Visual Basic Raycasting: como calcular o tamanho da linha vertical?

[Cambalinho]

ao desenhar o raio, obtenho o comprimento do raio...
ao saber o comprimento do raio, como calculo a altura da linha? como posso evitar o efeito de peixe?
 

 Dim RayAngle As Double
    Do While (RayWay < RayCount)
        RayAngle = StartRadians + (RaySteps * RayWay)
        RayWidth = A.DrawLineWithAngleAndLength(Int(Player.PosX), Int(Player.PosY), RayAngle, 300, LevelMap0(), 33)
        
        
        lineHeight = 200 / RayWidth * 2
        drawStart = -lineHeight / 2 + 200 / 2
        If drawStart < 0 Then drawStart = 0
        drawEnd = lineHeight / 2 + 200 / 2
        If drawEnd >= 200 Then drawEnd = 200 - 1
        Me.Line (A.Width + RayWay, drawStart)-(A.Width + RayWay, drawEnd), vbWhite
        RayWay = RayWay + 1
    Loop

 

[devair1010]

@Cambalinho    olá , boa noite   !  ,  desculpe me , mas se você puder / quiser poste o código todo , por favor .

[Cambalinho]

eis o código todo mesmo...
não esquecer de mudar o nome do ficheiro no form_load().
 

Public Function BresenhamLine(X0 As Long, Y0 As Long, X1 As Long, Y1 As Long, ByRef Map() As Long, ObjectSize As Long, angle_rad As Double) As Long
   
    Dim dx As Long
    Dim dy As Long
    Dim steps As Double
    Dim Xincrement As Double
    Dim Yincrement As Double
    Dim x As Double
    Dim y As Double
    Dim MapX As Integer
    Dim MapY As Integer
    Dim LineWidth As Long
    x = X0
    y = Y0
    dx = X1 - X0
    dy = Y1 - Y0
    LineWidth = 0
    If (Abs(dx) > Abs(dy)) Then
        steps = Abs(dx)
    Else
        steps = Abs(dy)
    End If
    Xincrement = dx / (steps)
    Yincrement = dy / (steps)
    Dim v As Integer
    For v = 0 To steps
    
       x = x + Xincrement
       y = y + Yincrement
       MapX = Int(x / ObjectSize)
       MapY = Int(y / ObjectSize)
       LineWidth = LineWidth + 1
       If (Map(MapY, MapX) = vbBlue) Then
             Exit For
        End If
    Next v
    ForeColor vbRed
    DrawLine X0, Y0, Int(x), Int(y)
    LineWidth = LineWidth / Cos(angle_rad)

    BresenhamLine = LineWidth
End Function

Public Function DrawLineWithAngleAndLength(X1 As Long, Y1 As Long, angle_rad As Double, Length As Long, Map() As Long, ObjectSize As Long) As Long
   
    ' Calcular as coordenadas finais da linha
    Dim X2 As Long
    Dim Y2 As Long
    X2 = X1 + Length * Cos(angle_rad)
    Y2 = Y1 + Length * Sin(angle_rad)
    
    ' Chame a função BresenhamLine com as coordenadas finais
    DrawLineWithAngleAndLength = BresenhamLine(X1, Y1, X2, Y2, Map(), ObjectSize, angle_rad)
End Function



Private Sub DrawRays(StartRadians As Double, EndRadians As Double, VisionRadians As Double, ScreenWidth As Long, Optional Precision As Long = 1)
    Dim RayCount As Long
    Dim RaySteps As Double
    Dim RayWay As Long
    Dim RayWidth As Long
    Dim RayAngle As Double
    Dim RayHeight As Double
    
    'number of rays:
    RayCount = ScreenWidth / CLng(VisionRadians) * Precision
    
    'getting increment ray:
    RaySteps = (EndRadians - StartRadians) / CDbl(RayCount)
    Do While (RayWay < RayCount)
        'calcule the ray angle\radians:
        RayAngle = StartRadians + (RaySteps * RayWay)
        
        'draw ray and get ray width:
        RayWidth = A.DrawLineWithAngleAndLength(Int(Player.PosX), Int(Player.PosY), RayAngle, 300, LevelMap0(), 33)
        RayHeight = 66 / RayWidth * ScreenWidth / 2
        'Debug.Print RayHeight
        A.ForeColor vbBlue
        A.DrawLine 475 + 50 + RayWay, 200 / 2 - RayHeight / 2, 475 + 50 + RayWay, 200 / 2 + RayHeight / 2
        RayWay = RayWay + 1
    Loop
    
