/*
 * This file is subject to the terms of the GFX License. If a copy of
 * the license was not distributed with this file, you can obtain one at:
 *
 *              http://ugfx.org/license.html
 */

/**
 * @file    src/gdisp/gdisp_image.h
 *
 * @defgroup Image Image
 * @ingroup GDISP
 *
 * @brief   Sub-Module for image handling.
 *
 * @{
 */

#ifndef _GDISP_IMAGE_H
#define _GDISP_IMAGE_H
#if (GFX_USE_GDISP && GDISP_NEED_IMAGE) || defined(__DOXYGEN__)

/**
 * @brief	The type of image
 */
typedef uint16_t	gdispImageType;
	#define GDISP_IMAGE_TYPE_UNKNOWN	0
	#define GDISP_IMAGE_TYPE_NATIVE		1
	#define GDISP_IMAGE_TYPE_GIF		2
	#define GDISP_IMAGE_TYPE_BMP		3
	#define GDISP_IMAGE_TYPE_JPG		4
	#define GDISP_IMAGE_TYPE_PNG		5

/**
 * @brief	An image error code
 */
typedef uint16_t	gdispImageError;
	#define GDISP_IMAGE_ERR_OK					0
	#define GDISP_IMAGE_ERR_UNRECOVERABLE		0x8000
	#define GDISP_IMAGE_ERR_BADFORMAT			(GDISP_IMAGE_ERR_UNRECOVERABLE+1)
	#define GDISP_IMAGE_ERR_BADDATA				(GDISP_IMAGE_ERR_UNRECOVERABLE+2)
	#define GDISP_IMAGE_ERR_UNSUPPORTED			(GDISP_IMAGE_ERR_UNRECOVERABLE+3)
	#define GDISP_IMAGE_ERR_UNSUPPORTED_OK		3
	#define GDISP_IMAGE_ERR_NOMEMORY			(GDISP_IMAGE_ERR_UNRECOVERABLE+4)
	#define GDISP_IMAGE_ERR_NOSUCHFILE			(GDISP_IMAGE_ERR_UNRECOVERABLE+5)

/**
 * @brief	Image flags
 */
typedef uint16_t	gdispImageFlags;
	#define GDISP_IMAGE_FLG_TRANSPARENT			0x0001	/* The image has transparency */
	#define GDISP_IMAGE_FLG_ANIMATED			0x0002	/* The image has animation */
	#define GDISP_IMAGE_FLG_MULTIPAGE			0x0004	/* The image has multiple pages */

/**
 * @brief	The structure for an image
 */
typedef struct gdispImage {
	gdispImageType						type;				/* @< The image type */
	gdispImageFlags						flags;				/* @< The image flags */
	color_t								bgcolor;			/* @< The default background color */
	coord_t								width, height;		/* @< The image dimensions */
	GFILE *								f;					/* @< The underlying GFILE */
	#if GDISP_NEED_IMAGE_ACCOUNTING
		uint32_t						memused;			/* @< How much RAM is currently allocated */
		uint32_t						maxmemused;			/* @< How much RAM has been allocated (maximum) */
	#endif
	const struct gdispImageHandlers *	fns;				/* @< Don't mess with this! */
	void *								priv;				/* @< Don't mess with this! */
} gdispImage;
	
#ifdef __cplusplus
extern "C" {
#endif

	/**
	 * @brief	Initialise a gdispImage object
	 *
	 * @param[in] img  		The image structure to initialise
	 *
	 */
	void gdispImageInit(gdispImage *img);

	/**
	 * @brief	Open an image using an open GFILE and get it ready for drawing
	 * @details	Determine the image format and get ready to decode the first image frame
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 *
	 * @param[in] img  		The image structure
	 * @param[in] f			The open GFILE stream.
	 *
	 * @pre		The GFILE must be open for reading.
	 * 
	 * @note	This determines which decoder to use and then initialises all other fields
	 * 			in the gdispImage structure.
	 * @note	The image background color is set to White.
	 * @note	There are three types of return - everything OK, partial success and unrecoverable
	 * 			failures. For everything OK it returns GDISP_IMAGE_ERR_OK. A partial success can
	 * 			be distinguished from a unrecoverable failure by testing the GDISP_IMAGE_ERR_UNRECOVERABLE
	 * 			bit in the error code.
	 * 			A partial success return code means an image can still be drawn but perhaps with
	 * 			reduced functionality eg only the first page of a multi-page image.
	 * @note	@p gdispImageClose() should be called when finished with the image. This will close
	 * 			the image and its underlying GFILE file. Note that images opened with partial success
	 * 			(eg GDISP_IMAGE_ERR_UNSUPPORTED_OK)
	 * 			still need to be closed when you are finished with them.
	 */
	gdispImageError gdispImageOpenGFile(gdispImage *img, GFILE *f);

