Bizarre graphics timing / resolution problem

BlitzMax Forums/BlitzMax Beginners Area/Bizarre graphics timing / resolution problem

DaMaul (Posted 2007) [#1]

Hi guys, I've been experimenting with trying to get movement as solid as possible, so I've been messing around with various frame timing techniques. Along the way I've been noticing weird flickering and glitching at certain resolutions and vsync settings and I can't figure out if the problem is down to my coding, my pc, my monitor or some weird bug deep down inside blitzmax. I've put together this test app which hopefully will show the problem: SuperStrict Global NativeWidth% = 1600 Global NativeHeight% = 1200 '====================================================================================================================================== 'Test case 1 - Noticable constant flickering in d3d mode, no flickering at all in opengl Global DRV$="D3D", WIDTH% = NativeWidth, HEIGHT% = NativeHeight, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Global DRV$="OGL", WIDTH% = NativeWidth, HEIGHT% = NativeHeight, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Test case 2 - Both drivers act pretty much the same, constant flickering with a much bigger flicker/glitch at regular intervals ( about 2.5 seconds ) 'Global DRV$="D3D", WIDTH% = 1024, HEIGHT% = 768, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Global DRV$="OGL", WIDTH% = 1024, HEIGHT% = 768, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Test Case 3 - Very bad constant flickering in d3d, smooth as silk in opengl 'Notice this is half of my monitors native resolution 'Global DRV$="D3D", WIDTH% = 800, HEIGHT% = 600, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Global DRV$="OGL", WIDTH% = 800, HEIGHT% = 600, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 1, CLEARSCREEN% = 0 'Test Case 4 - Movement of starts quite smooth in both cases 'Global DRV$="D3D", WIDTH% = NativeWidth, HEIGHT% = NativeHeight, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 0, CLEARSCREEN% = 1 'Global DRV$="OGL", WIDTH% = NativeWidth, HEIGHT% = NativeHeight, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 0, CLEARSCREEN% = 1 'Test Case 5 - I can spot a noticeable judder of the stars movement at regular intervals 'Notice this is half of my monitors native resolution 'Global DRV$="D3D", WIDTH% = 800, HEIGHT% = 600, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 0, CLEARSCREEN% = 1 'Global DRV$="OGL", WIDTH% = 800, HEIGHT% = 600, DEPTH% = 32, VSYNC% = 1, DRAWTOBOTHBUFFERS% = 0, CLEARSCREEN% = 1 Global HERTZ% = 60 '====================================================================================================================================== '------------------------------------------------------------------------------------------------------------------------ ' Start Program If DRV="OGL" Then SetGraphicsDriver( GLMax2DDriver() ) Else SetGraphicsDriver( D3D7Max2DDriver() ) End If Graphics WIDTH,HEIGHT,DEPTH,HERTZ HideMouse Const Star_Count:Int = 1500 ' Stars Count Const MAX_SIZE:Int = 12 ' Maximum stars Const MAX_ROTSPD! = 50.0 ' How much rotation goin on Global Delta_X!, Delta_Y!, Delta_Ang! = 0, tick! = 0 Global DeltaTime:Double = 0.017 '------------------------------------------------------------------------------------------------------------------------ Type TSTARFIELD_Entity Field x:Double, y:Double Method Update() Abstract Method Draw() Abstract EndType '------------------------------------------------------------------------------------------------------------------------ Type TStar Extends TSTARFIELD_Entity Field s:Double Field size# 'Size of the star in both directions Field alp# 'alpha blend values Field rot# Field tcol%[3] Field vtype:Int Field rotv# Method Update( ) Local cs!, sn! 