Added per-model cull mode

Author: photonstorm

src/geom/mesh/Model.js

@@ -239,6 +239,22 @@ var Model = new Class({
          */
         this.transformMatrix = new Matrix4();
 
+        /**
+         * The culling mode used by this Model during rendering.
+         *
+         * Specifies whether front or back facing polygons are candidates
+         * for culling. The default value is `gl.BACK`. Possible values are:
+         *
+         * `gl.FRONT` (1028)
+         * `gl.BACK` (1029)
+         * `gl.FRONT_AND_BACK` (1032)
+         *
+         * @name Phaser.Geom.Mesh.Model#cullMode
+         * @type {GLenum}
+         * @since 3.50.0
+         */
+        this.cullMode = 1029;
+
         /**
          * An internal cache, used to compare position, rotation, scale and verts data
          * each frame, to avoid math calculates in `preUpdate`.

src/renderer/webgl/pipelines/MeshPipeline.js

@@ -105,6 +105,8 @@ var MeshPipeline = new Class({
             -1, -1, -1,
             -1
         ];
+
+        this.cullMode = 1029;
     },
 
     /**
@@ -266,6 +268,13 @@ var MeshPipeline = new Class({
         //  All the uniforms are finally bound, so let's buffer our data
         var gl = this.gl;
 
+        if (model.cullMode !== this.cullMode)
+        {
+            this.cullMode = model.cullMode;
+
+            gl.cullFace(model.cullMode);
+        }
+
         //  STATIC because the buffer data doesn't change, the uniforms do
         gl.bufferData(gl.ARRAY_BUFFER, model.vertexData, gl.STATIC_DRAW);