Antialiasing

[yetifoot]

there are various ways, but i use this

C = RGB(64, 127, 234)

B = C AND &HFF
G = (C AND &HFF00) SHR 8
R = (C AND &HFF0000) SHR 16

Print R, G, B

Sleep

[Zack]

Thanks yetifoot. Bitwise operators to the rescue!

[Zack]

OK, I have some extremely crude code. It does blur, but it makes everything that was blurred look grey.

Code:

TYPE Pixel
    R AS INTEGER
    G AS INTEGER
    B AS INTEGER
END TYPE
DECLARE FUNCTION BlurPixel(INTEGER,INTEGER,INTEGER,INTEGER,INTEGER,INTEGER,INTEGER,INTEGER,INTEGER) AS Pixel
SCREENRES 300,200,24
RANDOMIZE TIMER
FOR I=1 TO 1000
    CIRCLE (INT(RND*300),INT(RND*200)),INT(RND*15),RGB(INT(RND*255),INT(RND*255),INT(RND*255))
NEXT
SLEEP
DIM AS Pixel NewPixel
FOR X=100 TO 200
    FOR Y=50 TO 150
        TL=POINT(X-1,Y-1)
        TM=POINT(X,Y-1)
        TR=POINT(X+1,Y-1)
        ML=POINT(X-1,Y)
        MM=POINT(X,Y)
        MR=POINT(X+1,Y)
        BL=POINT(X-1,Y+1)
        BM=POINT(X,Y+1)
        BR=POINT(X+1,Y+1)
        NewPixel=BlurPixel(TL,TM,TR,ML,MM,MR,BL,BM,BR)
        PSET (X,Y),RGB(NewPixel.R,NewPixel.G,NewPixel.B)
    NEXT
NEXT
SLEEP
FUNCTION BlurPixel(TL AS INTEGER,TM AS INTEGER,TR AS INTEGER,ML AS INTEGER,MM AS INTEGER,MR AS INTEGER,BL AS INTEGER,BM AS INTEGER,BR AS INTEGER) AS Pixel
        DIM AS BYTE R,G,B
        DIM AS Pixel Pixels(1 TO 9),RetPixel
        DIM AS INTEGER I,RTotal,GTotal,BTotal,RetVal
        Pixels(1).R=(TL AND &HFF0000) SHR 16
        Pixels(2).R=(TM AND &HFF0000) SHR 16
        Pixels(3).R=(TR AND &HFF0000) SHR 16
        Pixels(4).R=(TM AND &HFF0000) SHR 16
        Pixels(5).R=(MM AND &HFF0000) SHR 16
        Pixels(6).R=(MR AND &HFF0000) SHR 16
        Pixels(7).R=(BL AND &HFF0000) SHR 16
        Pixels(8).R=(BM AND &HFF0000) SHR 16
        Pixels(9).R=(BR AND &HFF0000) SHR 16
        
        Pixels(1).G=(TL AND &HFF00) SHR 8
        Pixels(2).G=(TM AND &HFF00) SHR 8
        Pixels(3).G=(TR AND &HFF00) SHR 8
        Pixels(4).G=(ML AND &HFF00) SHR 8
        Pixels(5).G=(MM AND &HFF00) SHR 8
        Pixels(6).G=(MR AND &HFF00) SHR 8
        Pixels(7).G=(ML AND &HFF00) SHR 8
        Pixels(8).G=(BM AND &HFF00) SHR 8
        Pixels(9).G=(BR AND &HFF00) SHR 8
        
        Pixels(1).B=TL AND &HFF
        Pixels(1).B=TM AND &HFF
        Pixels(1).B=TR AND &HFF
        Pixels(1).B=ML AND &HFF
        Pixels(1).B=MM AND &HFF
        Pixels(1).B=MR AND &HFF
        Pixels(1).B=BL AND &HFF
        Pixels(1).B=BM AND &HFF
        Pixels(1).B=BR AND &HFF
        
        FOR I=1 TO 9
            RetPixel.R=RetPixel.R+Pixels(I).R
            RetPixel.G=RetPixel.R+Pixels(I).G
            RetPixel.B=RetPixel.R+Pixels(I).B
        NEXT
        RetPixel.R=RetPixel.R/9
        RetPixel.G=RetPixel.G/9
        RetPixel.B=RetPixel.B/9
        RETURN RetPixel
END FUNCTION

I know, I know...But I couldn't think of an elegant way to do it!

