diff options
Diffstat (limited to 'macosx/tkMacOSXImage.c')
| -rw-r--r-- | macosx/tkMacOSXImage.c | 172 |
1 files changed, 113 insertions, 59 deletions
diff --git a/macosx/tkMacOSXImage.c b/macosx/tkMacOSXImage.c index 2adebe8..092b589 100644 --- a/macosx/tkMacOSXImage.c +++ b/macosx/tkMacOSXImage.c @@ -6,7 +6,7 @@ * Copyright (c) 1995-1997 Sun Microsystems, Inc. * Copyright 2001-2009, Apple Inc. * Copyright (c) 2005-2009 Daniel A. Steffen <das@users.sourceforge.net> - * Copyright (c) 2017-2020 Marc Culler. + * Copyright (c) 2017-2021 Marc Culler. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. @@ -19,6 +19,71 @@ static CGImageRef CreateCGImageFromPixmap(Drawable pixmap); static CGImageRef CreateCGImageFromDrawableRect( Drawable drawable, int x, int y, unsigned int width, unsigned int height); +/* Pixel formats + * + * Tk uses the XImage structure defined in Xlib.h for storing images. The + * image data in an XImage is a 32-bit aligned array of bytes. Interpretation + * of that data is not specified, but the structure includes parameters which + * provide interpretation hints so that an application can use a family of + * different data structures. + * + * The possible values for the XImage format field are XYBitmap, XYPixmap and + * ZPixmap. The macOS port does not support the XYPixmap format. This means + * that bitmap images are stored as a single bit plane (XYBitmap) and that + * color images are stored as a sequence of pixel values (ZPixmap). + * + * For a ZPixmap, the number of bits allocated to each pixel is specified by + * the bits_per_pixel field of the XImage structure. The functions in this + * module which convert between XImage and native CGImage or NSImage structures + * only support XImages with 32 bits per pixel. The ImageGetPixel and PutPixel + * implementations in this file allow 1, 4, 8, 16 or 32 bits per pixel, however. + * + * In tkImgPhInstance.c the layout used for pixels is determined by the values + * of the red_mask, blue_mask and green_mask fields in the XImage structure. + * The Aqua port always sets red_mask = 0xFF0000, green_mask = 0xFF00, and + * blue_mask = 0xFF. This means that a 32bpp ZPixmap XImage uses ARGB32 pixels, + * with small-endian byte order BGRA. The data array for such an XImage can be + * passed directly to construct a CGBitmapImageRep if one specifies the + * bitmapInfo as kCGBitmapByteOrder32Big | kCGImageAlphaLast. + * + * The structures below describe the bitfields in two common 32 bpp pixel + * layouts. Note that bit field layouts are compiler dependent. The layouts + * shown in the comments are those produced by clang and gcc. Also note + * that kCGBitmapByteOrder32Big is consistently set when creating CGImages or + * CGImageBitmapReps. + */ + +/* RGBA32 0xRRGGBBAA (Byte order is RGBA on big-endian systems.) + * This is used by NSBitmapImageRep when the bitmapFormat property is 0, + * the default value. + */ + +typedef struct RGBA32pixel_t { + unsigned red: 8; + unsigned green: 8; + unsigned blue: 8; + unsigned alpha: 8; +} RGBA32pixel; + +/* + * ARGB32 0xAARRGGBB (Byte order is ARGB on big-endian systems.) + * This is used by Aqua Tk for XImages and by NSBitmapImageReps whose + * bitmapFormat property is NSBitmapFormatAlphaFirst. + */ + +typedef struct ARGB32pixel_t { + unsigned blue: 8; + unsigned green: 8; + unsigned red: 8; + unsigned alpha: 8; +} ARGB32pixel; + +typedef union pixel32_t { + unsigned int uint; + RGBA32pixel rgba; + ARGB32pixel argb; +} pixel32; + #pragma mark XImage