android GPUImage使用的问题？

Question

目前使用GPUImage和GLSurfaceView实现了一个滤镜相机的效果，但是当后置摄像头切换到前置摄像头后，前置画面不能全屏，这个问题很困恼。
查看了GPUImage的源码，在TextureRotationUtil类中，根据旋转角度会得到一个8位的数组，现在想请问这8位的数字各代表什么意思？
TextureRotationUtil类的源码如下：

public class TextureRotationUtil {

    public static final float TEXTURE_NO_ROTATION[] = {
            0.0f, 1.0f,
            1.0f, 1.0f,
            0.0f, 0.0f,
            1.0f, 0.0f,
    };

    public static final float TEXTURE_ROTATED_90[] = {
            1.0f, 1.0f,
            1.0f, 0.0f,
            0.0f, 1.0f,
            0.0f, 0.0f,
    };
    public static final float TEXTURE_ROTATED_180[] = {
            1.0f, 0.0f,
            0.0f, 0.0f,
            1.0f, 1.0f,
            0.0f, 1.0f,
    };
    public static final float TEXTURE_ROTATED_270[] = {
            0.0f, 0.0f,
            0.0f, 1.0f,
            1.0f, 0.0f,
            1.0f, 1.0f,
    };

    private TextureRotationUtil() {
    }

    public static float[] getRotation(final Rotation rotation, final boolean flipHorizontal,
                                                         final boolean flipVertical) {
        float[] rotatedTex;
        switch (rotation) {
            case ROTATION_90:
                rotatedTex = TEXTURE_ROTATED_90;
                break;
            case ROTATION_180:
                rotatedTex = TEXTURE_ROTATED_180;
                break;
            case ROTATION_270:
                rotatedTex = TEXTURE_ROTATED_270;
                break;
            case NORMAL:
            default:
                rotatedTex = TEXTURE_NO_ROTATION;
                break;
        }
        if (flipHorizontal) {
            rotatedTex = new float[]{
                    flip(rotatedTex[0]), rotatedTex[1],
                    flip(rotatedTex[2]), rotatedTex[3],
                    flip(rotatedTex[4]), rotatedTex[5],
                    flip(rotatedTex[6]), rotatedTex[7],
            };
        }
        if (flipVertical) {
            rotatedTex = new float[]{
                    rotatedTex[0], flip(rotatedTex[1]),
                    rotatedTex[2], flip(rotatedTex[3]),
                    rotatedTex[4], flip(rotatedTex[5]),
                    rotatedTex[6], flip(rotatedTex[7]),
            };
        }
        return rotatedTex;
    }


    private static float flip(final float i) {
        if (i == 0.0f) {
            return 1.0f;
        }
        return 0.0f;
    }
}

Answer 1

图像旋转矩阵，数学问题了，即把图像分成一个 4 * 2 矩阵