// Two 10x10 mm panels meeting at one edge, 45-degree dihedral angle,
// with a rounded fillet on the outer face of the junction.

t = 2;   // panel thickness
s = 10;  // panel size (10x10 mm face)
r = 2;   // fillet radius
$fn = 64;

// Cross-section is built in the YZ plane, extruded in X.
//
// Panel 1 outer face: y=0
// Panel 2 outer face: z = y+10  (i.e. the plane after 45-deg pivot)
//
// Fillet circle tangent to both faces at distance r:
//   centre_y = r
//   centre_z = 10 + r*(1 - sqrt(2))
//
// Tangent point on Panel 1 face (y=0) is at angle 180° from centre.
// Tangent point on Panel 2 face is at angle 135° from centre.
// Arc sweeps 180° → 135°.

fc = [r, 10 + r*(1 - sqrt(2))];

rotate([90, 0, 90])
linear_extrude(s)
polygon(concat(
  // Panel 1 outer face: bottom to fillet start
  [[0, 0]],
  // Fillet arc (180° → 135°)
  [for (a = [180:-1:135]) [fc[0]+r*cos(a), fc[1]+r*sin(a)]],
  // Panel 2 outer face: fillet end to far tip
  [[s*sin(45), 10+s*cos(45)]],
  // Across Panel 2 far end, down Panel 2 inner face, down Panel 1 inner face
  [[s*sin(45)+t*cos(45), 10+s*cos(45)-t*sin(45)],
   [t, fc[1]],
   [t, 0]]
));