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+/*
+ * tkImgPhInstance.c --
+ *
+ * Implements the rendering of images of type "photo" for Tk. Photo
+ * images are stored in full color (32 bits per pixel including alpha
+ * channel) and displayed using dithering if necessary.
+ *
+ * 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: tkImgPhInstance.c,v 1.4 2010/11/19 14:48:00 nijtmans Exp $
+ */
+
+#include "tkImgPhoto.h"
+
+/*
+ * Declaration for internal Xlib function used here:
+ */
+
+extern int _XInitImageFuncPtrs(XImage *image);
+
+/*
+ * Forward declarations
+ */
+
+static void BlendComplexAlpha(XImage *bgImg, PhotoInstance *iPtr,
+ int xOffset, int yOffset, int width, int height);
+static int IsValidPalette(PhotoInstance *instancePtr,
+ const char *palette);
+static int CountBits(pixel mask);
+static void GetColorTable(PhotoInstance *instancePtr);
+static void FreeColorTable(ColorTable *colorPtr, int force);
+static void AllocateColors(ColorTable *colorPtr);
+static void DisposeColorTable(ClientData clientData);
+static int ReclaimColors(ColorTableId *id, int numColors);
+
+/*
+ * Hash table used to hash from (display, colormap, palette, gamma) to
+ * ColorTable address.
+ */
+
+static Tcl_HashTable imgPhotoColorHash;
+static int imgPhotoColorHashInitialized;
+#define N_COLOR_HASH (sizeof(ColorTableId) / sizeof(int))
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgPhotoConfigureInstance --
+ *
+ * This function is called to create displaying information for a photo
+ * image instance based on the configuration information in the master.
+ * It is invoked both when new instances are created and when the master
+ * is reconfigured.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Generates errors via Tcl_BackgroundError if there are problems in
+ * setting up the instance.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgPhotoConfigureInstance(
+ PhotoInstance *instancePtr) /* Instance to reconfigure. */
+{
+ PhotoMaster *masterPtr = instancePtr->masterPtr;
+ XImage *imagePtr;
+ int bitsPerPixel;
+ ColorTable *colorTablePtr;
+ XRectangle validBox;
+
+ /*
+ * If the -palette configuration option has been set for the master, use
+ * the value specified for our palette, but only if it is a valid palette
+ * for our windows. Use the gamma value specified the master.
+ */
+
+ if ((masterPtr->palette && masterPtr->palette[0])
+ && IsValidPalette(instancePtr, masterPtr->palette)) {
+ instancePtr->palette = masterPtr->palette;
+ } else {
+ instancePtr->palette = instancePtr->defaultPalette;
+ }
+ instancePtr->gamma = masterPtr->gamma;
+
+ /*
+ * If we don't currently have a color table, or if the one we have no
+ * longer applies (e.g. because our palette or gamma has changed), get a
+ * new one.
+ */
+
+ colorTablePtr = instancePtr->colorTablePtr;
+ if ((colorTablePtr == NULL)
+ || (instancePtr->colormap != colorTablePtr->id.colormap)
+ || (instancePtr->palette != colorTablePtr->id.palette)
+ || (instancePtr->gamma != colorTablePtr->id.gamma)) {
+ /*
+ * Free up our old color table, and get a new one.
+ */
+
+ if (colorTablePtr != NULL) {
+ colorTablePtr->liveRefCount -= 1;
+ FreeColorTable(colorTablePtr, 0);
+ }
+ GetColorTable(instancePtr);
+
+ /*
+ * Create a new XImage structure for sending data to the X server, if
+ * necessary.
+ */
+
+ if (instancePtr->colorTablePtr->flags & BLACK_AND_WHITE) {
+ bitsPerPixel = 1;
+ } else {
+ bitsPerPixel = instancePtr->visualInfo.depth;
+ }
+
+ if ((instancePtr->imagePtr == NULL)
+ || (instancePtr->imagePtr->bits_per_pixel != bitsPerPixel)) {
+ if (instancePtr->imagePtr != NULL) {
+ XDestroyImage(instancePtr->imagePtr);
+ }
+ imagePtr = XCreateImage(instancePtr->display,
+ instancePtr->visualInfo.visual, (unsigned) bitsPerPixel,
+ (bitsPerPixel > 1? ZPixmap: XYBitmap), 0, NULL,
+ 1, 1, 32, 0);
+ instancePtr->imagePtr = imagePtr;
+
+ /*
+ * We create images using the local host's endianness, rather than
+ * the endianness of the server; otherwise we would have to
+ * byte-swap any 16 or 32 bit values that we store in the image
+ * if the server's endianness is different from ours.
+ */
+
+ if (imagePtr != NULL) {
+#ifdef WORDS_BIGENDIAN
+ imagePtr->byte_order = MSBFirst;
+#else
+ imagePtr->byte_order = LSBFirst;
+#endif
+ _XInitImageFuncPtrs(imagePtr);
+ }
+ }
+ }
+
+ /*
+ * If the user has specified a width and/or height for the master which is
+ * different from our current width/height, set the size to the values
+ * specified by the user. If we have no pixmap, we do this also, since it
+ * has the side effect of allocating a pixmap for us.
+ */
+
+ if ((instancePtr->pixels == None) || (instancePtr->error == NULL)
+ || (instancePtr->width != masterPtr->width)
+ || (instancePtr->height != masterPtr->height)) {
+ TkImgPhotoInstanceSetSize(instancePtr);
+ }
+
+ /*
+ * Redither this instance if necessary.
+ */
+
+ if ((masterPtr->flags & IMAGE_CHANGED)
+ || (instancePtr->colorTablePtr != colorTablePtr)) {
+ TkClipBox(masterPtr->validRegion, &validBox);
+ if ((validBox.width > 0) && (validBox.height > 0)) {
+ TkImgDitherInstance(instancePtr, validBox.x, validBox.y,
+ validBox.width, validBox.height);
+ }
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgPhotoGet --
+ *
+ * This function is called for each use of a photo image in a widget.
+ *
+ * Results:
+ * The return value is a token for the instance, which is passed back to
+ * us in calls to TkImgPhotoDisplay and ImgPhotoFree.
+ *
+ * Side effects:
+ * A data structure is set up for the instance (or, an existing instance
+ * is re-used for the new one).
+ *
+ *----------------------------------------------------------------------
+ */
+
+ClientData
+TkImgPhotoGet(
+ Tk_Window tkwin, /* Window in which the instance will be
+ * used. */
+ ClientData masterData) /* Pointer to our master structure for the
+ * image. */
+{
+ PhotoMaster *masterPtr = masterData;
+ PhotoInstance *instancePtr;
+ Colormap colormap;
+ int mono, nRed, nGreen, nBlue, numVisuals;
+ XVisualInfo visualInfo, *visInfoPtr;
+ char buf[TCL_INTEGER_SPACE * 3];
+ XColor *white, *black;
+ XGCValues gcValues;
+
+ /*
+ * Table of "best" choices for palette for PseudoColor displays with
+ * between 3 and 15 bits/pixel.
+ */
+
+ static const int paletteChoice[13][3] = {
+ /* #red, #green, #blue */
+ {2, 2, 2, /* 3 bits, 8 colors */},
+ {2, 3, 2, /* 4 bits, 12 colors */},
+ {3, 4, 2, /* 5 bits, 24 colors */},
+ {4, 5, 3, /* 6 bits, 60 colors */},
+ {5, 6, 4, /* 7 bits, 120 colors */},
+ {7, 7, 4, /* 8 bits, 198 colors */},
+ {8, 10, 6, /* 9 bits, 480 colors */},
+ {10, 12, 8, /* 10 bits, 960 colors */},
+ {14, 15, 9, /* 11 bits, 1890 colors */},
+ {16, 20, 12, /* 12 bits, 3840 colors */},
+ {20, 24, 16, /* 13 bits, 7680 colors */},
+ {26, 30, 20, /* 14 bits, 15600 colors */},
+ {32, 32, 30, /* 15 bits, 30720 colors */}
+ };
+
+ /*
+ * See if there is already an instance for windows using the same
+ * colormap. If so then just re-use it.
+ */
+
+ colormap = Tk_Colormap(tkwin);
+ for (instancePtr = masterPtr->instancePtr; instancePtr != NULL;
+ instancePtr = instancePtr->nextPtr) {
+ if ((colormap == instancePtr->colormap)
+ && (Tk_Display(tkwin) == instancePtr->display)) {
+ /*
+ * Re-use this instance.
+ */
+
+ if (instancePtr->refCount == 0) {
+ /*
+ * We are resurrecting this instance.
+ */
+
+ Tcl_CancelIdleCall(TkImgDisposeInstance, instancePtr);
+ if (instancePtr->colorTablePtr != NULL) {
+ FreeColorTable(instancePtr->colorTablePtr, 0);
+ }
+ GetColorTable(instancePtr);
+ }
+ instancePtr->refCount++;
+ return instancePtr;
+ }
+ }
+
+ /*
+ * The image isn't already in use in a window with the same colormap. Make
+ * a new instance of the image.
+ */
+
+ instancePtr = ckalloc(sizeof(PhotoInstance));
+ instancePtr->masterPtr = masterPtr;
+ instancePtr->display = Tk_Display(tkwin);
+ instancePtr->colormap = Tk_Colormap(tkwin);
+ Tk_PreserveColormap(instancePtr->display, instancePtr->colormap);
+ instancePtr->refCount = 1;
+ instancePtr->colorTablePtr = NULL;
+ instancePtr->pixels = None;
+ instancePtr->error = NULL;
+ instancePtr->width = 0;
+ instancePtr->height = 0;
+ instancePtr->imagePtr = 0;
+ instancePtr->nextPtr = masterPtr->instancePtr;
+ masterPtr->instancePtr = instancePtr;
+
+ /*
+ * Obtain information about the visual and decide on the default palette.
+ */
+
+ visualInfo.screen = Tk_ScreenNumber(tkwin);
+ visualInfo.visualid = XVisualIDFromVisual(Tk_Visual(tkwin));
+ visInfoPtr = XGetVisualInfo(Tk_Display(tkwin),
+ VisualScreenMask | VisualIDMask, &visualInfo, &numVisuals);
+ if (visInfoPtr == NULL) {
+ Tcl_Panic("TkImgPhotoGet couldn't find visual for window");
+ }
+
+ nRed = 2;
+ nGreen = nBlue = 0;
+ mono = 1;
+ instancePtr->visualInfo = *visInfoPtr;
+ switch (visInfoPtr->class) {
+ case DirectColor:
+ case TrueColor:
+ nRed = 1 << CountBits(visInfoPtr->red_mask);
+ nGreen = 1 << CountBits(visInfoPtr->green_mask);
+ nBlue = 1 << CountBits(visInfoPtr->blue_mask);
+ mono = 0;
+ break;
+ case PseudoColor:
+ case StaticColor:
+ if (visInfoPtr->depth > 15) {
+ nRed = 32;
+ nGreen = 32;
+ nBlue = 32;
+ mono = 0;
+ } else if (visInfoPtr->depth >= 3) {
+ const int *ip = paletteChoice[visInfoPtr->depth - 3];
+
+ nRed = ip[0];
+ nGreen = ip[1];
+ nBlue = ip[2];
+ mono = 0;
+ }
+ break;
+ case GrayScale:
+ case StaticGray:
+ nRed = 1 << visInfoPtr->depth;
+ break;
+ }
+ XFree((char *) visInfoPtr);
+
+ if (mono) {
+ sprintf(buf, "%d", nRed);
+ } else {
+ sprintf(buf, "%d/%d/%d", nRed, nGreen, nBlue);
+ }
+ instancePtr->defaultPalette = Tk_GetUid(buf);
+
+ /*
+ * Make a GC with background = black and foreground = white.
+ */
+
+ white = Tk_GetColor(masterPtr->interp, tkwin, "white");
+ black = Tk_GetColor(masterPtr->interp, tkwin, "black");
+ gcValues.foreground = (white != NULL)? white->pixel:
+ WhitePixelOfScreen(Tk_Screen(tkwin));
+ gcValues.background = (black != NULL)? black->pixel:
+ BlackPixelOfScreen(Tk_Screen(tkwin));
+ Tk_FreeColor(white);
+ Tk_FreeColor(black);
+ gcValues.graphics_exposures = False;
+ instancePtr->gc = Tk_GetGC(tkwin,
+ GCForeground|GCBackground|GCGraphicsExposures, &gcValues);
+
+ /*
+ * Set configuration options and finish the initialization of the
+ * instance. This will also dither the image if necessary.
+ */
+
+ TkImgPhotoConfigureInstance(instancePtr);
+
+ /*
+ * If this is the first instance, must set the size of the image.
+ */
+
+ if (instancePtr->nextPtr == NULL) {
+ Tk_ImageChanged(masterPtr->tkMaster, 0, 0, 0, 0,
+ masterPtr->width, masterPtr->height);
+ }
+
+ return instancePtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * BlendComplexAlpha --
+ *
+ * This function is called when an image with partially transparent
+ * pixels must be drawn over another image. It blends the photo data onto
+ * a local copy of the surface that we are drawing on, *including* the
+ * pixels drawn by everything that should be drawn underneath the image.
+ *
+ * Much of this code has hard-coded values in for speed because this
+ * routine is performance critical for complex image drawing.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Background image passed in gets drawn over with image data.
+ *
+ * Notes:
+ * This should work on all platforms that set mask and shift data
+ * properly from the visualInfo. RGB is really only a 24+ bpp version
+ * whereas RGB15 is the correct version and works for 15bpp+, but it
+ * slower, so it's only used for 15bpp+.
+ *
+ * Note that Win32 pre-defines those operations that we really need.
+ *
+ *----------------------------------------------------------------------
+ */
+
+#ifndef __WIN32__
+#define GetRValue(rgb) (UCHAR(((rgb) & red_mask) >> red_shift))
+#define GetGValue(rgb) (UCHAR(((rgb) & green_mask) >> green_shift))
+#define GetBValue(rgb) (UCHAR(((rgb) & blue_mask) >> blue_shift))
+#define RGB(r, g, b) ((unsigned)( \
+ (UCHAR(r) << red_shift) | \
+ (UCHAR(g) << green_shift) | \
+ (UCHAR(b) << blue_shift) ))
+#define RGB15(r, g, b) ((unsigned)( \
+ (((r) * red_mask / 255) & red_mask) | \
+ (((g) * green_mask / 255) & green_mask) | \
+ (((b) * blue_mask / 255) & blue_mask) ))
+#endif /* !__WIN32__ */
+
+static void
+BlendComplexAlpha(
+ XImage *bgImg, /* Background image to draw on. */
+ PhotoInstance *iPtr, /* Image instance to draw. */
+ int xOffset, int yOffset, /* X & Y offset into image instance to
+ * draw. */
+ int width, int height) /* Width & height of image to draw. */
+{
+ int x, y, line;
+ unsigned long pixel;
+ unsigned char r, g, b, alpha, unalpha, *masterPtr;
+ unsigned char *alphaAr = iPtr->masterPtr->pix32;
+
+ /*
+ * This blending is an integer version of the Source-Over compositing rule
+ * (see Porter&Duff, "Compositing Digital Images", proceedings of SIGGRAPH
+ * 1984) that has been hard-coded (for speed) to work with targetting a
+ * solid surface.
+ *
+ * The 'unalpha' field must be 255-alpha; it is separated out to encourage
+ * more efficient compilation.
