Yes, I think that is what I am doing already. Here's some code which may help:
#include "cBitmap.h"cBitmap::cBitmap(){ // Prepare to create a bitmap BITMAPINFO bmi; ZeroMemory( &bmi.bmiHeader, sizeof(BITMAPINFOHEADER) ); bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmi.bmiHeader.biWidth = g_numVerts; bmi.bmiHeader.biHeight = -g_numVerts; bmi.bmiHeader.biPlanes = 1; bmi.bmiHeader.biCompression = BI_RGB; bmi.bmiHeader.biBitCount = 16; VOID *pvBits; // Create a DC and a bitmap m_hbmDC = CreateCompatibleDC( NULL ); m_hBitmap = CreateDIBSection( m_hbmDC, &bmi, DIB_RGB_COLORS, &pvBits, NULL, 0 ); SetMapMode( m_hbmDC, MM_TEXT ); SelectObject( m_hbmDC, m_hBitmap ); g_log->Log( "Bitmap Created\n" );}cBitmap::~cBitmap(){ g_log->Log( "Bitmap Deleted\n" ); DeleteObject( m_hbmDC );}///////////////////////////////////void cBitmap::DrawGreyPixel( int x, int y, WORD intensity ){/// a WORD is passed to enable future modification... if ( intensity > 255 ) intensity = 255; COLORREF ret = SetPixel( m_hbmDC, x, y, RGB((BYTE)intensity, (BYTE)intensity, (BYTE)intensity ) ); if ( ret == 1 ) MessageBox( NULL, "Error", "cBitmap::DrawGreyPixel", MB_OK );}void cBitmap::SaveBitmap(){ g_log->Log( "Bitmap saved\n" ); PBITMAPINFO pbmi = CreateBitmapInfoStruct(); CreateBMPFile( "output.bmp", pbmi );}HBITMAP cBitmap::GetHandle(){ return m_hBitmap; }PBITMAPINFO cBitmap::CreateBitmapInfoStruct(){ BITMAP bmp; PBITMAPINFO pbmi; WORD cClrBits; // Retrieve the bitmap color format, width, and height. GetObject(m_hBitmap, sizeof(BITMAP), (LPSTR)&bmp); // Convert the color format to a count of bits. cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); if (cClrBits == 1) cClrBits = 1; else if (cClrBits <= 4) cClrBits = 4; else if (cClrBits <= 8) cClrBits = 8; else if (cClrBits <= 16) cClrBits = 16; else if (cClrBits <= 24) cClrBits = 24; else cClrBits = 32; // Allocate memory for the BITMAPINFO structure. (This structure // contains a BITMAPINFOHEADER structure and an array of RGBQUAD // data structures.) if (cClrBits != 24) pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * (1<< cClrBits)); // There is no RGBQUAD array for the 24-bit-per-pixel format. else pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER)); // Initialize the fields in the BITMAPINFO structure. pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); pbmi->bmiHeader.biWidth = bmp.bmWidth; pbmi->bmiHeader.biHeight = bmp.bmHeight; pbmi->bmiHeader.biPlanes = bmp.bmPlanes; pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel; if (cClrBits < 24) pbmi->bmiHeader.biClrUsed = (1<<cClrBits); // If the bitmap is not compressed, set the BI_RGB flag. pbmi->bmiHeader.biCompression = BI_RGB; // Compute the number of bytes in the array of color // indices and store the result in biSizeImage. // For Windows NT, the width must be DWORD aligned unless // the bitmap is RLE compressed. This example shows this. // For Windows 95/98/Me, the width must be WORD aligned unless the // bitmap is RLE compressed. pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 * pbmi->bmiHeader.biHeight; // Set biClrImportant to 0, indicating that all of the // device colors are important. pbmi->bmiHeader.biClrImportant = 0; return pbmi; } void cBitmap::CreateBMPFile( LPTSTR pszFile, PBITMAPINFO pbmi ) { HANDLE hf; // file handle BITMAPFILEHEADER hdr; // bitmap file-header PBITMAPINFOHEADER pbih; // bitmap info-header LPBYTE lpBits; // memory pointer DWORD dwTotal; // total count of bytes DWORD cb; // incremental count of bytes BYTE *hp; // byte pointer DWORD dwTmp; pbih = (PBITMAPINFOHEADER) pbmi;// pbi; lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage); // Retrieve the color table (RGBQUAD array) and the bits // (array of palette indices) from the DIB. GetDIBits(m_hbmDC, m_hBitmap, 0, (WORD) pbih->biHeight, lpBits, pbmi, DIB_RGB_COLORS); // Create the .BMP file. hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL); hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M" // Compute the size of the entire file. hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof(RGBQUAD) + pbih->biSizeImage); hdr.bfReserved1 = 0; hdr.bfReserved2 = 0; // Compute the offset to the array of color indices. hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof (RGBQUAD); // Copy the BITMAPFILEHEADER into the .BMP file. WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL) ; // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL)) ; // Copy the array of color indices into the .BMP file. dwTotal = cb = pbih->biSizeImage; hp = lpBits; WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL); // Close the .BMP file. CloseHandle(hf); // Free memory. GlobalFree((HGLOBAL)lpBits);}
You can see cBitmap::GetHandle() just returns the HBITMAP m_hBitmap.
To use it I do this:
cBitmap* g_bitmap = NULL;g_bitmap = new cBitmap();g_bitmap->DrawGreyPixel(10,10, 255 ); // white dot// attempt to get the handle for using in WM_PAINT case WM_PAINT: if ( g_bitmap ) { hdc = BeginPaint(hWnd, &ps); hdcMem = CreateCompatibleDC(hdc); SelectObject(hdcMem, g_bitmap->GetHandle()); GetObject(g_bitmap->GetHandle(), sizeof(bm), &bm); BitBlt(hdc, 100, 100, bm.bmWidth, bm.bmHeight, hdcMem, 0, 0, SRCCOPY); DeleteDC(hdcMem); EndPaint(hWnd, &ps); } break;g_bitmap->SaveBitmap();SAFE_DELETE(g_bitmap);
I want to display this bitmap in the tool app, but am having trouble showing it.
I first tried this in the main windows messageHandler:
