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Diffstat (limited to 'generic/tkImgPhInstance.c')
| -rw-r--r-- | generic/tkImgPhInstance.c | 1966 |
1 files changed, 1966 insertions, 0 deletions
diff --git a/generic/tkImgPhInstance.c b/generic/tkImgPhInstance.c new file mode 100644 index 0000000..666a9b0 --- /dev/null +++ b/generic/tkImgPhInstance.c @@ -0,0 +1,1966 @@ +/* + * 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. + */ + +#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_BackgroundException 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); + /* We failed to get the image so draw without blending alpha. It's the best we can do */ + goto fallBack; + } + + 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. + */ + + fallBack: + 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)) { + 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) { + Tcl_CancelIdleCall(DisposeColorTable, colorPtr); + colorPtr->flags &= ~DISPOSE_PENDING; + } + DisposeColorTable(colorPtr); + } else if (!(colorPtr->flags & DISPOSE_PENDING)) { + 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) { + c += (unsigned) (srcPtr[0] * 11 + srcPtr[1] * 16 + + srcPtr[2] * 5 + 16) >> 5; + } else { + c += srcPtr[0]; + } + 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) { + c += (unsigned)(srcPtr[0] * 11 + srcPtr[1] * 16 + + srcPtr[2] * 5 + 16) >> 5; + } else { + c += srcPtr[0]; + } + 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: + */ |