Hi,
I have a problem, I need to get Bitmap structure(https://msdn.microsoft.com/en-us/library/windows/desktop/dd183371%28v=vs.85%29.aspx) in DirectX, when I create a bitmap thought CreateBitmapRenderTarget. Espesially I need a value: bmWidthBytes, bmBitsPixel and bmBits. Anybody can help me, in what way I can do it?
I don't know exactly what you want. Do you have a BMP image and want to extract the width and height?
std::vector<BYTE>Buffer = LoadBmpFile("myimage.bmp");
BITMAPFILEHEADER* pFHeader = (BITMAPFILEHEADER*)Buffer.data();
BITMAPINFO* pIHeader = (BITMAPINFO*)(Buffer.data() + sizeof(BITMAPFILEHEADER));
if (pFHeader->bfType != 0x4d42) //BM = 0x4d42
throw std::exception("File type does not match header description in file");
if (pFHeader->bfSize != Buffer.size())
throw std::exception("File size does not match header description in file");
BYTE* pImageData = Buffer.data() + pFHeader->bfOffBits;
UINT Width = pIHeader->bmiHeader.biWidth;
UINT Height = pIHeader->bmiHeader.biHeight;
You don't exacly understand me. I have that code:
IDWriteBitmapRenderTarget *pRenderTarget;
hResult = pGDIInterop->CreateBitmapRenderTarget(
NULL,
m_renderTargetWidth,
m_renderTargetHeight,
&pRenderTarget
);
if (FAILED(hResult)) {
m_lastError = L"Failed to create bitmap render target";
}
else {
hResult = pRenderTarget->SetPixelsPerDip(1.0f);
hResult = S_OK;
HDC hDC = pRenderTarget->GetMemoryDC();
if (hDC == NULL) {
m_lastError = L"Failed to get render target DC";
hResult = E_FAIL;
}
else {
HBRUSH hBrush = CreateSolidBrush(RGB(0, 0, 0));
if (hBrush == NULL) {
m_lastError = L"Failed to create brush";
hResult = E_FAIL;
}
else {
HBITMAP hBitmap = static_cast<HBITMAP>(GetCurrentObject(hDC, OBJ_BITMAP));
if (hBitmap == NULL) {
m_lastError = L"GetCurrentObject failed";
hResult = E_FAIL;
}
else {
DIBSECTION dib;
int iResult = GetObject(hBitmap, sizeof(dib), &dib);
if (iResult < sizeof(dib)) {
m_lastError = L"GetObject failed";
hResult = E_FAIL;
}
else {
// Store render target resources and info
m_pRenderTarget = pRenderTarget;
m_hDC = hDC;
m_hBlackBrush = hBrush;
m_bmBits = dib.dsBm.bmBits;
m_bmWidthBytes = static_cast<UINT>(dib.dsBm.bmWidthBytes);
m_bmBytesPixel = static_cast<UINT>(dib.dsBm.bmBitsPixel) / 8;
hResult = S_OK;
}
}
if (FAILED(hResult))
DeleteObject(hBrush);
}
}
if (FAILED(hResult))
pRenderTarget->Release();
}
pGDIInterop->Release();
The API of my project didn't allow me to use functions: CreateSolidBrush, GetCurrentObject and GetObject. With solid brush I don't have a problem, because in directX i had a functions, that allow me to do it, but with the two others, I havea problem, because I cannot use it, so I cannot get a BITMAP structure, so I don't have a value for bmBits, bmWidthBytes and bmBitsPixel. I must get this values, so is there another way to get it?
#pragma pack( push, 1 )
/** The bitmap file header. */
typedef struct LSI_BITMAPFILEHEADER {
LSUINT16 ui16Header;
LSUINT32 ui32Size;
LSUINT16 ui16Reserved1;
LSUINT16 ui16Reserved2;
LSUINT32 ui32Offset;
} * LPLSI_BITMAPFILEHEADER, * const LPCLSI_BITMAPFILEHEADER;
/** The bitmap info header. */
typedef struct LSI_BITMAPINFOHEADER {
LSUINT32 ui32InfoSize;
LSUINT32 ui32Width;
LSUINT32 ui32Height;
LSUINT16 ui16Planes;
LSUINT16 ui16BitsPerPixel;
LSUINT32 ui32Compression;
LSUINT32 ui32ImageSize;
LSUINT32 ui32PixelsPerMeterX;
LSUINT32 ui32PixelsPerMeterY;
LSUINT32 ui32ColorsInPalette;
LSUINT32 ui32ImportantColors;
} * LPLSI_BITMAPINFOHEADER, * const LPCLSI_BITMAPINFOHEADER;
/** Bitmap color mask. */
typedef struct LSI_BITMAPCOLORMASK {
LSUINT32 ui32Red,
ui32Green,
ui32Blue,
ui32Alpha;
} * LPLSI_BITMAPCOLORMASK, * const LPCLSI_BITMAPCOLORMASK;
/** Bitmap palette data. */
typedef union LSI_BITMAPPALETTE {
struct LSI_BM_COLOR {
LSUINT8 ui8Red,
ui8Green,
ui8Blue,
ui8Alpha;
};
LSUINT32 ui32Color;
} * LPLSI_BITMAPPALETTE, * const LPCLSI_BITMAPPALETTE;
#pragma pack( pop )Ok, but how can I use it? I repeat that I cannot put informations to this structures,becuase my api doesn't support this functions. I'm looking for the new functions replace old one.
If Tispe had proposed a function named “LoadFileToMemory(),” rather than, “LoadBmpFile(),” it might have been more obvious to you.
Load the file to memory and then perform the same casts as he showed in his sample code.
L. Spiro
Ok, I understand. But problem is in another place, because how can i convert IDWriteBitmapRenderTarget to something like that std::vector<BYTE>Buffer and then get some information about it?
IDWriteBitmapRenderTarget::GetMemoryDC
"An application can use the device context to draw using GDI functions. An application can obtain the bitmap handle (HBITMAP) by calling GetCurrentObject. An application that wants information about the underlying bitmap, including a pointer to the pixel data, can call GetObject to fill in a DIBSECTION structure. The bitmap is always a 32-bit top-down DIB."
