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Topic: Change Display Width/Height (Read 272 times) |
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Rod
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Re: Change Display Width/Height
« Reply #8 on: Jan 23rd, 2018, 12:30pm » |
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I am able to use the built in buffer now and I can get smooth blitting. I still don't fully understand how to sync the update. In this code the timer brings back the conflict but left to loop it can run really fast, although a sleep is required.
You will need this bmp, right click and save as wolf.bmp in your project directory.
Code: 'From http://lodev.org/cgtutor/raycasting.html
nomainwin
mapWidth = 24
mapHeight = 24
dim worldMap(mapWidth, mapHeight)
gosub [readMap]
dim wallTexture(5)
wallTexture(1)=128
wallTexture(2)=64
wallTexture(3)=384
wallTexture(4)=512
wallTexture(5)=448
WindowWidth = DisplayWidth
WindowHeight = DisplayHeight
graphicbox #raycaster.gb 0,0,DisplayWidth,DisplayHeight
open "Raycaster " for window_popup as #raycaster
#raycaster "trapclose [quit]"
loadbmp "wolf","wolf.bmp"
'LBB has a screen DC and a buffer DC, we only need a resource DC
'get the handle of our graphicbox
hWnd=hwnd(#raycaster.gb)
'get the handle to its associated DC
'LBB intercepts this call and passes us the buffer DC
bDC=GetDC(hWnd)
'create a copy called rDC (Resource)
'and load image
rDC=CreateCompatibleDC(bDC)
hBitmap=hbmp("wolf")
oldBmp=SelectObject(rDC,hBitmap)
'#raycaster.gb " down ; setfocus"
w=800
h=600
moveSpeed = .2
rotSpeed = .1
posX = 22: posY = 12
dirX = -1: dirY = 0
planeX = 0: planeY = 0.66
'timer 16,[blit]
'wait
[blit]
'blit the buffer full screen from its 800x600 origin
'the graphics are drawn to the buffer 800x600, we expand this to full
'screen once each cycle
call StretchBlt,bDC,0,0,DisplayWidth,DisplayHeight,bDC,0,0,800,600
'tell Windows the full area of the buffer needs flipped onscreen
calldll #user32, "InvalidateRect", hWnd as ulong, 0 as long, 0 as long, ret as void
'pause a little, else it is too fast and buffer conflict/flicker
calldll #kernel32, "Sleep",16 as ulong, NULL as void
'clear the 800x600 area of buffer by blitting the sky and ground images from rDC
call StretchBlt,bDC,0,0,800,600,rDC,0,0,64,128
[drawingloop]
scan
cameraX = 2 * x / w - 1 'x-coordinate in camera space
rayPosX = posX
rayPosY = posY
rayDirX = dirX + planeX * cameraX
rayDirY = dirY + planeY * cameraX
mapX = int(rayPosX)
mapY = int(rayPosY)
select case
case rayDirY=0
deltaDistX = 1: deltaDistY=999999
case rayDirX=0
deltaDistX = 999999: deltaDistY=1
case else
deltaDistX = sqr(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX))
deltaDistY = sqr(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY))
end select
if rayDirX<0 then
stepX=-1
sideDistX=(rayPosX-mapX)*deltaDistX
else
stepX=1
sideDistX=(mapX+1-rayPosX)*deltaDistX
end if
if rayDirY<0 then
stepY=-1
sideDistY=(rayPosY-mapY)*deltaDistY
else
stepY=1
sideDistY=(mapY+1-rayPosY)*deltaDistY
end if
while worldMap(mapX,mapY)=0
if sideDistX<sideDistY then
sideDistX = sideDistX+deltaDistX
mapX=mapX+stepX
side=0
else
sideDistY=sideDistY+deltaDistY
mapY=mapY+stepY
side=1
end if
wend
if (side = 0) then
perpWallDist = abs((mapX - rayPosX + (1 - stepX) / 2) / rayDirX)
else
perpWallDist = abs((mapY - rayPosY + (1 - stepY) / 2) / rayDirY)
end if
lineHeight = abs(int(h / perpWallDist))
drawStart = int(0-lineHeight / 2 + h / 2)
if (side = 1) then
wallX = rayPosX + ((mapY - rayPosY + (1 - stepY) / 2) / rayDirY) * rayDirX
ws=64
else
wallX = rayPosY + ((mapX - rayPosX + (1 - stepX) / 2) / rayDirX) * rayDirY
ws=0
end if
wallX = wallX - int((wallX))
texW=64
texX=int(wallX*texW)
if side=0 and rayDirX>0 then texX=texW-texX-1
if side=1 and rayDirY<0 then texX=texW-texX-1
srcW=int(lineHeight/32+1)
'draw the relevant line segment to the 800x600 area of the buffer from rDC
call StretchBlt,bDC,x,drawStart,srcW,lineHeight,rDC,wallTexture(worldMap(mapX,mapY))+texX,ws,2,64
x=x+srcW
if x<800 then goto [drawingloop]
x=0
if GetAsnycKeyState(_VK_ESCAPE) then goto [quit]
if GetAsnycKeyState(_VK_UP) then
if(worldMap(int(posX + dirX * moveSpeed),int(posY)) = 0) then posX = posX +dirX * moveSpeed
if(worldMap(int(posX),int(posY + dirY * moveSpeed)) = 0) then posY = posY +dirY * moveSpeed
end if
if GetAsnycKeyState(_VK_DOWN) then
if(worldMap(int(posX - dirX * moveSpeed),int(posY)) = 0) then posX = posX -dirX * moveSpeed
