/*------------------------------------- * PNGFILE.C -- Image File Functions *------------------------------------- * * Copyright 2000,2017 Willem van Schaik. * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h */ #include #include #include #include #include #include "png.h" #include "pngfile.h" #include "cexcept.h" define_exception_type(const char *); extern struct exception_context the_exception_context[1]; struct exception_context the_exception_context[1]; png_const_charp msg; static OPENFILENAME ofn; static png_structp png_ptr = NULL; static png_infop info_ptr = NULL; /* cexcept interface */ static void png_cexcept_error(png_structp png_ptr, png_const_charp msg) { if(png_ptr) ; #ifdef PNG_CONSOLE_IO_SUPPORTED fprintf(stderr, "libpng error: %s\n", msg); #endif { Throw msg; } } /* Windows open-file functions */ void PngFileInitialize (HWND hwnd) { static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0") TEXT ("All Files (*.*)\0*.*\0\0"); ofn.lStructSize = sizeof (OPENFILENAME); ofn.hwndOwner = hwnd; ofn.hInstance = NULL; ofn.lpstrFilter = szFilter; ofn.lpstrCustomFilter = NULL; ofn.nMaxCustFilter = 0; ofn.nFilterIndex = 0; ofn.lpstrFile = NULL; /* Set in Open and Close functions */ ofn.nMaxFile = MAX_PATH; ofn.lpstrFileTitle = NULL; /* Set in Open and Close functions */ ofn.nMaxFileTitle = MAX_PATH; ofn.lpstrInitialDir = NULL; ofn.lpstrTitle = NULL; ofn.Flags = 0; /* Set in Open and Close functions */ ofn.nFileOffset = 0; ofn.nFileExtension = 0; ofn.lpstrDefExt = TEXT ("png"); ofn.lCustData = 0; ofn.lpfnHook = NULL; ofn.lpTemplateName = NULL; } BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) { ofn.hwndOwner = hwnd; ofn.lpstrFile = pstrFileName; ofn.lpstrFileTitle = pstrTitleName; ofn.Flags = OFN_HIDEREADONLY; return GetOpenFileName (&ofn); } BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) { ofn.hwndOwner = hwnd; ofn.lpstrFile = pstrFileName; ofn.lpstrFileTitle = pstrTitleName; ofn.Flags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT; return GetSaveFileName (&ofn); } /* PNG image handler functions */ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor) { static FILE *pfFile; png_byte pbSig[8]; int iBitDepth; int iColorType; double dGamma; png_color_16 *pBackground; png_uint_32 ulChannels; png_uint_32 ulRowBytes; png_byte *pbImageData = *ppbImageData; static png_byte **ppbRowPointers = NULL; int i; /* open the PNG input file */ if (!pstrFileName) { *ppbImageData = pbImageData = NULL; return FALSE; } if (!(pfFile = fopen(pstrFileName, "rb"))) { *ppbImageData = pbImageData = NULL; return FALSE; } /* first check the eight byte PNG signature */ fread(pbSig, 1, 8, pfFile); if (png_sig_cmp(pbSig, 0, 8)) { *ppbImageData = pbImageData = NULL; return FALSE; } /* create the two png(-info) structures */ png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL); if (!png_ptr) { *ppbImageData = pbImageData = NULL; return FALSE; } info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_read_struct(&png_ptr, NULL, NULL); *ppbImageData = pbImageData = NULL; return FALSE; } Try { /* initialize the png structure */ #ifdef PNG_STDIO_SUPPORTED png_init_io(png_ptr, pfFile); #else png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data); #endif png_set_sig_bytes(png_ptr, 8); /* read all PNG info up to image data */ png_read_info(png_ptr, info_ptr); /* get width, height, bit-depth and color-type */ png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth, &iColorType, NULL, NULL, NULL); /* expand images of all color-type and bit-depth to 3x8-bit RGB */ /* let the library process alpha, transparency, background, etc. */ #ifdef PNG_READ_16_TO_8_SUPPORTED if (iBitDepth == 16) # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED png_set_scale_16(png_ptr); # else png_set_strip_16(png_ptr); # endif #endif if (iColorType == PNG_COLOR_TYPE_PALETTE) png_set_expand(png_ptr); if (iBitDepth < 8) png_set_expand(png_ptr); if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_expand(png_ptr); if (iColorType == PNG_COLOR_TYPE_GRAY || iColorType == PNG_COLOR_TYPE_GRAY_ALPHA) png_set_gray_to_rgb(png_ptr); /* set the background color to draw transparent and alpha images over */ if (png_get_bKGD(png_ptr, info_ptr, &pBackground)) { png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); pBkgColor->red = (byte) pBackground->red; pBkgColor->green = (byte) pBackground->green; pBkgColor->blue = (byte) pBackground->blue; } else { pBkgColor = NULL; } /* if required set gamma conversion */ if (png_get_gAMA(png_ptr, info_ptr, &dGamma)) png_set_gamma(png_ptr, (double) 