+ */
+
+#define ALPHA_BLEND(bgPix, imgPix, alpha, unalpha) \
+ ((bgPix * unalpha + imgPix * alpha) / 255)
+
+ /*
+ * We have to get the mask and shift info from the visual on non-Win32 so
+ * that the macros Get*Value(), RGB() and RGB15() work correctly. This
+ * might be cached for better performance.
+ */
+
+#ifndef __WIN32__
+ unsigned long red_mask, green_mask, blue_mask;
+ unsigned long red_shift, green_shift, blue_shift;
+ Visual *visual = iPtr->visualInfo.visual;
+
+ red_mask = visual->red_mask;
+ green_mask = visual->green_mask;
+ blue_mask = visual->blue_mask;
+ red_shift = 0;
+ green_shift = 0;
+ blue_shift = 0;
+ while ((0x0001 & (red_mask >> red_shift)) == 0) {
+ red_shift++;
+ }
+ while ((0x0001 & (green_mask >> green_shift)) == 0) {
+ green_shift++;
+ }
+ while ((0x0001 & (blue_mask >> blue_shift)) == 0) {
+ blue_shift++;
+ }
+#endif /* !__WIN32__ */
+
+ /*
+ * Only UNIX requires the special case for <24bpp. It varies with 3 extra
+ * shifts and uses RGB15. The 24+bpp version could also then be further
+ * optimized.
+ */
+
+#if !(defined(__WIN32__) || defined(MAC_OSX_TK))
+ if (bgImg->depth < 24) {
+ unsigned char red_mlen, green_mlen, blue_mlen;
+
+ red_mlen = 8 - CountBits(red_mask >> red_shift);
+ green_mlen = 8 - CountBits(green_mask >> green_shift);
+ blue_mlen = 8 - CountBits(blue_mask >> blue_shift);
+ for (y = 0; y < height; y++) {
+ line = (y + yOffset) * iPtr->masterPtr->width;
+ for (x = 0; x < width; x++) {
+ masterPtr = alphaAr + ((line + x + xOffset) * 4);
+ alpha = masterPtr[3];
+
+ /*
+ * Ignore pixels that are fully transparent
+ */
+
+ if (alpha) {
+ /*
+ * We could perhaps be more efficient than XGetPixel for
+ * 24 and 32 bit displays, but this seems "fast enough".
+ */
+
+ r = masterPtr[0];
+ g = masterPtr[1];
+ b = masterPtr[2];
+ if (alpha != 255) {
+ /*
+ * Only blend pixels that have some transparency
+ */
+
+ unsigned char ra, ga, ba;
+
+ pixel = XGetPixel(bgImg, x, y);
+ ra = GetRValue(pixel) << red_mlen;
+ ga = GetGValue(pixel) << green_mlen;
+ ba = GetBValue(pixel) << blue_mlen;
+ unalpha = 255 - alpha; /* Calculate once. */
+ r = ALPHA_BLEND(ra, r, alpha, unalpha);
+ g = ALPHA_BLEND(ga, g, alpha, unalpha);
+ b = ALPHA_BLEND(ba, b, alpha, unalpha);
+ }
+ XPutPixel(bgImg, x, y, RGB15(r, g, b));
+ }
+ }
+ }
+ return;
+ }
+#endif /* !__WIN32__ && !MAC_OSX_TK */
+
+ for (y = 0; y < height; y++) {
+ line = (y + yOffset) * iPtr->masterPtr->width;
+ for (x = 0; x < width; x++) {
+ masterPtr = alphaAr + ((line + x + xOffset) * 4);
+ alpha = masterPtr[3];
+
+ /*
+ * Ignore pixels that are fully transparent
+ */
+
+ if (alpha) {
+ /*
+ * We could perhaps be more efficient than XGetPixel for 24
+ * and 32 bit displays, but this seems "fast enough".
+ */
+
+ r = masterPtr[0];
+ g = masterPtr[1];
+ b = masterPtr[2];
+ if (alpha != 255) {
+ /*
+ * Only blend pixels that have some transparency
+ */
+
+ unsigned char ra, ga, ba;
+
+ pixel = XGetPixel(bgImg, x, y);
+ ra = GetRValue(pixel);
+ ga = GetGValue(pixel);
+ ba = GetBValue(pixel);
+ unalpha = 255 - alpha; /* Calculate once. */
+ r = ALPHA_BLEND(ra, r, alpha, unalpha);
+ g = ALPHA_BLEND(ga, g, alpha, unalpha);
+ b = ALPHA_BLEND(ba, b, alpha, unalpha);
+ }
+ XPutPixel(bgImg, x, y, RGB(r, g, b));
+ }
+ }
+ }
+#undef ALPHA_BLEND
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgPhotoDisplay --
+ *
+ * This function is invoked to draw a photo image.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * A portion of the image gets rendered in a pixmap or window.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgPhotoDisplay(
+ ClientData clientData, /* Pointer to PhotoInstance structure for
+ * instance to be displayed. */
+ Display *display, /* Display on which to draw image. */
+ Drawable drawable, /* Pixmap or window in which to draw image. */
+ int imageX, int imageY, /* Upper-left corner of region within image to
+ * draw. */
+ int width, int height, /* Dimensions of region within image to
+ * draw. */
+ int drawableX,int drawableY)/* Coordinates within drawable that correspond
+ * to imageX and imageY. */
+{
+ PhotoInstance *instancePtr = clientData;
+ XVisualInfo visInfo = instancePtr->visualInfo;
+
+ /*
+ * If there's no pixmap, it means that an error occurred while creating
+ * the image instance so it can't be displayed.
+ */
+
+ if (instancePtr->pixels == None) {
+ return;
+ }
+
+ if ((instancePtr->masterPtr->flags & COMPLEX_ALPHA)
+ && visInfo.depth >= 15
+ && (visInfo.class == DirectColor || visInfo.class == TrueColor)) {
+ Tk_ErrorHandler handler;
+ XImage *bgImg = NULL;
+
+ /*
+ * Create an error handler to suppress the case where the input was
+ * not properly constrained, which can cause an X error. [Bug 979239]
+ */
+
+ handler = Tk_CreateErrorHandler(display, -1, -1, -1, NULL, NULL);
+
+ /*
+ * Pull the current background from the display to blend with
+ */
+
+ bgImg = XGetImage(display, drawable, drawableX, drawableY,
+ (unsigned int)width, (unsigned int)height, AllPlanes, ZPixmap);
+ if (bgImg == NULL) {
+ Tk_DeleteErrorHandler(handler);
+ return;
+ }
+
+ BlendComplexAlpha(bgImg, instancePtr, imageX, imageY, width, height);
+
+ /*
+ * Color info is unimportant as we only do this operation for depth >=
+ * 15.
+ */
+
+ TkPutImage(NULL, 0, display, drawable, instancePtr->gc,
+ bgImg, 0, 0, drawableX, drawableY,
+ (unsigned int) width, (unsigned int) height);
+ XDestroyImage(bgImg);
+ Tk_DeleteErrorHandler(handler);
+ } else {
+ /*
+ * masterPtr->region describes which parts of the image contain valid
+ * data. We set this region as the clip mask for the gc, setting its
+ * origin appropriately, and use it when drawing the image.
