#TS = 48 ; Tile size

Procedure Mix(Col1, Col2, Alpha)
    R = Red(Col1)
    B = Blue(Col1)
    G = Green(Col1)
    
    R2 = Red(Col2)
    B2 = Blue(Col2)
    G2 = Green(Col2)
    
    R = ((R*Alpha)/255) + ((R2*(255-Alpha)) / 255)
    G = ((G*Alpha)/255) + ((G2*(255-Alpha)) / 255)
    B = ((B*Alpha)/255) + ((B2*(255-Alpha)) / 255)
    
  ProcedureReturn RGB(R, G, B)
EndProcedure

Procedure PlotA(X, Y, Col, Alpha)
  If X >= 0 And Y >= 0
    Plot(X, Y, Mix(Col, Point(X, Y), Alpha))
  EndIf
EndProcedure

Procedure LineXA(X, Y, Width, Col, Alpha)
  Width + X
  For X = X To Width-1
    PlotA(X, Y, Col, Alpha)
  Next
EndProcedure

Procedure LineYA(X, Y, Height, Col, Alpha)
  Height + Y
  For Y = Y To Height-1
    PlotA(X, Y, Col, Alpha)
  Next
EndProcedure

Procedure DrawSky()
  For I = 0 To 600
    C = 255-(i*0.2)
    C = RGB(C-20, C-40, C)
    Line(0, I, 800, 0, C)
  Next
EndProcedure

Procedure DrawCloud(BX, BY, Width, Height, ClumpSize, Seed, Color=#White)
  RandomSeed(Seed)
  For I = 0 To Width*0.6
    YO = Random(Height*2)
    If YO > Height
      YO - (YO-Height)
    EndIf
    Circle(BX+Random(Width), BY+YO, Random(ClumpSize), Color)
  Next
EndProcedure

Procedure DrawClouds()
  DrawCloud(-60, 80,  200,  60, 20, 2345678)
  DrawCloud(100, 280, 50,   10, 8, 17698, RGB(220, 200, 255))
  DrawCloud(300, 80,  50,   10, 8, 17611, RGB(245, 245, 255))
  DrawCloud(400, 100, 200,  60, 20, 176695)
  DrawCloud(750, 180, 200,  30, 10, 176695)
  DrawCloud(150, 180, 200,  30, 10, 176704, RGB(220, 200, 255))
EndProcedure

Procedure MRGB(R, G, B)
  If R > 255
    R = 255
  EndIf
  If G > 255
    G = 255
  EndIf
  If B > 255
    B = 255
  EndIf
  ProcedureReturn RGB(R, G, B)
EndProcedure

Procedure Algo1FillArea(X, Y, CX, CY, Col, Stretch)
  RandomSeed(12349)
  X*#TS
  Y*#TS
  CX*#TS
  CY*#TS
  R = Red(Col)
  B = Blue(Col)
  G = Green(Col)
  For I = 0 To CX-1
    Rnd = Random(Stretch)+1
    For J = 0 To CY-1
      Col = MRGB(R+(I+J)%Rnd, G+(I+J)%Rnd, B+(I+J)%Rnd)
      Plot(X+I, Y+J, Col)
    Next
  Next
EndProcedure

Procedure Algo2FillArea(X, Y, CX, CY, Col)
  RandomSeed(1235)
  X*#TS
  Y*#TS
  CX*#TS
  CY*#TS
  R = Red(Col)
  B = Blue(Col)
  G = Green(Col)
  Box(X, Y, CX, CY, Col)
  C1 = #White
  C2 = #Black
  For I = 1 To CX-1
    For J = 1 To CY-1
      If Random(1) = 0
        PlotA(X+I, Y+J, C1, 32)
        PlotA(X+I-1, Y+J-1, C2, 32)
        Swap C1, C2
      EndIf
    Next
  Next
EndProcedure

Procedure Border(X, Y, CX, CY)
  X*#TS
  Y*#TS
  CX*#TS
  CY*#TS
  LineXA(X, Y, CX, #White, 100)
  LineXA(X, Y+CY-1, CX, #Black, 100)
  
