Finish documentation

src/drawables/drawable-descriptor.ts

@@ -1,13 +1,63 @@
 import { Drawable } from './drawable';
 
+/**
+ * Used for containing the required information to compile drawables into
+ * shader code.
+ *
+ * Each [[Drawable]] must have a static property of this type, called descriptor.
+ *
+ * For more information on how to create your own DrawableDescriptor-s, look at the
+ * code of [[Circle]] or [[InvertedTunnel]].
+ */
 export interface DrawableDescriptor {
+  /**
+   * An object describing the relationship between the object returned by a [[Drawable]]'s
+   * getObjectToSerialize and the name of the arrays used in the GLSL code.
+   */
   propertyUniformMapping: { [property: string]: string };
+
+  /**
+   * The name of the uniform int used in the code to refer to the
+   * number of drawables of this type.
+   */
   uniformCountMacroName: string;
+
+  /**
+   * Required property for shapes having physical dimensions.
+   */
   sdf?: {
+    /**
+     * The actual GLSL code for observing the drawables represented by this descriptor.
+     *
+     * Your code should work with both version 100 and version 300 es
+     */
     shader: string;
-    isInverted?: boolean;
+    /**
+     * The name of the function defined in the value of `shader`.
+     * Its signature should look like this:
+     * ```glsl
+     *  float (in vec2 target, out float colorIndex)
+     * ```
+     */
     distanceFunctionName: string;
+
+    /**
+     * By default, drawables are not inverted.
+     */
+    isInverted?: boolean;
   };
+
+  /**
+   * Number of possible drawables around each tile.
+   *
+   * For each step, a shader will be generated. And at runtime the closes matching
+   * shader will be used to render a given part of the scene.
+   */
   shaderCombinationSteps: Array<number>;
+
+  /**
+   * When no shaderCombinationStep matches the current number of drawables exactly,
+   * the value of `empty` is used to pad out arrays.
+   */
   readonly empty: Drawable;
 }