/*------------------------------------
* VisualPng.C -- Shows a PNG image
*------------------------------------
*
* 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
*/
/* switches */
/* defines */
#define PROGNAME "VisualPng"
#define LONGNAME "Win32 Viewer for PNG-files"
#define VERSION "1.0 of 2000 June 07"
/* constants */
#define MARGIN 8
/* standard includes */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#include <zlib.h>
/* application includes */
#include "png.h"
#include "pngfile.h"
#include "resource.h"
/* macros */
/* function prototypes */
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
BOOL CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
BOOL CenterAbout (HWND hwndChild, HWND hwndParent);
BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
int *pFileIndex);
BOOL SearchPngList (TCHAR *pFileList, int FileCount, int *pFileIndex,
PTSTR pstrPrevName, PTSTR pstrNextName);
BOOL LoadImageFile(HWND hwnd, PTSTR pstrPathName,
png_byte **ppbImage, int *pxImgSize, int *pyImgSize, int *piChannels,
png_color *pBkgColor);
BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
BYTE **ppDiData, int cxWinSize, int cyWinSize,
BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
BOOL bStretched);
BOOL InitBitmap (
BYTE *pDiData, int cxWinSize, int cyWinSize);
BOOL FillBitmap (
BYTE *pDiData, int cxWinSize, int cyWinSize,
BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
BOOL bStretched);
/* a few global variables */
static char *szProgName = PROGNAME;
static char *szAppName = LONGNAME;
static char *szIconName = PROGNAME;
static char szCmdFileName [MAX_PATH];
/* MAIN routine */
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
HACCEL hAccel;
HWND hwnd;
MSG msg;
WNDCLASS wndclass;
int ixBorders, iyBorders;
wndclass.style = CS_HREDRAW | CS_VREDRAW;
wndclass.lpfnWndProc = WndProc;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hInstance = hInstance;
wndclass.hIcon = LoadIcon (hInstance, szIconName) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW);
wndclass.hbrBackground = NULL; /* (HBRUSH) GetStockObject (GRAY_BRUSH); */
wndclass.lpszMenuName = szProgName;
wndclass.lpszClassName = szProgName;
if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("Error: this program requires Windows NT!"),
szProgName, MB_ICONERROR);
return 0;
}
/* if filename given on commandline, store it */
if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
if (szCmdLine[0] == '"')
strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
else
strcpy (szCmdFileName, szCmdLine);
else
strcpy (szCmdFileName, "");
/* calculate size of window-borders */
ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
GetSystemMetrics (SM_CXDLGFRAME));
iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
GetSystemMetrics (SM_CYDLGFRAME)) +
GetSystemMetrics (SM_CYCAPTION) +
GetSystemMetrics (SM_CYMENUSIZE) +
1; /* WvS: don't ask me why? */
hwnd = CreateWindow (szProgName, szAppName,
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
/* CW_USEDEFAULT, CW_USEDEFAULT, */
NULL, NULL, hInstance, NULL);
ShowWindow (hwnd, iCmdShow);
UpdateWindow (hwnd);
hAccel = LoadAccelerators (hInstance, szProgName);
while (GetMessage (&msg, NULL, 0, 0))
{
if (!TranslateAccelerator (hwnd, hAccel, &msg))
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}
return msg.wParam;
}
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
LPARAM lParam)
{
static HINSTANCE hInstance ;
static HDC hdc;
static PAINTSTRUCT ps;
static HMENU hMenu;
static BITMAPFILEHEADER *pbmfh;
static BITMAPINFOHEADER *pbmih;
static BYTE *pbImage;
static int cxWinSize, cyWinSize;
static int cxImgSize, cyImgSize;
static int cImgChannels;
static png_color bkgColor = {127, 127, 127};
