Bitmap Rohdaten blitten?

[ble1frei]

Hi,

Wie kann man Image-Rohdaten aus einer bmp Datei an ein HDC übergeben oder schlicht auf den Bildschirm zeichnen?

// Load bitmap file
long __stdcall LoadBitmapFile(HDC hdc, char *filename, char *data)
{
	FILE				*filePtr;			// file pointer
	BITMAPFILEHEADER	bitmapFileHeader;	// bitmap file header	
	BITMAPINFOHEADER	bitmapInfoHeader;	// bitmap info header
	unsigned char		*bitmapImage;		// bitmap image data

	unsigned long		imageIdx = 0;		// image index counter
	unsigned char		tempRGB;			// swap variable

	// open filename in "read binary" mode
	filePtr = fopen(filename, "rb");

	if(filePtr == NULL)
	{
		MessageBox(NULL, "No file", "Error", MB_OK);
		return 0;
	}

	// read the bitmap file header
	fread(&bitmapFileHeader, sizeof(BITMAPFILEHEADER), 1, filePtr);

	// verify that this is a bitmap by checking for the univeral bitmap id
	if(bitmapFileHeader.bfType != BITMAP_ID)
	{
		fclose(filePtr);
		MessageBox(NULL, "No bitmap file", "Error", MB_OK);
		return 0;
	}

	// read the bitmap information header
	fread(&bitmapInfoHeader, sizeof(BITMAPINFOHEADER), 1, filePtr);

	// move file pointer to beginning of bitmap data
	fseek(filePtr, bitmapFileHeader.bfOffBits, SEEK_SET);

	// allocate enough memory for the bitmap image data
	bitmapImage = (unsigned char*)malloc(bitmapInfoHeader.biSizeImage);

	// verify memory allocation
	if(!bitmapImage)
	{
		free(bitmapImage);
		fclose(filePtr);
		MessageBox(NULL, "Memory allocation error", "Error", MB_OK);
		return 0;
	}

	// read in the bitmap image data
	fread(bitmapImage, 1, bitmapInfoHeader.biSizeImage, filePtr);

	// make sure bitmap data was read
	if(bitmapImage == NULL)
	{
		fclose(filePtr);
		MessageBox(NULL, "Couldn't read bitmap data", "Error", MB_OK);
		return 0;
	}

	// swap the R and B values to get RGB since the bitmap color format is in BGR
	for(imageIdx = 0; imageIdx < bitmapInfoHeader.biSizeImage; imageIdx+=3)
	{
		tempRGB = bitmapImage[imageIdx];
		bitmapImage[imageIdx] = bitmapImage[imageIdx + 2];
		bitmapImage[imageIdx + 2] = tempRGB;
	}

	// copy image data into the data parameter
	memcpy(data, bitmapImage, len);

	// blit image to hdc
	BitBlt(hdc, 0, 0, bitmapInfoHeader.biWidth, bitmapInfoHeader.biHeight, SOURCE_HDC, 0, 0, SRCCOPY);
// -> Wie bekommt man die Image-Rohdaten "data" in ein HDC um es per BitBlt auf einen anderen HDC anzeigen zu können?

	// free memory
	free(bitmapImage);

	// close the file and return the bitmap image data
	fclose(filePtr);

	return 1;
}

[Ringding]

Du willst SetDIBits oder SetDIBitsToDevice.