Method: GraphHelper#draw_line

Defined in:
lib/graph_helper.rb

#draw_line(x1, y1, x2, y2, r, g, b, graph_function = false) ⇒ Object

This function will draw an aliased line between points (x1,y1) and (x2,y2). The last 3 parameters are used to set the line color. The last optional parameter is used for internal calls made by graphing function.If set to true, only portions of line inside the graph area will be drawn.



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# File 'lib/graph_helper.rb', line 267

def draw_line(x1,y1,x2,y2,r,g,b,graph_function=false)
  if ( @line_dot_size > 1 )
    draw_dotted_line(x1,y1,x2,y2,@line_dot_size,r,g,b,graph_function)
  else
    b, g, r = validate_color(b, g, r)
    distance = Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)) rescue 0
    if ( distance == 0 )
      return -1
    else
      x_step = (x2-x1) / distance
      y_step = (y2-y1) / distance
      i =0
      while i<=distance
        x = i * x_step + x1
        y = i * y_step + y1
        if((x >= @g_area_x1.to_f && x <= @g_area_x2.to_f && y >= @g_area_y1.to_f && y <= @g_area_y2.to_f) || !graph_function )
          if ( @line_width == 1 )
            draw_antialias_pixel(x,y,r,g,b)
          else
            start_offset = -(@line_width/2)
            end_offset = (@line_width/2)
            j = start_offset

            while j<=end_offset
              draw_antialias_pixel(x+j,y+j,r,g,b)
              j+=1
            end
          end
        end
        i =i+1
      end
    end
  end
end