From 7c9484c11fa44bf1fec028498c7893f30d9fe01e Mon Sep 17 00:00:00 2001
From: Jakub Valtar <jakub.valtar@gmail.com>
Date: Sat, 1 Nov 2014 18:05:41 +0100
Subject: [PATCH] OpenGL blending - fixed SUBTRACT

O = D - (S * SA)
now matches Java2D
---
 core/src/processing/opengl/PGraphicsOpenGL.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/src/processing/opengl/PGraphicsOpenGL.java b/core/src/processing/opengl/PGraphicsOpenGL.java
index 72d7dff47..03df5d4c8 100644
--- a/core/src/processing/opengl/PGraphicsOpenGL.java
+++ b/core/src/processing/opengl/PGraphicsOpenGL.java
@@ -6025,7 +6025,7 @@ public class PGraphicsOpenGL extends PGraphics {
     } else if (blendMode == SUBTRACT) {
       if (blendEqSupported) {
         pgl.blendEquation(PGL.FUNC_REVERSE_SUBTRACT);
-        pgl.blendFunc(PGL.ONE, PGL.SRC_ALPHA);
+        pgl.blendFunc(PGL.SRC_ALPHA, PGL.ONE);
       } else {
         PGraphics.showWarning(BLEND_DRIVER_ERROR, "SUBTRACT");
       }