module Prawn::Graphics::Transformation

# File lib/prawn/graphics/transformation.rb, line 36
def rotate(angle, options = {}, &block)
  Prawn.verify_options(:origin, options)
  rad = degree_to_rad(angle)
  cos = Math.cos(rad)
  sin = Math.sin(rad)
  if options[:origin].nil?
    transformation_matrix(cos, sin, -sin, cos, 0, 0, &block)
  else
    raise Prawn::Errors::BlockRequired unless block

    x = options[:origin][0] + bounds.absolute_left
    y = options[:origin][1] + bounds.absolute_bottom
    x_prime = (x * cos) - (y * sin)
    y_prime = (x * sin) + (y * cos)
    translate(x - x_prime, y - y_prime) do
      transformation_matrix(cos, sin, -sin, cos, 0, 0, &block)
    end
  end
end

Rotate the user space. If a block is not provided, then you must save and restore the graphics state yourself.

@example

save_graphics_state
rotate 30
text "rotated text"
restore_graphics_state

@example Rotating a rectangle around its upper-left corner

x = 300
y = 300
width = 150
height = 200
angle = 30
pdf.rotate(angle, :origin => [x, y]) do
  pdf.stroke_rectangle([x, y], width, height)
end

@param angle [Number] Angle in degrees. @param options [Hash{Symbol => any}] @option options :origin [Array(Number, Number)] Rotation origin point.

A block must be provided if specified.

@yield @raise [Prawn::Errors::BlockRequired] if an ‘:origin` option is

provided, but no block is given.

@return [void]

# File lib/prawn/graphics/transformation.rb, line 109
def scale(factor, options = {}, &block)
  Prawn.verify_options(:origin, options)
  if options[:origin].nil?
    transformation_matrix(factor, 0, 0, factor, 0, 0, &block)
  else
    raise Prawn::Errors::BlockRequired unless block

    x = options[:origin][0] + bounds.absolute_left
    y = options[:origin][1] + bounds.absolute_bottom
    x_prime = factor * x
    y_prime = factor * y
    translate(x - x_prime, y - y_prime) do
      transformation_matrix(factor, 0, 0, factor, 0, 0, &block)
    end
  end
end

Scale the user space. If a block is not provided, then you must save and restore the graphics state yourself.

@example

save_graphics_state
scale 1.5
text "scaled text"
restore_graphics_state

@example Scale a rectangle from its upper-left corner

x = 300
y = 300
width = 150
height = 200
factor = 1.5
pdf.scale(angle, :origin => [x, y]) do
  pdf.stroke_rectangle([x, y], width, height)
end

@param factor [Number] Scale factor. @param options [Hash{Symbol => any}] @option options :origin [Array(Number, Number)] The point from which to

scale. A block must be provided if specified.

@yield @raise [Prawn::Errors::BlockRequired] If an ‘:origin` option is

provided, but no block is given.

@return [void]

# File lib/prawn/graphics/transformation.rb, line 154
def transformation_matrix(*matrix)
  if matrix.length != 6
    raise ArgumentError,
      'Transformation matrix must have exacty 6 elements'
  end
  save_graphics_state if block_given?

  add_to_transformation_stack(*matrix)

  values = PDF::Core.real_params(matrix)
  renderer.add_content("#{values} cm")
  if block_given?
    yield
    restore_graphics_state
  end
end

Transform the user space (see notes for rotate regarding graphics state) Generally, one would use the {rotate}, {scale}, and {translate} convenience methods instead of calling transformation_matrix directly

@param matrix [Array(Number, Number, Number, Number, Number, Number)]

Transformation matrix.

The six elements correspond to the following elements of the
transformation matrix:

```plain
a b 0
c d 0
e f 0
```

@yield @return [void]

# File lib/prawn/graphics/transformation.rb, line 78
def translate(x, y, &block)
  transformation_matrix(1, 0, 0, 1, x, y, &block)
end

Translate the user space. If a block is not provided, then you must save and restore the graphics state yourself.

@example Move the text up and over 10

save_graphics_state
translate(10, 10)
text "scaled text"
restore_graphics_state

@example draw a rectangle with its upper-left corner at x + 10, y + 10

x = 300
y = 300
width = 150
height = 200
pdf.translate(10, 10) do
  pdf.stroke_rectangle([x, y], width, height)
end

@param x [Number] @param y [Number] @yield @return [void]