+ */
+
+ TkSetRegion(display, instancePtr->gc,
+ instancePtr->masterPtr->validRegion);
+ XSetClipOrigin(display, instancePtr->gc, drawableX - imageX,
+ drawableY - imageY);
+ XCopyArea(display, instancePtr->pixels, drawable, instancePtr->gc,
+ imageX, imageY, (unsigned) width, (unsigned) height,
+ drawableX, drawableY);
+ XSetClipMask(display, instancePtr->gc, None);
+ XSetClipOrigin(display, instancePtr->gc, 0, 0);
+ }
+ XFlush(display);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgPhotoFree --
+ *
+ * This function is called when a widget ceases to use a particular
+ * instance of an image. We don't actually get rid of the instance until
+ * later because we may be about to get this instance again.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Internal data structures get cleaned up, later.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgPhotoFree(
+ ClientData clientData, /* Pointer to PhotoInstance structure for
+ * instance to be displayed. */
+ Display *display) /* Display containing window that used
+ * image. */
+{
+ PhotoInstance *instancePtr = clientData;
+ ColorTable *colorPtr;
+
+ instancePtr->refCount -= 1;
+ if (instancePtr->refCount > 0) {
+ return;
+ }
+
+ /*
+ * There are no more uses of the image within this widget. Decrement the
+ * count of live uses of its color table, so that its colors can be
+ * reclaimed if necessary, and set up an idle call to free the instance
+ * structure.
+ */
+
+ colorPtr = instancePtr->colorTablePtr;
+ if (colorPtr != NULL) {
+ colorPtr->liveRefCount -= 1;
+ }
+
+ Tcl_DoWhenIdle(TkImgDisposeInstance, instancePtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgPhotoInstanceSetSize --
+ *
+ * This function reallocates the instance pixmap and dithering error
+ * array for a photo instance, as necessary, to change the image's size
+ * to `width' x `height' pixels.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Storage gets reallocated, here and in the X server.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgPhotoInstanceSetSize(
+ PhotoInstance *instancePtr) /* Instance whose size is to be changed. */
+{
+ PhotoMaster *masterPtr;
+ schar *newError, *errSrcPtr, *errDestPtr;
+ int h, offset;
+ XRectangle validBox;
+ Pixmap newPixmap;
+
+ masterPtr = instancePtr->masterPtr;
+ TkClipBox(masterPtr->validRegion, &validBox);
+
+ if ((instancePtr->width != masterPtr->width)
+ || (instancePtr->height != masterPtr->height)
+ || (instancePtr->pixels == None)) {
+ newPixmap = Tk_GetPixmap(instancePtr->display,
+ RootWindow(instancePtr->display,
+ instancePtr->visualInfo.screen),
+ (masterPtr->width > 0) ? masterPtr->width: 1,
+ (masterPtr->height > 0) ? masterPtr->height: 1,
+ instancePtr->visualInfo.depth);
+ if (!newPixmap) {
+ Tcl_Panic("Fail to create pixmap with Tk_GetPixmap in TkImgPhotoInstanceSetSize");
+ }
+
+ /*
+ * The following is a gross hack needed to properly support colormaps
+ * under Windows. Before the pixels can be copied to the pixmap, the
+ * relevent colormap must be associated with the drawable. Normally we
+ * can infer this association from the window that was used to create
+ * the pixmap. However, in this case we're using the root window, so
+ * we have to be more explicit.
+ */
+
+ TkSetPixmapColormap(newPixmap, instancePtr->colormap);
+
+ if (instancePtr->pixels != None) {
+ /*
+ * Copy any common pixels from the old pixmap and free it.
+ */
+
+ XCopyArea(instancePtr->display, instancePtr->pixels, newPixmap,
+ instancePtr->gc, validBox.x, validBox.y,
+ validBox.width, validBox.height, validBox.x, validBox.y);
+ Tk_FreePixmap(instancePtr->display, instancePtr->pixels);
+ }
+ instancePtr->pixels = newPixmap;
+ }
+
+ if ((instancePtr->width != masterPtr->width)
+ || (instancePtr->height != masterPtr->height)
+ || (instancePtr->error == NULL)) {
+ if (masterPtr->height > 0 && masterPtr->width > 0) {
+ /*
+ * TODO: use attemptckalloc() here once there is a strategy that
+ * will allow us to recover from failure. Right now, there's no
+ * such possibility.
+ */
+
+ newError = ckalloc(masterPtr->height * masterPtr->width
+ * 3 * sizeof(schar));
+
+ /*
+ * Zero the new array so that we don't get bogus error values
+ * propagating into areas we dither later.
+ */
+
+ if ((instancePtr->error != NULL)
+ && ((instancePtr->width == masterPtr->width)
+ || (validBox.width == masterPtr->width))) {
+ if (validBox.y > 0) {
+ memset(newError, 0, (size_t)
+ validBox.y * masterPtr->width * 3 * sizeof(schar));
+ }
+ h = validBox.y + validBox.height;
+ if (h < masterPtr->height) {
+ memset(newError + h*masterPtr->width*3, 0,
+ (size_t) (masterPtr->height - h)
+ * masterPtr->width * 3 * sizeof(schar));
+ }
+ } else {
+ memset(newError, 0, (size_t)
+ masterPtr->height * masterPtr->width *3*sizeof(schar));
+ }
+ } else {
+ newError = NULL;
+ }
+
+ if (instancePtr->error != NULL) {
+ /*
+ * Copy the common area over to the new array and free the old
+ * array.
+ */
+
+ if (masterPtr->width == instancePtr->width) {
+ offset = validBox.y * masterPtr->width * 3;
+ memcpy(newError + offset, instancePtr->error + offset,
+ (size_t) (validBox.height
+ * masterPtr->width * 3 * sizeof(schar)));
+
+ } else if (validBox.width > 0 && validBox.height > 0) {
+ errDestPtr = newError +
+ (validBox.y * masterPtr->width + validBox.x) * 3;
+ errSrcPtr = instancePtr->error +
+ (validBox.y * instancePtr->width + validBox.x) * 3;
+
+ for (h = validBox.height; h > 0; --h) {
+ memcpy(errDestPtr, errSrcPtr,
+ validBox.width * 3 * sizeof(schar));
+ errDestPtr += masterPtr->width * 3;
+ errSrcPtr += instancePtr->width * 3;
+ }
+ }
+ ckfree(instancePtr->error);
+ }
+
+ instancePtr->error = newError;
+ }
+
+ instancePtr->width = masterPtr->width;
+ instancePtr->height = masterPtr->height;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * IsValidPalette --
+ *
+ * This function is called to check whether a value given for the
+ * -palette option is valid for a particular instance of a photo image.
+ *
+ * Results:
+ * A boolean value: 1 if the palette is acceptable, 0 otherwise.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+IsValidPalette(
+ PhotoInstance *instancePtr, /* Instance to which the palette specification
+ * is to be applied. */
+ const char *palette) /* Palette specification string. */
+{
+ int nRed, nGreen, nBlue, mono, numColors;
+ char *endp;
+
+ /*
+ * First parse the specification: it must be of the form %d or %d/%d/%d.
+ */
+
+ nRed = strtol(palette, &endp, 10);
+ if ((endp == palette) || ((*endp != 0) && (*endp != '/'))
+ || (nRed < 2) || (nRed > 256)) {
+ return 0;
+ }
+
+ if (*endp == 0) {
+ mono = 1;
+ nGreen = nBlue = nRed;
+ } else {
+ palette = endp + 1;
+ nGreen = strtol(palette, &endp, 10);
+ if ((endp == palette) || (*endp != '/') || (nGreen < 2)
+ || (nGreen > 256)) {
+ return 0;
+ }
+ palette = endp + 1;
+ nBlue = strtol(palette, &endp, 10);
+ if ((endp == palette) || (*endp != 0) || (nBlue < 2)
+ || (nBlue > 256)) {
+ return 0;
+ }
+ mono = 0;
+ }
+
+ switch (instancePtr->visualInfo.class) {
+ case DirectColor:
+ case TrueColor:
+ if ((nRed > (1 << CountBits(instancePtr->visualInfo.red_mask)))
+ || (nGreen>(1<<CountBits(instancePtr->visualInfo.green_mask)))
+ || (nBlue>(1<<CountBits(instancePtr->visualInfo.blue_mask)))) {
+ return 0;
+ }
+ break;
+ case PseudoColor:
+ case StaticColor:
+ numColors = nRed;
+ if (!mono) {
+ numColors *= nGreen * nBlue;
+ }
+ if (numColors > (1 << instancePtr->visualInfo.depth)) {
+ return 0;
+ }
+ break;
+ case GrayScale:
+ case StaticGray:
+ if (!mono || (nRed > (1 << instancePtr->visualInfo.depth))) {
+ return 0;
+ }
+ break;
+ }
+
+ return 1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * CountBits --
+ *
+ * This function counts how many bits are set to 1 in `mask'.
