Add OES_standard_derivatives if available

Author: iLauncherDev

src/openfl/display/OpenGLRenderer.hx

@@ -55,6 +55,7 @@ import lime.math.Matrix4;
 class OpenGLRenderer extends DisplayObjectRenderer
 {
 	@:noCompletion private static var __blendMinMaxSupported:Null<Bool>;
+	@:noCompletion private static var __standardDerivativesSupported:Null<Bool>;
 	@:noCompletion private static var __complexBlendsSupported:Null<Bool>;
 	@:noCompletion private static var __coherentBlendsSupported:Null<Bool>;
 	@:noCompletion private static var __sRGBWriteControlSupported:Null<Bool>;
@@ -172,6 +173,10 @@ class OpenGLRenderer extends DisplayObjectRenderer
 		{
 			__coherentBlendsSupported = exts.contains("KHR_blend_equation_advanced_coherent");
 		}
+		if (__standardDerivativesSupported == null)
+		{
+			__standardDerivativesSupported = exts.contains("OES_standard_derivatives");
+		}
 
 		#if (js && html5)
 		__softwareRenderer = new CanvasRenderer(null);

src/openfl/display/Shader.hx

@@ -627,6 +627,7 @@ class Shader
 		}
 
 		var complexBlendsSupported = OpenGLRenderer.__complexBlendsSupported && isFragment;
+		var standardDerivativesSupported = OpenGLRenderer.__standardDerivativesSupported && isFragment;
 
 		#if lime
 		if (__context.__context.type == OPENGL)
@@ -653,6 +654,11 @@ class Shader
 			#end
 		}
 
+		if (standardDerivativesSupported)
+		{
+			extensions += "#extension GL_OES_standard_derivatives : enable\n";
+		}
+
 		// #version must be the first directive and cannot be repeated,
 		// while #extension directives must be before any non-preprocessor tokens.