Writing pixels to screen FAST?

BlitzMax Forums/BlitzMax Programming/Writing pixels to screen FAST?

bytecode77 (Posted 2008) [#1]

hi again! is there a way to write pixels to the screen without using a pixmap. pixmaps are slow for that matter. also plot is too slow for this either. this should not be done via openGL. at best, it should be software rendered thanks :) (i promise, i will not post so many topics soon anymore)

GfK (Posted 2008) [#2]

draw pixels on pixmap, unlock pixmap (= TImage), draw TImage?

bytecode77 (Posted 2008) [#3]

k, will do that thx!

EOF (Posted 2008) [#4]

Have a look at this method. Although it uses pixmaps the method used to set the pixels is really fast (The demo only seems to work in non-debug mode for me though) Rem Binary Therapys Fire Demo Mods (Jim Brown): Stripped dependancies EndRem Strict Framework BRL.GLMax2D 'Framework BRL.D3D7Max2D Import BRL.Bank Import BRL.Random Import BRL.BMPLoader SetGraphicsDriver GLMax2DDriver() 'SetGraphicsDriver D3D7Max2DDriver() Global particle_list:TList=New TList Const glevel1=1 Const glevel2=2 Const glevel3=4 Const maxx=239 Const maxy=239 Const particle_life=1000 Global firepix:TPixmap=CreatePixmap(480 , 480 , PF_RGBA8888) Global cfb:TBank = CreateBank(57600) Global hfb:TBank = CreateBank(57600) Global creds=0 SeedRnd MilliSecs() AppTitle = "BlitzMax Firedemo" Global quittime=0 Global qta=1 Global gradient[256] , col[5] col[0]=$000000 col[1]=$400040 col[2]=$000080 col[3]=$C00000 col[4]=$FFFF00 SetupGradient() Graphics 640,480 , 32 Local angl:Double = 0 Type Particle Field x#,y# Field speed#,direction,angle,life Global pcount=0 Method New() x=0 y=0 speed#=Rnd (.2 , .6) direction=Rand(0,359) angle=direction life=particle_life pcount:+1 particle_list.AddLast(Self) End Method Method Update() If x < -120 Then x = -120 If x > 119 Then x = 119 If y < -120 Then y = -120 If y > 119 Then y = 119 Local bofs= Int(x+120) + Int(y+120)*240 Local myPtr:Byte Ptr = BankBuf (cfb) Local valu=myPtr[bofs] valu=valu+20 If valu<80 life:-1 EndIf If life <=0 x=0 y=0 speed#=Rnd (.2 , .6) direction=Rand(0,359) angle=direction life=particle_life Else If valu>255 Then valu=255 myPtr [bofs] = valu Local surfangle = ATan2 ( y , x ) x = x + speed * Cos( direction ) y = y + speed * Sin( direction ) If (x*x + y*y)>10000 angle = surfangle - 180 Else If angle = direction angle=Rand(0,359) EndIf EndIf angle=(angle + 360) Mod 360 direction=(direction + 360) Mod 360 Local angc:Double If angle<direction angc=360+angle-direction Else angc=angle-direction EndIf If angc>180 direction=direction-1 ElseIf angc>0 direction=direction+1 EndIf EndIf EndMethod End Type ' ##################################### Repeat Flip False Cls Local startime = MilliSecs() For Local p:Particle = EachIn particle_list p.update Next For Local yco=0 To maxy For Local xco=0 To maxx Local myPtr:Byte Ptr = BankBuf(cfb) Local rb:Byte = myPtr [xco + yco*240] If rb>0 Local