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Added scaling to uiImage on Windows. We'll need this for what we're about to do.

This commit is contained in:
Pietro Gagliardi 2018-06-15 22:28:37 -04:00
parent 32ee36eb22
commit d6cebf4ca0
2 changed files with 54 additions and 15 deletions
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67
windows/image.cpp
View File

@ -120,10 +120,12 @@ IWICBitmap *uiprivImageAppropriateForDC(uiImage *i, HDC dc)
return m.best;
}
// TODO see if we can really pass NULL to CreateDIBSection()'s HDC parameter, and if so, use HBITMAPs before WIC maybe?
// TODO this needs to actually scale down to fit if the image size isn't perfectly equal to a requested size I need to pass as a parameter here...
HBITMAP uiprivWICToGDI(IWICBitmap *b, HDC dc)
// TODO this needs to center images if the given size is not the same aspect ratio
HRESULT uiprivWICToGDI(IWICBitmap *b, HDC dc, int width, int height, HBITMAP *hb)
{
UINT ux, uy;
int x, y;
IWICImageSource *src;
BITMAPINFO bmi;
UINT width, height;
HBITMAP hb;
@ -131,29 +133,66 @@ HBITMAP uiprivWICToGDI(IWICBitmap *b, HDC dc)
BITMAP bmp;
HRESULT hr;
hr = b->GetSize(&ux, &uy);
if (hr != S_OK)
return hr;
x = ux;
y = uy;
if (width == 0)
width = x;
if (height == 0)
height = y;
// special case: don't invoke a scaler if the size is the same
if (width == x && height == y) {
b->AddRef(); // for the Release() later
src = b;
} else {
IWICBitmapScaler *scaler;
hr = uiprivWICFactory->CreateBitmapScaler(&scaler);
if (hr != S_OK)
return hr;
hr = scaler->Initialize(b, width, height,
// according to https://stackoverflow.com/questions/4250738/is-stretchblt-halftone-bilinear-for-all-scaling, this is what StretchBlt(COLORONCOLOR) does (with COLORONCOLOR being what's supported by AlphaBlend())
WICBitmapInterpolationModeNearestNeighbor);
if (hr != S_OK) {
scaler->Release();
return hr;
}
src = scaler;
}
ZeroMemory(&bmi, sizeof (BITMAPINFO));
bmi.bmiHeader.biSize = sizeof (BITMAPINFOHEADER);
hr = b->GetSize(&width, &height);
if (hr != S_OK)
logHRESULT(L"error calling GetSize() in uiprivWICToGDI()", hr);
bmi.bmiHeader.biWidth = width;
bmi.bmiHeader.biHeight = -((int) height);
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 32;
bmi.bmiHeader.biCompression = BI_RGB;
hb = CreateDIBSection(dc, &bmi, DIB_RGB_COLORS,
*hb = CreateDIBSection(dc, &bmi, DIB_RGB_COLORS,
&bits, NULL, 0);
if (hb == NULL)
logLastError(L"error calling CreateDIBSection() in uiprivWICToGDI()");
if (*hb == NULL) {
logLastError(L"CreateDIBSection()");
hr = E_FAIL;
goto fail;
}
// now we need to figure out the stride of the image data GDI gave us
// TODO find out if CreateDIBSection fills that in bmi for us
if (GetObject(hb, sizeof (BITMAP), &bmp) == 0)
// TODO find out if CreateDIBSection() fills that in bmi for us
// TODO fill in the error returns here too
if (GetObject(*hb, sizeof (BITMAP), &bmp) == 0)
logLastError(L"error calling GetObject() in uiprivWICToGDI()");
hr = b->CopyPixels(NULL, bmp.bmWidthBytes,
bmp.bmWidthBytes * bmp.bmHeight, (BYTE *) bits);
if (hr != S_OK)
logHRESULT(L"error calling CopyPixels() in uiprivWICToGDI()", hr);
return hb;
hr = S_OK;
fail:
if (*hb != NULL && hr != S_OK) {
// don't bother with the error returned here
DeleteObject(*hb);
*hb = NULL;
}
src->Release();
return hr;
}

2
windows/uipriv_windows.hpp
View File

@ -169,4 +169,4 @@ extern IWICImagingFactory *uiprivWICFactory;
extern HRESULT uiprivInitImage(void);
extern void uiprivUninitImage(void);
extern IWICBitmap *uiprivImageAppropriateForDC(uiImage *i, HDC dc);
extern HBITMAP uiprivWICToGDI(IWICBitmap *b, HDC dc);
extern HRESULT uiprivWICToGDI(IWICBitmap *b, HDC dc, int width, int height, HBITMAP *hb);