jpayne@69: /*
jpayne@69:  * tkImgPhoto.h --
jpayne@69:  *
jpayne@69:  *	Declarations for images of type "photo" for Tk.
jpayne@69:  *
jpayne@69:  * Copyright (c) 1994 The Australian National University.
jpayne@69:  * Copyright (c) 1994-1997 Sun Microsystems, Inc.
jpayne@69:  * Copyright (c) 2002-2008 Donal K. Fellows
jpayne@69:  * Copyright (c) 2003 ActiveState Corporation.
jpayne@69:  *
jpayne@69:  * See the file "license.terms" for information on usage and redistribution of
jpayne@69:  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
jpayne@69:  *
jpayne@69:  * Author: Paul Mackerras (paulus@cs.anu.edu.au),
jpayne@69:  *	   Department of Computer Science,
jpayne@69:  *	   Australian National University.
jpayne@69:  */
jpayne@69: 
jpayne@69: #include "tkInt.h"
jpayne@69: #ifdef _WIN32
jpayne@69: #include "tkWinInt.h"
jpayne@69: #elif defined(__CYGWIN__)
jpayne@69: #include "tkUnixInt.h"
jpayne@69: #endif
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Forward declarations of the structures we define.
jpayne@69:  */
jpayne@69: 
jpayne@69: #define PhotoModel PhotoMaster
jpayne@69: typedef struct ColorTableId	ColorTableId;
jpayne@69: typedef struct ColorTable	ColorTable;
jpayne@69: typedef struct PhotoInstance	PhotoInstance;
jpayne@69: typedef struct PhotoMaster	PhotoMaster;
jpayne@69: 
jpayne@69: /*
jpayne@69:  * A signed 8-bit integral type. If chars are unsigned and the compiler isn't
jpayne@69:  * an ANSI one, then we have to use short instead (which wastes space) to get
jpayne@69:  * signed behavior.
jpayne@69:  */
jpayne@69: 
jpayne@69: #if defined(__STDC__) || defined(_AIX)
jpayne@69:     typedef signed char schar;
jpayne@69: #else
jpayne@69: #   ifndef __CHAR_UNSIGNED__
jpayne@69: 	typedef char schar;
jpayne@69: #   else
jpayne@69: 	typedef short schar;
jpayne@69: #   endif
jpayne@69: #endif
jpayne@69: 
jpayne@69: /*
jpayne@69:  * An unsigned 32-bit integral type, used for pixel values. We use int rather
jpayne@69:  * than long here to accommodate those systems where longs are 64 bits.
jpayne@69:  */
jpayne@69: 
jpayne@69: typedef unsigned int pixel;
jpayne@69: 
jpayne@69: /*
jpayne@69:  * The maximum number of pixels to transmit to the server in a single
jpayne@69:  * XPutImage call.
jpayne@69:  */
jpayne@69: 
jpayne@69: #define MAX_PIXELS 65536
jpayne@69: 
jpayne@69: /*
jpayne@69:  * The set of colors required to display a photo image in a window depends on:
jpayne@69:  *	- the visual used by the window
jpayne@69:  *	- the palette, which specifies how many levels of each primary color to
jpayne@69:  *	  use, and
jpayne@69:  *	- the gamma value for the image.
jpayne@69:  *
jpayne@69:  * Pixel values allocated for specific colors are valid only for the colormap
jpayne@69:  * in which they were allocated. Sets of pixel values allocated for displaying
jpayne@69:  * photos are re-used in other windows if possible, that is, if the display,
jpayne@69:  * colormap, palette and gamma values match. A hash table is used to locate
jpayne@69:  * these sets of pixel values, using the following data structure as key:
jpayne@69:  */
jpayne@69: 
jpayne@69: struct ColorTableId {
jpayne@69:     Display *display;		/* Qualifies the colormap resource ID. */
jpayne@69:     Colormap colormap;		/* Colormap that the windows are using. */
jpayne@69:     double gamma;		/* Gamma exponent value for images. */
jpayne@69:     Tk_Uid palette;		/* Specifies how many shades of each primary
jpayne@69: 				 * we want to allocate. */
jpayne@69: };
jpayne@69: 
jpayne@69: /*
jpayne@69:  * For a particular (display, colormap, palette, gamma) combination, a data
jpayne@69:  * structure of the following type is used to store the allocated pixel values
jpayne@69:  * and other information:
jpayne@69:  */
jpayne@69: 
jpayne@69: struct ColorTable {
jpayne@69:     ColorTableId id;		/* Information used in selecting this color
jpayne@69: 				 * table. */
jpayne@69:     int	flags;			/* See below. */
jpayne@69:     int	refCount;		/* Number of instances using this map. */
jpayne@69:     int liveRefCount;		/* Number of instances which are actually in
jpayne@69: 				 * use, using this map. */
jpayne@69:     int	numColors;		/* Number of colors allocated for this map. */
jpayne@69: 
jpayne@69:     XVisualInfo	visualInfo;	/* Information about the visual for windows
jpayne@69: 				 * using this color table. */
jpayne@69: 
jpayne@69:     pixel redValues[256];	/* Maps 8-bit values of red intensity to a
jpayne@69: 				 * pixel value or index in pixelMap. */
jpayne@69:     pixel greenValues[256];	/* Ditto for green intensity. */
jpayne@69:     pixel blueValues[256];	/* Ditto for blue intensity. */
jpayne@69:     unsigned long *pixelMap;	/* Actual pixel values allocated. */
jpayne@69: 
jpayne@69:     unsigned char colorQuant[3][256];
jpayne@69: 				/* Maps 8-bit intensities to quantized
jpayne@69: 				 * intensities. The first index is 0 for red,
jpayne@69: 				 * 1 for green, 2 for blue. */
jpayne@69: };
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Bit definitions for the flags field of a ColorTable.
