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authordkf <donal.k.fellows@manchester.ac.uk>2008-08-25 11:44:01 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2008-08-25 11:44:01 (GMT)
commitff6b265906d93fd7c16d9401b03a8a52a380a281 (patch)
tree66d55579b3e8cbfa2e07d8b09a73795f0a08b87f /generic/tkImgPhoto.h
parentc56c373d2d86786d9f354d45144b1900dcd63304 (diff)
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Split the photo image core into two pieces to make it easier to maintain.
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+/*
+ * tkImgPhoto.h --
+ *
+ * Declarations for images of type "photo" for Tk.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * Copyright (c) 1994-1997 Sun Microsystems, Inc.
+ * Copyright (c) 2002-2008 Donal K. Fellows
+ * Copyright (c) 2003 ActiveState Corporation.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * Author: Paul Mackerras (paulus@cs.anu.edu.au),
+ * Department of Computer Science,
+ * Australian National University.
+ *
+ * RCS: @(#) $Id: tkImgPhoto.h,v 1.1 2008/08/25 11:44:04 dkf Exp $
+ */
+
+#include "tkInt.h"
+#ifdef __WIN32__
+#include "tkWinInt.h"
+#endif
+
+/*
+ * Forward declarations of the structures we define.
+ */
+
+typedef struct ColorTableId ColorTableId;
+typedef struct ColorTable ColorTable;
+typedef struct PhotoInstance PhotoInstance;
+typedef struct PhotoMaster PhotoMaster;
+
+/*
+ * A signed 8-bit integral type. If chars are unsigned and the compiler isn't
+ * an ANSI one, then we have to use short instead (which wastes space) to get
+ * signed behavior.
+ */
+
+#if defined(__STDC__) || defined(_AIX)
+ typedef signed char schar;
+#else
+# ifndef __CHAR_UNSIGNED__
+ typedef char schar;
+# else
+ typedef short schar;
+# endif
+#endif
+
+/*
+ * An unsigned 32-bit integral type, used for pixel values. We use int rather
+ * than long here to accommodate those systems where longs are 64 bits.
+ */
+
+typedef unsigned int pixel;
+
+/*
+ * The maximum number of pixels to transmit to the server in a single
+ * XPutImage call.
+ */
+
+#define MAX_PIXELS 65536
+
+/*
+ * The set of colors required to display a photo image in a window depends on:
+ * - the visual used by the window
+ * - the palette, which specifies how many levels of each primary color to
+ * use, and
+ * - the gamma value for the image.
+ *
+ * Pixel values allocated for specific colors are valid only for the colormap
+ * in which they were allocated. Sets of pixel values allocated for displaying
+ * photos are re-used in other windows if possible, that is, if the display,
+ * colormap, palette and gamma values match. A hash table is used to locate
+ * these sets of pixel values, using the following data structure as key:
+ */
+
+struct ColorTableId {
+ Display *display; /* Qualifies the colormap resource ID. */
+ Colormap colormap; /* Colormap that the windows are using. */
+ double gamma; /* Gamma exponent value for images. */
+ Tk_Uid palette; /* Specifies how many shades of each primary
+ * we want to allocate. */
+};
+
+/*
+ * For a particular (display, colormap, palette, gamma) combination, a data
+ * structure of the following type is used to store the allocated pixel values
+ * and other information:
+ */
+
+struct ColorTable {
+ ColorTableId id; /* Information used in selecting this color
+ * table. */
+ int flags; /* See below. */
+ int refCount; /* Number of instances using this map. */
+ int liveRefCount; /* Number of instances which are actually in
+ * use, using this map. */
+ int numColors; /* Number of colors allocated for this map. */
+
+ XVisualInfo visualInfo; /* Information about the visual for windows
+ * using this color table. */
+
+ pixel redValues[256]; /* Maps 8-bit values of red intensity to a
+ * pixel value or index in pixelMap. */
+ pixel greenValues[256]; /* Ditto for green intensity. */
+ pixel blueValues[256]; /* Ditto for blue intensity. */
+ unsigned long *pixelMap; /* Actual pixel values allocated. */
+
+ unsigned char colorQuant[3][256];
+ /* Maps 8-bit intensities to quantized
+ * intensities. The first index is 0 for red,
+ * 1 for green, 2 for blue. */
+};
+
+/*
+ * Bit definitions for the flags field of a ColorTable.
+ * BLACK_AND_WHITE: 1 means only black and white colors are
+ * available.
+ * COLOR_WINDOW: 1 means a full 3-D color cube has been
+ * allocated.
+ * DISPOSE_PENDING: 1 means a call to DisposeColorTable has been
+ * scheduled as an idle handler, but it hasn't
+ * been invoked yet.
+ * MAP_COLORS: 1 means pixel values should be mapped through
+ * pixelMap.
+ */
+
+#ifdef COLOR_WINDOW
+#undef COLOR_WINDOW
+#endif
+
+#define BLACK_AND_WHITE 1
+#define COLOR_WINDOW 2
+#define DISPOSE_PENDING 4
+#define MAP_COLORS 8
+
+/*
+ * Definition of the data associated with each photo image master.
+ */
+
+struct PhotoMaster {
+ Tk_ImageMaster tkMaster; /* Tk's token for image master. NULL means the
+ * image is being deleted. */
+ Tcl_Interp *interp; /* Interpreter associated with the application
+ * using this image. */
+ Tcl_Command imageCmd; /* Token for image command (used to delete it
+ * when the image goes away). NULL means the
+ * image command has already been deleted. */
+ int flags; /* Sundry flags, defined below. */
+ int width, height; /* Dimensions of image. */
+ int userWidth, userHeight; /* User-declared image dimensions. */
+ Tk_Uid palette; /* User-specified default palette for
+ * instances of this image. */
+ double gamma; /* Display gamma value to correct for. */
+ char *fileString; /* Name of file to read into image. */
+ Tcl_Obj *dataString; /* Object to use as contents of image. */
+ Tcl_Obj *format; /* User-specified format of data in image file
+ * or string value. */
+ unsigned char *pix32; /* Local storage for 32-bit image. */
+ int ditherX, ditherY; /* Location of first incorrectly dithered
+ * pixel in image. */
+ TkRegion validRegion; /* Tk region indicating which parts of the
+ * image have valid image data. */
+ PhotoInstance *instancePtr; /* First in the list of instances associated
+ * with this master. */
+};
+
+/*
+ * Bit definitions for the flags field of a PhotoMaster.
+ * COLOR_IMAGE: 1 means that the image has different color
+ * components.
+ * IMAGE_CHANGED: 1 means that the instances of this image need
+ * to be redithered.
+ * COMPLEX_ALPHA: 1 means that the instances of this image have
+ * alpha values that aren't 0 or 255, and so need
+ * the copy-merge-replace renderer .
+ */
+
+#define COLOR_IMAGE 1
+#define IMAGE_CHANGED 2
+#define COMPLEX_ALPHA 4
+
+/*
+ * Flag to OR with the compositing rule to indicate that the source, despite
+ * having an alpha channel, has simple alpha.
+ */
+
+#define SOURCE_IS_SIMPLE_ALPHA_PHOTO 0x10000000
+
+/*
+ * The following data structure represents all of the instances of a photo
+ * image in windows on a given screen that are using the same colormap.
+ */
+
+struct PhotoInstance {
+ PhotoMaster *masterPtr; /* Pointer to master for image. */
+ Display *display; /* Display for windows using this instance. */
+ Colormap colormap; /* The image may only be used in windows with
+ * this particular colormap. */
+ PhotoInstance *nextPtr; /* Pointer to the next instance in the list of
+ * instances associated with this master. */
+ int refCount; /* Number of instances using this structure. */
+ Tk_Uid palette; /* Palette for these particular instances. */
+ double gamma; /* Gamma value for these instances. */
+ Tk_Uid defaultPalette; /* Default palette to use if a palette is not
+ * specified for the master. */
+ ColorTable *colorTablePtr; /* Pointer to information about colors
+ * allocated for image display in windows like
+ * this one. */
+ Pixmap pixels; /* X pixmap containing dithered image. */
+ int width, height; /* Dimensions of the pixmap. */
+ schar *error; /* Error image, used in dithering. */
+ XImage *imagePtr; /* Image structure for converted pixels. */
+ XVisualInfo visualInfo; /* Information about the visual that these
+ * windows are using. */
+ GC gc; /* Graphics context for writing images to the
+ * pixmap. */
+};
+
+/*
+ * Implementation of the Porter-Duff Source-Over compositing rule.
+ */
+
+#define PD_SRC_OVER(srcColor,srcAlpha,dstColor,dstAlpha) \
+ (srcColor*srcAlpha/255) + dstAlpha*(255-srcAlpha)/255*dstColor/255
+#define PD_SRC_OVER_ALPHA(srcAlpha,dstAlpha) \
+ (srcAlpha + (255-srcAlpha)*dstAlpha/255)
+
+#undef MIN
+#define MIN(a, b) ((a) < (b)? (a): (b))
+#undef MAX
+#define MAX(a, b) ((a) > (b)? (a): (b))
+
+/*
+ * Declarations of functions shared between the different parts of the
+ * photo image implementation.
+ */
+
+MODULE_SCOPE void TkImgPhotoConfigureInstance(
+ PhotoInstance *instancePtr);
+MODULE_SCOPE void TkImgDisposeInstance(ClientData clientData);
+MODULE_SCOPE void TkImgPhotoInstanceSetSize(PhotoInstance *instancePtr);
+MODULE_SCOPE ClientData TkImgPhotoGet(Tk_Window tkwin, ClientData clientData);
+MODULE_SCOPE void TkImgDitherInstance(PhotoInstance *instancePtr, int x,
+ int y, int width, int height);
+MODULE_SCOPE void TkImgPhotoDisplay(ClientData clientData,
+ Display *display, Drawable drawable,
+ int imageX, int imageY, int width, int height,
+ int drawableX, int drawableY);
+MODULE_SCOPE void TkImgPhotoFree(ClientData clientData,
+ Display *display);
+MODULE_SCOPE void TkImgResetDither(PhotoInstance *instancePtr);
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */