Method fill

src/laybasic/laybasic/layBitmap.cc:353–382

static const uint32_t all_ones = 0xffffffff;

void 
Bitmap::fill (unsigned int y, unsigned int x1, unsigned int x2)
{
  unsigned int b1 = x1 / 32;

  uint32_t *sl = scanline (y);
  sl += b1;

  unsigned int b = x2 / 32 - b1;
  if (b == 0) {

    *sl |= (masks [x2 % 32] & ~masks [x1 % 32]);

  } else if (b > 0) {

    *sl++ |= ~masks [x1 % 32];
    while (b > 1) {
      *sl++ |= all_ones;
      b--;
    }

    unsigned int m = masks [x2 % 32];
    //  Hint: if x2==width and width%32==0, sl must not be accessed. This is guaranteed by
    //  checking if m != 0.
    if (m) {
      *sl |= m;
    }

  }
}

void
Bitmap::clear (unsigned int y, unsigned int x1, unsigned int x2)