  LineYA(X, Y, CY, #White, 100)
  LineYA(X+CX-1, Y, CY, #Black, 100)
EndProcedure



Procedure Block(X, Y, CX, CY, Col)
  Algo2FillArea(X, Y, CX, CY, Col)
  Border(X, Y, CX, CY)
EndProcedure

Procedure Tube(X, Y, CY)
  X * #TS
  Y * #TS
  CY * #TS
  CX = #TS*2
  TopH = #TS/1.5
  IX = 6
  G1 = RGB(120, 220, 50)
  G2 = RGB(50, 125, 30)
  Box(X+IX, Y, CX-IX*2, CY, G2)
  LineYA(X+IX, Y, CY, 0, 192)
  LineYA(X+CX-IX, Y, CY, 0, 192)
  Box(X, Y, CX, TopH, Mix(0, G1, 192))
  Box(X+1, Y+1, CX-2, TopH-2, G2)
  Line(X+1, Y+1, CX-2, 0, G1)
  
  ; Gloss
  I = 6
  Box(X+I-3, Y+2, 1, TopH-2, G1)
  Box(X+I, Y+2, 2, TopH-2, G1)
  Box(X+I+5, Y+2, 5, TopH-2, G1)
  Box(X+I+15, Y+2, 2, TopH-2, G1)
  
  I + IX
  Box(X+I-3, Y+TopH, 1, CY-TopH, G1)
  Box(X+I, Y+TopH, 2, CY-TopH, G1)
  Box(X+I+5, Y+TopH, 5, CY-TopH, G1)
  Box(X+I+15, Y+TopH, 2, CY-TopH, G1)
  
  I = #TS+9
  Box(X+I, Y+2, 2, TopH-2, G1)
  I - 2
  Box(X+I, Y+TopH, 2, CY-TopH, G1)
  
  ; Inverse gloss
  S = Mix(0, G1, 192)
  I + 14
  Box(X+I, Y+2, 1, TopH-2, S)
  Box(X+I+6, Y+2, 2, TopH-2, S)
  Box(X+I+11, Y+2, 7, TopH-2, S)
  Box(X+CX-7, Y+2, 5, TopH-2, S)
  
  I - IX
  Box(X+I+1, Y+TopH, 1, CY-TopH, S)
  Box(X+I+6, Y+TopH, 2, CY-TopH, S)
  Box(X+I+11, Y+TopH, 7, CY-TopH, S)
  Box(X+I+20, Y+TopH, 6, CY-TopH, S)
  
  ; Top shadow
  Box(X, Y+TopH-5, CX, 5, 0)
EndProcedure

Procedure DrawTubes()
  Tube(14, 7, 2)
  Tube(8, 4, 1)
EndProcedure

Procedure DrawBlocks()
  Stone = RGB(130, 140, 150)
  Wood = RGB(170, 120, 60)
  Block(-1, 9, 5, 1, Stone)
  Block(8, 5, 3, 1, Wood)
  Block(7, 9, 2, 1, Stone)
  Block(14, 9, 3, 1, Wood)
EndProcedure

Procedure DrawWater()
  Water = RGB(50, 180, 255)
  Algo1FillArea(9, 9, 5, 4, Water, 70)
  For I = 0 To 25
    LineXA(9*#TS, 9*#TS+I, 5*#TS, #White, Pow((25-I)/1.7, 2))
  Next
EndProcedure

Procedure DoDraw()
  CreateImage(0, 800, 600, 32)
  StartDrawing(ImageOutput(0))
    DrawSky()
    DrawClouds()
    DrawWater()
    DrawBlocks()
    DrawTubes()
  StopDrawing()
EndProcedure

OpenWindow(0, 0, 0, 816, 616, "", #PB_Window_ScreenCentered | #PB_Window_BorderLess)
CreateGadgetList(WindowID(0))
SetWindowColor(0, #Black)
DoDraw()
ImageGadget(0, 8, 8, 0, 0, ImageID(0))


Repeat
  Select WaitWindowEvent()
    Case #PB_Event_CloseWindow, #WM_CHAR
      Break
  EndSelect
ForEver