Method initIterators

src/app/tools/ink_processing.h:91–94

class DoubleInkProcessing : public InkProcessing<Derived> {
public:
  void initIterators(ToolLoop* loop, int x1, int y) {
    m_srcAddress = (typename ImageTraits::address_t)loop->getSrcImage()->getPixelAddress(x1, y);
    m_dstAddress = (typename ImageTraits::address_t)loop->getDstImage()->getPixelAddress(x1, y);
  }

  void moveIterators() {
    ++m_srcAddress;