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/* $Header$ */ |
| 2 |
|
| 3 |
/* |
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* tkImgPPM.c -- |
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* |
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* A photo image file handler for PPM (Portable PixMap) files. |
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* |
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* Copyright (c) 1994 The Australian National University. |
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* Copyright (c) 1994-1997 Sun Microsystems, Inc. |
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* |
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* See the file "license.terms" for information on usage and redistribution |
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* of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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* |
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* Author: Paul Mackerras (paulus@cs.anu.edu.au), |
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* Department of Computer Science, |
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* Australian National University. |
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* |
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* RCS: @(#) $Id: tkimgppm.c,v 1.1.1.1 2001/06/13 05:03:30 dtashley Exp $ |
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*/ |
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|
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#define USE_OLD_IMAGE |
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|
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#include "tkInt.h" |
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#include "tkPort.h" |
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|
| 26 |
/* |
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* The maximum amount of memory to allocate for data read from the |
| 28 |
* file. If we need more than this, we do it in pieces. |
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*/ |
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|
| 31 |
#define MAX_MEMORY 10000 /* don't allocate > 10KB */ |
| 32 |
|
| 33 |
/* |
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* Define PGM and PPM, i.e. gray images and color images. |
| 35 |
*/ |
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|
| 37 |
#define PGM 1 |
| 38 |
#define PPM 2 |
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|
| 40 |
/* |
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* The format record for the PPM file format: |
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*/ |
| 43 |
|
| 44 |
static int FileMatchPPM _ANSI_ARGS_((Tcl_Channel chan, |
| 45 |
char *fileName, char *formatString, |
| 46 |
int *widthPtr, int *heightPtr)); |
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static int FileReadPPM _ANSI_ARGS_((Tcl_Interp *interp, |
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Tcl_Channel chan, char *fileName, |
| 49 |
char *formatString, Tk_PhotoHandle imageHandle, |
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int destX, int destY, int width, int height, |
| 51 |
int srcX, int srcY)); |
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static int FileWritePPM _ANSI_ARGS_((Tcl_Interp *interp, |
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char *fileName, char *formatString, |
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Tk_PhotoImageBlock *blockPtr)); |
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|
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Tk_PhotoImageFormat tkImgFmtPPM = { |
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"PPM", /* name */ |
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FileMatchPPM, /* fileMatchProc */ |
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NULL, /* stringMatchProc */ |
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FileReadPPM, /* fileReadProc */ |
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NULL, /* stringReadProc */ |
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FileWritePPM, /* fileWriteProc */ |
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NULL, /* stringWriteProc */ |
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}; |
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|
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/* |
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* Prototypes for local procedures defined in this file: |
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*/ |
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|
| 70 |
static int ReadPPMFileHeader _ANSI_ARGS_((Tcl_Channel chan, |
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int *widthPtr, int *heightPtr, |
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int *maxIntensityPtr)); |
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|
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/* |
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*---------------------------------------------------------------------- |
| 76 |
* |
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* FileMatchPPM -- |
| 78 |
* |
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* This procedure is invoked by the photo image type to see if |
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* a file contains image data in PPM format. |
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* |
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* Results: |
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* The return value is >0 if the first characters in file "f" look |
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* like PPM data, and 0 otherwise. |
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* |
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* Side effects: |
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* The access position in f may change. |
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* |
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*---------------------------------------------------------------------- |
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*/ |
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|
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static int |
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FileMatchPPM(chan, fileName, formatString, widthPtr, heightPtr) |
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Tcl_Channel chan; /* The image file, open for reading. */ |
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char *fileName; /* The name of the image file. */ |
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char *formatString; /* User-specified format string, or NULL. */ |
