/** This makes a cube that projects a different silhouette
    along 3 axes, and renders it in Waveform .obj format for 3-D printing.
    It takes 3 square black-and-white images, one for each axis.  (They can
    be different sizes; this resizes them to 200x200 pixels.) The white
    parts will be "cut out" of the cube.

    You will probably want to provide your own images, but here are the ones
    I used for the letters A, B, E:

    https://frinklang.org/frinksamp/A400x400.png
    https://frinklang.org/frinksamp/B400x400.png
    https://frinklang.org/frinksamp/E400x400.png
*/

// This sets the resolution of the final object in voxels.
w = h = 400

i1 = new image["file:E400x400.png"]
i1 = i1.resize[w,h]
[w1, h1] = i1.getSize[]

v = newJava["frink.graphics.VoxelArray", [w1,h1,h1,true]]

// Carve along Y axis
for x=0 to w1-1
   for y=0 to h1-1
   {
      [r,g,b] = i1.getPixel[x,y]
      if (r+g+b) > 1.5
         v.setRange[x,x,0,h1-1,h1-1-y,h1-1-y,false]
   }
      
i2 = new image["file:A400x400.png"]
i2 = i2.resize[w,h]
[w1, h1] = i2.getSize[]

// Carve along Z axis   
for x=0 to w1-1
   for y=0 to h1-1
   {
      [r,g,b] = i2.getPixel[x,y]
      if (r+g+b) > 1.5
         v.setRange[y,y,x,x,0,h1-1,false]
   }

i3 = new image["file:B400x400.png"]
i3 = i3.resize[w,h]
[w1, h1] = i3.getSize[]

// Carve along X axis
for x=0 to w1-1
   for y=0 to h1-1
   {
      [r,g,b] = i3.getPixel[x,y]
      if (r+g+b) > 1.5
         v.setRange[0,w1-1,y,y,x,x,false]
}

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

filename = "ABEcube.obj"
print["Writing $filename..."]
w = new Writer[filename]
w.println[v.toObjFormat["test", 1/10]]
w.close[]
println["done."]