pcsx2/common/EmbeddedImage.h

/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2010  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <wx/image.h>
#include <wx/mstream.h>
#include <wx/gdicmn.h>

//////////////////////////////////////////////////////////////////////////////////////////
// Interface for loadable embedded images.  See EmbeddedImage description for details.
//
class IEmbeddedImage
{
public:
	virtual const wxImage& Get() = 0;
	virtual wxImage Scale(int width, int height) = 0;
};

//////////////////////////////////////////////////////////////////////////////////////////
// EmbeddedImage - Helper class for loading images which have been embedded into the binary
// manifest of the executable file.  Images are only loaded when Get() is called,
// which allows this type to be passed to functions as a fallback or default action without
// incurring an unnecessary memory footprint.
//
// Note: Get() only loads the image once.  All subsequent calls to Get will use the
// previously loaded image data.
//
template <typename ImageType>
class EmbeddedImage : public IEmbeddedImage
{
protected:
	wxImage m_Image;
	const wxSize m_ResampleTo;

protected:
	// ------------------------------------------------------------------------
	// Internal function used to ensure the image is loaded before returning the image
	// handle (called from all methods that return an image handle).
	//
	void _loadImage()
	{
		if (!m_Image.Ok())
		{
			wxMemoryInputStream joe(ImageType::Data, ImageType::Length);
			m_Image.LoadFile(joe, ImageType::GetFormat());

			if (m_ResampleTo.IsFullySpecified() && (m_ResampleTo.GetWidth() != m_Image.GetWidth() || m_ResampleTo.GetHeight() != m_Image.GetHeight()))
				m_Image.Rescale(m_ResampleTo.GetWidth(), m_ResampleTo.GetHeight(), wxIMAGE_QUALITY_HIGH);
		}
	}

public:
	EmbeddedImage()
		: m_Image()
		, m_ResampleTo(wxDefaultSize)
	{
	}

	// ------------------------------------------------------------------------
	// Constructor for creating an embedded image that gets resampled to the specified size when
	// loaded.
	//
	// Implementation Note: This function uses wxWidgets ResamplBox method to resize the image.
	// wxWidgets ResampleBicubic appears to be buggy and produces fairly poor results when down-
	// sampling images (basically resembles a pixel resize).  ResampleBox produces much cleaner
	// results.
	//
	EmbeddedImage(int newWidth, int newHeight)
		: m_Image()
		, m_ResampleTo(newWidth, newHeight)
	{
	}

	// ------------------------------------------------------------------------
	// Loads and retrieves the embedded image.  The embedded image is only loaded from its em-
	// bedded format once.  Any subsequent calls to Get(), Rescale(), or Resample() will use
	// the pre-loaded copy.  Translation: the png/jpeg decoding overhead happens only once,
	// and only happens when the image is actually fetched.  Simply creating an instance
	// of an EmbeddedImage object uses no excess memory nor cpu overhead. :)
	//
	const wxImage& Get()
	{
		_loadImage();
		return m_Image;
	}

	wxIcon GetIcon()
	{
		wxIcon retval;
		retval.CopyFromBitmap(Get());
		return retval;
	}

	// ------------------------------------------------------------------------
	// Performs a pixel resize of the loaded image and returns a new image handle (EmbeddedImage
	// is left unmodified).
	//

	wxImage Scale(int width, int height)
	{
		_loadImage();
		// Not strictly necessary - wxWidgets does the dimensions check anyway.
		if (width != m_Image.GetWidth() || height != m_Image.GetHeight())
			return m_Image.Scale(width, height, wxIMAGE_QUALITY_HIGH);
		else
			return m_Image;
	}
};