	/**
	 * @brief	Open an image in a file and get it ready for drawing
	 * @details	Determine the image format and get ready to decode the first image frame
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 *
	 * @pre		You must have included the file-system support into GFILE that you want to use.
	 *
	 * @param[in] img  		The image structure
	 * @param[in] filename	The filename to open
	 *
	 * @note	This function just opens the GFILE using the filename and passes it to @p gdispImageOpenGFile().
	 */
	#define gdispImageOpenFile(img, filename)			gdispImageOpenGFile((img), gfileOpen((filename), "rb"))

	/**
	 * @brief	Open an image in a ChibiOS basefilestream and get it ready for drawing
	 * @details	Determine the image format and get ready to decode the first image frame
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 *
	 * @pre		GFILE_NEED_CHIBIOSFS and GFX_USE_OS_CHIBIOS must be TRUE. This only makes sense on the ChibiOS
	 * 			operating system.
	 *
	 * @param[in] img  				The image structure
	 * @param[in] BaseFileStreamPtr	A pointer to an open BaseFileStream
	 *
	 * @note	This function just opens the GFILE using the basefilestream and passes it to @p gdispImageOpenGFile().
	 */
	#define gdispImageOpenBaseFileStream(img, BaseFileStreamPtr)			gdispImageOpenGFile((img), gfileOpenBaseFileStream((BaseFileStreamPtr), "rb"))

	/**
	 * @brief	Open an image in memory and get it ready for drawing
	 * @details	Determine the image format and get ready to decode the first image frame
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 *
	 * @pre		GFILE_NEED_MEMFS must be TRUE
	 *
	 * @param[in] img  		The image structure
	 * @param[in] ptr		A pointer to the image bytes in memory
	 *
	 * @note	This function just opens the GFILE using the basefilestream and passes it to @p gdispImageOpenGFile().
	 */
	#define gdispImageOpenMemory(img, ptr)			gdispImageOpenGFile((img), gfileOpenMemory((void *)(ptr), "rb"))

	/**
	 * @brief	Close an image and release any dynamically allocated working storage.
	 * 
	 * @param[in] img   The image structure
	 * 
	 * @pre		gdispImageOpenFile() must have returned successfully.
	 *
	 * @note	Also calls the IO close function (if it hasn't already been called).
	 */
	void gdispImageClose(gdispImage *img);

	/**
	 * @brief	Is an image open.
	 * @return	TRUE if the image is currently open.
	 *
	 * @param[in] img   The image structure
	 *
	 * @note	Be careful with calling this on an uninitialized image structure as the image
	 * 			will contain random data which may be interpreted as meaning the image
	 * 			is open. Clearing the Image structure to 0's will guarantee the image
	 * 			is seen as being closed.
	 */
	bool_t gdispImageIsOpen(gdispImage *img);

	/**
	 * @brief	Set the background color of the image.
	 *
	 * @param[in] img   	The image structure
	 * @param[in] bgcolor	The background color to use
	 *
	 * @pre		gdispImageOpen() must have returned successfully.
	 *
	 * @note	This color is only used when an image has to restore part of the background before
	 * 			continuing with drawing that includes transparency eg some GIF animations.
	 */
	void gdispImageSetBgColor(gdispImage *img, color_t bgcolor);
	
	/**
	 * @brief	Cache the image
	 * @details	Decodes and caches the current frame into RAM.
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 *
	 * @param[in] img   The image structure
	 *
	 * @pre		gdispImageOpen() must have returned successfully.
	 *
	 * @note	This can use a LOT of RAM!
	 * @note	The decoder may choose to ignore the request for caching. If it does so it will
	 * 			return GDISP_IMAGE_ERR_UNSUPPORTED_OK.
	 * @note	A fatal error here does not necessarily mean that drawing the image will fail. For
	 * 			example, a GDISP_IMAGE_ERR_NOMEMORY error simply means there isn't enough RAM to
	 * 			cache the image.
	 */
	gdispImageError gdispImageCache(gdispImage *img);

