PngFile.c
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上传日期:2020-07-18
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文件大小:12k
- //-------------------------------------
- // PNGFILE.C -- Image File Functions
- //-------------------------------------
- // Copyright 2000, Willem van Schaik. For conditions of distribution and
- // use, see the copyright/license/disclaimer notice in png.h
- #include <windows.h>
- #include <commdlg.h>
- #include <stdio.h>
- #include <stdlib.h>
- #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)
- ;
- #ifndef PNG_NO_CONSOLE_IO
- fprintf(stderr, "libpng error: %sn", msg);
- #endif
- {
- Throw msg;
- }
- }
- // Windows open-file functions
- void PngFileInitialize (HWND hwnd)
- {
- static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG) *.png ")
- TEXT ("All Files (*.*) *.* ");
- 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_check_sig(pbSig, 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
-
- #if !defined(PNG_NO_STDIO)
- 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 images
- // let the library process things like alpha, transparency, background
-
- if (iBitDepth == 16)
- png_set_strip_16(png_ptr);
- 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 have been 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 ((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
-
- #if !defined(PNG_NO_STDIO)
- 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;
- }
- #ifdef PNG_NO_STDIO
- static void
- png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
- {
- png_size_t check;
- /* fread() returns 0 on error, so it is OK to store this in a png_size_t
- * instead of an int, which is what fread() actually returns.
- */
- check = (png_size_t)fread(data, (png_size_t)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, png_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
- //-----------------