handling int @@ -112,9 +177,7 @@ TkMacOSXCreateCGImageWithXImage( } bitsPerComponent = 8; bitsPerPixel = 32; - bitmapInfo = (image->byte_order == MSBFirst ? - kCGBitmapByteOrder32Little : kCGBitmapByteOrder32Big); - bitmapInfo |= alphaInfo; + bitmapInfo = kCGBitmapByteOrder32Big | alphaInfo; data = (char *)memcpy(ckalloc(len), image->data + image->xoffset, len); if (data) { provider = CGDataProviderCreateWithData(data, data, len, @@ -204,14 +267,12 @@ ImageGetPixel( switch (image->bits_per_pixel) { case 32: /* 8 bits per channel */ - b = (*((unsigned int*) srcPtr) >> 16) & 0xff; - g = (*((unsigned int*) srcPtr) >> 8) & 0xff; - r = (*((unsigned int*) srcPtr) ) & 0xff; - /*if (image->byte_order == LSBFirst) { - r = srcPtr[2]; g = srcPtr[1]; b = srcPtr[0]; - } else { - r = srcPtr[1]; g = srcPtr[2]; b = srcPtr[3]; - }*/ + { + ARGB32pixel *pixel = (ARGB32pixel *)srcPtr; + r = pixel->red; + g = pixel->green; + b = pixel->blue; + } break; case 16: /* 5 bits per channel */ r = (*((unsigned short*) srcPtr) >> 7) & 0xf8; @@ -248,7 +309,10 @@ ImageGetPixel( * * ImagePutPixel -- * - * Set a single pixel in an image. + * Set a single pixel in an image. The pixel is provided as an unsigned + * 32-bit integer. The value of that integer is interpreted by assuming + * that its low-order N bits have the format specified by the XImage, + * where N is equal to the bits_per_pixel field of the XImage. * * Results: * None. @@ -274,27 +338,20 @@ ImagePutPixel( if (image->bits_per_pixel == 32) { *((unsigned int*) dstPtr) = pixel; } else { - unsigned char r = ((pixel & image->red_mask) >> 16) & 0xff; - unsigned char g = ((pixel & image->green_mask) >> 8) & 0xff; - unsigned char b = ((pixel & image->blue_mask) ) & 0xff; switch (image->bits_per_pixel) { case 16: - *((unsigned short*) dstPtr) = ((r & 0xf8) << 7) | - ((g & 0xf8) << 2) | ((b & 0xf8) >> 3); + *((unsigned short*) dstPtr) = pixel & 0xffff; break; case 8: - *dstPtr = ((r & 0xc0) >> 2) | ((g & 0xc0) >> 4) | - ((b & 0xc0) >> 6); + *dstPtr = pixel & 0xff; break; case 4: { - unsigned char c = ((r & 0x80) >> 5) | ((g & 0x80) >> 6) | - ((b & 0x80) >> 7); - *dstPtr = (x % 2) ? ((*dstPtr & 0xf0) | (c & 0x0f)) : - ((*dstPtr & 0x0f) | ((c << 4) & 0xf0)); + *dstPtr = (x % 2) ? ((*dstPtr & 0xf0) | (pixel & 0x0f)) : + ((*dstPtr & 0x0f) | ((pixel << 4) & 0xf0)); break; } case 1: - *dstPtr = ((r|g|b) & 0x80) ? (*dstPtr | (0x80 >> (x % 8))) : + *dstPtr = pixel ? (*dstPtr | (0x80 >> (x % 8))) : (*dstPtr & ~(0x80 >> (x % 8))); break; } @@ -417,14 +474,12 @@ XCreateImage( *---------------------------------------------------------------------- */ -#define PIXEL_RGBA kCGImageAlphaLast -#define PIXEL_ARGB kCGImageAlphaFirst -#define PIXEL_XRGB kCGImageAlphaNoneSkipFirst -#define PIXEL_RGBX kCGImageAlphaNoneSkipLast +#define USE_ALPHA kCGImageAlphaLast +#define IGNORE_ALPHA kCGImageAlphaNoneSkipLast static int TkMacOSXPutImage( - uint32_t pixelFormat, + uint32_t pixelFormat, Display* display, /* Display. */ Drawable drawable, /* Drawable to place image on. */ GC gc, /* GC to use. */ @@ -476,7 +531,7 @@ TkMacOSXPutImage( int XPutImage(Display* display, Drawable drawable, GC gc, XImage* image, int src_x, int src_y, int dest_x, int dest_y, unsigned int width, unsigned int height) { - return TkMacOSXPutImage(PIXEL_RGBX, display, drawable, gc, image, + return TkMacOSXPutImage(IGNORE_ALPHA, display, drawable, gc, image, src_x, src_y, dest_x, dest_y, width, height); } @@ -484,7 +539,7 @@ int TkPutImage(unsigned long *colors, int ncolors, Display* display, Drawable