/**
* Copyright 2014 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions 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.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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*
* The views and conclusions contained in the software and documentation are those of the
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*/
package com.jogamp.opengl.math;
/**
* Horizontal and vertical field of view (FOV) halves,
* allowing a non-centered projection.
* <p>
* The values might be either in tangent or radians.
* </p>
*/
public final class FovHVHalves {
/** Half horizontal FOV from center to left, either in {@link #inTangents} or radians. */
public final float left;
/** Half horizontal FOV from center to right, either in {@link #inTangents} or radians. */
public final float right;
/** Half vertical FOV from center to top, either in {@link #inTangents} or radians. */
public final float top;
/** Half vertical FOV from center to bottom, either in {@link #inTangents} or radians. */
public final float bottom;
/** If true, values are in tangent, otherwise radians.*/
public final boolean inTangents;
/**
* Constructor for one {@link FovHVHalves} instance.
* <p>
* It is recommended to pass and store values in tangent
* if used for perspective FOV calculations, since it will avoid conversion to tangent later on.
* </p>
* @param left half horizontal FOV, left side, in tangent or radians
* @param right half horizontal FOV, right side, in tangent or radians
* @param top half vertical FOV, top side, in tangent or radians
* @param bottom half vertical FOV, bottom side, in tangent or radians
* @param inTangents if true, values are in tangent, otherwise radians
*/
public FovHVHalves(final float left, final float right, final float top, final float bottom, final boolean inTangents) {
this.left = left;
this.right = right;
this.top = top;
this.bottom = bottom;
this.inTangents = inTangents;
}
/**
* Returns a symmetrical centered {@link FovHVHalves} instance in {@link #inTangents}, using:
* <pre>
halfHorizFovTan = tan( horizontalFov / 2f );
halfVertFovTan = tan( verticalFov / 2f );
* </pre>
* @param horizontalFov whole horizontal FOV in radians
* @param verticalFov whole vertical FOV in radians
*/
public static FovHVHalves byRadians(final float horizontalFov, final float verticalFov) {
final float halfHorizFovTan = FloatUtil.tan(horizontalFov/2f);
final float halfVertFovTan = FloatUtil.tan(verticalFov/2f);
return new FovHVHalves(halfHorizFovTan, halfHorizFovTan, halfVertFovTan, halfVertFovTan, true);
}
/**
* Returns a symmetrical centered {@link FovHVHalves} instance in {@link #inTangents}, using:
* <pre>
top = bottom = tan( verticalFov / 2f );
left = right = aspect * top;
* </pre>
*
* @param verticalFov vertical FOV in radians
* @param aspect aspect ration width / height
*/
public static FovHVHalves byFovyRadianAndAspect(final float verticalFov, final float aspect) {
final float halfVertFovTan = FloatUtil.tan(verticalFov/2f);
final float halfHorizFovTan = aspect * halfVertFovTan;
return new FovHVHalves(halfHorizFovTan, halfHorizFovTan,
halfVertFovTan, halfVertFovTan, true);
}
/**
* Returns a custom symmetry {@link FovHVHalves} instance {@link #inTangents}, using:
* <pre>
left = tan( horizontalFov * horizCenterFromLeft )
right = tan( horizontalFov * ( 1f - horizCenterFromLeft ) )
top = tan( verticalFov * vertCenterFromTop )
bottom = tan( verticalFov * (1f - vertCenterFromTop ) )
* </pre>
* @param horizontalFov whole horizontal FOV in radians
* @param horizCenterFromLeft horizontal center from left in [0..1]
* @param verticalFov whole vertical FOV in radians
* @param vertCenterFromTop vertical center from top in [0..1]
*/
public static FovHVHalves byRadians(final float horizontalFov, final float horizCenterFromLeft,
final float verticalFov, final float vertCenterFromTop) {
return new FovHVHalves(FloatUtil.tan(horizontalFov * horizCenterFromLeft),
FloatUtil.tan(horizontalFov * ( 1f - horizCenterFromLeft )),
FloatUtil.tan(verticalFov * vertCenterFromTop),
FloatUtil.tan(verticalFov * (1f - vertCenterFromTop )),
true);
}
/**
* Returns a custom symmetry {@link FovHVHalves} instance {@link #inTangents},
* via computing the <code>horizontalFov</code> using:
* <pre>
halfVertFovTan = tan( verticalFov / 2f );
halfHorizFovTan = aspect * halfVertFovTan;
horizontalFov = atan( halfHorizFovTan ) * 2f;
return {@link #byRadians(float, float, float, float) byRadians}(horizontalFov, horizCenterFromLeft, verticalFov, vertCenterFromTop)
* </pre>
* @param verticalFov whole vertical FOV in radians
* @param vertCenterFromTop vertical center from top in [0..1]
* @param aspect aspect ration width / height
* @param horizCenterFromLeft horizontal center from left in [0..1]
*/
public static FovHVHalves byFovyRadianAndAspect(final float verticalFov, final float vertCenterFromTop,
final float aspect, final float horizCenterFromLeft) {
final float halfVertFovTan = FloatUtil.tan(verticalFov/2f);
final float halfHorizFovTan = aspect * halfVertFovTan;
final float horizontalFov = FloatUtil.atan(halfHorizFovTan) * 2f;
return byRadians(horizontalFov, horizCenterFromLeft, verticalFov, vertCenterFromTop);
}
/**
* Returns this instance <i>in tangent</i> values.
* <p>
* If this instance is {@link #inTangents} already, method returns this instance,
* otherwise a newly created instance w/ converted values to tangent.
* </p>
*/
public final FovHVHalves toTangents() {
if( inTangents ) {
return this;
} else {
return new FovHVHalves(FloatUtil.tan(left), FloatUtil.tan(right), FloatUtil.tan(top), FloatUtil.tan(bottom), true);
}
}
/** Returns the full horizontal FOV, i.e. {@link #left} + {@link #right}, either in {@link #inTangents} or radians. */
public final float horzFov() { return left+right; }
/** Returns the full vertical FOV, i.e. {@link #top} + {@link #bottom}, either in {@link #inTangents} or radians. */
public final float vertFov() { return top+bottom; }
public final String toString() {
return "FovHVH["+(inTangents?"tangents":"radians")+": "+left+" l, "+right+" r, "+top+" t, "+bottom+" b]";
}
public final String toStringInDegrees() {
final float f = 180.0f / FloatUtil.PI;
final String storedAs = inTangents?"tangents":"radians";
if( inTangents ) {
final float aleft = FloatUtil.atan(left);
final float aright = FloatUtil.atan(right);
final float atop = FloatUtil.atan(top);
final float abottom = FloatUtil.atan(bottom);
return "FovHVH[degrees: "+aleft*f+" l, "+aright*f+" r, "+atop*f+" t, "+abottom*f+" b, stored-as: "+storedAs+"]";
} else {
return "FovHVH[degrees: "+left*f+" l, "+right*f+" r, "+top*f+" t, "+bottom*f+" b, stored-as: "+storedAs+"]";
}
}
}