valu=rb*glevel3 Local x1 = xco-1 If x1<0 Then x1=x1+maxx Local x3 = xco+1 If x3>maxx Then x3=x3-maxx Local y1 = yco-1 If y1<0 Then y1=y1+maxy Local y3 = yco+1 If y3>maxy Then y3=y3-maxy rb=myPtr [x1 + y1 * 240] valu=valu+rb*glevel1 rb=myPtr [xco + y1 * 240] valu=valu+rb*glevel2 rb=myPtr [x3 + y1 * 240] valu=valu+rb*glevel1 rb=myPtr [x1 + yco * 240] valu=valu+rb*glevel2 rb=myPtr [ x3 + yco * 240 ] valu=valu+rb*glevel2 rb=myPtr [x1 + y3 * 240] valu=valu+rb*glevel1 rb=myPtr [xco + y3 * 240] valu=valu+rb*glevel2 rb=myPtr [x3 + y3 * 240] valu=valu+rb*glevel1 valu=valu Shr 4 PokeByte hfb,xco + yco * 240 , valu EndIf Next Next For Local yco=0 To maxy For Local xco=0 To maxx Local bofs=yco*240+xco Local valu=PeekByte(hfb,bofs) If valu>0 If valu>4 valu=valu-4 Else valu=0 EndIf PokeByte hfb,bofs,valu WritePixel firepix , xco*2 , yco*2 , gradient[valu] WritePixel firepix , xco*2+1 , yco*2 , gradient[valu] WritePixel firepix , xco*2+1 , yco*2+1 , gradient[valu] WritePixel firepix , xco*2 , yco*2+1 , gradient[valu] EndIf Next Next Local temp:TBank = cfb cfb = hfb hfb = temp DrawPixmap firepix , 80 , 0 angl=angl+12.5 If angl>180 Then angl=angl-180 Local frametime=MilliSecs()-startime If frametime<30 And qta>0 For Local i = 0 To 9 New Particle Next EndIf If Particle.pcount>0 Local part:String="Featuring "+Particle.pcount+" real-time blurred particles." DrawText part , 30,0 EndIf If KeyHit(KEY_ESCAPE) And quittime=64 particle_list.Clear() Particle.pcount = 0 quittime=63;qta=-qta EndIf If quittime<64 quittime=quittime+qta EndIf While frametime<33 frametime=MilliSecs()-startime Wend Until quittime=0 And qta < 0 End Function SetupGradient() Local ofs,grad,i While ofs<255 For i=0 To 63 Local perc#=i/63.0 Local x1=col[grad] Shr 16 & $FF Local xco=col[grad] Shr 8 & $FF Local x3=col[grad] & $FF Local y1=col[grad+1] Shr 16 & $FF Local yco=col[grad+1] Shr 8 & $FF Local y3=col[grad+1] & $FF gradient[i+ofs]=$FF000000 + Int(x1*(1-perc)+y1*perc) Shl 16 + Int(xco*(1-perc)+yco*perc) Shl 8 + Int(x3*(1-perc)+y3*perc) Next ofs=ofs+i;grad=grad+1 Wend EndFunction There is also a faster version of drawing a pixmap to the screen too (OpenGL): Function FastDrawPixmap(p:TPixmap,x,y,scalex#=1.0, scaley#=1.0) Local blend%=GetBlend() glDisable GL_TEXTURE_2D 'DisableTex SetBlend SOLIDBLEND Local t:TPixmap=p If t.format<>PF_RGBA8888 t=ConvertPixmap(p, PF_RGBA8888 ) glpixelzoom scalex#,-scaley# glRasterPos2i 0,0 glBitmap 0,0,0,0,x,-y,Null glPixelStorei GL_UNPACK_ROW_LENGTH, p.pitch Shr 2 glDrawPixels p.width, p.height, GL_RGBA, GL_UNSIGNED_BYTE, p.pixels glEnable GL_TEXTURE_2D SetBlend blend End Function

ImaginaryHuman (Posted 2008) [#5]

How is that drawpixmap faster? Are you saying that switching off blending and texturing makes it faster? And what is the glBitmap doing to help matters? DC - you may want to also try a vertex buffer of points.

bytecode77 (Posted 2008) [#6]

thanks for the example, i'll stick to the first one :)