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99e273a57d
git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@30448 72102866-910b-0410-8b05-ffd578937521
138 lines
3.8 KiB
Objective-C
138 lines
3.8 KiB
Objective-C
/* NSBitmapImageRep+PNM
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Methods for reading PNM images
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Copyright (C) 2003 Free Software Foundation, Inc.
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Written by: Adam Fedor <fedor@gnu.org>
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Date: Oct 2003
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This file is part of the GNUstep GUI Library.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; see the file COPYING.LIB.
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If not, see <http://www.gnu.org/licenses/> or write to the
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Free Software Foundation, 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA.
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*/
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#import <Foundation/NSData.h>
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#import <Foundation/NSString.h>
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#import "AppKit/NSGraphics.h"
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#import "NSBitmapImageRep+PNM.h"
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@implementation NSBitmapImageRep (PNM)
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/* Return YES if this is a pgm or ppm file (raw only for now) */
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+ (BOOL) _bitmapIsPNM: (NSData *)imageData
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{
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const char *bytes = [imageData bytes];
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/*
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3/4 bytes header line, 4/5 bytes size, 2/3 bytes depth. Thus, the image
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must have a least 9 bytes.
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*/
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if ([imageData length]<9)
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return NO;
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if (bytes[0] == 'P' && (bytes[2]=='\n' || bytes[2]=='\r'))
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{
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if (bytes[1] == '5' || bytes[1] == '6')
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return YES;
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}
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return NO;
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}
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#define GET_LINE() \
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do \
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{ \
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char *p = buffer; \
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while (*ptr != '\n' && *ptr != '\r' && (ptr-bytes) < length) \
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{ \
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*p++ = *ptr++; \
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if (p == &buffer[sizeof(buffer)]) \
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{ \
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ERRMSG(@"PNM header line too long"); \
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} \
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} \
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ptr++; \
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*p = '\0'; \
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} while (0)
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#define ERRMSG(msg) \
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do { NSLog(@"Error loading PNM: %@", msg); if (error) *error = msg; RELEASE(self); return nil; } while (0)
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/* Read the ppm image. Assume it is a ppm file and imageData is not nil */
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-(id) _initBitmapFromPNM: (NSData *)imageData errorMessage: (NSString **)error
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{
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int num, xsize, ysize, levels;
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char ptype;
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char buffer[256];
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unsigned char *pchar;
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unsigned length;
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id colorspace;
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const char *ptr;
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const char *bytes = [imageData bytes];
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/* magic number */
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ptr = bytes;
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length = [imageData length];
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GET_LINE();
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if (bytes[0] != 'P')
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ERRMSG(@"Invalid PNM header (magic number)");
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ptype = bytes[1];
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if (ptype != '5' && ptype != '6')
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ERRMSG(@"Unsupported PNM type");
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do
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{
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GET_LINE();
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} while (buffer[0] == '#');
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num = sscanf(buffer, "%d %d", &xsize, &ysize);
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if (num != 2 || xsize <= 0 || ysize <= 0)
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ERRMSG(@"Invalid PNM header (xsize/ysize)");
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if (xsize * ysize > (1 << 31))
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ERRMSG(@"Invalid PNM header (image size:xsize*ysize too large)");
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GET_LINE();
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num = sscanf(buffer, "%d", &levels);
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if (num != 1)
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ERRMSG(@"Invalid PNM header (levels)");
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colorspace = (ptype == '5') ? NSDeviceBlackColorSpace : NSDeviceRGBColorSpace;
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self = [self initWithBitmapDataPlanes: NULL
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pixelsWide: xsize
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pixelsHigh: ysize
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bitsPerSample: 8
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samplesPerPixel: (ptype == '5') ? 1 : 3
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hasAlpha: NO
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isPlanar: NO
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colorSpaceName: colorspace
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bytesPerRow: 0
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bitsPerPixel: 0];
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if ([self bytesPerRow] * ysize > (length - (ptr - bytes)))
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ERRMSG(@"Invalid PNM file (short data)");
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pchar = [self bitmapData];
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if (levels < 256)
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{
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memcpy(pchar, ptr, [self bytesPerRow] * ysize);
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}
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else
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{
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ERRMSG(@"Cannot handle > 256 level PNM files");
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}
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return self;
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}
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@end
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