Add Icosahedron example

nicklockwood · nicklockwood · commit b7b7eb72ba88 · 2023-07-08T10:20:10.000+01:00
diff --git a/Examples/Icosahedron.shape b/Examples/Icosahedron.shape
@@ -0,0 +1,58 @@
+// ShapeScript document
+
+define points {
+    define t 1 + sqrt(2) / 2
+
+    (-1  t  0)
+    ( 1  t  0)
+    (-1 -t  0)
+    ( 1 -t  0)
+
+    ( 0 -1  t)
+    ( 0  1  t)
+    ( 0 -1 -t)
+    ( 0  1 -t)
+
+    ( t  0 -1)
+    ( t  0  1)
+    (-t  0 -1)
+    (-t  0  1)
+}
+
+define triangle(a b c) {
+    polygon {
+        point a
+        point b
+        point c
+    }
+}
+
+mesh {
+    // 5 triangles around first point
+    triangle points.first points.twelfth points.sixth
+    triangle points.first points.sixth points.second
+    triangle points.first points.second points.eighth
+    triangle points.first points.eighth points.eleventh
+    triangle points.first points.eleventh points.twelfth
+
+    // 5 adjacent triangles
+    triangle points.second points.sixth points.tenth
+    triangle points.sixth points.twelfth points.fifth
+    triangle points.twelfth points.eleventh points.third
+    triangle points.eleventh points.eighth points.seventh
+    triangle points.eighth points.second points.ninth
+
+    // 5 triangles around fourth point
+    triangle points.fourth points.tenth points.fifth
+    triangle points.fourth points.fifth points.third
+    triangle points.fourth points.third points.seventh
+    triangle points.fourth points.seventh points.ninth
+    triangle points.fourth points.ninth points.tenth
+
+    // 5 adjacent triangles
+    triangle points.fifth points.tenth points.sixth
+    triangle points.third points.fifth points.twelfth
+    triangle points.seventh points.third points.eleventh
+    triangle points.ninth points.seventh points.eighth
+    triangle points.tenth points.ninth points.second
+}
diff --git a/docs/images/icosahedron.png b/docs/images/icosahedron.png
diff --git a/docs/ios/examples.md b/docs/ios/examples.md
@@ -27,6 +27,12 @@ The Earth example demonstrates use of the [texture](materials.md#texture) comman
 
 ![Earth](../images/earth.png)
 
+## Icosahedron
+
+The Icosahedron demonstrates the use of the [mesh command](meshes.md) along with [structured data](literals.md#structured-data) and [custom functions](functions.md#custom-functions) to create a complex shape that cannot easily be derived from the built-in primitives.
+
+![Icosahedron](../images/icosahedron.png)
+
 ## Spirals
 
 The Spirals example demonstrates using the [extrude](builders.md#extrude) command to create a spiral. This example also demonstrates the use of [for loops](control-flow.md#loops) and user-defined [options](blocks.md#options).
diff --git a/docs/ios/index.md b/docs/ios/index.md
@@ -158,6 +158,7 @@ ShapeScript Help
     - [Chessboard](examples.md#chessboard)
     - [Cog](examples.md#cog)
     - [Earth](examples.md#earth)
+    - [Icosahedron](examples.md#icosahedron)
     - [Spirals](examples.md#spirals)
     - [Spring](examples.md#spring)
     - [Train](examples.md#train)
diff --git a/docs/mac/examples.md b/docs/mac/examples.md
@@ -27,6 +27,12 @@ The Earth example demonstrates use of the [texture](materials.md#texture) comman
 
 ![Earth](../images/earth.png)
 
+## Icosahedron
+
+The Icosahedron demonstrates the use of the [mesh command](meshes.md) along with [structured data](literals.md#structured-data) and [custom functions](functions.md#custom-functions) to create a complex shape that cannot easily be derived from the built-in primitives.
+
+![Icosahedron](../images/icosahedron.png)
+
 ## Spirals
 
 The Spirals example demonstrates using the [extrude](builders.md#extrude) command to create a spiral. This example also demonstrates the use of [for loops](control-flow.md#loops) and user-defined [options](blocks.md#options).
diff --git a/docs/mac/index.md b/docs/mac/index.md
@@ -158,6 +158,7 @@ ShapeScript Help
     - [Chessboard](examples.md#chessboard)
     - [Cog](examples.md#cog)
     - [Earth](examples.md#earth)
+    - [Icosahedron](examples.md#icosahedron)
     - [Spirals](examples.md#spirals)
     - [Spring](examples.md#spring)
     - [Train](examples.md#train)
diff --git a/docs/src/examples.md b/docs/src/examples.md
@@ -27,6 +27,12 @@ The Earth example demonstrates use of the [texture](materials.md#texture) comman
 
 ![Earth](../images/earth.png)
 
+## Icosahedron
+
+The Icosahedron demonstrates the use of the [mesh command](meshes.md) along with [structured data](literals.md#structured-data) and [custom functions](functions.md#custom-functions) to create a complex shape that cannot easily be derived from the built-in primitives.
+
+![Icosahedron](../images/icosahedron.png)
+
 ## Spirals
 
 The Spirals example demonstrates using the [extrude](builders.md#extrude) command to create a spiral. This example also demonstrates the use of [for loops](control-flow.md#loops) and user-defined [options](blocks.md#options).
diff --git a/docs/src/index.md b/docs/src/index.md
@@ -158,6 +158,7 @@ ShapeScript Help
     - [Chessboard](examples.md#chessboard)
     - [Cog](examples.md#cog)
     - [Earth](examples.md#earth)
+    - [Icosahedron](examples.md#icosahedron)
     - [Spirals](examples.md#spirals)
     - [Spring](examples.md#spring)
     - [Train](examples.md#train)
