Canvas drawText 方法问题？

[funnyone]

文档上是这样描述的。

/**
     * Draw the text, with origin at (x,y), using the specified paint. The
     * origin is interpreted based on the Align setting in the paint.
     *
     * @param text  The text to be drawn
     * @param x     The x-coordinate of the origin of the text being drawn
     * @param y     The y-coordinate of the origin of the text being drawn
     * @param paint The paint used for the text (e.g. color, size, style)
     */
    public void drawText(String text, float x, float y, Paint paint) {
        native_drawText(mNativeCanvas, text, 0, text.length(), x, y, paint.mBidiFlags,
                paint.mNativePaint);
    }

但是我测试后发现根本不对
float x, float y 指的是一个字体左上角的坐标。

主要代码是：

@Override
	protected void onDraw(Canvas canvas) {
		canvas.save();
		float px = getWidth() / 2;
		float py = getHeight() / 2;
		float radius = Math.min(px, py);
		canvas.drawCircle(px, py, radius, paint);

		for (int i = 0; i <= 3; ++i) {
			canvas.drawText(i + "", px - textWidth / 2, py - radius , textPaint);
			canvas.rotate(90, px, py);
		}
		canvas.restore();
		super.onDraw(canvas);
	}

那个0，2不见啦这是什麽原因？

效果是：

[儿大不由爷]

半径太大了 吧