End Sub

 

RayCasting3.7z

[Cambalinho]

finalmente consegui resultados mais corretos:
 

Public Function BresenhamLine(X0 As Long, Y0 As Long, X1 As Long, Y1 As Long, ByRef Map() As Long, ObjectSize As Long, angle_rad As Double) As Long
   
    Dim dx As Long
    Dim dy As Long
    Dim steps As Double
    Dim Xincrement As Double
    Dim Yincrement As Double
    Dim x As Double
    Dim y As Double
    Dim MapX As Integer
    Dim MapY As Integer
    Dim LineWidth As Long
    x = X0
    y = Y0
    dx = X1 - X0
    dy = Y1 - Y0
    LineWidth = 0
    If (Abs(dx) > Abs(dy)) Then
        steps = Abs(dx)
    Else
        steps = Abs(dy)
    End If
    Xincrement = dx / (steps)
    Yincrement = dy / (steps)
    Dim v As Integer
    For v = 0 To steps
    
       x = x + Xincrement
       y = y + Yincrement
       MapX = Int(x / ObjectSize)
       MapY = Int(y / ObjectSize)
       LineWidth = LineWidth + 1
       If (Map(MapY, MapX) = vbBlue) Then
             Exit For
        End If
    Next v
    ForeColor vbRed
    DrawLine X0, Y0, Int(x), Int(y)
    'Calculate the Distance between Origin and Destination line:
    'CatetoAdjacente=(x - X0)
    'CatetoOposto=(y - Y0)
    'Hip = RaizQuadrada(CatetoAdjacente ^ 2 + CatetoOposto ^ 2)
    LineWidth = Sqr((x - X0) * (x - X0) + (y - Y0) * (y - Y0))
    BresenhamLine = LineWidth
End Function

Public Function DrawLineWithAngleAndLength(X1 As Long, Y1 As Long, angle_rad As Double, Length As Long, Map() As Long, ObjectSize As Long) As Long
   
    ' Calcular as coordenadas finais da linha
    Dim X2 As Long
    Dim Y2 As Long
    X2 = X1 + Length * Cos(angle_rad)
    Y2 = Y1 + Length * Sin(angle_rad)
    
    ' Chame a função BresenhamLine com as coordenadas finais
    DrawLineWithAngleAndLength = BresenhamLine(X1, Y1, X2, Y2, Map(), ObjectSize, angle_rad)
End Function

 

Private Sub DrawRays(StartRadians As Double, EndRadians As Double, VisionRadians As Double, ScreenWidth As Long, Optional Precision As Long = 1)
    Dim RayCount As Long
    Dim RaySteps As Double
    Dim RayWay As Long
    Dim RayWidth As Long
    Dim RayAngle As Double
    Dim RayHeight As Double
    
    'number of rays:
    RayCount = ScreenWidth / CLng(VisionRadians) * Precision
    
    'getting increment ray:
    RaySteps = (EndRadians - StartRadians) / CDbl(RayCount)
    Do While (RayWay < RayCount)
        'calcule the ray angle\radians:
        RayAngle = StartRadians + (RaySteps * RayWay)
        
        'draw ray and get ray width:
        RayWidth = A.DrawLineWithAngleAndLength(Int(Player.PosX), Int(Player.PosY), RayAngle, 300, LevelMap0(), 33)
        RayHeight = 66 / RayWidth * ScreenWidth
        A.ForeColor vbBlue
        A.DrawLine 475 + 50 + RayWay, 200 / 2 - RayHeight / 2, 475 + 50 + RayWay, 200 / 2 + RayHeight / 2
        RayWay = RayWay + 1
    Loop
    
End Sub

eu sei que os cálculos estão corretos, porque agora obtenho resultados esperados...
eis como obtenho a altura de linha:

'draw ray and get ray width:
        RayWidth = A.DrawLineWithAngleAndLength(Int(Player.PosX), Int(Player.PosY), RayAngle, 300, LevelMap0(), 33)
        RayHeight = 66 / RayWidth * ScreenWidth

a partir daqui, como evito o Efeito de Peixe?
demorei imenso chegar aqui... ao menos aprendi
mas usei pixel a pixel e não o triangulo para percorrer a linha... sim é mais lento.... mas agora quero corrigir o Efeito de Peixe