/** This renders a 3-D model to fix my telescope viewfinder to Wavefront .obj
    file format for 3-D printing.

    This is a second attempt using constructive solid geometry in Frink.  The
    first attempt is in TelescopeViewFinder.frink

    See: http://paulbourke.net/dataformats/obj/
*/

stopDiam = 1.25 in
cylDiam = 1.195 in
b = .6757 in    // Distance from end of pipe to center of mirror holder

z0 = 0 mm
z1 = -2 mm
r = 300/in     // This is the resolution of the model.  All dimensioned
               // measurements are multiplied by this to get dimensionless
               // numbers to feed to the dimensionless integer VoxelArray class

// Stopper
v = callJava["frink.graphics.VoxelArray", "makeCylinder", [0,0,z0 r, 0,0,z1 r, stopDiam/2 r]]

// Main cylinder
v = v.union[callJava["frink.graphics.VoxelArray", "makeCylinder", [0,0,z0 r, 0,0,2 in r, cylDiam/2 r]]]

// Cut a face from the main cylinder
plane = newJava["frink.graphics.Plane3DFloat", [0,0, b r, -1, 0, 1]]
v.removeOutside[plane]

v.projectX[undef].show["X"]
v.projectY[undef].show["Y"]
v.projectZ[undef].show["Z"]

filename = "TelescopeViewfinder2.obj"
print["Writing $filename..."]
w = new Writer[filename]
w.println[v.toObjFormat["telescope", 1/(r mm)]]
w.close[]
println["done."]