Bug 801: Fix 183e1bc1868699b99eb9f9c8bf18d646d1120a48 'window box' Calculation

Commit 183e1bc1868699b99eb9f9c8bf18d646d1120a48 only mapped object's bbox max/min points
to window space, which is wrong due to possible rotation in 3d space.

This commit adds AABBox.mapToWindow(..) method,
which correctly either uses 4 points of the bbox in 3d space (using center-z)
or all 8-points and creating a new bounding box.

The resulting width and height of this window bbox gives the
maximum amount of rectangular pixels for AA.

1 files changed, 48 insertions, 0 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/math/geom/AABBox.java b/src/jogl/classes/com/jogamp/opengl/math/geom/AABBox.java
index 81928888c..d0566b54e 100644
--- a/src/jogl/classes/com/jogamp/opengl/math/geom/AABBox.java
+++ b/src/jogl/classes/com/jogamp/opengl/math/geom/AABBox.java
@@ -28,6 +28,7 @@
 package com.jogamp.opengl.math.geom;
 
 import com.jogamp.opengl.math.VectorUtil;
+import com.jogamp.opengl.util.PMVMatrix;
 
 
 /**
@@ -350,6 +351,53 @@ public class AABBox implements Cloneable {
                VectorUtil.checkEquality(high, other.high) ;
     }
 
+    /**
+     * Assume this bounding box as being in object space and
+     * compute the window bounding box.
+     * <p>
+     * If <code>useCenterZ</code> is <code>true</code>,
+     * only 4 {@link PMVMatrix#gluProject(float, float, float, int[], int, float[], int) gluProject}
+     * operations are made on points [1..4] using {@link #getCenter()}'s z-value.
+     * Otherwise 8 {@link PMVMatrix#gluProject(float, float, float, int[], int, float[], int) gluProject}
+     * operation on all 8 points are made.
+     * </p>
+     * <pre>
+     *  [2] ------ [4]
+     *   |          |
+     *   |          |
+     *  [1] ------ [3]
+     * </pre>
+     * @param pmv
+     * @param view
+     * @param useCenterZ
+     * @param tmpV3 TODO
+     * @return
+     */
+    public AABBox mapToWindow(final AABBox result, final PMVMatrix pmv, final int[] view, final boolean useCenterZ, float[] tmpV3) {
+        float objZ = useCenterZ ? center[2] : getMinZ();
+        pmv.gluProject(getMinX(), getMinY(), objZ, view, 0, tmpV3, 0);
+        result.reset();
+        result.resize(tmpV3, 0);
+        pmv.gluProject(getMinX(), getMaxY(), objZ, view, 0, tmpV3, 0);
+        result.resize(tmpV3, 0);
+        pmv.gluProject(getMaxX(), getMinY(), objZ, view, 0, tmpV3, 0);
+        result.resize(tmpV3, 0);
+        pmv.gluProject(getMaxX(), getMaxY(), objZ, view, 0, tmpV3, 0);
+        result.resize(tmpV3, 0);
+        if( !useCenterZ ) {
+            objZ = getMaxZ();
+            pmv.gluProject(getMinX(), getMinY(), objZ, view, 0, tmpV3, 0);
+            result.resize(tmpV3, 0);
+            pmv.gluProject(getMinX(), getMaxY(), objZ, view, 0, tmpV3, 0);
+            result.resize(tmpV3, 0);
+            pmv.gluProject(getMaxX(), getMinY(), objZ, view, 0, tmpV3, 0);
+            result.resize(tmpV3, 0);
+            pmv.gluProject(getMaxX(), getMaxY(), objZ, view, 0, tmpV3, 0);
+            result.resize(tmpV3, 0);
+        }
+        return result;
+    }
+
     @Override
     public final String toString() {
         return "[ dim "+getWidth()+" x "+getHeight()+" x "+getDepth()+