Class: Ashton::Texture

Inherits:
Object
  • Object
show all
Includes:
Mixins::VersionChecking
Defined in:
lib/ashton/texture.rb

Direct Known Subclasses

WindowBuffer

Constant Summary collapse

DEFAULT_DRAW_COLOR = 
Gosu::Color::WHITE
VALID_DRAW_MODES = 
[:alpha_blend, :add, :multiply, :replace]

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Mixins::VersionChecking

#check_opengl_extension, #check_opengl_version

Constructor Details

#initialize(image) ⇒ Texture #initialize(blob, width, height) ⇒ Texture #initialize(width, height) ⇒ Texture

Returns a new instance of Texture.

Overloads:

  • #initialize(image) ⇒ Texture

    Create a texture from a Gosu::Image

    Parameters:

    See Also:

    • Image#to_texture
  • #initialize(blob, width, height) ⇒ Texture

    Create a texture from a binary blob.

    Parameters:

    • blob (String)
    • width (Integer)
    • height (Integer)
  • #initialize(width, height) ⇒ Texture

    Create a blank (transparent) texture.

    Parameters:

    • width (Integer)
    • height (Integer) 


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# File 'lib/ashton/texture.rb', line 37

def initialize(*args)
  case args.size
    when 1
      # Create from Gosu::Image
      image = args[0]
      raise TypeError, "Expected Gosu::Image" unless image.is_a? Gosu::Image
      initialize_ image.width, image.height, nil

      render do
        # TODO: Ideally we'd draw the image in replacement mode, but Gosu doesn't support that.
        $window.gl do
          info = image.gl_tex_info
          glEnable GL_TEXTURE_2D
          glBindTexture GL_TEXTURE_2D, info.tex_name
          glEnable GL_BLEND
          glBlendFunc GL_ONE, GL_ZERO

          glBegin GL_QUADS do
            glTexCoord2d info.left, info.top
            glVertex2d 0, height # BL

            glTexCoord2d info.left, info.bottom
            glVertex2d 0, 0 # TL

            glTexCoord2d info.right, info.bottom
            glVertex2d width, 0 # TR

            glTexCoord2d info.right, info.top
            glVertex2d width, height # BR
          end
        end
      end

    when 2
      # Create blank image.
      width, height = *args
      initialize_ width, height, nil
      clear

    when 3
      # Create from blob - create a Gosu image first.
      blob, width, height = *args
      raise ArgumentError, "Blob data is not of expected size" if blob.length != width * height * 4
      initialize_ width, height, blob

    else
      raise ArgumentError, "Expected 1, 2 or 3 parameters."
  end

  @rendering = false
end

Class Attribute Details

.pixelated=(value) ⇒ Object (writeonly)

Boolean

Whether or not to pixelate (rather than smooth) on #draw



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# File 'lib/ashton/texture.rb', line 10

def pixelated=(value)
  @pixelated = value
end

Class Method Details

.pixelated? ⇒ Boolean

Boolean

Whether or not to pixelate (rather than smooth) on #draw. Set true when Gosu::enable_undocumented_retrofication called.

Returns:

  • (Boolean) 


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# File 'lib/ashton/texture.rb', line 12

def pixelated?; @pixelated end

Instance Method Details

#clear(options = {}) ⇒ Object

Clears the buffer, optionally to a specific color.

Parameters:

  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :color (Gosu::Color, Array<Float>) — default: transparent 


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# File 'lib/ashton/texture.rb', line 93

def clear(options = {})
  options = {
      color: [0.0, 0.0, 0.0, 0.0],
  }.merge! options

  color = options[:color]
  color = color.to_opengl if color.is_a? Gosu::Color

  glBindFramebufferEXT GL_FRAMEBUFFER_EXT, fbo_id unless rendering?

  glDisable GL_BLEND # Need to replace the alpha too.
  glClearColor(*color)
  glClear GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT
  glEnable GL_BLEND

  glBindFramebufferEXT GL_FRAMEBUFFER_EXT, 0 unless rendering?

  nil
end

#dup ⇒ Object 



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# File 'lib/ashton/texture.rb', line 177

def dup
  # Create a new texture and draw self into it.
  new_texture = Texture.new width, height
  new_texture.render do
    draw 0, 0, 0, mode: :replace
  end
  new_texture
end

#render ⇒ Object

Enable the texture to use (e.g. to draw or convert it).

Raises:

  • (ArgumentError) 


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# File 'lib/ashton/texture.rb', line 115

def render
  raise ArgumentError, "Block required" unless block_given?
  raise Error, "Can't nest rendering" if rendering?

  $window.flush # Ensure that any drawing _before_ the render block is drawn to screen, rather than into the buffer.

  render_

  @rendering = true

  # Project onto the texture itself, using Gosu (inverted) coordinates.
  glPushMatrix
  glMatrixMode GL_PROJECTION
  glLoadIdentity
  glViewport 0, 0, width, height
  glOrtho 0, width, height, 0, -1, 1

  begin
    yield self
  ensure
    $window.flush # Force all the drawing to draw now!
    glBindFramebufferEXT GL_FRAMEBUFFER_EXT, 0

    @rendering = false

    glPopMatrix

    cache.refresh # Force lazy reloading of the cache.
  end

  self
end

#rendering? ⇒ Boolean

Boolean

Is this texture being rendered to currently?

Returns:

  • (Boolean) 


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# File 'lib/ashton/texture.rb', line 17

def rendering?; @rendering end

#to_image(*args) ⇒ Object

Convert the current contents of the buffer into a Gosu::Image

Parameters:

  • options (Hash) —

    a customizable set of options



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# File 'lib/ashton/texture.rb', line 173

def to_image(*args)
  cache.to_image(*args)
end