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int *widthPtr, *heightPtr; /* The dimensions of the image are |
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* returned here if the file is a valid |
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* raw PPM file. */ |
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{ |
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int dummy; |
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|
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return ReadPPMFileHeader(chan, widthPtr, heightPtr, &dummy); |
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} |
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|
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/* |
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*---------------------------------------------------------------------- |
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* |
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* FileReadPPM -- |
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* |
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* This procedure is called by the photo image type to read |
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* PPM format data from a file and write it into a given |
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* photo image. |
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* |
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* Results: |
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* A standard TCL completion code. If TCL_ERROR is returned |
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* then an error message is left in the interp's result. |
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* |
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* Side effects: |
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* The access position in file f is changed, and new data is |
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* added to the image given by imageHandle. |
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* |
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*---------------------------------------------------------------------- |
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*/ |
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|
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static int |
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FileReadPPM(interp, chan, fileName, formatString, imageHandle, destX, destY, |
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width, height, srcX, srcY) |
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Tcl_Interp *interp; /* Interpreter to use for reporting errors. */ |
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Tcl_Channel chan; /* The image file, open for reading. */ |
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char *fileName; /* The name of the image file. */ |
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char *formatString; /* User-specified format string, or NULL. */ |
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Tk_PhotoHandle imageHandle; /* The photo image to write into. */ |
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int destX, destY; /* Coordinates of top-left pixel in |
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* photo image to be written to. */ |
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int width, height; /* Dimensions of block of photo image to |
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* be written to. */ |
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int srcX, srcY; /* Coordinates of top-left pixel to be used |
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* in image being read. */ |
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{ |
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int fileWidth, fileHeight, maxIntensity; |
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int nLines, nBytes, h, type, count; |
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unsigned char *pixelPtr; |
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Tk_PhotoImageBlock block; |
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|
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type = ReadPPMFileHeader(chan, &fileWidth, &fileHeight, &maxIntensity); |
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if (type == 0) { |
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Tcl_AppendResult(interp, "couldn't read raw PPM header from file \"", |
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fileName, "\"", NULL); |
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return TCL_ERROR; |
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} |
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if ((fileWidth <= 0) || (fileHeight <= 0)) { |
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Tcl_AppendResult(interp, "PPM image file \"", fileName, |
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"\" has dimension(s) <= 0", (char *) NULL); |
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return TCL_ERROR; |
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} |
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if ((maxIntensity <= 0) || (maxIntensity >= 256)) { |
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char buffer[TCL_INTEGER_SPACE]; |
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|
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sprintf(buffer, "%d", maxIntensity); |
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Tcl_AppendResult(interp, "PPM image file \"", fileName, |
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"\" has bad maximum intensity value ", buffer, |
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(char *) NULL); |
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return TCL_ERROR; |
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} |
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|
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if ((srcX + width) > fileWidth) { |
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width = fileWidth - srcX; |
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} |
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if ((srcY + height) > fileHeight) { |
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height = fileHeight - srcY; |
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} |
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if ((width <= 0) || (height <= 0) |
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|| (srcX >= fileWidth) || (srcY >= fileHeight)) { |
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return TCL_OK; |
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} |
