in Texassemble/AnimatedGif.cpp [115:411]
HRESULT LoadAnimatedGif(const wchar_t* szFile, std::vector<std::unique_ptr<ScratchImage>>& loadedImages, bool usebgcolor)
{
bool iswic2;
auto pWIC = GetWICFactory(iswic2);
if (!pWIC)
return E_NOINTERFACE;
ComPtr<IWICBitmapDecoder> decoder;
HRESULT hr = pWIC->CreateDecoderFromFilename(szFile, nullptr, GENERIC_READ, WICDecodeMetadataCacheOnDemand, decoder.GetAddressOf());
if (FAILED(hr))
return hr;
{
GUID containerFormat;
hr = decoder->GetContainerFormat(&containerFormat);
if (FAILED(hr))
return hr;
if (memcmp(&containerFormat, &GUID_ContainerFormatGif, sizeof(GUID)) != 0)
{
// This function only works for GIF
return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
}
}
ComPtr<IWICMetadataQueryReader> metareader;
hr = decoder->GetMetadataQueryReader(metareader.GetAddressOf());
if (FAILED(hr))
return hr;
PROPVARIANT propValue;
PropVariantInit(&propValue);
// Get palette
WICColor rgbColors[256] = {};
UINT actualColors = 0;
{
ComPtr<IWICPalette> palette;
hr = pWIC->CreatePalette(palette.GetAddressOf());
if (FAILED(hr))
return hr;
hr = decoder->CopyPalette(palette.Get());
if (FAILED(hr))
return hr;
hr = palette->GetColors(static_cast<UINT>(std::size(rgbColors)), rgbColors, &actualColors);
if (FAILED(hr))
return hr;
}
// Get background color
UINT bgColor = 0;
if (usebgcolor)
{
// Most browsers just ignore the background color metadata and always use transparency
hr = metareader->GetMetadataByName(L"/logscrdesc/GlobalColorTableFlag", &propValue);
if (SUCCEEDED(hr))
{
bool hasTable = (propValue.vt == VT_BOOL && propValue.boolVal);
PropVariantClear(&propValue);
if (hasTable)
{
hr = metareader->GetMetadataByName(L"/logscrdesc/BackgroundColorIndex", &propValue);
if (SUCCEEDED(hr))
{
if (propValue.vt == VT_UI1)
{
uint8_t index = propValue.bVal;
if (index < actualColors)
{
bgColor = rgbColors[index];
}
}
PropVariantClear(&propValue);
}
}
}
}
// Get global frame size
UINT width = 0;
UINT height = 0;
hr = metareader->GetMetadataByName(L"/logscrdesc/Width", &propValue);
if (FAILED(hr))
return hr;
if (propValue.vt != VT_UI2)
return E_FAIL;
width = propValue.uiVal;
PropVariantClear(&propValue);
hr = metareader->GetMetadataByName(L"/logscrdesc/Height", &propValue);
if (FAILED(hr))
return hr;
if (propValue.vt != VT_UI2)
return E_FAIL;
height = propValue.uiVal;
PropVariantClear(&propValue);
UINT fcount;
hr = decoder->GetFrameCount(&fcount);
if (FAILED(hr))
return hr;
UINT disposal = DM_UNDEFINED;
RECT rct = {};
UINT previousFrame = 0;
for (UINT iframe = 0; iframe < fcount; ++iframe)
{
int transparentIndex = -1;
std::unique_ptr<ScratchImage> frameImage(new (std::nothrow) ScratchImage);
if (!frameImage)
return E_OUTOFMEMORY;
if (disposal == DM_PREVIOUS)
{
hr = frameImage->InitializeFromImage(*loadedImages[previousFrame]->GetImage(0, 0, 0));
}
else if (iframe > 0)
{
hr = frameImage->InitializeFromImage(*loadedImages[iframe - 1]->GetImage(0, 0, 0));
}
else
{
hr = frameImage->Initialize2D(DXGI_FORMAT_B8G8R8A8_UNORM, width, height, 1, 1);
}
if (FAILED(hr))
return hr;
auto composedImage = frameImage->GetImage(0, 0, 0);
if (!iframe)
{
RECT fullRct = { 0, 0, static_cast<long>(width), static_cast<long>(height) };
FillRectangle(*composedImage, fullRct, bgColor);
}
else if (disposal == DM_BACKGROUND)
{
FillRectangle(*composedImage, rct, bgColor);
}
ComPtr<IWICBitmapFrameDecode> frame;
hr = decoder->GetFrame(iframe, frame.GetAddressOf());
if (FAILED(hr))
return hr;
WICPixelFormatGUID pixelFormat;
hr = frame->GetPixelFormat(&pixelFormat);
if (FAILED(hr))
return hr;
if (memcmp(&pixelFormat, &GUID_WICPixelFormat8bppIndexed, sizeof(GUID)) != 0)
{
// GIF is always loaded as this format
return E_UNEXPECTED;
}
ComPtr<IWICMetadataQueryReader> frameMeta;
hr = frame->GetMetadataQueryReader(frameMeta.GetAddressOf());
if (SUCCEEDED(hr))
{
hr = frameMeta->GetMetadataByName(L"/imgdesc/Left", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI2 ? S_OK : E_FAIL);
if (SUCCEEDED(hr))
{
rct.left = static_cast<long>(propValue.uiVal);
}
PropVariantClear(&propValue);
}
hr = frameMeta->GetMetadataByName(L"/imgdesc/Top", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI2 ? S_OK : E_FAIL);
if (SUCCEEDED(hr))
{
rct.top = static_cast<long>(propValue.uiVal);
}
PropVariantClear(&propValue);
}
hr = frameMeta->GetMetadataByName(L"/imgdesc/Width", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI2 ? S_OK : E_FAIL);
if (SUCCEEDED(hr))
{
rct.right = static_cast<long>(propValue.uiVal) + rct.left;
}
PropVariantClear(&propValue);
}
hr = frameMeta->GetMetadataByName(L"/imgdesc/Height", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI2 ? S_OK : E_FAIL);
if (SUCCEEDED(hr))
{
rct.bottom = static_cast<long>(propValue.uiVal) + rct.top;
}
PropVariantClear(&propValue);
}
disposal = DM_UNDEFINED;
hr = frameMeta->GetMetadataByName(L"/grctlext/Disposal", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI1 ? S_OK : E_FAIL);
if (SUCCEEDED(hr))
{
disposal = propValue.bVal;
}
PropVariantClear(&propValue);
}
hr = frameMeta->GetMetadataByName(L"/grctlext/TransparencyFlag", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_BOOL ? S_OK : E_FAIL);
if (SUCCEEDED(hr) && propValue.boolVal)
{
PropVariantClear(&propValue);
hr = frameMeta->GetMetadataByName(L"/grctlext/TransparentColorIndex", &propValue);
if (SUCCEEDED(hr))
{
hr = (propValue.vt == VT_UI1 ? S_OK : E_FAIL);
if (SUCCEEDED(hr) && propValue.uiVal < actualColors)
{
transparentIndex = static_cast<int>(propValue.uiVal);
}
}
}
PropVariantClear(&propValue);
}
}
UINT w, h;
hr = frame->GetSize(&w, &h);
if (FAILED(hr))
return hr;
ScratchImage rawFrame;
hr = rawFrame.Initialize2D(DXGI_FORMAT_B8G8R8A8_UNORM, w, h, 1, 1);
if (FAILED(hr))
return hr;
ComPtr<IWICFormatConverter> FC;
hr = pWIC->CreateFormatConverter(FC.GetAddressOf());
if (FAILED(hr))
return hr;
hr = FC->Initialize(frame.Get(), GUID_WICPixelFormat32bppBGRA, WICBitmapDitherTypeNone, nullptr, 0, WICBitmapPaletteTypeMedianCut);
if (FAILED(hr))
return hr;
auto img = rawFrame.GetImage(0, 0, 0);
hr = FC->CopyPixels(nullptr, static_cast<UINT>(img->rowPitch), static_cast<UINT>(img->slicePitch), img->pixels);
if (FAILED(hr))
return hr;
if (!iframe || transparentIndex == -1)
{
Rect fullRect(0, 0, img->width, img->height);
hr = CopyRectangle(*img, fullRect, *composedImage, TEX_FILTER_DEFAULT, size_t(rct.left), size_t(rct.top));
if (FAILED(hr))
return hr;
}
else
{
BlendRectangle(*composedImage, *img, rct, rgbColors[transparentIndex]);
}
if (disposal == DM_UNDEFINED || disposal == DM_NONE)
{
previousFrame = iframe;
}
loadedImages.emplace_back(std::move(frameImage));
}
PropVariantClear(&propValue);
return S_OK;
}