protected void filter()

in src/main/java/org/apache/pdfbox/jbig2/image/Scanline.java [229:281]
43 lines of code
14 McCabe index (conditional complexity)

        protected void filter(final int[] preShift, final int[] postShift, final Weighttab[] tabs,
                final Scanline dst)
        {
            final IntegerSinglePixelPackedScanline ispps = (IntegerSinglePixelPackedScanline) dst;
            final int nx = dst.length;

            // start sum at 1<<shift-1 for rounding
            final int start[] = tmp;
            for (int c = 0; c < componentCount; c++)
                start[c] = 1 << postShift[c] - 1;

            final int abuf[] = data;
            final int bbuf[] = ispps.data;

            // the next two blocks are duplicated except for the missing shift
            // operation if preShift==0.
            boolean hasPreShift = false;
            for (int c = 0; c < componentCount && !hasPreShift; c++)
                hasPreShift |= preShift[c] != 0;
            if (hasPreShift)
                for (int bp = 0, b = 0; b < nx; b++)
                {
                    final Weighttab wtab = tabs[b];
                    final int an = wtab.weights.length;

                    for (int c = 0; c < componentCount; c++)
                    {
                        int sum = start[c];
                        for (int wp = 0, ap = wtab.i0 * componentCount + c; wp < an
                                && ap < abuf.length; wp++, ap += componentCount)
                            sum += wtab.weights[wp] * (abuf[ap] >> preShift[c]);

                        final int t = sum >> postShift[c];
                        bbuf[bp++] = t < 0 ? 0 : t > 255 ? 255 : t;
                    }
                }
            else
                for (int bp = 0, b = 0; b < nx; b++)
                {
                    final Weighttab wtab = tabs[b];
                    final int an = wtab.weights.length;

                    for (int c = 0; c < componentCount; c++)
                    {
                        int sum = start[c];
                        for (int wp = 0, ap = wtab.i0 * componentCount + c; wp < an
                                && ap < abuf.length; wp++, ap += componentCount)
                            sum += wtab.weights[wp] * abuf[ap];

                        bbuf[bp++] = sum >> postShift[c];
                    }
                }
        }