jpayne@69:  * BLACK_AND_WHITE:		1 means only black and white colors are
jpayne@69:  *				available.
jpayne@69:  * COLOR_WINDOW:		1 means a full 3-D color cube has been
jpayne@69:  *				allocated.
jpayne@69:  * DISPOSE_PENDING:		1 means a call to DisposeColorTable has been
jpayne@69:  *				scheduled as an idle handler, but it hasn't
jpayne@69:  *				been invoked yet.
jpayne@69:  * MAP_COLORS:			1 means pixel values should be mapped through
jpayne@69:  *				pixelMap.
jpayne@69:  */
jpayne@69: 
jpayne@69: #ifdef COLOR_WINDOW
jpayne@69: #undef COLOR_WINDOW
jpayne@69: #endif
jpayne@69: 
jpayne@69: #define BLACK_AND_WHITE		1
jpayne@69: #define COLOR_WINDOW		2
jpayne@69: #define DISPOSE_PENDING		4
jpayne@69: #define MAP_COLORS		8
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Definition of the data associated with each photo image model.
jpayne@69:  */
jpayne@69: 
jpayne@69: struct PhotoMaster {
jpayne@69:     Tk_ImageMaster tkMaster;	/* Tk's token for image model. NULL means the
jpayne@69: 				 * image is being deleted. */
jpayne@69:     Tcl_Interp *interp;		/* Interpreter associated with the application
jpayne@69: 				 * using this image. */
jpayne@69:     Tcl_Command imageCmd;	/* Token for image command (used to delete it
jpayne@69: 				 * when the image goes away). NULL means the
jpayne@69: 				 * image command has already been deleted. */
jpayne@69:     int	flags;			/* Sundry flags, defined below. */
jpayne@69:     int	width, height;		/* Dimensions of image. */
jpayne@69:     int userWidth, userHeight;	/* User-declared image dimensions. */
jpayne@69:     Tk_Uid palette;		/* User-specified default palette for
jpayne@69: 				 * instances of this image. */
jpayne@69:     double gamma;		/* Display gamma value to correct for. */
jpayne@69:     char *fileString;		/* Name of file to read into image. */
jpayne@69:     Tcl_Obj *dataString;	/* Object to use as contents of image. */
jpayne@69:     Tcl_Obj *format;		/* User-specified format of data in image file
jpayne@69: 				 * or string value. */
jpayne@69:     unsigned char *pix32;	/* Local storage for 32-bit image. */
jpayne@69:     int ditherX, ditherY;	/* Location of first incorrectly dithered
jpayne@69: 				 * pixel in image. */
jpayne@69:     TkRegion validRegion;	/* Tk region indicating which parts of the
jpayne@69: 				 * image have valid image data. */
jpayne@69:     PhotoInstance *instancePtr;	/* First in the list of instances associated
jpayne@69: 				 * with this model. */
jpayne@69: };
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Bit definitions for the flags field of a PhotoMaster.
jpayne@69:  * COLOR_IMAGE:			1 means that the image has different color
jpayne@69:  *				components.
jpayne@69:  * IMAGE_CHANGED:		1 means that the instances of this image need
jpayne@69:  *				to be redithered.
jpayne@69:  * COMPLEX_ALPHA:		1 means that the instances of this image have
jpayne@69:  *				alpha values that aren't 0 or 255, and so need
jpayne@69:  *				the copy-merge-replace renderer .
