Thread: SetTimer().. WM_TIMER window flickers

Originally Posted by matsp

1000 milliseconds is 1 second, which is quite often. I suggested a value of about 20-50 (50-20 Hz, which happens to be roughly the range where things stop flickering and start being smooth - perhaps 35 is a good value -> ~28Hz update frequency ?)

--
Mats

lost you now... 35ms or 35s (35000)

Originally Posted by matsp

35 milliseconds. 35 seconds would definitely make the updates "jump" (unless the user got bored and looked away before the screen got updated).

--
Mats

Anything less than 500 doesn't look good. In fact since i'm displaying a lot of text with different font levels, after a little while with the flickering suddenly the font changes all text to bold, and removes any italics existing on text.. Some stages aligns text incorrectly!

Originally Posted by matsp

I suspect you are entering your WM_PAINT twice within a single draw.

So if less than 500 is not good, then you probably better stick with the jerky 1000 - not much difference if it's jerky twice as often.

Another thought would of course be to not update as much of the screen each time - perhaps you can draw just parts of it?

--
Mats

This is my messages switch statement

Code:

	switch (uMsg)
	{
	case WM_CREATE:
		{
			/* Create timer to refresh screen */ 
			SetTimer(hwnd, IDT_REFRESH, REFRESHTIME,(TIMERPROC) NULL); 

			/* Create edit controls */
			EditBoxes(hwnd, cs);

			/* Create radio buttons */
			RadioButtons(hwnd, cs);
		}
		return 0;

	case WM_PAINT:
		{
			hdc=BeginPaint(hwnd, &pntS);

			/* *** User Interface *** */
			DrawArea(hwnd, hdc, colors);
			RadioButtonsText(hwnd, hdc, polarLbl, stdFont);
			TargetText(hwnd, targetLbl, sqm, mtrs, hdc, stdFont);
			GenParams(hwnd, genPara, fareRng, dpRng, hdc, stdFont);
			RadaAntennaText(hwnd, rdrAntenaLbl, deg, db, halfMin, mtrs, hdc, stdFont);
			DisplayResultsBox(hwnd, hdc, rdrTrans_recv, targetLbl, rsltFont);
			RadarReceiverText(hwnd, rdrTrans_recv, hz, mhz, mtrs, kw, usec, db, wvlnthFig, hdc, stdFont);
			
			// Calculate & show results
			output = ProcessData(hwnd);
			DisplayResults(hwnd, hdc, &output, rsltFont);

			EndPaint(hwnd, &pntS);
		}
		return 0;

	case WM_COMMAND:
		{
			// Listen to the input commands
			switch( LOWORD(wParam) )
			{
			case ID_FILE_EXIT:
				{
					PostMessage(hwnd, WM_CLOSE, 0, 0);
					break;
				}

			case ID_EDIT_CLEAR01:
				{
					ClearEditControls(hwnd, indata);
					break;
				}
			case ID_FILE_OPEN01:
				{
					// Load data from file to edit controls
					DoFileOpen(hwnd);
					SetValues(hwnd, &indata);
					break;
				}
			case ID_FILE_SAVEAS:
				{
					// Save data on edit controls to file
 					DoFileSaveAs(hwnd);
					break;
				}
			case ID_FILE_SAVE01:
				{
					// Save data on edit controls to file
					WriteToFile(hwnd, "RFSDataFile.dat");
					break;
				}
			}
		}
		return 0;

	case WM_GETDLGCODE:
		{
			break;
		}
	case WM_TIMER: 
		{
			// Refresh screen
			InvalidateRect (hwnd, NULL, TRUE);
			UpdateWindow(hwnd);
		}
		break;

	case WM_DESTROY:
		KillTimer(hwnd, IDT_REFRESH);
		PostQuitMessage(0);    
		return 0;
	default:
		//let system deal with msg
		return DefWindowProc(hwnd,uMsg,wParam,lParam);  
	}

Originally Posted by matsp

That's not much help - I'm just asking if you need to redraw everything. I can't say from that what actually happens in your functions that do the actual drawing.

--
Mats

Actually i need to redraw a portion of the window. I have five rectangles (4 have edit boxes, 1 has results table) in one window. Really i only need to update the results (the Fifth rectangle) every time thew user changes the values on the other 4 rectangles... Any suggestions on how to do this?