org.joml.Matrix3fStack Maven / Gradle / Ivy
/*
* The MIT License
*
* Copyright (c) 2018-2020 JOML
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.joml;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
/**
* A stack of many {@link Matrix3f} instances. This resembles the matrix stack known from legacy OpenGL.
*
* This {@link Matrix3fStack} class inherits from {@link Matrix3f}, so the current/top matrix is always the
* {@link Matrix3fStack}/{@link Matrix3f} itself. This affects all operations in {@link Matrix3f} that take another
* {@link Matrix3f} as parameter. If a {@link Matrix3fStack} is used as argument to those methods, the effective
* argument will always be the current matrix of the matrix stack.
*
* @author Kai Burjack
*/
public class Matrix3fStack extends Matrix3f {
private static final long serialVersionUID = 1L;
/**
* The matrix stack as a non-growable array. The size of the stack must be specified in the {@link #Matrix3fStack(int) constructor}.
*/
private Matrix3f[] mats;
/**
* The index of the "current" matrix within {@link #mats}.
*/
private int curr;
/**
* Create a new {@link Matrix3fStack} of the given size.
*
* Initially the stack pointer is at zero and the current matrix is set to identity.
*
* @param stackSize
* the size of the stack. This must be at least 1, in which case the {@link Matrix3fStack} simply only consists of this
* {@link Matrix3f}
*/
public Matrix3fStack(int stackSize) {
if (stackSize < 1) {
throw new IllegalArgumentException("stackSize must be >= 1"); //$NON-NLS-1$
}
mats = new Matrix3f[stackSize - 1];
// Allocate all matrices up front to keep the promise of being "allocation-free"
for (int i = 0; i < mats.length; i++) {
mats[i] = new Matrix3f();
}
}
/**
* Do not invoke manually! Only meant for serialization.
*
* Invoking this constructor from client code will result in an inconsistent state of the
* created {@link Matrix3fStack} instance.
*/
public Matrix3fStack() {
/* Empty! */
}
/**
* Set the stack pointer to zero and set the current/bottom matrix to {@link #identity() identity}.
*
* @return this
*/
public Matrix3fStack clear() {
curr = 0;
identity();
return this;
}
/**
* Increment the stack pointer by one and set the values of the new current matrix to the one directly below it.
*
* @return this
*/
public Matrix3fStack pushMatrix() {
if (curr == mats.length) {
throw new IllegalStateException("max stack size of " + (curr + 1) + " reached"); //$NON-NLS-1$ //$NON-NLS-2$
}
mats[curr++].set(this);
return this;
}
/**
* Decrement the stack pointer by one.
*
* This will effectively dispose of the current matrix.
*
* @return this
*/
public Matrix3fStack popMatrix() {
if (curr == 0) {
throw new IllegalStateException("already at the buttom of the stack"); //$NON-NLS-1$
}
set(mats[--curr]);
return this;
}
public int hashCode() {
final int prime = 31;
int result = super.hashCode();
result = prime * result + curr;
for (int i = 0; i < curr; i++) {
result = prime * result + mats[i].hashCode();
}
return result;
}
/*
* Contract between Matrix3f and Matrix3fStack:
*
* - Matrix3f.equals(Matrix3fStack) is true iff all the 9 matrix elements are equal
* - Matrix3fStack.equals(Matrix3f) is true iff all the 9 matrix elements are equal
* - Matrix3fStack.equals(Matrix3fStack) is true iff all 9 matrix elements are equal AND the matrix arrays as well as the stack pointer are equal
* - everything else is inequal
*/
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!super.equals(obj))
return false;
if (obj instanceof Matrix3fStack) {
Matrix3fStack other = (Matrix3fStack) obj;
if (curr != other.curr)
return false;
for (int i = 0; i < curr; i++) {
if (!mats[i].equals(other.mats[i]))
return false;
}
}
return true;
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal(out);
out.writeInt(curr);
for (int i = 0; i < curr; i++) {
out.writeObject(mats[i]);
}
}
public void readExternal(ObjectInput in) throws IOException {
super.readExternal(in);
curr = in.readInt();
mats = new Matrix3fStack[curr];
for (int i = 0; i < curr; i++) {
Matrix3f m = new Matrix3f();
m.readExternal(in);
mats[i] = m;
}
}
}