static BOOL bStretched = TRUE;
static BYTE *pDib = NULL;
static BYTE *pDiData = NULL;
static TCHAR szImgPathName [MAX_PATH];
static TCHAR szTitleName [MAX_PATH];
static TCHAR *pPngFileList = NULL;
static int iPngFileCount;
static int iPngFileIndex;
BOOL bOk;
switch (message)
{
case WM_CREATE:
hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
PngFileInitialize (hwnd);
strcpy (szImgPathName, "");
/* in case we process file given on command-line */
if (szCmdFileName[0] != '\0')
{
strcpy (szImgPathName, szCmdFileName);
/* read the other png-files in the directory for later */
/* next/previous commands */
BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
&iPngFileIndex);
/* load the image from file */
if (!LoadImageFile (hwnd, szImgPathName,
&pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
return 0;
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
}
return 0;
case WM_SIZE:
cxWinSize = LOWORD (lParam);
cyWinSize = HIWORD (lParam);
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
return 0;
case WM_INITMENUPOPUP:
hMenu = GetMenu (hwnd);
if (pbImage)
EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_ENABLED);
else
EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_GRAYED);
return 0;
case WM_COMMAND:
hMenu = GetMenu (hwnd);
switch (LOWORD (wParam))
{
case IDM_FILE_OPEN:
/* show the File Open dialog box */
if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
return 0;
/* read the other png-files in the directory for later */
/* next/previous commands */
BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
&iPngFileIndex);
/* load the image from file */
if (!LoadImageFile (hwnd, szImgPathName,
&pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
return 0;
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
return 0;
case IDM_FILE_SAVE:
/* show the File Save dialog box */
if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
return 0;
/* save the PNG to a disk file */
SetCursor (LoadCursor (NULL, IDC_WAIT));
ShowCursor (TRUE);
bOk = PngSaveImage (szImgPathName, pDiData, cxWinSize, cyWinSize,
bkgColor);
ShowCursor (FALSE);
SetCursor (LoadCursor (NULL, IDC_ARROW));
if (!bOk)
MessageBox (hwnd, TEXT ("Error in saving the PNG image"),
szProgName, MB_ICONEXCLAMATION | MB_OK);
return 0;
case IDM_FILE_NEXT:
/* read next entry in the directory */
if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
NULL, szImgPathName))
{
if (strcmp (szImgPathName, "") == 0)
return 0;
/* load the image from file */
if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
&cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
return 0;
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
}
return 0;
case IDM_FILE_PREVIOUS:
/* read previous entry in the directory */
if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
szImgPathName, NULL))
{
if (strcmp (szImgPathName, "") == 0)
return 0;
/* load the image from file */
if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
&cyImgSize, &cImgChannels, &bkgColor))
return 0;
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
}
return 0;
case IDM_FILE_EXIT:
/* more cleanup needed... */
/* free image buffer */
if (pDib != NULL)
{
free (pDib);
pDib = NULL;
}
/* free file-list */
if (pPngFileList != NULL)
{
free (pPngFileList);
pPngFileList = NULL;
}
/* let's go ... */
exit (0);
return 0;
case IDM_OPTIONS_STRETCH:
bStretched = !bStretched;
if (bStretched)
CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_CHECKED);
else
CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
/* invalidate the client area for later update */
InvalidateRect (hwnd, NULL, TRUE);
/* display the PNG into the DIBitmap */
DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
