java 源码有关问题 SinglePixelPackedSampleModel类

 public void setPixels(int x, int y, int w, int h,                          int iArray[], DataBuffer data) {        int x1 = x + w;        int y1 = y + h;        if (x < 0 || x >= width || w > width || x1 < 0 || x1 > width ||            y < 0 || y >= height || h > height || y1 < 0 || y1 >  height)        {            throw new ArrayIndexOutOfBoundsException                ("Coordinate out of bounds!");        }        int lineOffset = y*scanlineStride + x;        int srcOffset = 0;        for (int i = 0; i < h; i++) {           for (int j = 0; j < w; j++) {               int value = data.getElem(lineOffset+j);               for (int k=0; k < numBands; k++) {                   value &= ~bitMasks[k];                   int srcValue = iArray[srcOffset++];                   value |= ((srcValue << bitOffsets[k])                             & bitMasks[k]);               }               data.setElem(lineOffset+j, value);           }           lineOffset += scanlineStride;        }    }