'Sin and cos for global starfield rotation Local tx!, ty! 'Previous frame's coordinates 'Move the stars out from the center x :+ Double( x - 319.99999 ) * ( s * DeltaTime ) y :+ Double( y - 239.99999 ) * ( s * DeltaTime ) x = x - 320 y = y - 240 cs = Cos( Delta_Ang ) sn = Sin( Delta_Ang ) tx = x ty = y 'This is the rotation of the entire starfield x = tx * cs - ty * sn y = tx * sn + ty * Cs x = x + 320 y = y + 240 'Pitch Horizontal and Vertical x = x + ( Delta_X / s ) * 0.017 y = y + ( Delta_Y / s ) * 0.017 'Check screen edges 'If( ( x < -300 ) Or ( x > WIDTH + 300 ) ) If( ( x < 10 ) Or ( x > WIDTH - 10 ) ) x = Rnd ( WIDTH ) alp = 0 EndIf 'If( ( y < -300 ) Or ( y > HEIGHT + 300 ) ) If( ( y < 10 ) Or ( y > HEIGHT - 10 ) ) y = Rnd( HEIGHT ) alp = 0 EndIf If( alp < 1 ) alp = alp + .05 EndIf SetBlend( LIGHTBLEND ) SetRotation( rot ) SetAlpha( alp ) 'Update the star rotation rot = rot + rotv Draw() End Method Method Draw( ) SetBlend( LIGHTBLEND ) SetColor( tcol[0], tcol[1], tcol[2] ) Select( vtype ) Case 0 SetHandle( size * .5, .5 ) DrawRect( x, y, size, 1 ) SetHandle( .5, size * .5 ) DrawRect( x, y, 1, size ) SetHandle( 0, 0 ) Case 1 SetHandle( size * .5, size * .5 ) DrawRect( x, y, size, size ) SetHandle( 0, 0 ) End Select End Method 'Creates a new star Function CreateStar:TStar( ) Local s:TStar = New TStar Local r% = Rand( 128 ) s.x = Rnd( WIDTH ) s.y = Rnd( HEIGHT ) s.s = Rnd( 1, 2 ) s.tcol = [ r, r, r ] s.size = Rnd( 1, MAX_SIZE ) s.vtype = Rnd( 0, 1 ) s.rotv = Rnd( -5.0, 5.0 ) Return s EndFunction End Type '------------------------------------------------------------------------------------------------------------------------ Type TStarfield Field StarList:TList Method Init( ) Local a% StarList = New TList 'Initialise Stars For a= 0 To Star_Count-1 StarList.AddLast( TStar.CreateStar() ) Next End Method Method Update( ) Delta_X = ( 1000 * Cos( tick ) ) * DeltaTime Delta_Y = ( 1000 * Sin( tick ) ) * DeltaTime Delta_Ang = ( MAX_ROTSPD * Cos( tick ) ) * DeltaTime tick = tick + .5 Local c:TSTARFIELD_Entity For c = EachIn StarList c.Update Next End Method Method Draw() Local c:TSTARFIELD_Entity For c = EachIn StarList c.Draw() Next End Method End Type Local Starfield:TStarfield = New TStarfield Starfield.Init( ) Cls Flip Cls '------------------------------------------------------------------------------------------------------------------------ ' Main Loop While Not KeyHit( KEY_ESCAPE ) If( CLEARSCREEN = 1 ) Cls End If SetRotation( 0 ) SetBlend( SOLIDBLEND ) SetColor 32,32,32 'So I can see what ATI tray tools is writing in the top right of the screen! DrawRect( WIDTH-310, 0, WIDTH, 40 ) Starfield.Update( ) Flip( VSYNC ) If( DRAWTOBOTHBUFFERS=1 ) SetRotation( 0 ) SetBlend( SOLIDBLEND ) SetColor 32,32,32 'So I can see what ATI tray tools is writing in the top right of the screen! DrawRect( WIDTH-310, 0, WIDTH, 40 ) Starfield.Draw() Flip( VSYNC ) End If Wend It's a modified version of the starfield example from the blitzmax examples. I've set up lots of test case at the start of the program, please try uncommenting them one at a time and running the program. Hopefully it should be fairly obvious what is happening differently in each case. I'd be very interested in whether or not people spot the same results as me. As I think it could be a hardware thing, my spec is: Acer Ferrari laptop running into an external monitor. Athlon XP64 processor, ATI mobilty radeon 9700 and a Dell 2001fp LCD monitor ( native resolution 1600*1200 at 60hz ). Thanks in advance to anyone who takes the time to help me out! :)

DaMaul (Posted 2007) [#2]

-duplicate post removed :)