		NORMAL 0 0 1
		VCTUP 0 1 0
		poly_s
		blue
	}
}

# The camera from which the frame will be rendered.

DEFINE camera CAMERA
{
	ORIG -2 2 0
	LOOKDIR 0.5 -0.5 1
	VCTUP 0 1 0

	ORTHOGONALIZE TRUE	# This causes up/left/lookat to be orthogonal
	FOCAL 1.5
	PRINTSTATUS TRUE	# Print current scan number.
}

# The scene to be rendered.

SCENE
{
	floor

	wall
	wall2

	# This is the sphere with C, S, and G cut out of it:
	OBJ_BOOL
	{
		TYPE DIFF

		LEFT OBJ_BOOL
		{
			TYPE DIFF

			LEFT OBJ_BOOL
			{
				TYPE DIFF

				LEFT OBJECT
				{
					SPHERE
					{
						ORIG 0 0.5 4
						RADIUS 1.1

						gold
					}
				}

				RIGHT g
			}

			RIGHT c
		}

		RIGHT s
	}

	# These are the lights, at nigh-near infinity, set to project along
	# the x, y, and z axes.
	LIGHT
	{
		COLOUR 0.433 .433 .433 0 0 0
		ORIG 0 40 4 
	}
	LIGHT
	{
		COLOUR 0.433 .433 .433 0 0 0
		ORIG 0 0.5 -30
	}
	LIGHT
	{
		COLOUR 0.433 .433 .433 0 0 0
		ORIG -40 0.5 4
	}

	# This sets the ambient light levels.

	AMBIENT 0.3

	camera
}