使用矩阵

Question

我有一个自定义视图扩展了ImageView，我希望在其中使用矩阵来应用缩放，平移，翻转和旋转等操作。

缩放和平移在ontouch事件中运行良好，并且翻转在onclick中也能正常工作。但旋转不如预期。

从中心翻转

public void flip(String flipmode)
{
    Matrix matrix = getImageMatrix();

    float tx = getMatrixValue(matrix, Matrix.MTRANS_X);
    float ty = getMatrixValue(matrix, Matrix.MTRANS_Y);

    float scaleX = getMatrixValue(matrix, Matrix.MSCALE_X);
    float scaleY = getMatrixValue(matrix, Matrix.MSCALE_Y);

    Drawable drawable = getDrawable();
    if (drawable == null) {

        return ;
    }

    float width = scaleX * drawable.getIntrinsicWidth();
    float height = scaleY * drawable.getIntrinsicHeight();

    float skewX = getMatrixValue(matrix, Matrix.MSKEW_X);
    float rAngle = Math.round(Math.atan2(scaleX, skewX) * (180 / Math.PI));

    if (DEBUG) {

        Log.e(TAG, "onUp: " + tx + " " + ty);
        Log.e(TAG, "scaleX:    " + scaleX+"   scaleY:    " + scaleY);
        Log.e(TAG, "drawable size: " + drawable.getIntrinsicWidth() + " " + drawable.getIntrinsicHeight());
        Log.e(TAG, "Rotate Angle: " + rAngle);
        Log.e(TAG, "x center : " + (width/2)+tx + "   y center  " + (height/2)+ty);
    }

    if (flipmode == "ORIENTATION_FLIP_HORIZONTAL") {

        matrix.postScale(-1.0f, 1.0f, (width / 2) + tx, (height / 2) + ty);

    } else if (flipmode == "ORIENTATION_FLIP_VERTICAL") {


        matrix.postScale(1.0f, -1.0f, (width / 2) + tx, (height / 2) + ty);

    }


    setImageMatrix(matrix);
    invalidate();

}

从中心旋转

public void rotate(int rotateAngle)
{
    Matrix matrix = getImageMatrix();

    float tx = getMatrixValue(matrix, Matrix.MTRANS_X);
    float ty = getMatrixValue(matrix, Matrix.MTRANS_Y);

    float scaleX = getMatrixValue(matrix, Matrix.MSCALE_X);
    float scaleY = getMatrixValue(matrix, Matrix.MSCALE_Y);

    float skewX = getMatrixValue(matrix, Matrix.MSKEW_X);
    float skewY = getMatrixValue(matrix, Matrix.MSKEW_Y);


    Drawable drawable = getDrawable();
    if (drawable == null) {

        return ;
    }

    float sx = (float)Math.sqrt((scaleX*scaleX)+(skewY*skewY));
    float sy = (float)Math.sqrt((scaleY*scaleY)+(skewX*skewX));

    float width = sx * drawable.getIntrinsicWidth();
    float height = sy * drawable.getIntrinsicHeight();

    float rAngle = Math.round(Math.atan2(scaleX, skewX) * (180 / Math.PI));

    if (DEBUG) {

        Log.e(TAG, "onUp: " + tx + " " + ty);
        Log.e(TAG, "scaleX:    " + scaleX+"   scaleY:    " + scaleY);
        Log.e(TAG, "scaleX new :    " + sx+"   scaleY new:    " + sy);
        Log.e(TAG, "drawable size: " + drawable.getIntrinsicWidth() + " " + drawable.getIntrinsicHeight());
        Log.e(TAG, "Rotate Angle: " + rAngle);
        Log.e(TAG, "x center : " + (width/2)+tx + "   y center  " + (height/2)+ty);
    }



    matrix.postRotate(rotateAngle, (width/2)+tx, (height/2)+ty);

    setImageMatrix(matrix);

    invalidate();

}

我在第一次轮换后看到了非常奇怪的行为。 问题：新坐标不符合预期 记录初始值：

ImageView: onUp: 144.0 0.0
ImageView: scaleX:    0.6   scaleY:    0.6
ImageView: scaleX new :    0.6   scaleY new:    0.6
ImageView: drawable size: 800 1280
ImageView: Rotate Angle: 90.0
ImageView: x center : 240.00002144.0   y center  384.00.0

记录：应用旋转后

ImageView: onUp: 0.0 624.0
ImageView: scaleX:    0.0   scaleY:    0.0
ImageView: scaleX new :    0.6   scaleY new:    0.6
ImageView: drawable size: 800 1280
ImageView: Rotate Angle: 0.0
ImageView: x center : 240.000020.0   y center  384.0624.0

如何正确应用旧矩阵中的旋转..？