Merge pull request phaserjs#5416 from rexrainbow/generate-grid-verts-modify

Add flipY optional argument

Author: photonstorm

src/geom/mesh/GenerateGridVerts.js

@@ -63,6 +63,7 @@ var GenerateGridVerts = function (config)
     var colors = GetFastValue(config, 'colors', [ 0xffffff ]);
     var alphas = GetFastValue(config, 'alphas', [ 1 ]);
     var tile = GetFastValue(config, 'tile', false);
+    var flipY = GetFastValue(config, 'flipY', false);
 
     var widthSet = GetFastValue(config, 'width', null);
 
@@ -125,8 +126,17 @@ var GenerateGridVerts = function (config)
     {
         frameU0 = textureFrame.u0;
         frameU1 = textureFrame.u1;
-        frameV0 = textureFrame.v0;
-        frameV1 = textureFrame.v1;
+
+        if (!flipY)
+        {
+            frameV0 = textureFrame.v0;
+            frameV1 = textureFrame.v1;
+        }
+        else
+        {
+            frameV0 = textureFrame.v1;
+            frameV1 = textureFrame.v0;
+        }
     }
 
     var frameU = frameU1 - frameU0;

src/geom/mesh/typedefs/GenerateGridConfig.js

@@ -15,4 +15,5 @@
  * @property {number|number[]} [alphas=1] - An array of alpha values, one per vertex, or a single alpha value applied to all vertices.
  * @property {boolean} [tile=false] - Should the texture tile (repeat) across the grid segments, or display as a single texture?
  * @property {boolean} [isOrtho=false] - If set and using a texture with an ortho Mesh, the `width` and `height` parameters will be calculated based on the frame size for you.
+ * @property {boolean} [flipY=false] - If set and using a texture, vertically flipping render result.
  */