return 0;
case IDM_HELP_ABOUT:
DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
return 0;
} /* end switch */
break;
case WM_PAINT:
hdc = BeginPaint (hwnd, &ps);
if (pDib)
SetDIBitsToDevice (hdc, 0, 0, cxWinSize, cyWinSize, 0, 0,
0, cyWinSize, pDiData, (BITMAPINFO *) pDib, DIB_RGB_COLORS);
EndPaint (hwnd, &ps);
return 0;
case WM_DESTROY:
if (pbmfh)
{
free (pbmfh);
pbmfh = NULL;
}
PostQuitMessage (0);
return 0;
}
return DefWindowProc (hwnd, message, wParam, lParam);
}
BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_INITDIALOG :
ShowWindow (hDlg, SW_HIDE);
CenterAbout (hDlg, GetWindow (hDlg, GW_OWNER));
ShowWindow (hDlg, SW_SHOW);
return TRUE ;
case WM_COMMAND :
switch (LOWORD (wParam))
{
case IDOK :
case IDCANCEL :
EndDialog (hDlg, 0) ;
return TRUE ;
}
break ;
}
return FALSE ;
}
/*---------------
* CenterAbout
*---------------
*/
BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
{
RECT rChild, rParent, rWorkArea;
int wChild, hChild, wParent, hParent;
int xNew, yNew;
BOOL bResult;
/* Get the Height and Width of the child window */
GetWindowRect (hwndChild, &rChild);
wChild = rChild.right - rChild.left;
hChild = rChild.bottom - rChild.top;
/* Get the Height and Width of the parent window */
GetWindowRect (hwndParent, &rParent);
wParent = rParent.right - rParent.left;
hParent = rParent.bottom - rParent.top;
/* Get the limits of the 'workarea' */
bResult = SystemParametersInfo(
SPI_GETWORKAREA, /* system parameter to query or set */
sizeof(RECT),
&rWorkArea,
0);
if (!bResult) {
rWorkArea.left = rWorkArea.top = 0;
rWorkArea.right = GetSystemMetrics(SM_CXSCREEN);
rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
}
/* Calculate new X position, then adjust for workarea */
xNew = rParent.left + ((wParent - wChild) /2);
if (xNew < rWorkArea.left) {
xNew = rWorkArea.left;
} else if ((xNew+wChild) > rWorkArea.right) {
xNew = rWorkArea.right - wChild;
}
/* Calculate new Y position, then adjust for workarea */
yNew = rParent.top + ((hParent - hChild) /2);
if (yNew < rWorkArea.top) {
yNew = rWorkArea.top;
} else if ((yNew+hChild) > rWorkArea.bottom) {
yNew = rWorkArea.bottom - hChild;
}
/* Set it, and return */
return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
SWP_NOZORDER);
}
/*----------------
* BuildPngList
*----------------
*/
BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
int *pFileIndex)
{
static TCHAR szImgPathName [MAX_PATH];
static TCHAR szImgFileName [MAX_PATH];
static TCHAR szImgFindName [MAX_PATH];
WIN32_FIND_DATA finddata;
HANDLE hFind;
static TCHAR szTmp [MAX_PATH];
BOOL bOk;
int i, ii;
int j, jj;
/* free previous file-list */
if (*ppFileList != NULL)
{
free (*ppFileList);
*ppFileList = NULL;
}
/* extract foldername, filename and search-name */
strcpy (szImgPathName, pstrPathName);
strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
strcpy (szImgFindName, szImgPathName);
*(strrchr (szImgFindName, '\\') + 1) = '\0';
strcat (szImgFindName, "*.png");
/* first cycle: count number of files in directory for memory allocation */
*pFileCount = 0;
hFind = FindFirstFile(szImgFindName, &finddata);
bOk = (hFind != (HANDLE) -1);
while (bOk)
{
*pFileCount += 1;
bOk = FindNextFile(hFind, &finddata);
}
FindClose(hFind);
/* allocation memory for file-list */
*ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
/* second cycle: read directory and store filenames in file-list */
hFind = FindFirstFile(szImgFindName, &finddata);
bOk = (hFind != (HANDLE) -1);
i = 0;
ii = 0;
while (bOk)
{
strcpy (*ppFileList + ii, szImgPathName);
strcpy (strrchr(*ppFileList + ii, '\\') + 1, finddata.cFileName);
if (strcmp(pstrPathName, *ppFileList + ii) == 0)
*pFileIndex = i;
ii += MAX_PATH;
