OpenGL::Image::Common - copyright 2007 Graphcomp - ALL RIGHTS RESERVED
  Author: Bob "grafman" Free - grafman@graphcomp.com

  This program is free software; you can redistribute it and/or
  modify it under the same terms as Perl itself.

  This module provides a base class for OpenGL imaging engines.
  Requires the OpenGL module.

  ##########
  # Check for installed imaging engines

  use OpenGL::Image::Common;
  my $img = new OpenGL::Image::Common(%params);




  ##########
  # Must supply width and height, or source:

  # source - source image file path (some engines supports URLs).
  # width,height - width and height in pixels for cache allocation.




  ##########
  # Optional params:

  # engine - specifies imaging engine; defaults to 'Targa'.




  ##########
  # Methods defined in this Common module:

  # Get native engine object
  # Note: must not change image dimensions
  my $obj = $img->Native;
  $obj->Quantize() if ($obj);

  # Alternately (Assuming the native engine supports Blur):
  $img->Native->Blur();

  # Test if image width is a power of 2
  if ($img->IsPowerOf2());

  # Test if all listed values are a power of 2
  if ($img->IsPowerOf2(@list));

  # Get largest power of 2 size within dimensions of image
  my $size = $img->GetPowerOf2();

  # Get all parameters as a hashref
  my $params = $img->Get();

  # Get one or more parameter values
  my @values = $img->Get(@params);

  # Get/Set Pixel values (normalized to 1.0)
  my($r,$g,$b,$a) = $img->GetPixel($x,$y);

  # Sync cache after done modifying pixels
  $img->SetPixel($x,$y,$r,$g,$b,$a);
  $frame->Sync();




  ##########
  # Supported parameters:

  # version - version of the engine
  # source - source image, if defined
  # width - width of image in pixels
  # height - height of image in pixels
  # pixels - number of pixels
  # components - number of pixel components
  # size - bytes per component
  # length - cache size in bytes
  # endian - 1 if big endian; otherwise 0
  # alpha - 1 if has alpha channel, -1 if has inverted alpha channel; 0 if none
  # flipped - 1 bit set if cache scanlines are top to bottom; others reserved
  # gl_internalformat - internal GL pixel format. eg: GL_RGBA8, GL_RGBA16
  # gl_format - GL pixel format. eg: GL_RGBA, GL_BGRA
  # gl_type - GL data type.  eg: GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT




  ##########
  # APIs defined in engine modules:

  # Get engine version
  my $ver = OpenGL::Image::ENGINE_MODULE::EngineVersion();

  # Get engine description
  my $desc = OpenGL::Image::ENGINE_MODULE::EngineDescription();




  ##########
  # Methods defined in engine modules:

  # Sync the image cache after modifying pixels.
  # Used by some engines for paged caches; otherwise a NOP.
  $img->Sync();

  # Return the image's cache as an OpenGL::Array object.
  # Note: OGA may change after a cache update
  my $oga = $img->GetArray();

  # Return a C pointer to the image's cache.
  # For use with OpenGL's "_c" APIs.
  # Note: pointer may change after a cache update
  $img->Ptr();

  # Save the image to a PNG file (assuming the native engine supports PNGs).
  $img->Save('MyImage.png');

  # Get image blob.
  my $blob = $img->GetBlob();