	/**
	 * @brief	Draw the image
	 * @return	GDISP_IMAGE_ERR_OK (0) on success or an error code.
	 * 
	 * @param[in] g   	The display to draw on
	 * @param[in] img   The image structure
	 * @param[in] x,y	The screen location to draw the image
	 * @param[in] cx,cy	The area on the screen to draw
	 * @param[in] sx,sy	The image position to start drawing at
	 * 
	 * @pre		gdispImageOpen() must have returned successfully.
	 *
	 * @note	If sx,sy + cx,cy is outside the image boundaries the area outside the image
	 * 			is simply not drawn.
	 * @note	If @p gdispImageCache() has been called first for this frame, this routine will draw using a
	 * 			fast blit from the cached frame. If not, it reads the input and decodes it as it
	 * 			is drawing. This may be significantly slower than if the image has been cached (but
	 * 			uses a lot less RAM)
	 */
	gdispImageError gdispGImageDraw(GDisplay *g, gdispImage *img, coord_t x, coord_t y, coord_t cx, coord_t cy, coord_t sx, coord_t sy);
	#define gdispImageDraw(img,x,y,cx,cy,sx,sy)		gdispGImageDraw(GDISP,img,x,y,cx,cy,sx,sy)

	/**
	 * @brief	Prepare for the next frame/page in the image file.
	 * @return	A time in milliseconds to keep displaying the current frame before trying to draw
	 * 			the next frame. Watch out for the special values TIME_IMMEDIATE and TIME_INFINITE.
	 * 
	 * @param[in] img   The image structure
	 * 
	 * @pre		gdispImageOpen() must have returned successfully.
	 *
	 * @note	It will return TIME_IMMEDIATE if the first frame/page hasn't been drawn or if the next frame
	 * 			should be drawn immediately.
	 * @note	It will return TIME_INFINITE if another image frame doesn't exist or an error has occurred.
	 * @note	Images that support multiple pages (eg TIFF files) will return TIME_IMMEDIATE between pages
	 * 			and then TIME_INFINITE when there are no more pages.
	 * @note	An image that displays a looped animation will never return TIME_INFINITE unless it
	 * 			gets an error.
	 * @note	Calling gdispImageDraw() after getting a TIME_INFINITE will go back to drawing the first
	 * 			frame/page.
	 */
	delaytime_t gdispImageNext(gdispImage *img);

	/**
	 * @brief	Get the number of entries in the color palette.
	 * @return	The number of entries in the color palette or 0 if the image doesn't use a color palette.
	 *
	 * @param[in] img	The image structure
	 * 
	 * @pre		gdispImageOpen() must have returned successfully.
	 */
	uint16_t gdispImageGetPaletteSize(gdispImage *img);
	
	/**
	 * @brief	Get an entry in the color palette.
	 * @return	The color value at a given position in the color palette.
	 *
	 * @param[in] img	The image structure
	 * @param[in] index	The index of the color palette entry
	 * 
	 * @pre		gdispImageOpen() must have returned successfully.
	 *
	 * @note	This function will return 0 if the index is out of bounds or if the image doesn't use a color palette.
	 */
	color_t gdispImageGetPalette(gdispImage *img, uint16_t index);
	
	/**
	 * @brief	Modify an entry in the color palette.
	 * @return	@p TRUE on success, @p FALSE otherwise.
	 *
	 * @param[in] img		The image structure
	 * @param[in] index		The index of the color palette entry
	 * @param[in] newColor	The new color value of the specified entry
	 * 
	 * @pre		gdispImageOpen() must have returned successfully.
	 * @note	This function will return @p FALSE if the index is out of bounds or if the image doesn't use a color palette.
	 */
	bool_t gdispImageAdjustPalette(gdispImage *img, uint16_t index, color_t newColor);
	
#ifdef __cplusplus
}
#endif

#endif /* GFX_USE_GDISP && GDISP_NEED_IMAGE */
#endif /* _GDISP_IMAGE_H */
/** @} */