i++;
bOk = FindNextFile(hFind, &finddata);
}
FindClose(hFind);
/* finally we must sort the file-list */
for (i = 0; i < *pFileCount - 1; i++)
{
ii = i * MAX_PATH;
for (j = i+1; j < *pFileCount; j++)
{
jj = j * MAX_PATH;
if (strcmp (*ppFileList + ii, *ppFileList + jj) > 0)
{
strcpy (szTmp, *ppFileList + jj);
strcpy (*ppFileList + jj, *ppFileList + ii);
strcpy (*ppFileList + ii, szTmp);
/* check if this was the current image that we moved */
if (*pFileIndex == i)
*pFileIndex = j;
else
if (*pFileIndex == j)
*pFileIndex = i;
}
}
}
return TRUE;
}
/*----------------
* SearchPngList
*----------------
*/
BOOL SearchPngList (
TCHAR *pFileList, int FileCount, int *pFileIndex,
PTSTR pstrPrevName, PTSTR pstrNextName)
{
if (FileCount > 0)
{
/* get previous entry */
if (pstrPrevName != NULL)
{
if (*pFileIndex > 0)
*pFileIndex -= 1;
else
*pFileIndex = FileCount - 1;
strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
}
/* get next entry */
if (pstrNextName != NULL)
{
if (*pFileIndex < FileCount - 1)
*pFileIndex += 1;
else
*pFileIndex = 0;
strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
}
return TRUE;
}
else
{
return FALSE;
}
}
/*-----------------
* LoadImageFile
*-----------------
*/
BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
int *piChannels, png_color *pBkgColor)
{
static TCHAR szTmp [MAX_PATH];
/* if there's an existing PNG, free the memory */
if (*ppbImage)
{
free (*ppbImage);
*ppbImage = NULL;
}
/* Load the entire PNG into memory */
SetCursor (LoadCursor (NULL, IDC_WAIT));
ShowCursor (TRUE);
PngLoadImage (pstrPathName, ppbImage, pxImgSize, pyImgSize, piChannels,
pBkgColor);
ShowCursor (FALSE);
SetCursor (LoadCursor (NULL, IDC_ARROW));
if (*ppbImage != NULL)
{
sprintf (szTmp, "VisualPng - %s", strrchr(pstrPathName, '\\') + 1);
SetWindowText (hwnd, szTmp);
}
else
{
MessageBox (hwnd, TEXT ("Error in loading the PNG image"),
szProgName, MB_ICONEXCLAMATION | MB_OK);
return FALSE;
}
return TRUE;
}
/*----------------
* DisplayImage
*----------------
*/
BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
BYTE **ppDiData, int cxWinSize, int cyWinSize,
BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
BOOL bStretched)
{
BYTE *pDib = *ppDib;
BYTE *pDiData = *ppDiData;
/* BITMAPFILEHEADER *pbmfh; */
BITMAPINFOHEADER *pbmih;
WORD wDIRowBytes;
png_color bkgBlack = {0, 0, 0};
png_color bkgGray = {127, 127, 127};
png_color bkgWhite = {255, 255, 255};
/* allocate memory for the Device Independant bitmap */
wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
if (pDib)
{
free (pDib);
pDib = NULL;
}
if (cyWinSize > ((size_t)(-1))/wDIRowBytes) {
{
MessageBox (hwnd, TEXT ("Visual PNG: image is too big");
}
if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
wDIRowBytes * cyWinSize)))
{
MessageBox (hwnd, TEXT ("Error in displaying the PNG image"),
szProgName, MB_ICONEXCLAMATION | MB_OK);
*ppDib = pDib = NULL;
return FALSE;
}
*ppDib = pDib;
memset (pDib, 0, sizeof(BITMAPINFOHEADER));
/* initialize the dib-structure */
pbmih = (BITMAPINFOHEADER *) pDib;
pbmih->biSize = sizeof(BITMAPINFOHEADER);
pbmih->biWidth = cxWinSize;
pbmih->biHeight = -((long) cyWinSize);
pbmih->biPlanes = 1;
pbmih->biBitCount = 24;
pbmih->biCompression = 0;
pDiData = pDib + sizeof(BITMAPINFOHEADER);
*ppDiData = pDiData;
/* first fill bitmap with gray and image border */
InitBitmap (pDiData, cxWinSize, cyWinSize);
/* then fill bitmap with image */
if (pbImage)
{
FillBitmap (
pDiData, cxWinSize, cyWinSize,
pbImage, cxImgSize, cyImgSize, cImgChannels,
bStretched);
}
return TRUE;
}
/*--------------
* InitBitmap
*--------------
*/
BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
{
BYTE *dst;
int x, y, col;
