--- projs/trunk/shared_source/c_tk_base_7_5_w_mods/tkimgppm.c 2016/10/14 02:09:58 44 +++ projs/trunk/shared_source/c_tk_base_7_5_w_mods/tkimgppm.c 2016/11/05 11:07:06 71 @@ -1,442 +1,433 @@ -/* $Header: /cvsroot/esrg/sfesrg/esrgpcpj/shared/tk_base/tkimgppm.c,v 1.1.1.1 2001/06/13 05:03:30 dtashley Exp $ */ - -/* - * tkImgPPM.c -- - * - * A photo image file handler for PPM (Portable PixMap) files. - * - * Copyright (c) 1994 The Australian National University. - * Copyright (c) 1994-1997 Sun Microsystems, Inc. - * - * See the file "license.terms" for information on usage and redistribution - * of this file, and for a DISCLAIMER OF ALL WARRANTIES. - * - * Author: Paul Mackerras (paulus@cs.anu.edu.au), - * Department of Computer Science, - * Australian National University. - * - * RCS: @(#) $Id: tkimgppm.c,v 1.1.1.1 2001/06/13 05:03:30 dtashley Exp $ - */ - -#define USE_OLD_IMAGE - -#include "tkInt.h" -#include "tkPort.h" - -/* - * The maximum amount of memory to allocate for data read from the - * file. If we need more than this, we do it in pieces. - */ - -#define MAX_MEMORY 10000 /* don't allocate > 10KB */ - -/* - * Define PGM and PPM, i.e. gray images and color images. - */ - -#define PGM 1 -#define PPM 2 - -/* - * The format record for the PPM file format: - */ - -static int FileMatchPPM _ANSI_ARGS_((Tcl_Channel chan, - char *fileName, char *formatString, - int *widthPtr, int *heightPtr)); -static int FileReadPPM _ANSI_ARGS_((Tcl_Interp *interp, - Tcl_Channel chan, char *fileName, - char *formatString, Tk_PhotoHandle imageHandle, - int destX, int destY, int width, int height, - int srcX, int srcY)); -static int FileWritePPM _ANSI_ARGS_((Tcl_Interp *interp, - char *fileName, char *formatString, - Tk_PhotoImageBlock *blockPtr)); - -Tk_PhotoImageFormat tkImgFmtPPM = { - "PPM", /* name */ - FileMatchPPM, /* fileMatchProc */ - NULL, /* stringMatchProc */ - FileReadPPM, /* fileReadProc */ - NULL, /* stringReadProc */ - FileWritePPM, /* fileWriteProc */ - NULL, /* stringWriteProc */ -}; - -/* - * Prototypes for local procedures defined in this file: - */ - -static int ReadPPMFileHeader _ANSI_ARGS_((Tcl_Channel chan, - int *widthPtr, int *heightPtr, - int *maxIntensityPtr)); - -/* - *---------------------------------------------------------------------- - * - * FileMatchPPM -- - * - * This procedure is invoked by the photo image type to see if - * a file contains image data in PPM format. - * - * Results: - * The return value is >0 if the first characters in file "f" look - * like PPM data, and 0 otherwise. - * - * Side effects: - * The access position in f may change. - * - *---------------------------------------------------------------------- - */ - -static int -FileMatchPPM(chan, fileName, formatString, widthPtr, heightPtr) - Tcl_Channel chan; /* The image file, open for reading. */ - char *fileName; /* The name of the image file. */ - char *formatString; /* User-specified format string, or NULL. */ - int *widthPtr, *heightPtr; /* The dimensions of the image are - * returned here if the file is a valid - * raw PPM file. */ -{ - int dummy; - - return ReadPPMFileHeader(chan, widthPtr, heightPtr, &dummy); -} - -/* - *---------------------------------------------------------------------- - * - * FileReadPPM -- - * - * This procedure is called by the photo image type to read - * PPM format data from a file and write it into a given - * photo image. - * - * Results: - * A standard TCL completion code. If TCL_ERROR is returned - * then an error message is left in the interp's result. - * - * Side effects: - * The access position in file f is changed, and new data is - * added to the image given by imageHandle. - * - *---------------------------------------------------------------------- - */ - -static int -FileReadPPM(interp, chan, fileName, formatString, imageHandle, destX, destY, - width, height, srcX, srcY) - Tcl_Interp *interp; /* Interpreter to use for reporting errors. */ - Tcl_Channel chan; /* The image file, open for reading. */ - char *fileName; /* The name of the image file. */ - char *formatString; /* User-specified format string, or NULL. */ - Tk_PhotoHandle imageHandle; /* The photo image to write into. */ - int destX, destY; /* Coordinates of top-left pixel in - * photo image to be written to. */ - int width, height; /* Dimensions of block of photo image to - * be written to. */ - int srcX, srcY; /* Coordinates of top-left pixel to be used - * in image being read. */ -{ - int fileWidth, fileHeight, maxIntensity; - int nLines, nBytes, h, type, count; - unsigned char *pixelPtr; - Tk_PhotoImageBlock block; - - type = ReadPPMFileHeader(chan, &fileWidth, &fileHeight, &maxIntensity); - if (type == 0) { - Tcl_AppendResult(interp, "couldn't read raw PPM header from file \"", - fileName, "\"", NULL); - return TCL_ERROR; - } - if ((fileWidth <= 0) || (fileHeight <= 0)) { - Tcl_AppendResult(interp, "PPM image file \"", fileName, - "\" has dimension(s) <= 0", (char *) NULL); - return TCL_ERROR; - } - if ((maxIntensity <= 0) || (maxIntensity >= 256)) { - char buffer[TCL_INTEGER_SPACE]; - - sprintf(buffer, "%d", maxIntensity); - Tcl_AppendResult(interp, "PPM image file \"", fileName, - "\" has bad maximum intensity value ", buffer, - (char *) NULL); - return TCL_ERROR; - } - - if ((srcX + width) > fileWidth) { - width = fileWidth - srcX; - } - if ((srcY + height) > fileHeight) { - height = fileHeight - srcY; - } - if ((width <= 0) || (height <= 0) - || (srcX >= fileWidth) || (srcY >= fileHeight)) { - return TCL_OK; - } - - if (type == PGM) { - block.pixelSize = 1; - block.offset[0] = 0; - block.offset[1] = 0; - block.offset[2] = 0; - } - else { - block.pixelSize = 3; - block.offset[0] = 0; - block.offset[1] = 1; - block.offset[2] = 2; - } - block.offset[3] = 0; - block.width = width; - block.pitch = block.pixelSize * fileWidth; - - Tk_PhotoExpand(imageHandle, destX + width, destY + height); - - if (srcY > 0) { - Tcl_Seek(chan, (srcY * block.pitch), SEEK_CUR); - } - - nLines = (MAX_MEMORY + block.pitch - 1) / block.pitch; - if (nLines > height) { - nLines = height; - } - if (nLines <= 0) { - nLines = 1; - } - nBytes = nLines * block.pitch; - pixelPtr = (unsigned char *) ckalloc((unsigned) nBytes); - block.pixelPtr = pixelPtr + srcX * block.pixelSize; - - for (h = height; h > 0; h -= nLines) { - if (nLines > h) { - nLines = h; - nBytes = nLines * block.pitch; - } - count = Tcl_Read(chan, (char *) pixelPtr, nBytes); - if (count != nBytes) { - Tcl_AppendResult(interp, "error reading PPM image file \"", - fileName, "\": ", - Tcl_Eof(chan) ? "not enough data" : Tcl_PosixError(interp), - (char *) NULL); - ckfree((char *) pixelPtr); - return TCL_ERROR; - } - if (maxIntensity != 255) { - unsigned char *p; - - for (p = pixelPtr; count > 0; count--, p++) { - *p = (((int) *p) * 255)/maxIntensity; - } - } - block.height = nLines; - Tk_PhotoPutBlock(imageHandle, &block, destX, destY, width, nLines); - destY += nLines; - } - - ckfree((char *) pixelPtr); - return TCL_OK; -} - -/* - *---------------------------------------------------------------------- - * - * FileWritePPM -- - * - * This procedure is invoked to write image data to a file in PPM - * format. - * - * Results: - * A standard TCL completion code. If TCL_ERROR is returned - * then an error message is left in the interp's result. - * - * Side effects: - * Data is written to the file given by "fileName". - * - *---------------------------------------------------------------------- - */ - -static int -FileWritePPM(interp, fileName, formatString, blockPtr) - Tcl_Interp *interp; - char *fileName; - char *formatString; - Tk_PhotoImageBlock *blockPtr; -{ - Tcl_Channel chan; - int w, h; - int