Lines#

Lines are 1 pixel wide and can be diagonal.

Minimum Code#

Creates a black line from the bottom left corner to the top right corner.

#                       X1  Y1    X2   Y2
args.outputs.lines << [  0,  0, 1280, 720]

Creates a black vertical line through the center of the scene.

#                        X1  Y1    X2   Y2
args.outputs.lines << [ 640,  0,  640, 720]

Creates a black horizontal line through the center of the scene.

#                       X1   Y1     X2   Y2
args.outputs.lines << [  0, 360,  1280, 360]

RGBA - Colors and Alpha#

The value for the color and alpha is an number between 0 and 255. The alpha property is optional and will be set to 255 if not specified.

Creates a green horizontal line through the center of the scene with an opacity of 50%.

#                       X1   Y1     X2   Y2   RED  GREEN  BLUE  ALPHA
args.outputs.lines << [  0, 360,  1280, 360,    0,   255,    0,   128]

Creates a green vertical line through the center of the scene. The opacity is excluded because it's 100% opaque (which has a value of 255).

#                        X1   Y1    X2    Y2  RED  GREEN  BLUE
args.outputs.lines << [ 640,   0,  640,  720,   0,   255,    0]

Hash (Advanced)#

If you want a more readable invocation. You can use the following hash to create a line. Any parameters that are not specified will be given a default value. The keys of the hash can be provided in any order.

args.outputs.lines << {
  x:    0,
  y:    0,
  x2: 1280,
  y2:  720,
  r:    0,
  g:  255,
  b:    0,
  a:  255
}

Duck Typing (Advanced)#

You can also create a class with line properties and render it as a primitive. ALL properties must on the class. ADDITIONALLY, a method called primitive_marker must be defined on the class.

Here is an example:

# Create type with ALL line properties AND primitive_marker
class Line
  attr_accessor :x, :y, :x2, :y2, :r, :g, :b, :a

  def primitive_marker
    :line
  end
end

# Inherit from type
class VerticalLine < Line

  # constructor
  def initialize x, y, h
    self.x = x
    self.y = y
    self.x2 = x
    self.y2 = y + h
  end
end

# render line

args.outputs.lines << VerticalLine.new(10, 10, 100)
  • 01_api_02_lines
  • 01_api_99_tech_demo (includes recording)
  • 06_coordinate_systems (includes recording)
  • 19_lowrez_jam_01_hello_world
  • 99_sample_game_pong (includes recording)