The default BaseShader vertex shader has a new uniform uResolution which is set during the Shader init and load to be the size of the Game Object to which the shader is bound.

CHANGELOG.md

@@ -5,7 +5,8 @@
 ### Updates
 
 * `Zones` will now use the new `customHitArea` property introduced in 3.17 to avoid their hit areas from being resized if you specified your own custom hit area (thanks @rexrainbow)
-* The default `BaseShader` vertex shader will now set the `fragCoord` varying to be the viewport height minus the y inPosition. This will give the correct y axis in the fragment shader, causing 'inverted' shaders to display normally when using the default vertex code.
+* The default `BaseShader` vertex shader has a new uniform `uResolution` which is set during the Shader init and load to be the size of the Game Object to which the shader is bound.
+* The default `BaseShader` vertex shader will now set the `fragCoord` varying to be the Game Object height minus the y inPosition. This will give the correct y axis in the fragment shader, causing 'inverted' shaders to display normally when using the default vertex code.
 
 ### Bug Fixes
 

src/display/shader/BaseShader.js

@@ -61,6 +61,7 @@ var BaseShader = new Class({
 
                 'uniform mat4 uProjectionMatrix;',
                 'uniform mat4 uViewMatrix;',
+                'uniform vec2 uResolution;',
 
                 'attribute vec2 inPosition;',
 
@@ -68,7 +69,7 @@ var BaseShader = new Class({
 
                 'void main () {',
                 'gl_Position = uProjectionMatrix * uViewMatrix * vec4(inPosition, 1.0, 1.0);',
-                'fragCoord = vec2(inPosition.x, uViewMatrix[2][0] - inPosition.y);',
+                'fragCoord = vec2(inPosition.x, uResolution.y - inPosition.y);',
                 '}'
             ].join('\n');
         }

src/gameobjects/shader/Shader.js

@@ -350,13 +350,16 @@ var Shader = new Class({
 
         var program = renderer.createProgram(this.shader.vertexSrc, this.shader.fragmentSrc);
 
+        //  The default uniforms available within the vertex shader
         renderer.setMatrix4(program, 'uViewMatrix', false, this.viewMatrix);
         renderer.setMatrix4(program, 'uProjectionMatrix', false, this.projectionMatrix);
+        renderer.setFloat2(program, 'uResolution', this.width, this.height);
 
         this.program = program;
 
         var d = new Date();
 
+        //  The default uniforms available within the fragment shader
         var defaultUniforms = {
             resolution: { type: '2f', value: { x: this.width, y: this.height }},
             time: { type: '1f', value: 0 },
@@ -831,9 +834,12 @@ var Shader = new Class({
         vm[12] = vm[0] * x + vm[4] * y;
         vm[13] = vm[1] * x + vm[5] * y;
 
-        this.renderer.setMatrix4(program, 'uViewMatrix', false, this.viewMatrix);
+        //  Update vertex shader uniforms
 
-        //  Update common uniforms
+        this.renderer.setMatrix4(program, 'uViewMatrix', false, this.viewMatrix);
+        this.renderer.setFloat2(program, 'uResolution', this.width, this.height);
+
+        //  Update fragment shader uniforms
 
         var uniforms = this.uniforms;
         var res = uniforms.resolution;