From db24df36aba97076283beebfec65823d341c4abf Mon Sep 17 00:00:00 2001
From: codeanticode <andres.colubri@gmail.com>
Date: Sat, 8 May 2010 08:05:44 +0000
Subject: [PATCH] Enabling/disabling of depth mask in PShape3D

---
 .../processing/core/PGraphicsAndroid3D.java   |  2 +-
 .../core/src/processing/core/PShape3D.java    | 25 +++++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/android/core/src/processing/core/PGraphicsAndroid3D.java b/android/core/src/processing/core/PGraphicsAndroid3D.java
index 2442e6dab..d719dd077 100644
--- a/android/core/src/processing/core/PGraphicsAndroid3D.java
+++ b/android/core/src/processing/core/PGraphicsAndroid3D.java
@@ -537,7 +537,7 @@ public class PGraphicsAndroid3D extends PGraphics {
     }
     // use <= since that's what processing.core does
     gl.glDepthFunc(GL10.GL_LEQUAL);
-
+    
     // because y is flipped
     gl.glFrontFace(GL10.GL_CW);    
     
diff --git a/android/core/src/processing/core/PShape3D.java b/android/core/src/processing/core/PShape3D.java
index 85aab76d4..0542fb08e 100644
--- a/android/core/src/processing/core/PShape3D.java
+++ b/android/core/src/processing/core/PShape3D.java
@@ -85,6 +85,8 @@ public class PShape3D extends PShape implements PConstants {
   
   protected float ptDistAtt[] = { 1.0f, 0.0f, 0.01f, 1.0f };
   
+  protected boolean depthMaskEnabled = true;
+  
   protected static final int SIZEOF_FLOAT = Float.SIZE / 8;
   
   
@@ -1369,6 +1371,14 @@ public class PShape3D extends PShape implements PConstants {
   
   // Parameters   
   
+  public void noDepthMask() {
+    depthMaskEnabled = false;  
+  }
+  
+  public void depthMask() {
+    depthMaskEnabled = true;    
+  }
+
   
   public void setDrawMode(int mode) {
     pointSprites = false;
@@ -1742,7 +1752,14 @@ public class PShape3D extends PShape implements PConstants {
 	  // Setting line width and point size from stroke value.
 		pointSize = PApplet.min(a3d.strokeWeight, a3d.maxPointSize);
     gl.glPointSize(pointSize);
-	    
+  
+    if (!depthMaskEnabled) {
+      // Disabling writing to depth mask. This is useful to avoid artifacts when rendering particle systems.
+      // Proper rendering of a particle system with particles that have transparency involves depth-sorting,
+      // but it is expensive. In most cases, doing this is good enough.      
+      gl.glDepthMask(false);
+    }
+    
     gl.glEnableClientState(GL11.GL_NORMAL_ARRAY);
     gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, glNormalBufferID[0]);
     gl.glNormalPointer(GL11.GL_FLOAT, 0, 0);    
@@ -1774,7 +1791,7 @@ public class PShape3D extends PShape implements PConstants {
          
         if (pointSprites) {
           // Texturing with point sprites.
-              
+                        
           // This is how will our point sprite's size will be modified by 
           // distance from the viewer             
           gl.glPointParameterfv(GL11.GL_POINT_DISTANCE_ATTENUATION, ptDistAtt, 0);
@@ -1831,6 +1848,10 @@ public class PShape3D extends PShape implements PConstants {
         gl.glDisable(texTarget);
       }       
     }
+
+    if (!depthMaskEnabled) {
+      gl.glDepthMask(true);
+    }
     
     gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
     gl.glDisableClientState(GL11.GL_VERTEX_ARRAY);