TB9.2 Example Applications: examples/PIPS/antiword/src/png2eps.c Source File

00001 /*
-00002  * png2eps.c
-00003  * Copyright (C) 2000-2002 A.J. van Os; Released under GPL
-00004  *
-00005  * Description:
-00006  * Functions to translate png images into eps
-00007  *
-00008  */
-00009 
-00010 #include <stdio.h>
-00011 #include <ctype.h>
-00012 #include "antiword.h"
-00013 
-00014 #if defined(DEBUG)
-00015 static int      iPicCounter = 0;
-00016 #endif /* DEBUG */
-00017 
-00018 
-00019 /*
-00020  * tSkipToData - skip until a IDAT chunk is found
-00021  *
-00022  * returns the length of the pixeldata or -1 in case of error
-00023  */
-00024 static size_t
-00025 tSkipToData(FILE *pFile, size_t tMaxBytes, size_t *ptSkipped)
-00026 {
-00027         ULONG   ulName, ulTmp;
-00028         size_t  tDataLength, tToSkip;
-00029         int     iCounter;
-00030 
-00031         fail(pFile == NULL);
-00032         fail(ptSkipped == NULL);
-00033 
-00034         /* Examine chunks */
-00035         while (*ptSkipped + 8 < tMaxBytes) {
-00036                 tDataLength = (size_t)ulNextLongBE(pFile);
-00037                 DBG_DEC(tDataLength);
-00038                 *ptSkipped += 4;
-00039 
-00040                 ulName = 0x00;
-00041                 for (iCounter = 0; iCounter < 4; iCounter++) {
-00042                         ulTmp = (ULONG)iNextByte(pFile);
-00043                         if (!isalpha((int)ulTmp)) {
-00044                                 DBG_HEX(ulTmp);
-00045                                 return (size_t)-1;
-00046                         }
-00047                         ulName <<= 8;
-00048                         ulName |= ulTmp;
-00049                 }
-00050                 DBG_HEX(ulName);
-00051                 *ptSkipped += 4;
-00052 
-00053                 if (ulName == PNG_CN_IEND) {
-00054                         break;
-00055                 }
-00056                 if (ulName == PNG_CN_IDAT) {
-00057                         return tDataLength;
-00058                 }
-00059 
-00060                 tToSkip = tDataLength + 4;
-00061                 if (tToSkip >= tMaxBytes - *ptSkipped) {
-00062                         DBG_DEC(tToSkip);
-00063                         DBG_DEC(tMaxBytes - *ptSkipped);
-00064                         return (size_t)-1;
-00065                 }
-00066                 (void)tSkipBytes(pFile, tToSkip);
-00067                 *ptSkipped += tToSkip;
-00068         }
-00069 
-00070         return (size_t)-1;
-00071 } /* end of iSkipToData */
-00072 
-00073 /*
-00074  * iFindFirstPixelData - find the first pixeldata if a PNG image
-00075  *
-00076  * returns the length of the pixeldata or -1 in case of error
-00077  */
-00078 static size_t
-00079 tFindFirstPixelData(FILE *pFile, size_t tMaxBytes, size_t *ptSkipped)
-00080 {
-00081         fail(pFile == NULL);
-00082         fail(tMaxBytes == 0);
-00083         fail(ptSkipped == NULL);
-00084 
-00085         if (tMaxBytes < 8) {
-00086                 DBG_DEC(tMaxBytes);
-00087                 return (size_t)-1;
-00088         }
-00089 
-00090         /* Skip over the PNG signature */
-00091         (void)tSkipBytes(pFile, 8);
-00092         *ptSkipped = 8;
-00093 
-00094         return tSkipToData(pFile, tMaxBytes, ptSkipped);
-00095 } /* end of iFindFirstPixelData */
-00096 
-00097 /*
-00098  * tFindNextPixelData - find the next pixeldata if a PNG image
-00099  *
-00100  * returns the length of the pixeldata or -1 in case of error
-00101  */
-00102 static size_t
-00103 tFindNextPixelData(FILE *pFile, size_t tMaxBytes, size_t *ptSkipped)
-00104 {
-00105         fail(pFile == NULL);
-00106         fail(tMaxBytes == 0);
-00107         fail(ptSkipped == NULL);
-00108 
-00109         if (tMaxBytes < 4) {
-00110                 DBG_DEC(tMaxBytes);
-00111                 return (size_t)-1;
-00112         }
-00113 
-00114         /* Skip over the crc */
-00115         (void)tSkipBytes(pFile, 4);
-00116         *ptSkipped = 4;
-00117 
-00118         return tSkipToData(pFile, tMaxBytes, ptSkipped);
-00119 } /* end of tFindNextPixelData */
-00120 
-00121 #if defined(DEBUG)
-00122 /*
-00123  * vCopy2File
-00124  */
-00125 static void
-00126 vCopy2File(FILE *pFile, ULONG ulFileOffset, size_t tPictureLen)
-00127 {
-00128         FILE    *pOutFile;
-00129         size_t  tIndex;
-00130         int     iTmp;
-00131         char    szFilename[30];
-00132 
-00133         if (!bSetDataOffset(pFile, ulFileOffset)) {
-00134                 return;
-00135         }
-00136 
-00137         sprintf(szFilename, "/tmp/pic/pic%04d.png", ++iPicCounter);
-00138         pOutFile = fopen(szFilename, "wb");
-00139         if (pOutFile == NULL) {
-00140                 return;
-00141         }
-00142         for (tIndex = 0; tIndex < tPictureLen; tIndex++) {
-00143                 iTmp = iNextByte(pFile);
-00144                 if (putc(iTmp, pOutFile) == EOF) {
-00145                         break;
-00146                 }
-00147         }
-00148         (void)fclose(pOutFile);
-00149 } /* end of vCopy2File */
-00150 #endif /* DEBUG */
-00151 
-00152 /*
-00153  * bTranslatePNG - translate a PNG image
-00154  *
-00155  * This function translates an image from png to eps
-00156  *
-00157  * return TRUE when sucessful, otherwise FALSE
-00158  */
-00159 BOOL
-00160 bTranslatePNG(diagram_type *pDiag, FILE *pFile,
-00161         ULONG ulFileOffset, size_t tPictureLen, const imagedata_type *pImg)
-00162 {
-00163         size_t  tMaxBytes, tDataLength, tSkipped;
-00164 
-00165 #if defined(DEBUG)
-00166         vCopy2File(pFile, ulFileOffset, tPictureLen);
-00167 #endif /* DEBUG */
-00168 
-00169         /* Seek to start position of PNG data */
-00170         if (!bSetDataOffset(pFile, ulFileOffset)) {
-00171                 return FALSE;
-00172         }
-00173 
-00174         tMaxBytes = tPictureLen;
-00175         tDataLength = tFindFirstPixelData(pFile, tMaxBytes, &tSkipped);
-00176         if (tDataLength == (size_t)-1) {
-00177                 return FALSE;
-00178         }
-00179 
-00180         vImagePrologue(pDiag, pImg);
-00181         do {
-00182                 tMaxBytes -= tSkipped;
-00183                 vASCII85EncodeArray(pFile, pDiag->pOutFile, tDataLength);
-00184                 tMaxBytes -= tDataLength;
-00185                 tDataLength = tFindNextPixelData(pFile, tMaxBytes, &tSkipped);
-00186         } while (tDataLength != (size_t)-1);
-00187         vASCII85EncodeByte(pDiag->pOutFile, EOF);
-00188         vImageEpilogue(pDiag);
-00189 
-00190         return TRUE;
-00191 } /* end of bTranslatePNG */
-