2.2, dGamma); /* after the transformations are registered, update info_ptr data */ png_read_update_info(png_ptr, info_ptr); /* get again width, height and the new bit-depth and color-type */ png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth, &iColorType, NULL, NULL, NULL); /* row_bytes is the width x number of channels */ ulRowBytes = png_get_rowbytes(png_ptr, info_ptr); ulChannels = png_get_channels(png_ptr, info_ptr); *piChannels = ulChannels; /* now we can allocate memory to store the image */ if (pbImageData) { free (pbImageData); pbImageData = NULL; } if ((*piHeight) > ((size_t)(-1))/ulRowBytes) { { png_error(png_ptr, "Visual PNG: image is too big"); } if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight) * sizeof(png_byte))) == NULL) { png_error(png_ptr, "Visual PNG: out of memory"); } *ppbImageData = pbImageData; /* and allocate memory for an array of row-pointers */ if ((ppbRowPointers = (png_bytepp) malloc((*piHeight) * sizeof(png_bytep))) == NULL) { png_error(png_ptr, "Visual PNG: out of memory"); } /* set the individual row-pointers to point at the correct offsets */ for (i = 0; i < (*piHeight); i++) ppbRowPointers[i] = pbImageData + i * ulRowBytes; /* now we can go ahead and just read the whole image */ png_read_image(png_ptr, ppbRowPointers); /* read the additional chunks in the PNG file (not really needed) */ png_read_end(png_ptr, NULL); /* and we're done */ free (ppbRowPointers); ppbRowPointers = NULL; /* yepp, done */ } Catch (msg) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); *ppbImageData = pbImageData = NULL; if(ppbRowPointers) free (ppbRowPointers); fclose(pfFile); return FALSE; } fclose (pfFile); return TRUE; } BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData, int iWidth, int iHeight, png_color bkgColor) { const int ciBitDepth = 8; const int ciChannels = 3; static FILE *pfFile; png_uint_32 ulRowBytes; static png_byte **ppbRowPointers = NULL; int i; /* open the PNG output file */ if (!pstrFileName) return FALSE; if (!(pfFile = fopen(pstrFileName, "wb"))) return FALSE; /* prepare the standard PNG structures */ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL); if (!png_ptr) { fclose(pfFile); return FALSE; } info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { fclose(pfFile); png_destroy_write_struct(&png_ptr, (png_infopp) NULL); return FALSE; } Try { /* initialize the png structure */ #ifdef PNG_STDIO_SUPPORTED png_init_io(png_ptr, pfFile); #else png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush); #endif /* we're going to write a very simple 3x8-bit RGB image */ png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); /* write the file header information */ png_write_info(png_ptr, info_ptr); /* swap the BGR pixels in the DiData structure to RGB */ png_set_bgr(png_ptr); /* row_bytes is the width x number of channels */ ulRowBytes = iWidth * ciChannels; /* we can allocate memory for an array of row-pointers */ if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL) Throw "Visualpng: Out of memory"; /* set the individual row-pointers to point at the correct offsets */ for (i = 0; i < iHeight; i++) ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2); /* write out the entire image data in one call */ png_write_image (png_ptr, ppbRowPointers); /* write the additional chunks to the PNG file (not really needed) */ png_write_end(png_ptr, info_ptr); /* and we're done */ free (ppbRowPointers); ppbRowPointers = NULL; /* clean up after the write, and free any memory allocated */ png_destroy_write_struct(&png_ptr, (png_infopp) NULL); /* yepp, done */ } Catch (msg) { png_destroy_write_struct(&png_ptr, (png_infopp) NULL); if(ppbRowPointers) free (ppbRowPointers); fclose(pfFile); return FALSE; } fclose (pfFile); return TRUE; } #ifndef PNG_STDIO_SUPPORTED static void png_read_data(png_structp png_ptr, png_bytep data, size_t length) { size_t check; /* fread() returns 0 on error, so it is OK to store this in a size_t * instead of an int, which is what fread() actually returns. */ check = fread(data, 1, length, (FILE *)png_ptr->io_ptr); if (check != length) { png_error(png_ptr, "Read Error"); } } static void png_write_data(png_structp png_ptr, png_bytep data, size_t length) { png_uint_32 check; check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); if (check != length) { png_error(png_ptr, "Write Error"); } } static void png_flush(png_structp png_ptr) { FILE *io_ptr; io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); if (io_ptr != NULL) fflush(io_ptr); } #endif /*----------------- * end of source *----------------- */