Added PerspectiveCamera.getWidthAngle(). Removed commented-out code

from Camera. Added error checking code to Group.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/joglutils/trunk@54 83d24430-9974-4f80-8418-2cc3294053b9

3 files changed, 24 insertions, 3 deletions

diff --git a/src/net/java/joglutils/msg/nodes/Camera.java b/src/net/java/joglutils/msg/nodes/Camera.java
index 5333f81..04380f1 100644
--- a/src/net/java/joglutils/msg/nodes/Camera.java
+++ b/src/net/java/joglutils/msg/nodes/Camera.java
@@ -79,7 +79,6 @@ public abstract class Camera extends Node {
   public Camera() {
     position = new Vec3f(0, 0, 1);
     orientation = new Rotf();
-    //    orientation = new Rotf(new Vec3f(0, 1, 0), (float) (Math.PI));
 
     projMatrix = new Mat4f();
     viewMatrix = new Mat4f();
@@ -109,13 +108,15 @@ public abstract class Camera extends Node {
     return orientation;
   }
 
-  /** Sets the aspect ratio of the camera. */
+  /** Sets the aspect ratio of the camera -- the width of the viewport
+      divided by the height of the viewport. */
   public void setAspectRatio(float aspectRatio) {
     this.aspectRatio = aspectRatio;
     projDirty = true;
   }
 
-  /** Returns the aspect ratio of the camera. */
+  /** Returns the aspect ratio of the camera -- the width of the
+      viewport divided by the height of the viewport. */
   public float getAspectRatio() {
     return aspectRatio;
   }
diff --git a/src/net/java/joglutils/msg/nodes/Group.java b/src/net/java/joglutils/msg/nodes/Group.java
index df3232d..ccf06f0 100644
--- a/src/net/java/joglutils/msg/nodes/Group.java
+++ b/src/net/java/joglutils/msg/nodes/Group.java
@@ -48,11 +48,15 @@ public class Group extends Node {
 
   /** Append a child node to the list of children nodes this group node is managing. */
   public void addChild(Node child) {
+    if (child == null)
+      throw new IllegalArgumentException("child may not be null");
     children.add(child);
   }
 
   /** Adds a child so that it becomes the one with the given index. */
   public void insertChild(int index, Node child) {
+    if (child == null)
+      throw new IllegalArgumentException("child may not be null");
     children.add(index, child);
   }
 
@@ -102,6 +106,8 @@ public class Group extends Node {
      greater than the number of children
   */
   public void replaceChild(int index, Node newChild) throws IndexOutOfBoundsException {
+    if (newChild == null)
+      throw new IllegalArgumentException("child may not be null");
     removeChild(index);
     insertChild(index, newChild);
   }
@@ -111,6 +117,8 @@ public class Group extends Node {
       oldChild as argument, and call replaceChild(int, SoNode*) if the
       child is found. */
   public void replaceChild(Node oldChild, Node newChild) {
+    if (newChild == null)
+      throw new IllegalArgumentException("child may not be null");
     int idx = findChild(oldChild);
     if (idx >= 0)
       replaceChild(idx, newChild);
diff --git a/src/net/java/joglutils/msg/nodes/PerspectiveCamera.java b/src/net/java/joglutils/msg/nodes/PerspectiveCamera.java
index 96ce717..0bffd88 100644
--- a/src/net/java/joglutils/msg/nodes/PerspectiveCamera.java
+++ b/src/net/java/joglutils/msg/nodes/PerspectiveCamera.java
@@ -93,6 +93,18 @@ public class PerspectiveCamera extends Camera {
     return vertFOVScale * DEFAULT_HEIGHT_ANGLE;
   }
 
+  /** Returns the width angle, in radians, of this perspective
+      camera, assuming the passed-in aspect ratio. */
+  public float getWidthAngle(float aspectRatio) {
+    return (float) Math.atan(aspectRatio * Math.tan(getHeightAngle()));
+  }
+
+  /** Returns the width angle, in radians, of this perspective camera,
+      assuming the camera's currently-set aspect ratio. */
+  public float getWidthAngle() {
+    return getWidthAngle(getAspectRatio());
+  }
+
   public void render(GLRenderAction action) {
     // FIXME: unclear whether we should be doing this, or whether we
     // should have a mechanism which doesn't require mutation of the