greenOffset, blueOffset, nBytes; - unsigned char *pixelPtr, *pixLinePtr; - char header[16 + TCL_INTEGER_SPACE * 2]; - - chan = Tcl_OpenFileChannel(interp, fileName, "w", 0666); - if (chan == NULL) { - return TCL_ERROR; - } - - if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") - != TCL_OK) { - return TCL_ERROR; - } - if (Tcl_SetChannelOption(interp, chan, "-encoding", "binary") - != TCL_OK) { - return TCL_ERROR; - } - - sprintf(header, "P6\n%d %d\n255\n", blockPtr->width, blockPtr->height); - Tcl_Write(chan, header, -1); - - pixLinePtr = blockPtr->pixelPtr + blockPtr->offset[0]; - greenOffset = blockPtr->offset[1] - blockPtr->offset[0]; - blueOffset = blockPtr->offset[2] - blockPtr->offset[0]; - - if ((greenOffset == 1) && (blueOffset == 2) && (blockPtr->pixelSize == 3) - && (blockPtr->pitch == (blockPtr->width * 3))) { - nBytes = blockPtr->height * blockPtr->pitch; - if (Tcl_Write(chan, (char *) pixLinePtr, nBytes) != nBytes) { - goto writeerror; - } - } else { - for (h = blockPtr->height; h > 0; h--) { - pixelPtr = pixLinePtr; - for (w = blockPtr->width; w > 0; w--) { - if ((Tcl_Write(chan, (char *) &pixelPtr[0], 1) == -1) - || (Tcl_Write(chan, (char *) &pixelPtr[greenOffset], 1) == -1) - || (Tcl_Write(chan, (char *) &pixelPtr[blueOffset], 1) == -1)) { - goto writeerror; - } - pixelPtr += blockPtr->pixelSize; - } - pixLinePtr += blockPtr->pitch; - } - } - - if (Tcl_Close(NULL, chan) == 0) { - return TCL_OK; - } - chan = NULL; - - writeerror: - Tcl_AppendResult(interp, "error writing \"", fileName, "\": ", - Tcl_PosixError(interp), (char *) NULL); - if (chan != NULL) { - Tcl_Close(NULL, chan); - } - return TCL_ERROR; -} - -/* - *---------------------------------------------------------------------- - * - * ReadPPMFileHeader -- - * - * This procedure reads the PPM header from the beginning of a - * PPM file and returns information from the header. - * - * Results: - * The return value is PGM if file "f" appears to start with - * a valid PGM header, PPM if "f" appears to start with a valid - * PPM header, and 0 otherwise. If the header is valid, - * then *widthPtr and *heightPtr are modified to hold the - * dimensions of the image and *maxIntensityPtr is modified to - * hold the value of a "fully on" intensity value. - * - * Side effects: - * The access position in f advances. - * - *---------------------------------------------------------------------- - */ - -static int -ReadPPMFileHeader(chan, widthPtr, heightPtr, maxIntensityPtr) - Tcl_Channel chan; /* Image file to read the header from */ - int *widthPtr, *heightPtr; /* The dimensions of the image are - * returned here. */ - int *maxIntensityPtr; /* The maximum intensity value for - * the image is stored here. */ -{ -#define BUFFER_SIZE 1000 - char buffer[BUFFER_SIZE]; - int i, numFields; - int type = 0; - char c; - - /* - * Read 4 space-separated fields from the file, ignoring - * comments (any line that starts with "#"). - */ - - if (Tcl_Read(chan, &c, 1) != 1) { - return 0; - } - i = 0; - for (numFields = 0; numFields < 4; numFields++) { - /* - * Skip comments and white space. - */ - - while (1) { - while (isspace(UCHAR(c))) { - if (Tcl_Read(chan, &c, 1) != 1) { - return 0; - } - } - if (c != '#') { - break; - } - do { - if (Tcl_Read(chan, &c, 1) != 1) { - return 0; - } - } while (c != '\n'); - } - - /* - * Read a field (everything up to the next white space). - */ - - while (!isspace(UCHAR(c))) { - if (i < (BUFFER_SIZE-2)) { - buffer[i] = c; - i++; - } - if (Tcl_Read(chan, &c, 1) != 1) { - goto done; - } - } - if (i < (BUFFER_SIZE-1)) { - buffer[i] = ' '; - i++; - } - } - done: - buffer[i] = 0; - - /* - * Parse the fields, which are: id, width, height, maxIntensity. - */ - - if (strncmp(buffer, "P6 ", 3) == 0) { - type = PPM; - } else if (strncmp(buffer, "P5 ", 3) == 0) { - type = PGM; - } else { - return 0; - } - if (sscanf(buffer+3, "%d %d %d", widthPtr, heightPtr, maxIntensityPtr) - != 3) { - return 0; - } - return type; -} - - -/* $History: tkImgPPM.c $ - * - * ***************** Version 1 ***************** - * User: Dtashley Date: 1/02/01 Time: 2:53a - * Created in $/IjuScripter, IjuConsole/Source/Tk Base - * Initial check-in. - */ - -/* End of TKIMGPPM.C */ \ No newline at end of file +/* $Header$ */ + +/* + * tkImgPPM.c -- + * + * A photo image file handler for PPM (Portable PixMap) files. + * + * Copyright (c) 1994 The Australian National University. + * Copyright (c) 1994-1997 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * Author: Paul Mackerras (paulus@cs.anu.edu.au), + * Department of Computer Science, + * Australian National University. + * + * RCS: @(#) $Id: tkimgppm.c,v 1.1.1.1 2001/06/13 05:03:30 dtashley Exp $ + */ + +#define USE_OLD_IMAGE + +#include "tkInt.h" +#include "tkPort.h" + +/* + * The maximum amount of memory to allocate for data read from the + * file. If we need more than this, we do it in pieces. + */ + +#define MAX_MEMORY 10000 /* don't allocate > 10KB */ + +/* + * Define PGM and PPM, i.e. gray images and color images. + */ + +#define PGM 1 +#define PPM 2 + +/* + * The format record for the PPM file format: + */ + +static int FileMatchPPM _ANSI_ARGS_((Tcl_Channel chan, + char *fileName, char *formatString, + int *widthPtr, int *heightPtr)); +static int FileReadPPM _ANSI_ARGS_((Tcl_Interp *interp, + Tcl_Channel chan, char *fileName, + char *formatString, Tk_PhotoHandle imageHandle, + int destX, int destY, int width, int height, + int srcX, int srcY)); +static int FileWritePPM _ANSI_ARGS_((Tcl_Interp *interp, + char *fileName, char *formatString, + Tk_PhotoImageBlock *blockPtr)); + +Tk_PhotoImageFormat tkImgFmtPPM = { + "PPM", /* name */ + FileMatchPPM, /* fileMatchProc */ + NULL, /* stringMatchProc */ + FileReadPPM, /* fileReadProc */ + NULL, /* stringReadProc */ + FileWritePPM, /* fileWriteProc */ + NULL, /* stringWriteProc */ +}; + +/* + * Prototypes for local procedures defined in this file: + */ + +static int ReadPPMFileHeader _ANSI_ARGS_((Tcl_Channel chan, + int *widthPtr, int *heightPtr, + int *maxIntensityPtr)); + +/* + *---------------------------------------------------------------------- + * + * FileMatchPPM -- + * + * This procedure is invoked by the photo image type to see if + * a file contains image data in PPM format. + * + * Results: + * The return value is >0 if the first characters in file "f" look + * like PPM data, and 0 otherwise. + * + * Side effects: + * The access position in f may change. + * + *---------------------------------------------------------------------- + */ + +static int +FileMatchPPM(chan, fileName, formatString, widthPtr, heightPtr) + Tcl_Channel chan; /* The image file, open for reading. */ + char *fileName; /* The name of the image file. */ + char *formatString; /* User-specified format string, or NULL. */ + int *widthPtr, *heightPtr; /* The dimensions of the image are + * returned here if the file is a valid + * raw PPM file. */ +{ + int dummy; + + return ReadPPMFileHeader(chan, widthPtr, heightPtr, &dummy); +} + +/* + *---------------------------------------------------------------------- + * + * FileReadPPM -- + * + * This procedure is called by the photo image type to read + * PPM format data from a file and write it into a given + * photo image. + * + * Results: + * A standard TCL completion code. If TCL_ERROR is returned + * then an error message is left in the interp's result. + * + * Side effects: + * The access position in file f is changed, and new data is + * added to the image given by imageHandle. + * + *---------------------------------------------------------------------- + */ + +static int +FileReadPPM(interp, chan, fileName, formatString, imageHandle, destX, destY, + width, height, srcX, srcY) + Tcl_Interp *interp; /* Interpreter to use for reporting errors. */ + Tcl_Channel chan; /* The image file, open for reading. */ + char *fileName; /* The name of the image file. */ + char *formatString; /* User-specified format string, or NULL. */ + Tk_PhotoHandle imageHandle; /* The photo image to write into. */ + int destX, destY; /* Coordinates of top-left pixel in + * photo image to be written to. */ + int width, height; /* Dimensions of block of photo image to + * be written to. */ + int srcX, srcY; /* Coordinates of top-left pixel to be used + * in image being read. */ +{ + int fileWidth, fileHeight, maxIntensity; + int nLines, nBytes, h, type, count; + unsigned char *pixelPtr; + Tk_PhotoImageBlock block; + + type = ReadPPMFileHeader(chan, &fileWidth, &fileHeight, &maxIntensity); + if (type == 0) { + Tcl_AppendResult(interp, "couldn't read raw PPM header from file \"", + fileName, "\"", NULL); + return TCL_ERROR; + } + if ((fileWidth <= 0) || (fileHeight <= 0)) { + Tcl_AppendResult(interp, "PPM image file \"", fileName, + "\" has dimension(s) <= 0", (char *) NULL); + return TCL_ERROR; + } + if ((maxIntensity <= 0) || (maxIntensity >= 256)) { + char buffer[TCL_INTEGER_SPACE]; + + sprintf(buffer, "%d", maxIntensity); + Tcl_AppendResult(interp, "PPM image file \"", fileName, + "\" has bad maximum intensity value ", buffer, + (char *) NULL); + return TCL_ERROR; + } + + if ((srcX + width) > fileWidth) { + width = fileWidth - srcX; + } + if ((srcY + height) > fileHeight) { + height = fileHeight - srcY; + } + if ((width <= 0) || (height <= 0) + || (srcX >= fileWidth) || (srcY >= fileHeight)) { + return TCL_OK; + } + + if (type == PGM) { + block.pixelSize = 1; + block.offset[0] = 0; + block.offset[1] = 0; + block.offset[2] = 0; + } + else { + block.pixelSize = 3; + block.offset[0] = 0; + block.offset[1] = 1; + block.offset[2] = 2; + } + block.offset[3] = 0; + block.width = width; + block.pitch = block.pixelSize * fileWidth; + + Tk_PhotoExpand(imageHandle, destX + width, destY + height); + + if (srcY > 0) { + Tcl_Seek(chan, (srcY * block.pitch), SEEK_CUR); + } + + nLines = (MAX_MEMORY + block.pitch - 1) / block.pitch; + if (nLines > height) { + nLines = height; + } + if (nLines <= 0) { + nLines = 1; + } + nBytes = nLines * block.pitch; + pixelPtr = (unsigned char *) ckalloc((unsigned) nBytes); + block.pixelPtr = pixelPtr + srcX * block.pixelSize; + + for (h = height; h > 0; h -= nLines) { + if (nLines > h) { + nLines = h; + nBytes = nLines * block.pitch; + } + count = Tcl_Read(chan, (char *) pixelPtr, nBytes); + if (count != nBytes) { + Tcl_AppendResult(interp, "error reading PPM image file \"", + fileName, "\": ", + Tcl_Eof(chan) ? "not enough data" : Tcl_PosixError(interp), + (char *) NULL); + ckfree((char *) pixelPtr); + return TCL_ERROR; + } + if (maxIntensity != 255) { + unsigned char *p; + + for (p = pixelPtr; count > 0; count--, p++) { + *p = (((int) *p) * 255)/maxIntensity; + } + } + block.height = nLines; + Tk_PhotoPutBlock(imageHandle, &block, destX, destY, width, nLines); + destY += nLines; + } + + ckfree((char *) pixelPtr); + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * FileWritePPM -- + * + * This procedure is invoked to write image data to a file in PPM + * format. + * + * Results: + * A standard TCL completion code. If TCL_ERROR is returned + * then an error message is left in the interp's result. + * + * Side effects: + * Data is written to the file given by "fileName". + * + *---------------------------------------------------------------------- + */ + +static int +FileWritePPM(interp, fileName, formatString, blockPtr) + Tcl_Interp *interp; + char *fileName; + char *formatString; + Tk_PhotoImageBlock *blockPtr; +{ + Tcl_Channel chan; + int w, h; + int greenOffset, blueOffset, nBytes; + unsigned char *pixelPtr, *pixLinePtr; + char header[16 + TCL_INTEGER_SPACE * 2]; + + chan = Tcl_OpenFileChannel(interp, fileName, "w", 0666); + if (chan == NULL) { + return TCL_ERROR; + } + + if (Tcl_SetChannelOption(interp, chan, "-translation", "binary") + != TCL_OK) { + return TCL_ERROR; + } + if (Tcl_SetChannelOption(interp, chan, "-encoding", "binary") + != TCL_OK) { + return TCL_ERROR; + } + + sprintf(header, "P6\n%d %d\n255\n", blockPtr->width, blockPtr->height); + Tcl_Write(chan, header, -1); + + pixLinePtr = blockPtr->pixelPtr + blockPtr->offset[0]; + greenOffset = blockPtr->offset[1] - blockPtr->offset[0]; + blueOffset = blockPtr->offset[2] - blockPtr->offset[0]; + + if ((greenOffset == 1) && (blueOffset == 2) && (blockPtr->pixelSize == 3) + && (blockPtr->pitch == (blockPtr->width * 3))) { + nBytes = blockPtr->height * blockPtr->pitch; + if (Tcl_Write(chan, (char *) pixLinePtr, nBytes) != nBytes) { + goto writeerror; + } + } else { + for (h = blockPtr->height; h > 0; h--) { + pixelPtr = pixLinePtr; + for (w = blockPtr->width; w > 0; w--) { + if ((Tcl_Write(chan, (char *) &pixelPtr[0], 1) == -1) + || (Tcl_Write(chan, (char *) &pixelPtr[greenOffset], 1) == -1) + || (Tcl_Write(chan, (char *) &pixelPtr[blueOffset], 1) == -1)) { + goto writeerror; + } + pixelPtr += blockPtr->pixelSize; + } + pixLinePtr += blockPtr->pitch; + } + } + + if (Tcl_Close(NULL, chan) == 0) { + return TCL_OK; + } + chan = NULL; + + writeerror: + Tcl_AppendResult(interp, "error writing \"", fileName, "\": ", + Tcl_PosixError(interp), (char *) NULL); + if (chan != NULL) { + Tcl_Close(NULL, chan); + } + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * + * ReadPPMFileHeader -- + * + * This procedure reads the PPM header from the beginning of a + * PPM file and returns information from the header. + * + * Results: + * The return value is PGM if file "f" appears to start with + * a valid PGM header, PPM if "f" appears to start with a valid + * PPM header, and 0 otherwise. If the header is valid, + * then *widthPtr and *heightPtr are modified to hold the + * dimensions of the image and *maxIntensityPtr is modified to + * hold the value of a "fully on" intensity value. + * + * Side effects: + * The access position in f advances. + * + *---------------------------------------------------------------------- + */ + +static int +ReadPPMFileHeader(chan, widthPtr, heightPtr, maxIntensityPtr) + Tcl_Channel chan; /* Image file to read the header from */ + int *widthPtr, *heightPtr; /* The dimensions of the image are + * returned here. */ + int *maxIntensityPtr; /* The maximum intensity value for + * the image is stored here. */ +{ +#define BUFFER_SIZE 1000 + char buffer[BUFFER_SIZE]; + int i, numFields; + int type = 0; + char c; + + /* + * Read 4 space-separated fields from the file, ignoring + * comments (any line that starts with "#"). + */ + + if (Tcl_Read(chan, &c, 1) != 1) { + return 0; + } + i = 0; + for (numFields = 0; numFields < 4; numFields++) { + /* + * Skip comments and white space. + */ + + while (1) { + while (isspace(UCHAR(c))) { + if (Tcl_Read(chan, &c, 1) != 1) { + return 0; + } + } + if (c != '#') { + break; + } + do { + if (Tcl_Read(chan, &c, 1) != 1) { + return 0; + } + } while (c != '\n'); + } + + /* + * Read a field (everything up to the next white space). + */ + + while (!isspace(UCHAR(c))) { + if (i < (BUFFER_SIZE-2)) { + buffer[i] = c; + i++; + } + if (Tcl_Read(chan, &c, 1) != 1) { + goto done; + } + } + if (i < (BUFFER_SIZE-1)) { + buffer[i] = ' '; + i++; + } + } + done: + buffer[i] = 0; + + /* + * Parse the fields, which are: id, width, height, maxIntensity. + */ + + if (strncmp(buffer, "P6 ", 3) == 0) { + type = PPM; + } else if (strncmp(buffer, "P5 ", 3) == 0) { + type = PGM; + } else { + return 0; + } + if (sscanf(buffer+3, "%d %d %d", widthPtr, heightPtr, maxIntensityPtr) + != 3) { + return 0; + } + return type; +} + +/* End of tkimgppm.c */