PureBoard

Code: Alles auswählen

Structure clip
  X1.l
  Y1.l
  X2.l
  Y2.l
EndStructure

Global Clip.clip

Procedure fill_triangle(X1.l, Y1.l, X2.l, Y2.l, X3.l, Y3.l, C.l)

  Define.l X, Y, XA, XB


  If Y1 > Y2
    fill_triangle(X2, Y2, X1, Y1, X3, Y3, C)
    ProcedureReturn
  EndIf

  If Y2 > Y3
    fill_triangle(X1, Y1, X3, Y3, X2, Y2, C)
    ProcedureReturn
  EndIf

  X1 << 3
  X2 << 3
  X3 << 3

  If Y1 < Clip\Y1:Y1 = Clip\Y1:EndIf
  If Y3 > Clip\Y2:Y3 = Clip\Y2:EndIf
  
  For Y = Y1 To Y3

    If Y <= Y2

      If (Y1 = Y2): XA = X2 : Else :XA = X1 + (X2 - X1) * (Y - Y1) / (Y2 - Y1):EndIf
      If (Y1 = Y3): XB = X3 : Else :XB = X1 + (X3 - X1) * (Y - Y1) / (Y3 - Y1):EndIf

    Else

      If (Y3 = Y2) :XA = X2 :Else : XA = X3 + (X2 - X3) * (Y - Y3) / (Y2 - Y3):EndIf
      If (Y3 = Y1) :XB = X1 :Else : XB = X3 + (X1 - X3) * (Y - Y3) / (Y1 - Y3):EndIf
      
    EndIf

    If(XB < XA)
      Swap XB, XA
    EndIf
    

    XA = (XA + 2) >> 3
    XB = (XB - 2) >> 3

    If(XB < Clip\X1) Or (XA > Clip\X2): Continue:EndIf
    If(XA < Clip\X1): XA = Clip\X1:EndIf
    If(XB > Clip\X2): XB = Clip\X2:EndIf

    For X = XA To XB
      Plot(X, Y, C)
    Next
    
  Next
EndProcedure



OpenWindow(0, 0, 0, 640, 480, "fill_triangle", #PB_Window_SystemMenu)

CreateImage(0, 640, 480)

ImageGadget(0, 0, 0, 640, 480, ImageID(0))

Clip\X1 = 50
Clip\Y1 = 50
Clip\X2 = 589
Clip\Y2 = 429

Ende    = #False

Repeat

  Event = WaitWindowEvent(20)

  StartDrawing(ImageOutput(0))
  fill_triangle(Random(840) - 100, Random(680) - 100, Random(840) - 100, Random(680) - 100, Random(840) - 100, Random(680) - 100, Random(#White))
  StopDrawing()
  
  SetGadgetState(0, ImageID(0))
  
  Select Event
    Case #PB_Event_CloseWindow
      Ende = #True
  EndSelect
Until Ende