+ *
+ * Results:
+ * The integer number of bits.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+CountBits(
+ pixel mask) /* Value to count the 1 bits in. */
+{
+ int n;
+
+ for (n=0 ; mask!=0 ; mask&=mask-1) {
+ n++;
+ }
+ return n;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetColorTable --
+ *
+ * This function is called to allocate a table of colormap information
+ * for an instance of a photo image. Only one such table is allocated for
+ * all photo instances using the same display, colormap, palette and
+ * gamma values, so that the application need only request a set of
+ * colors from the X server once for all such photo widgets. This
+ * function maintains a hash table to find previously-allocated
+ * ColorTables.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * A new ColorTable may be allocated and placed in the hash table, and
+ * have colors allocated for it.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+GetColorTable(
+ PhotoInstance *instancePtr) /* Instance needing a color table. */
+{
+ ColorTable *colorPtr;
+ Tcl_HashEntry *entry;
+ ColorTableId id;
+ int isNew;
+
+ /*
+ * Look for an existing ColorTable in the hash table.
+ */
+
+ memset(&id, 0, sizeof(id));
+ id.display = instancePtr->display;
+ id.colormap = instancePtr->colormap;
+ id.palette = instancePtr->palette;
+ id.gamma = instancePtr->gamma;
+ if (!imgPhotoColorHashInitialized) {
+ Tcl_InitHashTable(&imgPhotoColorHash, N_COLOR_HASH);
+ imgPhotoColorHashInitialized = 1;
+ }
+ entry = Tcl_CreateHashEntry(&imgPhotoColorHash, (char *) &id, &isNew);
+
+ if (!isNew) {
+ /*
+ * Re-use the existing entry.
+ */
+
+ colorPtr = Tcl_GetHashValue(entry);
+ } else {
+ /*
+ * No color table currently available; need to make one.
+ */
+
+ colorPtr = ckalloc(sizeof(ColorTable));
+
+ /*
+ * The following line of code should not normally be needed due to the
+ * assignment in the following line. However, it compensates for bugs
+ * in some compilers (HP, for example) where sizeof(ColorTable) is 24
+ * but the assignment only copies 20 bytes, leaving 4 bytes
+ * uninitialized; these cause problems when using the id for lookups
+ * in imgPhotoColorHash, and can result in core dumps.
+ */
+
+ memset(&colorPtr->id, 0, sizeof(ColorTableId));
+ colorPtr->id = id;
+ Tk_PreserveColormap(colorPtr->id.display, colorPtr->id.colormap);
+ colorPtr->flags = 0;
+ colorPtr->refCount = 0;
+ colorPtr->liveRefCount = 0;
+ colorPtr->numColors = 0;
+ colorPtr->visualInfo = instancePtr->visualInfo;
+ colorPtr->pixelMap = NULL;
+ Tcl_SetHashValue(entry, colorPtr);
+ }
+
+ colorPtr->refCount++;
+ colorPtr->liveRefCount++;
+ instancePtr->colorTablePtr = colorPtr;
+ if (colorPtr->flags & DISPOSE_PENDING) {
+ Tcl_CancelIdleCall(DisposeColorTable, colorPtr);
+ colorPtr->flags &= ~DISPOSE_PENDING;
+ }
+
+ /*
+ * Allocate colors for this color table if necessary.
+ */
+
+ if ((colorPtr->numColors == 0)
+ && ((colorPtr->flags & BLACK_AND_WHITE) == 0)) {
+ AllocateColors(colorPtr);
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * FreeColorTable --
+ *
+ * This function is called when an instance ceases using a color table.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * If no other instances are using this color table, a when-idle handler
+ * is registered to free up the color table and the colors allocated for
+ * it.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+FreeColorTable(
+ ColorTable *colorPtr, /* Pointer to the color table which is no
+ * longer required by an instance. */
+ int force) /* Force free to happen immediately. */
+{
+ colorPtr->refCount--;
+ if (colorPtr->refCount > 0) {
+ return;
+ }
+
+ if (force) {
+ if ((colorPtr->flags & DISPOSE_PENDING) != 0) {
+ Tcl_CancelIdleCall(DisposeColorTable, colorPtr);
+ colorPtr->flags &= ~DISPOSE_PENDING;
+ }
+ DisposeColorTable(colorPtr);
+ } else if ((colorPtr->flags & DISPOSE_PENDING) == 0) {
+ Tcl_DoWhenIdle(DisposeColorTable, colorPtr);
+ colorPtr->flags |= DISPOSE_PENDING;
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * AllocateColors --
+ *
+ * This function allocates the colors required by a color table, and sets
+ * up the fields in the color table data structure which are used in
+ * dithering.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Colors are allocated from the X server. Fields in the color table data
+ * structure are updated.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+AllocateColors(
+ ColorTable *colorPtr) /* Pointer to the color table requiring colors
+ * to be allocated. */
+{
+ int i, r, g, b, rMult, mono;
+ int numColors, nRed, nGreen, nBlue;
+ double fr, fg, fb, igam;
+ XColor *colors;
+ unsigned long *pixels;
+
+ /*
+ * 16-bit intensity value for i/n of full intensity.
+ */
+#define CFRAC(i, n) ((i) * 65535 / (n))
+
+ /* As for CFRAC, but apply exponent of g. */
+#define CGFRAC(i, n, g) ((int)(65535 * pow((double)(i) / (n), (g))))
+
+ /*
+ * First parse the palette specification to get the required number of
+ * shades of each primary.
+ */
+
+ mono = sscanf(colorPtr->id.palette, "%d/%d/%d", &nRed, &nGreen, &nBlue)
+ <= 1;
+ igam = 1.0 / colorPtr->id.gamma;
+
+ /*
+ * Each time around this loop, we reduce the number of colors we're trying
+ * to allocate until we succeed in allocating all of the colors we need.
+ */
+
+ for (;;) {
+ /*
+ * If we are using 1 bit/pixel, we don't need to allocate any colors
+ * (we just use the foreground and background colors in the GC).
+ */
+
+ if (mono && (nRed <= 2)) {
+ colorPtr->flags |= BLACK_AND_WHITE;
+ return;
+ }
+
+ /*
+ * Calculate the RGB coordinates of the colors we want to allocate and
+ * store them in *colors.
+ */
+
+ if ((colorPtr->visualInfo.class == DirectColor)
+ || (colorPtr->visualInfo.class == TrueColor)) {
+
+ /*
+ * Direct/True Color: allocate shades of red, green, blue
+ * independently.
+ */
+
+ if (mono) {
+ numColors = nGreen = nBlue = nRed;
+ } else {
+ numColors = MAX(MAX(nRed, nGreen), nBlue);
+ }
+ colors = ckalloc(numColors * sizeof(XColor));
+
+ for (i = 0; i < numColors; ++i) {
+ if (igam == 1.0) {
+ colors[i].red = CFRAC(i, nRed - 1);
+ colors[i].green = CFRAC(i, nGreen - 1);
+ colors[i].blue = CFRAC(i, nBlue - 1);
+ } else {
+ colors[i].red = CGFRAC(i, nRed - 1, igam);
+ colors[i].green = CGFRAC(i, nGreen - 1, igam);
+ colors[i].blue = CGFRAC(i, nBlue - 1, igam);
+ }
+ }
+ } else {
+ /*
+ * PseudoColor, StaticColor, GrayScale or StaticGray visual: we
+ * have to allocate each color in the color cube separately.
