png_provider_generic.h

这是一款2d游戏引擎

/*  $Id: png_provider_generic.h,v 1.9 2003/10/14 15:52:12 mbn Exp $
**
**  ClanLib Game SDK
**  Copyright (C) 2003  The ClanLib Team
**  For a total list of contributers see the file CREDITS.
**
**  This library 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 Foundation; either
**  version 2.1 of the License, or (at your option) any later version.
**
**  This library 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
**  Lesser General Public License for more details.
**
**  You should have received a copy of the GNU Lesser General Public
**  License along with this library; if not, write to the Free Software
**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
*/

#ifndef header_png_provider_generic
#define header_png_provider_generic

#if _MSC_VER > 1000
#pragma once
#endif

#include "API/Display/Providers/png_provider.h"
#include "Display/pixel_buffer_generic.h"

#include "API/Core/IOData/inputsource.h"
#include "API/Core/IOData/inputsource_provider.h"

#include <png.h>

class CL_PNGProvider_Generic : public CL_PixelBuffer_Generic
{
//! Construction:
public:
	CL_PNGProvider_Generic(
		const std::string &name, 
		CL_InputSourceProvider *provider = 0,
		bool transparent = true,
		bool ignore_alphachannel = false);

	~CL_PNGProvider_Generic();

//! Attributes:
public:
	//: returns Pointer to CL_InputSource
	//: (used by libpng-callback CL_PNGProvider::pngread_file() )
	CL_InputSource *get_input_source() { return input_source; }

	//: Returns the pitch of the image (bytes per line).
	unsigned int get_pitch() const { return pitch; }

	//: Returns the width of the image.
	unsigned int get_width() const { return width; }

	//: Returns the height of the image.
	unsigned int get_height() const { return height; }
	
	//: Returns the number of subsprites in the image.
	unsigned int get_num_frames() const { return 1; }

	//: Returns the transparency color used.
	unsigned int get_src_colorkey() const { return trans_col; }

	//: Returns whether a source colorkey is used.
	bool uses_src_colorkey() const { return m_uses_src_colorkey; }

	//: Returns whether the target uses an indexed color mode or not.
	bool is_indexed() const;
	
//! Operations:
public:
	//: Returns the image data. Provider must be locked before pointer is valid.
	virtual void *get_data();

	//: Locks the surface provider.
	virtual void perform_lock();

	//: Unlocks the surface provider.
	virtual void perform_unlock();
	
//! Implementation:
private:
	//: Callback used by libpng to retrieve the filedata. 
	//: (calls get_input_source()->read_uchar8())
	static void pngread_file(png_structp png_ptr, png_bytep data, png_size_t length);

	void read_data();

	void read_data_rgb();

	void read_data_rgba();

	void read_data_grayscale();

	void read_data_grayscale_alpha();

	void read_data_palette();

	std::string filename;

	bool m_uses_src_colorkey;
	
	unsigned char *image;
	int pitch;
	int no_sprs;
	int width;
	int height;

	bool transparent;
	bool ignore_alphachannel;

	bool indexed;
	int trans_col;
	int color_type;
	unsigned char trans_redcol, trans_greencol, trans_bluecol;

	CL_InputSourceProvider *provider;
	CL_InputSource *input_source;

	//PNGlib stuff:
	png_structp png_ptr;
	png_infop info_ptr;
	png_infop end_info;
};

#endif