[yetifoot]

heres some code from an old VB project of mine. Couldn't be bothered to update it yet!

the iDATA array is :first part is for rgb then second and third are x and y

hope it helps, maybe i'll convert it at some point.

Code:

Private Sub Smooth()
  Dim X As Long, Y As Long
  Dim r As Long, G As Long, B As Long

  For Y = 2 To PicInfo.bmHeight - 1
    For X = 2 To PicInfo.bmWidth - 1
      B = CLng(iDATA(1, X, Y)) + _
        CLng(iDATA(1, X - 1, Y)) + CLng(iDATA(1, X, Y - 1)) + _
        CLng(iDATA(1, X, Y + 1)) + CLng(iDATA(1, X + 1, Y))
      B = B \ 5
      G = CLng(iDATA(2, X, Y)) + _
        CLng(iDATA(2, X - 1, Y)) + CLng(iDATA(2, X, Y - 1)) + _
        CLng(iDATA(2, X, Y + 1)) + CLng(iDATA(2, X + 1, Y))
      G = G \ 5
      r = CLng(iDATA(3, X, Y)) + _
        CLng(iDATA(3, X - 1, Y)) + CLng(iDATA(3, X, Y - 1)) + _
        CLng(iDATA(3, X, Y + 1)) + CLng(iDATA(3, X + 1, Y))
      r = r \ 5
      iDATA(1, X, Y) = B
      iDATA(2, X, Y) = G
      iDATA(3, X, Y) = r
    Next X
  Next Y
End Sub

[Dr_Davenstein]

I changed a few things out of habit. It's basically what I did on that landmaker algo thing.

Code:

Option Explicit
Const Scr_Width As Integer = 320
Const SCR_Height As Integer = 200
Const Bits_Per_Plane As Integer = 24

Screenres Scr_Width,Scr_Height,Bits_Per_Plane
Randomize Timer

Type Pixel
    R As Integer
    G As Integer
    B As Integer
End Type

Declare Function BlurPixel(Byval X As Integer, Byval Y As Integer, Byval Strength As Integer) As Pixel

Dim As Pixel NewPixel
Dim As Integer I, X, Y

For I = 1 To 1000
    Circle (Int(Rnd*300),Int(Rnd*200)),Int(Rnd*15),Rgb(Int(Rnd*255),Int(Rnd*255),Int(Rnd*255))
Next
Sleep


For X=100 To 200
    For Y=50 To 150
        NewPixel = BlurPixel(X, Y, 1)
        Pset (X,Y),Rgb(NewPixel.R,NewPixel.G,NewPixel.B)
    Next
Next
Sleep





Function BlurPixel(Byval X As Integer, Byval Y As Integer, Byval Strength As Integer) As Pixel
    Dim As Integer ScanX, Scany, StartX, EndX, StartY, EndY, TempCol, Hits
    Dim TempRGB As Pixel
    
    If Strength <=0 Then
        TempCol = Point(X,Y)
        TempRGB.R += ((TempCol Shr 16) And &HFF)
        TempRGB.G += ((TempCol Shr 8 ) And &HFF)
        TempRGB.B += ((TempCol       ) And &HFF)
        Function = TempRGB
        Exit Function
    End If    
    
    StartY= Y-Strength
    EndY  = Y+Strength
    StartX= X-Strength
    EndX  = X+Strength
    
    If StartY< 0  Then StartY = 0
    If StartX< 0  Then StartX = 0
    If EndY>Scr_Height-1 Then EndY=Scr_Height-1
    If EndX>Scr_Width-1 Then EndX=Scr_Width-1
    
    For ScanY = StartY To EndY
        For ScanX = StartX To EndX
            TempCol = Point(ScanX,ScanY)
            TempRGB.R += ((TempCol Shr 16) And &HFF)
            TempRGB.G += ((TempCol Shr 8 ) And &HFF)
            TempRGB.B += ((TempCol       ) And &HFF)
            Hits+=1
        Next
    Next
    
    TempRgb.R\=Hits
    TempRgb.G\=Hits
    TempRgb.B\=Hits
    
    Function = TempRGB
End Function

[Zack]

I don't understand all of it, but it works much better than mine.

[Dr_Davenstein]

What is it that you don't understand? I'd be glad to explain... or I'm sure someone else will. 8)

[Zack]

Well...how it works, for one. It doesn't resemble my code at all.

[yetifoot]

his is still the same principle, which is an average of surrounding colours, but his has strength, which is how many pixels are sampled.

[Zack]

Well I looked at every line of the code and I understand it now.
But why does his maintain colour while mine makes everything grey?