if(worldMap(int(posX),int(posY - dirY * moveSpeed)) = 0) then posY = posY -dirY * moveSpeed
end if
if GetAsnycKeyState(_VK_RIGHT) then
oldDirX = dirX
dirX = dirX * cos(0-rotSpeed) - dirY * sin(0-rotSpeed)
dirY = oldDirX * sin(0-rotSpeed) + dirY * cos(0-rotSpeed)
oldPlaneX = planeX
planeX = planeX * cos(0-rotSpeed) - planeY * sin(0-rotSpeed)
planeY = oldPlaneX * sin(0-rotSpeed) + planeY * cos(0-rotSpeed)
end if
if GetAsnycKeyState(_VK_LEFT) then
oldDirX = dirX
dirX = dirX * cos(rotSpeed) - dirY * sin(rotSpeed)
dirY = oldDirX * sin(rotSpeed) + dirY * cos(rotSpeed)
oldPlaneX = planeX
planeX = planeX * cos(rotSpeed) - planeY * sin(rotSpeed)
planeY = oldPlaneX * sin(rotSpeed) + planeY * cos(rotSpeed)
end if
goto [blit]
wait
[quit]
timer 0
call ReleaseDC hwnd,bDC
call ReleaseDC hWnd,rDC
call DeleteDC rDC
close #raycaster
end
[readMap]
data "{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,1,1,2,1,1,0,0,0,0,3,0,3,0,3,0,0,0,1},"
data "{1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,3,0,0,0,3,0,0,0,1},"
data "{1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,1,1,0,1,1,0,0,0,0,3,0,3,0,3,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,5,0,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,5,0,5,0,0,0,0,0,0,1},"
data "{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,0,0,0,0,5,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,0,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},"
data "{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}"
for j= 1 to mapHeight
read a$
a$=mid$(a$,2)
for i = 1 to mapWidth
worldMap(i,j)=val(word$(a$,i,","))
'print worldMap(i,j);
next
'print
next
return
Function GetDC(hWnd)
CallDLL #user32, "GetDC",_
hWnd As Ulong,_
GetDC As Ulong
End Function
Sub ReleaseDC hWnd, hDC
CallDLL#user32,"ReleaseDC",_
hWnd As Ulong,_
hDC As Ulong,_
result As Long
End Sub
Function CreateCompatibleDC(hDC)
CallDLL #gdi32,"CreateCompatibleDC",_
hDC As Ulong,_
CreateCompatibleDC As Ulong
End Function
Sub DeleteDC hDC
CallDLL #gdi32, "DeleteDC",_
hDC As Ulong,_
result As Ulong
End Sub
Sub StretchBlt hDCdest,x,y,w,h,hDCsrc,x2,y2,w2,h2
CallDLL #gdi32, "StretchBlt",_
hDCdest As Ulong,_
x As Long,_
y As Long,_
w As Long,_
h As Long,_
hDCsrc As Ulong,_
x2 As Long,_
y2 As Long,_
w2 As Long,_
h2 As Long,_
_SRCCOPY As Ulong,_
result As Ulong
End Sub
Function SelectObject(hDC,hObject)
CallDLL #gdi32,"SelectObject",_
hDC As Ulong,_
hObject As Ulong,_
SelectObject As Ulong
End Function
function GetAsnycKeyState(key)
calldll #user32, "GetAsyncKeyState",_
key as long,ret as long
if ret <> 0 then GetAsnycKeyState = 1
end function
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| « Last Edit: Jan 23rd, 2018, 12:33pm by Rod » |
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Richard Russell
Administrator
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Posts: 1348
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Re: Change Display Width/Height
« Reply #9 on: Jan 23rd, 2018, 2:53pm » |
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on Jan 23rd, 2018, 12:30pm, Rod wrote:| I still don't fully understand how to sync the update. |
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The InvalidateRect call says that the screen needs to be updated, but still leaves it to Windows to decide when! If you have a time-critical application (such as real-time animation) in which you need to say to Windows "update the screen and do it now!" you need to make an extra call as follows:
Code: calldll #user32, "InvalidateRect", hWnd as ulong, 0 as long, 0 as long, ret as void
calldll #user32, "UpdateWindow", hWnd as ulong, ret as void
This may well use more CPU time, but will ensure that the screen is updated when you want it to be rather than when Windows wants it to be.
Unfortunately there's no easy way to synchronise your updates with the display refresh (vertical sync) - that requires the use of DirectDraw which is non-trivial - so there may still be tearing artefacts.
Richard.
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Rod
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Gender:
Posts: 110
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Re: Change Display Width/Height
« Reply #10 on: Jan 23rd, 2018, 5:57pm » |
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Sigh, vertical sync screen refresh, so simple and so in the past! Will try the code when I get time.
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