add math_constans

examples/math_constans.scad

@@ -0,0 +1,56 @@
+use <fibonacci_lattice.scad>;
+use <hull_polyline3d.scad>;
+use <polyhedron_hull.scad>;
+
+n = 150;
+radius = 12;
+constants = [
+    "π3.141592653589793238462643383279502884197169399375105820974944592307816406286",
+	"τ6.2831853071795864769252867665590057683943387987502116419498891846156328",
+	"φ1.6180339887498948482045868343656381177203091798057628621354486227052604",
+	"e2.7182818284590452353602874713526624977572470936999595749669676277240766303535"
+];
+
+font_name = "Arial Black";
+font_size = 2.5;
+txt_extrude = radius * 0.5;
+txt_scale = 1.5;
+
+math_constants(n, radius, constants, font_name, font_size, txt_extrude, txt_scale);
+
+module math_constants(n, radius, constants, font_name, font_size, txt_extrude, txt_scale) {
+
+	pts = fibonacci_lattice(n, radius);
+
+	polyhedron_hull(pts * 0.9);
+
+	spirals = [for(j = [0:9]) 
+		[for(i = j; i < len(pts); i = i + 8) pts[i]]
+	];
+
+	module constant_on_spiral(constant, spiral) {
+		for(i = [0:len(spiral) - 1]) {
+			x = spiral[i][0];
+			y = spiral[i][1];
+			z = spiral[i][2];
+			ya = atan2(z, sqrt(x * x + y * y));
+			za = atan2(y, x);
+
+			render() 
+			translate(spiral[i])
+			rotate([0, -ya, za])
+			rotate([90, 0, -90])
+			linear_extrude(txt_extrude, scale = txt_scale)
+			mirror([-1, 0, 0])
+				text(constant[i], size = font_size, font = font_name, valign = "center", halign = "center");
+		}
+	}
+
+	for(i = [0:2:8]) {
+		constant_on_spiral(constants[i / 2], spirals[i + 1]);
+	}
+
+	for(i = [0:2:9]) {
+		hull_polyline3d(spirals[i] * 0.9, 1, $fn = 4); 
+	}
+}