+ */
+
+ numColors = (mono) ? nRed: (nRed * nGreen * nBlue);
+ colors = ckalloc(numColors * sizeof(XColor));
+
+ if (!mono) {
+ /*
+ * Color display using a PseudoColor or StaticColor visual.
+ */
+
+ i = 0;
+ for (r = 0; r < nRed; ++r) {
+ for (g = 0; g < nGreen; ++g) {
+ for (b = 0; b < nBlue; ++b) {
+ if (igam == 1.0) {
+ colors[i].red = CFRAC(r, nRed - 1);
+ colors[i].green = CFRAC(g, nGreen - 1);
+ colors[i].blue = CFRAC(b, nBlue - 1);
+ } else {
+ colors[i].red = CGFRAC(r, nRed - 1, igam);
+ colors[i].green = CGFRAC(g, nGreen - 1, igam);
+ colors[i].blue = CGFRAC(b, nBlue - 1, igam);
+ }
+ i++;
+ }
+ }
+ }
+ } else {
+ /*
+ * Monochrome display - allocate the shades of grey we want.
+ */
+
+ for (i = 0; i < numColors; ++i) {
+ if (igam == 1.0) {
+ r = CFRAC(i, numColors - 1);
+ } else {
+ r = CGFRAC(i, numColors - 1, igam);
+ }
+ colors[i].red = colors[i].green = colors[i].blue = r;
+ }
+ }
+ }
+
+ /*
+ * Now try to allocate the colors we've calculated.
+ */
+
+ pixels = ckalloc(numColors * sizeof(unsigned long));
+ for (i = 0; i < numColors; ++i) {
+ if (!XAllocColor(colorPtr->id.display, colorPtr->id.colormap,
+ &colors[i])) {
+ /*
+ * Can't get all the colors we want in the default colormap;
+ * first try freeing colors from other unused color tables.
+ */
+
+ if (!ReclaimColors(&colorPtr->id, numColors - i)
+ || !XAllocColor(colorPtr->id.display,
+ colorPtr->id.colormap, &colors[i])) {
+ /*
+ * Still can't allocate the color.
+ */
+
+ break;
+ }
+ }
+ pixels[i] = colors[i].pixel;
+ }
+
+ /*
+ * If we didn't get all of the colors, reduce the resolution of the
+ * color cube, free the ones we got, and try again.
+ */
+
+ if (i >= numColors) {
+ break;
+ }
+ XFreeColors(colorPtr->id.display, colorPtr->id.colormap, pixels, i, 0);
+ ckfree(colors);
+ ckfree(pixels);
+
+ if (!mono) {
+ if ((nRed == 2) && (nGreen == 2) && (nBlue == 2)) {
+ /*
+ * Fall back to 1-bit monochrome display.
+ */
+
+ mono = 1;
+ } else {
+ /*
+ * Reduce the number of shades of each primary to about 3/4 of
+ * the previous value. This should reduce the total number of
+ * colors required to about half the previous value for
+ * PseudoColor displays.
+ */
+
+ nRed = (nRed * 3 + 2) / 4;
+ nGreen = (nGreen * 3 + 2) / 4;
+ nBlue = (nBlue * 3 + 2) / 4;
+ }
+ } else {
+ /*
+ * Reduce the number of shades of gray to about 1/2.
+ */
+
+ nRed = nRed / 2;
+ }
+ }
+
+ /*
+ * We have allocated all of the necessary colors: fill in various fields
+ * of the ColorTable record.
+ */
+
+ if (!mono) {
+ colorPtr->flags |= COLOR_WINDOW;
+
+ /*
+ * The following is a hairy hack. We only want to index into the
+ * pixelMap on colormap displays. However, if the display is on
+ * Windows, then we actually want to store the index not the value
+ * since we will be passing the color table into the TkPutImage call.
+ */
+
+#ifndef __WIN32__
+ if ((colorPtr->visualInfo.class != DirectColor)
+ && (colorPtr->visualInfo.class != TrueColor)) {
+ colorPtr->flags |= MAP_COLORS;
+ }
+#endif /* __WIN32__ */
+ }
+
+ colorPtr->numColors = numColors;
+ colorPtr->pixelMap = pixels;
+
+ /*
+ * Set up quantization tables for dithering.
+ */
+
+ rMult = nGreen * nBlue;
+ for (i = 0; i < 256; ++i) {
+ r = (i * (nRed - 1) + 127) / 255;
+ if (mono) {
+ fr = (double) colors[r].red / 65535.0;
+ if (colorPtr->id.gamma != 1.0 ) {
+ fr = pow(fr, colorPtr->id.gamma);
+ }
+ colorPtr->colorQuant[0][i] = (int)(fr * 255.99);
+ colorPtr->redValues[i] = colors[r].pixel;
+ } else {
+ g = (i * (nGreen - 1) + 127) / 255;
+ b = (i * (nBlue - 1) + 127) / 255;
+ if ((colorPtr->visualInfo.class == DirectColor)
+ || (colorPtr->visualInfo.class == TrueColor)) {
+ colorPtr->redValues[i] =
+ colors[r].pixel & colorPtr->visualInfo.red_mask;
+ colorPtr->greenValues[i] =
+ colors[g].pixel & colorPtr->visualInfo.green_mask;
+ colorPtr->blueValues[i] =
+ colors[b].pixel & colorPtr->visualInfo.blue_mask;
+ } else {
+ r *= rMult;
+ g *= nBlue;
+ colorPtr->redValues[i] = r;
+ colorPtr->greenValues[i] = g;
+ colorPtr->blueValues[i] = b;
+ }
+ fr = (double) colors[r].red / 65535.0;
+ fg = (double) colors[g].green / 65535.0;
+ fb = (double) colors[b].blue / 65535.0;
+ if (colorPtr->id.gamma != 1.0) {
+ fr = pow(fr, colorPtr->id.gamma);
+ fg = pow(fg, colorPtr->id.gamma);
+ fb = pow(fb, colorPtr->id.gamma);
+ }
+ colorPtr->colorQuant[0][i] = (int)(fr * 255.99);
+ colorPtr->colorQuant[1][i] = (int)(fg * 255.99);
+ colorPtr->colorQuant[2][i] = (int)(fb * 255.99);
+ }
+ }
+
+ ckfree(colors);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * DisposeColorTable --
+ *
+ * Release a color table and its associated resources.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The colors in the argument color table are freed, as is the color
+ * table structure itself. The color table is removed from the hash table
+ * which is used to locate color tables.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+DisposeColorTable(
+ ClientData clientData) /* Pointer to the ColorTable whose
+ * colors are to be released. */
+{
+ ColorTable *colorPtr = clientData;
+ Tcl_HashEntry *entry;
+
+ if (colorPtr->pixelMap != NULL) {
+ if (colorPtr->numColors > 0) {
+ XFreeColors(colorPtr->id.display, colorPtr->id.colormap,
+ colorPtr->pixelMap, colorPtr->numColors, 0);
+ Tk_FreeColormap(colorPtr->id.display, colorPtr->id.colormap);
+ }
+ ckfree(colorPtr->pixelMap);
+ }
+
+ entry = Tcl_FindHashEntry(&imgPhotoColorHash, (char *) &colorPtr->id);
+ if (entry == NULL) {
+ Tcl_Panic("DisposeColorTable couldn't find hash entry");
+ }
+ Tcl_DeleteHashEntry(entry);
+
+ ckfree(colorPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ReclaimColors --
+ *
+ * This function is called to try to free up colors in the colormap used
+ * by a color table. It looks for other color tables with the same
+ * colormap and with a zero live reference count, and frees their colors.
+ * It only does so if there is the possibility of freeing up at least
+ * `numColors' colors.
