Method: Map#pack_sections

Defined in:
lib/IFMapper/MapPrinting.rb

#pack_sections(xmax, ymax) ⇒ Object

This code section is largely a copy of similar code used in IFM’s C code. It tries to pack multiple map sections into a single page.



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# File 'lib/IFMapper/MapPrinting.rb', line 27

def pack_sections(xmax, ymax)
  spacing = 0.0

  # initialize -- one section per page
  pages = []
  @sections.each { |sect|
    xlen, ylen = sect.rooms_width_height
    sect.xoff = 0.0
    sect.yoff = 0.0

    page = Page.new(xlen+2, ylen+2)
    page.sections << sect
    pages << page
  }

  ratio   = xmax.to_f / ymax

  packed  = 1
  while packed > 0
    newpages = []
    pos = packed = 0
    while pos < pages.size
      p1 = pages[pos]
      x1 = p1.xlen
      y1 = p1.ylen

      # Check if it's better off rotated
      p1.rotate = ((x1 < y1 and xmax > ymax) or
                   (x1 > y1 and xmax < ymax))

      # Check if this is the last page
      if pos + 1 == pages.size
        newpages.push p1
        break
      end

      # Get following page
      p2 = pages[pos+1]
      x2 = p2.xlen
      y2 = p2.ylen

      # Try combining pages in X direction
      xc1 = x1 + x2 + spacing
      yc1 = [y1, y2].max
      v1  = (xc1 <= xmax and yc1 <= ymax)
      r1  = xc1.to_f / yc1

      # Try combining pages in Y direction
      xc2 = [x1, x2].max
      yc2 = y1 + y2 + spacing
      v2  = (xc2 <= xmax and yc2 <= ymax)
      r2  = xc2.to_f / yc2

      # See which is best
      if v1 and v2
        if (ratio - r1).abs < (ratio - r2).abs
          v2 = false
        else
          v1 = false
        end
      end

      # Just copy page if nothing can be done
      if not v1 and not v2
        newpages.push(p1)
        pos += 1
        next
      end

      # Create merged page
      page = Page.new
      xo1 = yo1 = xo2 = yo2 = 0

      if v1
        page.xlen = xc1
        page.ylen = yc1
        xo2 = x1 + spacing

        if y1 < y2
          yo1 = (yc1 - y1) / 2
        else
          yo2 = (yc1 - y2) / 2
        end
      end

      if v2
        page.xlen = xc2
        page.ylen = yc2
        yo1 = y2 + spacing

        if x1 < x2
          xo1 = (xc2 - x1) / 2
        else
          xo2 = (xc2 - x2) / 2
        end
      end

      # Copy sections to new page, updating offsets
      opsects = p1.sections
      opsects.each { |sect|
        page.sections.push sect
        sect.xoff += xo1
        sect.yoff += yo1
      }

      opsects = p2.sections
      opsects.each { |sect|
        page.sections.push sect
        sect.xoff += xo2
        sect.yoff += yo2
      }

      # Add merged page to list and go to next page pair
      newpages.push page
      pos += 2
      packed += 1
    end
    pages = newpages
  end

  # Give each section its page info and clean up
  num = 0
  pages.each { |page|
    psects = page.sections
    xlen  = page.xlen
    ylen  = page.ylen
    rflag = page.rotate

    num += 1
    psects.each { |sect|
      sect.page   = num
      sect.pxlen  = xlen
      sect.pylen  = ylen
      sect.rotate = rflag
    }
  }
  return num
end