Module: Quake::Debug::Screenshot

Defined in:
lib/quake/debug/screenshot.rb

Overview

Captures the current GL framebuffer to a PNG file via glReadPixels.

Class Method Summary collapse

Class Method Details

.capture(width, height) ⇒ Object

Read the current framebuffer as RGB bytes (bottom-up).



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# File 'lib/quake/debug/screenshot.rb', line 11

def self.capture(width, height)
  buf = ("\x00".b * (width * height * 3))
  GL.PixelStorei(GL::PACK_ALIGNMENT, 1)
  GL.ReadPixels(0, 0, width, height, GL::RGB, GL::UNSIGNED_BYTE, buf)
  buf
end

.save(filename, width, height) ⇒ Object

Save the current framebuffer as a PNG file.



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# File 'lib/quake/debug/screenshot.rb', line 19

def self.save(filename, width, height)
  raw = capture(width, height)
  flipped = PngWriter.flip_rows(raw, width, height)
  PngWriter.write(filename, width, height, flipped)
end