+ *
+ * Results:
+ * The return value is TRUE if any colors were freed, FALSE otherwise.
+ *
+ * Side effects:
+ * ColorTables which are not currently in use may lose their color
+ * allocations.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ReclaimColors(
+ ColorTableId *id, /* Pointer to information identifying
+ * the color table which needs more colors. */
+ int numColors) /* Number of colors required. */
+{
+ Tcl_HashSearch srch;
+ Tcl_HashEntry *entry;
+ ColorTable *colorPtr;
+ int nAvail = 0;
+
+ /*
+ * First scan through the color hash table to get an upper bound on how
+ * many colors we might be able to free.
+ */
+
+ entry = Tcl_FirstHashEntry(&imgPhotoColorHash, &srch);
+ while (entry != NULL) {
+ colorPtr = Tcl_GetHashValue(entry);
+ if ((colorPtr->id.display == id->display)
+ && (colorPtr->id.colormap == id->colormap)
+ && (colorPtr->liveRefCount == 0 )&& (colorPtr->numColors != 0)
+ && ((colorPtr->id.palette != id->palette)
+ || (colorPtr->id.gamma != id->gamma))) {
+ /*
+ * We could take this guy's colors off him.
+ */
+
+ nAvail += colorPtr->numColors;
+ }
+ entry = Tcl_NextHashEntry(&srch);
+ }
+
+ /*
+ * nAvail is an (over)estimate of the number of colors we could free.
+ */
+
+ if (nAvail < numColors) {
+ return 0;
+ }
+
+ /*
+ * Scan through a second time freeing colors.
+ */
+
+ entry = Tcl_FirstHashEntry(&imgPhotoColorHash, &srch);
+ while ((entry != NULL) && (numColors > 0)) {
+ colorPtr = Tcl_GetHashValue(entry);
+ if ((colorPtr->id.display == id->display)
+ && (colorPtr->id.colormap == id->colormap)
+ && (colorPtr->liveRefCount == 0) && (colorPtr->numColors != 0)
+ && ((colorPtr->id.palette != id->palette)
+ || (colorPtr->id.gamma != id->gamma))) {
+ /*
+ * Free the colors that this ColorTable has.
+ */
+
+ XFreeColors(colorPtr->id.display, colorPtr->id.colormap,
+ colorPtr->pixelMap, colorPtr->numColors, 0);
+ numColors -= colorPtr->numColors;
+ colorPtr->numColors = 0;
+ ckfree(colorPtr->pixelMap);
+ colorPtr->pixelMap = NULL;
+ }
+
+ entry = Tcl_NextHashEntry(&srch);
+ }
+ return 1; /* We freed some colors. */
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgDisposeInstance --
+ *
+ * This function is called to finally free up an instance of a photo
+ * image which is no longer required.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The instance data structure and the resources it references are freed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgDisposeInstance(
+ ClientData clientData) /* Pointer to the instance whose resources are
+ * to be released. */
+{
+ PhotoInstance *instancePtr = clientData;
+ PhotoInstance *prevPtr;
+
+ if (instancePtr->pixels != None) {
+ Tk_FreePixmap(instancePtr->display, instancePtr->pixels);
+ }
+ if (instancePtr->gc != None) {
+ Tk_FreeGC(instancePtr->display, instancePtr->gc);
+ }
+ if (instancePtr->imagePtr != NULL) {
+ XDestroyImage(instancePtr->imagePtr);
+ }
+ if (instancePtr->error != NULL) {
+ ckfree(instancePtr->error);
+ }
+ if (instancePtr->colorTablePtr != NULL) {
+ FreeColorTable(instancePtr->colorTablePtr, 1);
+ }
+
+ if (instancePtr->masterPtr->instancePtr == instancePtr) {
+ instancePtr->masterPtr->instancePtr = instancePtr->nextPtr;
+ } else {
+ for (prevPtr = instancePtr->masterPtr->instancePtr;
+ prevPtr->nextPtr != instancePtr; prevPtr = prevPtr->nextPtr) {
+ /* Empty loop body. */
+ }
+ prevPtr->nextPtr = instancePtr->nextPtr;
+ }
+ Tk_FreeColormap(instancePtr->display, instancePtr->colormap);
+ ckfree(instancePtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgDitherInstance --
+ *
+ * This function is called to update an area of an instance's pixmap by
+ * dithering the corresponding area of the master.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The instance's pixmap gets updated.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgDitherInstance(
+ PhotoInstance *instancePtr, /* The instance to be updated. */
+ int xStart, int yStart, /* Coordinates of the top-left pixel in the
+ * block to be dithered. */
+ int width, int height) /* Dimensions of the block to be dithered. */
+{
+ PhotoMaster *masterPtr = instancePtr->masterPtr;
+ ColorTable *colorPtr = instancePtr->colorTablePtr;
+ XImage *imagePtr;
+ int nLines, bigEndian, i, c, x, y, xEnd, doDithering = 1;
+ int bitsPerPixel, bytesPerLine, lineLength;
+ unsigned char *srcLinePtr;
+ schar *errLinePtr;
+ pixel firstBit, word, mask;
+
+ /*
+ * Turn dithering off in certain cases where it is not needed (TrueColor,
+ * DirectColor with many colors).
+ */
+
+ if ((colorPtr->visualInfo.class == DirectColor)
+ || (colorPtr->visualInfo.class == TrueColor)) {
+ int nRed, nGreen, nBlue, result;
+
+ result = sscanf(colorPtr->id.palette, "%d/%d/%d", &nRed,
+ &nGreen, &nBlue);
+ if ((nRed >= 256)
+ && ((result == 1) || ((nGreen >= 256) && (nBlue >= 256)))) {
+ doDithering = 0;
+ }
+ }
+
+ /*
+ * First work out how many lines to do at a time, then how many bytes
+ * we'll need for pixel storage, and allocate it.
+ */
+
+ nLines = (MAX_PIXELS + width - 1) / width;
+ if (nLines < 1) {
+ nLines = 1;
+ }
+ if (nLines > height ) {
+ nLines = height;
+ }
+
+ imagePtr = instancePtr->imagePtr;
+ if (imagePtr == NULL) {
+ return; /* We must be really tight on memory. */
+ }
+ bitsPerPixel = imagePtr->bits_per_pixel;
+ bytesPerLine = ((bitsPerPixel * width + 31) >> 3) & ~3;
+ imagePtr->width = width;
+ imagePtr->height = nLines;
+ imagePtr->bytes_per_line = bytesPerLine;
+
+ /*
+ * TODO: use attemptckalloc() here once we have some strategy for
+ * recovering from the failure.
+ */
+
+ imagePtr->data = ckalloc(imagePtr->bytes_per_line * nLines);
+ bigEndian = imagePtr->bitmap_bit_order == MSBFirst;
+ firstBit = bigEndian? (1 << (imagePtr->bitmap_unit - 1)): 1;
+
+ lineLength = masterPtr->width * 3;
+ srcLinePtr = masterPtr->pix32 + (yStart * masterPtr->width + xStart) * 4;
+ errLinePtr = instancePtr->error + yStart * lineLength + xStart * 3;
+ xEnd = xStart + width;
+
+ /*
+ * Loop over the image, doing at most nLines lines before updating the
+ * screen image.
+ */
+
+ for (; height > 0; height -= nLines) {
+ unsigned char *dstLinePtr = (unsigned char *) imagePtr->data;
+ int yEnd;
+
+ if (nLines > height) {
+ nLines = height;
+ }
+ yEnd = yStart + nLines;
+ for (y = yStart; y < yEnd; ++y) {
+ unsigned char *srcPtr = srcLinePtr;
+ schar *errPtr = errLinePtr;
+ unsigned char *destBytePtr = dstLinePtr;
+ pixel *destLongPtr = (pixel *) dstLinePtr;
+
+ if (colorPtr->flags & COLOR_WINDOW) {
+ /*
+ * Color window. We dither the three components independently,
+ * using Floyd-Steinberg dithering, which propagates errors
+ * from the quantization of pixels to the pixels below and to
+ * the right.
