MatrixHelper.java

/*
 * Copyright 2014 Google Inc. All Rights Reserved.

 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.cardboard.photosphere;

/**
 * @author Sree Kumar A.V
 */
public class MatrixHelper {
    public static void perspectiveM(float[] m, float yFovInDegrees, float aspect,
        float n, float f) {
        final float angleInRadians = (float) (yFovInDegrees * Math.PI / 180.0);
        final float a = (float) (1.0 / Math.tan(angleInRadians / 2.0));

        m[0] = a / aspect;
        m[1] = 0f;
        m[2] = 0f;
        m[3] = 0f;

        m[4] = 0f;
        m[5] = a;
        m[6] = 0f;
        m[7] = 0f;

        m[8] = 0f;
        m[9] = 0f;
        m[10] = -((f + n) / (f - n));
        m[11] = -1f;
        
        m[12] = 0f;
        m[13] = 0f;
        m[14] = -((2f * f * n) / (f - n));
        m[15] = 0f;        
    }
}