/* initialize the background with gray */
dst = pDiData;
for (y = 0; y < cyWinSize; y++)
{
col = 0;
for (x = 0; x < cxWinSize; x++)
{
/* fill with GRAY */
*dst++ = 127;
*dst++ = 127;
*dst++ = 127;
col += 3;
}
/* rows start on 4 byte boundaries */
while ((col % 4) != 0)
{
dst++;
col++;
}
}
return TRUE;
}
/*--------------
* FillBitmap
*--------------
*/
BOOL FillBitmap (
BYTE *pDiData, int cxWinSize, int cyWinSize,
BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
BOOL bStretched)
{
BYTE *pStretchedImage;
BYTE *pImg;
BYTE *src, *dst;
BYTE r, g, b, a;
const int cDIChannels = 3;
WORD wImgRowBytes;
WORD wDIRowBytes;
int cxNewSize, cyNewSize;
int cxImgPos, cyImgPos;
int xImg, yImg;
int xWin, yWin;
int xOld, yOld;
int xNew, yNew;
if (bStretched)
{
cxNewSize = cxWinSize - 2 * MARGIN;
cyNewSize = cyWinSize - 2 * MARGIN;
/* stretch the image to it's window determined size */
/* the following two are mathematically the same, but the first
* has side-effects because of rounding
*/
/* if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize)) */
if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
{
cyNewSize = cxNewSize * cyImgSize / cxImgSize;
cxImgPos = MARGIN;
cyImgPos = (cyWinSize - cyNewSize) / 2;
}
else
{
cxNewSize = cyNewSize * cxImgSize / cyImgSize;
cyImgPos = MARGIN;
cxImgPos = (cxWinSize - cxNewSize) / 2;
}
if (cyNewSize > ((size_t)(-1))/(cImgChannels * cxNewSize)) {
{
MessageBox (hwnd, TEXT ("Visual PNG: stretched image is too big");
}
pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
pImg = pStretchedImage;
for (yNew = 0; yNew < cyNewSize; yNew++)
{
yOld = yNew * cyImgSize / cyNewSize;
for (xNew = 0; xNew < cxNewSize; xNew++)
{
xOld = xNew * cxImgSize / cxNewSize;
r = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 0);
g = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 1);
b = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 2);
*pImg++ = r;
*pImg++ = g;
*pImg++ = b;
if (cImgChannels == 4)
{
a = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld)
+ 3);
*pImg++ = a;
}
}
}
/* calculate row-bytes */
wImgRowBytes = cImgChannels * cxNewSize;
wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
/* copy image to screen */
for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
{
if (yWin >= cyWinSize - cyImgPos)
break;
src = pStretchedImage + yImg * wImgRowBytes;
dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
for (xImg = 0, xWin = cxImgPos; xImg < cxNewSize; xImg++, xWin++)
{
if (xWin >= cxWinSize - cxImgPos)
break;
r = *src++;
g = *src++;
b = *src++;
*dst++ = b; /* note the reverse order */
*dst++ = g;
*dst++ = r;
if (cImgChannels == 4)
{
a = *src++;
}
}
}
/* free memory */
if (pStretchedImage != NULL)
{
free (pStretchedImage);
pStretchedImage = NULL;
}
}
/* process the image not-stretched */
else
{
/* calculate the central position */
cxImgPos = (cxWinSize - cxImgSize) / 2;
cyImgPos = (cyWinSize - cyImgSize) / 2;
/* check for image larger than window */
if (cxImgPos < MARGIN)
cxImgPos = MARGIN;
if (cyImgPos < MARGIN)
cyImgPos = MARGIN;
/* calculate both row-bytes */
wImgRowBytes = cImgChannels * cxImgSize;
wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
/* copy image to screen */
for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
{
if (yWin >= cyWinSize - MARGIN)
break;
src = pbImage + yImg * wImgRowBytes;
dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
for (xImg = 0, xWin = cxImgPos; xImg < cxImgSize; xImg++, xWin++)
{
if (xWin >= cxWinSize - MARGIN)
break;
r = *src++;
g = *src++;
b = *src++;
*dst++ = b; /* note the reverse order */
*dst++ = g;
*dst++ = r;
if (cImgChannels == 4)
{
a = *src++;
}
}
}
}
return TRUE;
}
/*-----------------
* end of source
*-----------------
*/