drawable, GC gc, XImage* image, int src_x, int src_y, int dest_x, int dest_y, unsigned int width, unsigned int height) { - return TkMacOSXPutImage(PIXEL_RGBX, display, drawable, gc, image, + return TkMacOSXPutImage(IGNORE_ALPHA, display, drawable, gc, image, src_x, src_y, dest_x, dest_y, width, height); } @@ -492,7 +547,7 @@ int TkpPutRGBAImage(unsigned long *colors, int ncolors, Display* display, Drawable drawable, GC gc, XImage* image, int src_x, int src_y, int dest_x, int dest_y, unsigned int width, unsigned int height) { - return TkMacOSXPutImage(PIXEL_RGBA, display, drawable, gc, image, + return TkMacOSXPutImage(USE_ALPHA, display, drawable, gc, image, src_x, src_y, dest_x, dest_y, width, height); } @@ -578,7 +633,8 @@ CreateCGImageFromDrawableRect( CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); cg_context = CGBitmapContextCreate(imageData, width, height, bitsPerComponent, bytesPerRow, colorSpace, - kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); + kCGImageAlphaPremultipliedLast | + kCGBitmapByteOrder32Big); CFRelease(colorSpace); [view.layer renderInContext:cg_context]; } @@ -645,9 +701,6 @@ CreateCGImageFromPixmap( * *---------------------------------------------------------------------- */ -struct pixel_fmt {int r; int g; int b; int a;}; -static struct pixel_fmt bgra = {2, 1, 0, 3}; -static struct pixel_fmt abgr = {3, 2, 1, 0}; XImage * XGetImage( @@ -687,12 +740,11 @@ XGetImage( size = [bitmapRep bytesPerPlane]; bytes_per_row = [bitmapRep bytesPerRow]; bitmap = (char *)ckalloc(size); - if (!bitmap - || (bitmap_fmt != 0 && bitmap_fmt != 1) - || [bitmapRep samplesPerPixel] != 4 - || [bitmapRep isPlanar] != 0 - || bytes_per_row < 4 * width - || size != bytes_per_row * height) { + if ((bitmap_fmt != 0 && bitmap_fmt != NSBitmapFormatAlphaFirst) + || [bitmapRep samplesPerPixel] != 4 + || [bitmapRep isPlanar] != 0 + || bytes_per_row < 4 * width + || size != bytes_per_row * height) { TkMacOSXDbgMsg("XGetImage: Unrecognized bitmap format"); [bitmapRep release]; return NULL; @@ -700,35 +752,37 @@ XGetImage( memcpy(bitmap, (char *)[bitmapRep bitmapData], size); [bitmapRep release]; - /* - * When Apple extracts a bitmap from an NSView, it may be in either - * BGRA or ABGR format. For an XImage we need RGBA. - */ - - struct pixel_fmt pixel = bitmap_fmt == 0 ? bgra : abgr; - for (row = 0, n = 0; row < height; row++, n += bytes_per_row) { for (m = n; m < n + 4*width; m += 4) { - R = *(bitmap + m + pixel.r); - G = *(bitmap + m + pixel.g); - B = *(bitmap + m + pixel.b); - A = *(bitmap + m + pixel.a); - - *(bitmap + m) = R; - *(bitmap + m + 1) = G; - *(bitmap + m + 2) = B; - *(bitmap + m + 3) = A; + pixel32 pixel = *((pixel32 *)(bitmap + m)); + if (bitmap_fmt == 0) { // default format + + /* + * This pixel is in ARGB32 format. We need RGBA32. + */ + + pixel32 flipped; + flipped.rgba.red = pixel.argb.red; + flipped.rgba.green = pixel.argb.green; + flipped.rgba.blue = pixel.argb.blue; + flipped.rgba.alpha = pixel.argb.alpha; + *((pixel32 *)(bitmap + m)) = flipped; + } else { // bitmap_fmt = NSBitmapFormatAlphaFirst + *((pixel32 *)(bitmap + m)) = pixel; + } } } imagePtr = XCreateImage(display, NULL, depth, format, offset, (char*) bitmap, width, height, bitmap_pad, bytes_per_row); } else { + /* * There are some calls to XGetImage in the generic Tk code which pass * an XYPixmap rather than a ZPixmap. XYPixmaps should be handled * here. */ + TkMacOSXDbgMsg("XGetImage does not handle XYPixmaps at the moment."); } return imagePtr; |