jpayne@69:  */
jpayne@69: 
jpayne@69: #define COLOR_IMAGE		1
jpayne@69: #define IMAGE_CHANGED		2
jpayne@69: #define COMPLEX_ALPHA		4
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Flag to OR with the compositing rule to indicate that the source, despite
jpayne@69:  * having an alpha channel, has simple alpha.
jpayne@69:  */
jpayne@69: 
jpayne@69: #define SOURCE_IS_SIMPLE_ALPHA_PHOTO 0x10000000
jpayne@69: 
jpayne@69: /*
jpayne@69:  * The following data structure represents all of the instances of a photo
jpayne@69:  * image in windows on a given screen that are using the same colormap.
jpayne@69:  */
jpayne@69: 
jpayne@69: struct PhotoInstance {
jpayne@69:     PhotoMaster *masterPtr;	/* Pointer to model for image. */
jpayne@69:     Display *display;		/* Display for windows using this instance. */
jpayne@69:     Colormap colormap;		/* The image may only be used in windows with
jpayne@69: 				 * this particular colormap. */
jpayne@69:     PhotoInstance *nextPtr;	/* Pointer to the next instance in the list of
jpayne@69: 				 * instances associated with this model. */
jpayne@69:     int refCount;		/* Number of instances using this structure. */
jpayne@69:     Tk_Uid palette;		/* Palette for these particular instances. */
jpayne@69:     double gamma;		/* Gamma value for these instances. */
jpayne@69:     Tk_Uid defaultPalette;	/* Default palette to use if a palette is not
jpayne@69: 				 * specified for the model. */
jpayne@69:     ColorTable *colorTablePtr;	/* Pointer to information about colors
jpayne@69: 				 * allocated for image display in windows like
jpayne@69: 				 * this one. */
jpayne@69:     Pixmap pixels;		/* X pixmap containing dithered image. */
jpayne@69:     int width, height;		/* Dimensions of the pixmap. */
jpayne@69:     schar *error;		/* Error image, used in dithering. */
jpayne@69:     XImage *imagePtr;		/* Image structure for converted pixels. */
jpayne@69:     XVisualInfo visualInfo;	/* Information about the visual that these
jpayne@69: 				 * windows are using. */
jpayne@69:     GC gc;			/* Graphics context for writing images to the
jpayne@69: 				 * pixmap. */
jpayne@69: };
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Implementation of the Porter-Duff Source-Over compositing rule.
jpayne@69:  */
jpayne@69: 
jpayne@69: #define PD_SRC_OVER(srcColor, srcAlpha, dstColor, dstAlpha) \
jpayne@69: 	(srcColor*srcAlpha/255) + dstAlpha*(255-srcAlpha)/255*dstColor/255
jpayne@69: #define PD_SRC_OVER_ALPHA(srcAlpha, dstAlpha) \
jpayne@69: 	(srcAlpha + (255-srcAlpha)*dstAlpha/255)
jpayne@69: 
jpayne@69: #undef MIN
jpayne@69: #define MIN(a, b)	((a) < (b)? (a): (b))
jpayne@69: #undef MAX
jpayne@69: #define MAX(a, b)	((a) > (b)? (a): (b))
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Declarations of functions shared between the different parts of the
jpayne@69:  * photo image implementation.
jpayne@69:  */
jpayne@69: 
jpayne@69: MODULE_SCOPE void	TkImgPhotoConfigureInstance(
jpayne@69: 			    PhotoInstance *instancePtr);
jpayne@69: MODULE_SCOPE void	TkImgDisposeInstance(ClientData clientData);
jpayne@69: MODULE_SCOPE void	TkImgPhotoInstanceSetSize(PhotoInstance *instancePtr);
jpayne@69: MODULE_SCOPE ClientData	TkImgPhotoGet(Tk_Window tkwin, ClientData clientData);
jpayne@69: MODULE_SCOPE void	TkImgDitherInstance(PhotoInstance *instancePtr, int x,
jpayne@69: 			    int y, int width, int height);
jpayne@69: MODULE_SCOPE void	TkImgPhotoDisplay(ClientData clientData,
jpayne@69: 			    Display *display, Drawable drawable,
jpayne@69: 			    int imageX, int imageY, int width, int height,
jpayne@69: 			    int drawableX, int drawableY);
jpayne@69: MODULE_SCOPE void	TkImgPhotoFree(ClientData clientData,
jpayne@69: 			    Display *display);
jpayne@69: MODULE_SCOPE void	TkImgResetDither(PhotoInstance *instancePtr);
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Local Variables:
jpayne@69:  * mode: c
jpayne@69:  * c-basic-offset: 4
jpayne@69:  * fill-column: 78
jpayne@69:  * End:
jpayne@69:  */