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|
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if (type == PGM) { |
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block.pixelSize = 1; |
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block.offset[0] = 0; |
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block.offset[1] = 0; |
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block.offset[2] = 0; |
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} |
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else { |
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block.pixelSize = 3; |
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block.offset[0] = 0; |
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block.offset[1] = 1; |
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block.offset[2] = 2; |
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} |
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block.offset[3] = 0; |
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block.width = width; |
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block.pitch = block.pixelSize * fileWidth; |
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|
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Tk_PhotoExpand(imageHandle, destX + width, destY + height); |
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|
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if (srcY > 0) { |
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Tcl_Seek(chan, (srcY * block.pitch), SEEK_CUR); |
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} |
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|
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nLines = (MAX_MEMORY + block.pitch - 1) / block.pitch; |
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if (nLines > height) { |
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nLines = height; |
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} |
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if (nLines <= 0) { |
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nLines = 1; |
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} |
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nBytes = nLines * block.pitch; |
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pixelPtr = (unsigned char *) ckalloc((unsigned) nBytes); |
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block.pixelPtr = pixelPtr + srcX * block.pixelSize; |
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|
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for (h = height; h > 0; h -= nLines) { |
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if (nLines > h) { |
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nLines = h; |
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nBytes = nLines * block.pitch; |
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} |
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count = Tcl_Read(chan, (char *) pixelPtr, nBytes); |
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if (count != nBytes) { |
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Tcl_AppendResult(interp, "error reading PPM image file \"", |
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fileName, "\": ", |
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Tcl_Eof(chan) ? "not enough data" : Tcl_PosixError(interp), |
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(char *) NULL); |
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ckfree((char *) pixelPtr); |
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return TCL_ERROR; |
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} |
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if (maxIntensity != 255) { |
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unsigned char *p; |
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|
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for (p = pixelPtr; count > 0; count--, p++) { |
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*p = (((int) *p) * 255)/maxIntensity; |
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} |
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} |
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block.height = nLines; |
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Tk_PhotoPutBlock(imageHandle, &block, destX, destY, width, nLines); |
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destY += nLines; |
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} |
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|
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ckfree((char *) pixelPtr); |
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return TCL_OK; |
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} |
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|
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/* |
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*---------------------------------------------------------------------- |
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* |
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* FileWritePPM -- |
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* |
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* This procedure is invoked to write image data to a file in PPM |
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* format. |
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* |
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* Results: |
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* A standard TCL completion code. If TCL_ERROR is returned |
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* then an error message is left in the interp's result. |
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* |
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* Side effects: |
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* Data is written to the file given by "fileName". |
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* |
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*---------------------------------------------------------------------- |
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*/ |
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|
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static int |
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FileWritePPM(interp, fileName, formatString, blockPtr) |
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Tcl_Interp *interp; |
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char *fileName; |
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char *formatString; |
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Tk_PhotoImageBlock *blockPtr; |
