Thread: Noob question about GDI again.

NVM Figured it out.

Try CreateCompatibleBitmap()

but...

Your code will just copy a blank image to the screen

I think you want to create the mem DC at start,
load an image into it (LoadImage()).
use this mem DC to copy the image when a paint is required
and only release these on close.

I also suggest 'clearing' the current screen with something like FillRect()

I already have the image data in the BYTE* Display buffer, LoadImage is irrelevant, I'm not trying to display a bitmap from a file. The image in Display is updated frequently, so I need to recreate the bitmap each time to make sure it displays the latest frame.

So basically I have a RAW RGB 24 bits per pixel image, in Display[], and I need to get that image into a bitmap object, and GDI isn't being very cooperative.

I am getting an image, but it is mangled, its more than just a simple 32/24 bit incompatibility because if I upconvert the image, it is still mangled.

Current code used for the image -

Code:

		case WM_PAINT: 

			hdc = BeginPaint(hwnd, &ps);
			//hdc = GetDC(hwnd);
			hdcMem = CreateCompatibleDC(NULL);

			//bmi.bmiColors					= NULL;
			bmi.bmiHeader.biWidth			= 640;
			bmi.bmiHeader.biHeight			= 480;
			bmi.bmiHeader.biBitCount		= 24;
			bmi.bmiHeader.biPlanes			= 1;
			bmi.bmiHeader.biSize			= 1228800;
			bmi.bmiHeader.biSizeImage		= 0;
			bmi.bmiHeader.biClrImportant	= 0;
			bmi.bmiHeader.biClrUsed			= 0;
			bmi.bmiHeader.biCompression		= BI_RGB;
			bmi.bmiHeader.biXPelsPerMeter	= 1200;
			bmi.bmiHeader.biYPelsPerMeter	= 1200;
			

			//g_hbmDisplay = CreateBitmap(640 , 480 , 1 , 24 , Display);
			//g_hbmDisplay = CreateCompatibleBitmap(hdc , 640 , 480);
			g_hbmDisplay = CreateDIBitmap(hdc , &bmi.bmiHeader , 0 , Display , &bmi , DIB_RGB_COLORS);
			GetObjectA(g_hbmDisplay, sizeof(bm), &bm);

			//GetDIBits(hdc , g_hbmDisplay , 0 , 480 , NULL , &bmi , DIB_RGB_COLORS);

			
			if(g_hbmDisplay == NULL){
				Beep(1000 , 50);
				//g_hbmDisplay = (HBITMAP)LoadImageA(hThis,"640x480.bmp",IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
				//GetObjectA(g_hbmDisplay, sizeof(bm), &bm);
				//g_hbmDisplay = CreateDIBitmap(hdcMem , &bm , CBM_INIT , Display , &bm , DIB_RGB_COLORS);  
				}
			
			//hbmOld = (HBITMAP)SelectObject(hdcMem, g_hbmDisplay);

			//GetObject(g_hbmDisplay, sizeof(bm), &bm);

			
			SetBitmapBits(g_hbmDisplay , 921600 , Display);
			//SetDIBits(hdcMem , g_hbmDisplay , 0 , 480 , Display , &bmi , DIB_RGB_COLORS);
			SelectObject(hdcMem , g_hbmDisplay);
			BitBlt(hdc, 0, 0, 640, 480, hdcMem, 0, 0, SRCCOPY);

			//SelectObject(hdcMem, hbmOld);

			DeleteObject(g_hbmDisplay);
			DeleteDC(hdcMem);
			//DeleteDC(hdc)

			EndPaint(hwnd, &ps);

			return 0;

Solved it, turns out it WAS a 32/24 conversion issue, I just messed up the conversion function.