+ */
+
+ for (x = xStart; x < xEnd; ++x) {
+ int col[3];
+
+ if (doDithering) {
+ for (i = 0; i < 3; ++i) {
+ /*
+ * Compute the error propagated into this pixel
+ * for this component. If e[x,y] is the array of
+ * quantization error values, we compute
+ * 7/16 * e[x-1,y] + 1/16 * e[x-1,y-1]
+ * + 5/16 * e[x,y-1] + 3/16 * e[x+1,y-1]
+ * and round it to an integer.
+ *
+ * The expression ((c + 2056) >> 4) - 128 computes
+ * round(c / 16), and works correctly on machines
+ * without a sign-extending right shift.
+ */
+
+ c = (x > 0) ? errPtr[-3] * 7: 0;
+ if (y > 0) {
+ if (x > 0) {
+ c += errPtr[-lineLength-3];
+ }
+ c += errPtr[-lineLength] * 5;
+ if ((x + 1) < masterPtr->width) {
+ c += errPtr[-lineLength+3] * 3;
+ }
+ }
+
+ /*
+ * Add the propagated error to the value of this
+ * component, quantize it, and store the
+ * quantization error.
+ */
+
+ c = ((c + 2056) >> 4) - 128 + *srcPtr++;
+ if (c < 0) {
+ c = 0;
+ } else if (c > 255) {
+ c = 255;
+ }
+ col[i] = colorPtr->colorQuant[i][c];
+ *errPtr++ = c - col[i];
+ }
+ } else {
+ /*
+ * Output is virtually continuous in this case, so
+ * don't bother dithering.
+ */
+
+ col[0] = *srcPtr++;
+ col[1] = *srcPtr++;
+ col[2] = *srcPtr++;
+ }
+ srcPtr++;
+
+ /*
+ * Translate the quantized component values into an X
+ * pixel value, and store it in the image.
+ */
+
+ i = colorPtr->redValues[col[0]]
+ + colorPtr->greenValues[col[1]]
+ + colorPtr->blueValues[col[2]];
+ if (colorPtr->flags & MAP_COLORS) {
+ i = colorPtr->pixelMap[i];
+ }
+ switch (bitsPerPixel) {
+ case NBBY:
+ *destBytePtr++ = i;
+ break;
+#ifndef __WIN32__
+ /*
+ * This case is not valid for Windows because the
+ * image format is different from the pixel format in
+ * Win32. Eventually we need to fix the image code in
+ * Tk to use the Windows native image ordering. This
+ * would speed up the image code for all of the common
+ * sizes.
+ */
+
+ case NBBY * sizeof(pixel):
+ *destLongPtr++ = i;
+ break;
+#endif
+ default:
+ XPutPixel(imagePtr, x - xStart, y - yStart,
+ (unsigned) i);
+ }
+ }
+
+ } else if (bitsPerPixel > 1) {
+ /*
+ * Multibit monochrome window. The operation here is similar
+ * to the color window case above, except that there is only
+ * one component. If the master image is in color, use the
+ * luminance computed as
+ * 0.344 * red + 0.5 * green + 0.156 * blue.
+ */
+
+ for (x = xStart; x < xEnd; ++x) {
+ c = (x > 0) ? errPtr[-1] * 7: 0;
+ if (y > 0) {
+ if (x > 0) {
+ c += errPtr[-lineLength-1];
+ }
+ c += errPtr[-lineLength] * 5;
+ if (x + 1 < masterPtr->width) {
+ c += errPtr[-lineLength+1] * 3;
+ }
+ }
+ c = ((c + 2056) >> 4) - 128;
+
+ if ((masterPtr->flags & COLOR_IMAGE) == 0) {
+ c += srcPtr[0];
+ } else {
+ c += (unsigned) (srcPtr[0] * 11 + srcPtr[1] * 16
+ + srcPtr[2] * 5 + 16) >> 5;
+ }
+ srcPtr += 4;
+
+ if (c < 0) {
+ c = 0;
+ } else if (c > 255) {
+ c = 255;
+ }
+ i = colorPtr->colorQuant[0][c];
+ *errPtr++ = c - i;
+ i = colorPtr->redValues[i];
+ switch (bitsPerPixel) {
+ case NBBY:
+ *destBytePtr++ = i;
+ break;
+#ifndef __WIN32__
+ /*
+ * This case is not valid for Windows because the
+ * image format is different from the pixel format in
+ * Win32. Eventually we need to fix the image code in
+ * Tk to use the Windows native image ordering. This
+ * would speed up the image code for all of the common
+ * sizes.
+ */
+
+ case NBBY * sizeof(pixel):
+ *destLongPtr++ = i;
+ break;
+#endif
+ default:
+ XPutPixel(imagePtr, x - xStart, y - yStart,
+ (unsigned) i);
+ }
+ }
+ } else {
+ /*
+ * 1-bit monochrome window. This is similar to the multibit
+ * monochrome case above, except that the quantization is
+ * simpler (we only have black = 0 and white = 255), and we
+ * produce an XY-Bitmap.
+ */
+
+ word = 0;
+ mask = firstBit;
+ for (x = xStart; x < xEnd; ++x) {
+ /*
+ * If we have accumulated a whole word, store it in the
+ * image and start a new word.
+ */
+
+ if (mask == 0) {
+ *destLongPtr++ = word;
+ mask = firstBit;
+ word = 0;
+ }
+
+ c = (x > 0) ? errPtr[-1] * 7: 0;
+ if (y > 0) {
+ if (x > 0) {
+ c += errPtr[-lineLength-1];
+ }
+ c += errPtr[-lineLength] * 5;
+ if (x + 1 < masterPtr->width) {
+ c += errPtr[-lineLength+1] * 3;
+ }
+ }
+ c = ((c + 2056) >> 4) - 128;
+
+ if ((masterPtr->flags & COLOR_IMAGE) == 0) {
+ c += srcPtr[0];
+ } else {
+ c += (unsigned)(srcPtr[0] * 11 + srcPtr[1] * 16
+ + srcPtr[2] * 5 + 16) >> 5;
+ }
+ srcPtr += 4;
+
+ if (c < 0) {
+ c = 0;
+ } else if (c > 255) {
+ c = 255;
+ }
+ if (c >= 128) {
+ word |= mask;
+ *errPtr++ = c - 255;
+ } else {
+ *errPtr++ = c;
+ }
+ mask = bigEndian? (mask >> 1): (mask << 1);
+ }
+ *destLongPtr = word;
+ }
+ srcLinePtr += masterPtr->width * 4;
+ errLinePtr += lineLength;
+ dstLinePtr += bytesPerLine;
+ }
+
+ /*
+ * Update the pixmap for this instance with the block of pixels that
+ * we have just computed.
+ */
+
+ TkPutImage(colorPtr->pixelMap, colorPtr->numColors,
+ instancePtr->display, instancePtr->pixels,
+ instancePtr->gc, imagePtr, 0, 0, xStart, yStart,
+ (unsigned) width, (unsigned) nLines);
+ yStart = yEnd;
+ }
+
+ ckfree(imagePtr->data);
+ imagePtr->data = NULL;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkImgResetDither --
+ *
+ * This function is called to eliminate the content of a photo instance's
+ * dither error buffer. It's called when the overall image is blanked.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The instance's dither buffer gets cleared.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkImgResetDither(
+ PhotoInstance *instancePtr)
+{
+ if (instancePtr->error) {
+ memset(instancePtr->error, 0,
+ /*(size_t)*/ (instancePtr->masterPtr->width
+ * instancePtr->masterPtr->height * 3 * sizeof(schar)));
+ }
+}
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */