Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

import android.opengl.Matrix;

public class Main {
    /**
     * Returns layout transformation matrix that applies an optional mirror effect and compensates
     * for video vs display aspect ratio.
     */
    public static float[] getLayoutMatrix(boolean mirror, float videoAspectRatio, float displayAspectRatio) {
        float scaleX = 1;
        float scaleY = 1;
        // Scale X or Y dimension so that video and display size have same aspect ratio.
        if (displayAspectRatio > videoAspectRatio) {
            scaleY = videoAspectRatio / displayAspectRatio;
        } else {
            scaleX = displayAspectRatio / videoAspectRatio;
        }
        // Apply optional horizontal flip.
        if (mirror) {
            scaleX *= -1;
        }
        final float matrix[] = new float[16];
        Matrix.setIdentityM(matrix, 0);
        Matrix.scaleM(matrix, 0, scaleX, scaleY, 1);
        adjustOrigin(matrix);
        return matrix;
    }

    /**
     * Move |matrix| transformation origin to (0.5, 0.5). This is the origin for texture coordinates
     * that are in the range 0 to 1.
     */
    private static void adjustOrigin(float[] matrix) {
        // Note that OpenGL is using column-major order.
        // Pre translate with -0.5 to move coordinates to range [-0.5, 0.5].
        matrix[12] -= 0.5f * (matrix[0] + matrix[4]);
        matrix[13] -= 0.5f * (matrix[1] + matrix[5]);
        // Post translate with 0.5 to move coordinates to range [0, 1].
        matrix[12] += 0.5f;
        matrix[13] += 0.5f;
    }
}