// Loads a PNG image from the specified stream (using Windows Imaging Component).
IWICBitmapSource * LoadBitmapFromStream(IStream * ipImageStream)
{
// initialize return value
IWICBitmapSource * ipBitmap = NULL;
// load WIC's PNG decoder
IWICBitmapDecoder * ipDecoder = NULL;
IID i = IID_IWICBitmapDecoder;
if (FAILED(CoCreateInstance(CLSID_WICPngDecoder, NULL, CLSCTX_INPROC_SERVER,
i,//__uuidof(ipDecoder)
(void **)&ipDecoder)))
goto Return;
// load the PNG
if (FAILED(ipDecoder->Initialize(ipImageStream, WICDecodeMetadataCacheOnLoad)))
goto ReleaseDecoder;
// check for the presence of the first frame in the bitmap
UINT nFrameCount = 0;
if (FAILED(ipDecoder->GetFrameCount(&nFrameCount)) || nFrameCount != 1)
goto ReleaseDecoder;
// load the first frame (i.e., the image)
IWICBitmapFrameDecode * ipFrame = NULL;
if (FAILED(ipDecoder->GetFrame(0, &ipFrame)))
goto ReleaseDecoder;
// convert the image to 32bpp BGRA format with pre-multiplied alpha
// (it may not be stored in that format natively in the PNG resource,
// but we need this format to create the DIB to use on-screen)
WICConvertBitmapSource(GUID_WICPixelFormat32bppPBGRA, ipFrame, &ipBitmap);
ipFrame->Release();
ReleaseDecoder:
ipDecoder->Release();
Return:
return ipBitmap;
}
HBITMAP ImageUtil::LoadImage(string path) {
size_t pathFileExtDot = path.find_last_of('.');
if (pathFileExtDot == string::npos || pathFileExtDot + 1 >=
path.length())
throw INETRException("[imgLoadFailed]");
string ext = path.substr(pathFileExtDot + 1);
const GUID *decoderCLSID = nullptr;
if (ext == "png")
decoderCLSID = &CLSID_WICPngDecoder;
else if (ext == "bmp")
decoderCLSID = &CLSID_WICBmpDecoder;
else if (ext == "gif")
decoderCLSID = &CLSID_WICGifDecoder;
else if (ext == "jpg" || ext == "jpeg")
decoderCLSID = &CLSID_WICJpegDecoder;
if (decoderCLSID == nullptr)
throw INETRException("[unsupportedImg]: " + ext);
IStream *pngFileStream;
if (FAILED(SHCreateStreamOnFile(path.c_str(), STGM_READ,
&pngFileStream)))
throw INETRException("[imgLoadFailed]:\n" + path);
IWICBitmapDecoder *bmpDecoder = nullptr;
if (FAILED(CoCreateInstance(*decoderCLSID, nullptr,
CLSCTX_INPROC_SERVER, __uuidof(bmpDecoder),
reinterpret_cast<void**>(&bmpDecoder))))
throw INETRException("[imgDecFailed]");
if (FAILED(bmpDecoder->Initialize(pngFileStream,
WICDecodeMetadataCacheOnLoad))) {
bmpDecoder->Release();
throw INETRException("[imgDecFailed]");
}
UINT bmpFrameCount = 0;
if (FAILED(bmpDecoder->GetFrameCount(&bmpFrameCount)) && bmpFrameCount
!= 1) {
bmpDecoder->Release();
throw INETRException("[imgDecFailed]");
}
IWICBitmapFrameDecode *bmpFrame = nullptr;
if (FAILED(bmpDecoder->GetFrame(0, &bmpFrame))) {
bmpDecoder->Release();
throw INETRException("[imgDecFailed]");
}
IWICBitmapSource *bmpSource = nullptr;
WICConvertBitmapSource(GUID_WICPixelFormat32bppPBGRA, bmpFrame,
&bmpSource);
bmpFrame->Release();
bmpDecoder->Release();
UINT width = 0, height = 0;
if (FAILED(bmpSource->GetSize(&width, &height)) || width == 0 || height
== 0)
throw INETRException("[imgDecFailed]");
BITMAPINFO bmInfo;
ZeroMemory(&bmInfo, sizeof(bmInfo));
bmInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmInfo.bmiHeader.biWidth = width;
bmInfo.bmiHeader.biHeight = -((LONG)height);
bmInfo.bmiHeader.biPlanes = 1;
bmInfo.bmiHeader.biBitCount = 32;
bmInfo.bmiHeader.biCompression = BI_RGB;
HBITMAP hbmp = nullptr;
void *imageBits = nullptr;
HDC screenDC = GetDC(nullptr);
hbmp = CreateDIBSection(screenDC, &bmInfo, DIB_RGB_COLORS, &imageBits,
nullptr, 0);
ReleaseDC(nullptr, screenDC);
if (hbmp == nullptr)
throw INETRException("[imgDecFailed]");
const UINT bmpStride = width * 4;
const UINT bmpSize = bmpStride * height;
if (FAILED(bmpSource->CopyPixels(nullptr, bmpStride, bmpSize,
static_cast<BYTE*>(imageBits)))) {
DeleteObject(hbmp);
hbmp = nullptr;
throw INETRException("[imgDecFailed]");
}
bmpSource->Release();
return hbmp;
}