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/*
* Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistribution of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
* INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
* MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
* ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
* DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
* DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
* ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
* SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed or intended for use
* in the design, construction, operation or maintenance of any nuclear
* facility.
*
*/
package net.java.joglutils.msg.nodes;
import net.java.joglutils.msg.actions.GLRenderAction;
import net.java.joglutils.msg.math.Mat4f;
import net.java.joglutils.msg.math.Vec2f;
import net.java.joglutils.msg.math.Vec3f;
public class OrthographicCamera extends Camera {
private static final float DEFAULT_HEIGHT = 2.0f;
// Amount the most recently set height differed from the default
private float heightScale = 1.0f;
public Mat4f getProjectionMatrix() {
if (projDirty) {
projMatrix.makeIdent();
projDirty = false;
// Recompute matrix based on current parameters
float zNear = getNearDistance();
float zFar = getFarDistance();
float deltaZ = zFar - zNear;
float aspect = getAspectRatio();
float height = heightScale * DEFAULT_HEIGHT;
float width = height * aspect;
if ((height == 0) || (width == 0) || (deltaZ == 0))
return projMatrix;
// This is a simplified version of the orthographic projection
// matrix where it's symmetric about the origin
projMatrix.set(0, 0, 2.0f / width);
projMatrix.set(1, 1, 2.0f / height);
projMatrix.set(2, 2, -2.0f / deltaZ);
projMatrix.set(2, 3, -(zFar + zNear) / deltaZ);
}
return projMatrix;
}
/** Sets the height, in units, of the volume this orthographic
camera views. The default height is 2.0 units. */
public void setHeight(float height) {
heightScale = height / DEFAULT_HEIGHT;
}
/** Returns the height, in units, of the volume this orthographic
camera views. */
public float getHeight() {
return heightScale * DEFAULT_HEIGHT;
}
/** Returns the width, in units, of the volume this orthographic
camera views, assuming the passed-in aspect ratio. */
public float getWidth(float aspectRatio) {
return getHeight() * aspectRatio;
}
/** Returns the width, in units, of the volume this orthographic
camera views, assuming the camera's currently-set aspect
ratio. */
public float getWidth() {
return getWidth(getAspectRatio());
}
protected Vec3f getRayStartPoint(Vec2f point, Vec3f unprojectedPoint) {
// The easiest way to compute a reasonable ray start point is to
// start from the unprojected 3D point and go back along the Z-axis
Vec3f backward = Vec3f.Z_AXIS.times(getNearDistance());
backward = getOrientation().rotateVector(backward);
return unprojectedPoint.plus(backward);
}
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
// camera
setAspectRatio(action.getCurAspectRatio());
doAction(action);
}
}
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