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{ |
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Tcl_Channel chan; |
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int w, h; |
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int greenOffset, blueOffset, nBytes; |
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unsigned char *pixelPtr, *pixLinePtr; |
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char header[16 + TCL_INTEGER_SPACE * 2]; |
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|
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chan = Tcl_OpenFileChannel(interp, fileName, "w", 0666); |
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if (chan == NULL) { |
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return TCL_ERROR; |
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} |
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|
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if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") |
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!= TCL_OK) { |
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return TCL_ERROR; |
| 280 |
} |
| 281 |
if (Tcl_SetChannelOption(interp, chan, "-encoding", "binary") |
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!= TCL_OK) { |
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return TCL_ERROR; |
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} |
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|
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sprintf(header, "P6\n%d %d\n255\n", blockPtr->width, blockPtr->height); |
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Tcl_Write(chan, header, -1); |
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|
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pixLinePtr = blockPtr->pixelPtr + blockPtr->offset[0]; |
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greenOffset = blockPtr->offset[1] - blockPtr->offset[0]; |
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blueOffset = blockPtr->offset[2] - blockPtr->offset[0]; |
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|
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if ((greenOffset == 1) && (blueOffset == 2) && (blockPtr->pixelSize == 3) |
| 294 |
&& (blockPtr->pitch == (blockPtr->width * 3))) { |
| 295 |
nBytes = blockPtr->height * blockPtr->pitch; |
| 296 |
if (Tcl_Write(chan, (char *) pixLinePtr, nBytes) != nBytes) { |
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goto writeerror; |
| 298 |
} |
| 299 |
} else { |
| 300 |
for (h = blockPtr->height; h > 0; h--) { |
| 301 |
pixelPtr = pixLinePtr; |
| 302 |
for (w = blockPtr->width; w > 0; w--) { |
| 303 |
if ((Tcl_Write(chan, (char *) &pixelPtr[0], 1) == -1) |
| 304 |
|| (Tcl_Write(chan, (char *) &pixelPtr[greenOffset], 1) == -1) |
| 305 |
|| (Tcl_Write(chan, (char *) &pixelPtr[blueOffset], 1) == -1)) { |
| 306 |
goto writeerror; |
| 307 |
} |
| 308 |
pixelPtr += blockPtr->pixelSize; |
| 309 |
} |
| 310 |
pixLinePtr += blockPtr->pitch; |
| 311 |
} |
| 312 |
} |
| 313 |
|
| 314 |
if (Tcl_Close(NULL, chan) == 0) { |
| 315 |
return TCL_OK; |
| 316 |
} |
| 317 |
chan = NULL; |
| 318 |
|
| 319 |
writeerror: |
| 320 |
Tcl_AppendResult(interp, "error writing \"", fileName, "\": ", |
| 321 |
Tcl_PosixError(interp), (char *) NULL); |
| 322 |
if (chan != NULL) { |
| 323 |
Tcl_Close(NULL, chan); |
| 324 |
} |
| 325 |
return TCL_ERROR; |
| 326 |
} |
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|
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/* |
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*---------------------------------------------------------------------- |
| 330 |
* |
| 331 |
* ReadPPMFileHeader -- |
| 332 |
* |
| 333 |
* This procedure reads the PPM header from the beginning of a |
| 334 |
* PPM file and returns information from the header. |
| 335 |
* |
| 336 |
* Results: |
| 337 |
* The return value is PGM if file "f" appears to start with |
| 338 |
* a valid PGM header, PPM if "f" appears to start with a valid |
| 339 |
* PPM header, and 0 otherwise. If the header is valid, |
| 340 |
* then *widthPtr and *heightPtr are modified to hold the |
| 341 |
* dimensions of the image and *maxIntensityPtr is modified to |
| 342 |
* hold the value of a "fully on" intensity value. |
| 343 |
* |
| 344 |
* Side effects: |
| 345 |
* The access position in f advances. |
| 346 |
* |
| 347 |
*---------------------------------------------------------------------- |
| 348 |
*/ |
| 349 |
|
| 350 |
static int |
| 351 |
ReadPPMFileHeader(chan, widthPtr, heightPtr, maxIntensityPtr) |
| 352 |
Tcl_Channel chan; /* Image file to read the header from */ |
| 353 |
int *widthPtr, *heightPtr; /* The dimensions of the image are |
| 354 |
* returned here. */ |
| 355 |
int *maxIntensityPtr; /* The maximum intensity value for |
| 356 |
* the image is stored here. */ |
| 357 |
{ |
| 358 |
#define BUFFER_SIZE 1000 |
| 359 |
char buffer[BUFFER_SIZE]; |
| 360 |
int i, numFields; |
| 361 |
int type = 0; |
| 362 |
char c; |
| 363 |
|
| 364 |
/* |
| 365 |
* Read 4 space-separated fields from the file, ignoring |
| 366 |
* comments (any line that starts with "#"). |
| 367 |
*/ |
| 368 |
|
| 369 |
if (Tcl_Read(chan, &c, 1) != 1) { |
| 370 |
return 0; |
| 371 |
} |
| 372 |
i = 0; |
| 373 |
for (numFields = 0; numFields < 4; numFields++) { |
| 374 |
/* |
| 375 |
* Skip comments and white space. |
| 376 |
*/ |
| 377 |
|
| 378 |
while (1) { |
| 379 |
while (isspace(UCHAR(c))) { |
| 380 |
if (Tcl_Read(chan, &c, 1) != 1) { |
| 381 |
return 0; |
| 382 |
} |
| 383 |
} |
| 384 |
if (c != '#') { |
| 385 |
break; |
| 386 |
} |
| 387 |
do { |
| 388 |
if (Tcl_Read(chan, &c, 1) != 1) { |
| 389 |
return 0; |
| 390 |
} |
| 391 |
} while (c != '\n'); |
| 392 |
} |
| 393 |
|
| 394 |
/* |
| 395 |
* Read a field (everything up to the next white space). |
| 396 |
*/ |
| 397 |
|
| 398 |
while (!isspace(UCHAR(c))) { |
| 399 |
if (i < (BUFFER_SIZE-2)) { |
| 400 |
buffer[i] = c; |
| 401 |
i++; |
| 402 |
} |
| 403 |
if (Tcl_Read(chan, &c, 1) != 1) { |
| 404 |
goto done; |
| 405 |
} |
| 406 |
} |
| 407 |
if (i < (BUFFER_SIZE-1)) { |
| 408 |
buffer[i] = ' '; |
| 409 |
i++; |
| 410 |
} |
| 411 |
} |
| 412 |
done: |
| 413 |
buffer[i] = 0; |
| 414 |
|
| 415 |
/* |
| 416 |
* Parse the fields, which are: id, width, height, maxIntensity. |
| 417 |
*/ |
| 418 |
|
| 419 |
if (strncmp(buffer, "P6 ", 3) == 0) { |
| 420 |
type = PPM; |
| 421 |
} else if (strncmp(buffer, "P5 ", 3) == 0) { |
| 422 |
type = PGM; |
| 423 |
} else { |
| 424 |
return 0; |
| 425 |
} |
| 426 |
if (sscanf(buffer+3, "%d %d %d", widthPtr, heightPtr, maxIntensityPtr) |
| 427 |
!= 3) { |
| 428 |
return 0; |
| 429 |
} |
| 430 |
return type; |
| 431 |
} |
| 432 |
|
| 433 |
/* End of tkimgppm.c */ |
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