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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;
/** Represents a camera utilizing a perspective projection. <P>
The default height angle is Math.PI / 4 radians (45 degrees),
meaning that the camera has a total vertical field of view of 90
degrees.
*/
public class PerspectiveCamera extends Camera {
private static final float DEFAULT_HEIGHT_ANGLE = (float) (Math.PI / 4);
// Amount the most recently set height angle differed from the default
private float vertFOVScale = 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 radians = vertFOVScale * DEFAULT_HEIGHT_ANGLE;
float sine = (float) Math.sin(radians);
if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {
return projMatrix;
}
float cotangent = (float) Math.cos(radians) / sine;
projMatrix.set(0, 0, cotangent / aspect);
projMatrix.set(1, 1, cotangent);
projMatrix.set(2, 2, -(zFar + zNear) / deltaZ);
projMatrix.set(3, 2, -1);
projMatrix.set(2, 3, -2 * zNear * zFar / deltaZ);
projMatrix.set(3, 3, 0);
}
return projMatrix;
}
/** Sets the height angle, in radians, of this perspective camera.
The default height angle is Math.PI / 4 radians, or 45 degrees. */
public void setHeightAngle(float heightAngle) {
vertFOVScale = heightAngle / DEFAULT_HEIGHT_ANGLE;
projDirty = true;
}
/** Returns the height angle, in radians, of this perspective
camera. */
public float getHeightAngle() {
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());
}
protected Vec3f getRayStartPoint(Vec2f point, Vec3f unprojectedPoint) {
return getPosition();
}
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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