PureBasic

; *************************************************************************************
; *   P r o j e c t :    T u n n e l - F x   
; *************************************************************************************
; *
; *   Part3: Creating Angle Table / Texture:
; *   --------------------------------------
; *   This small example shows you, how to to create the needed angle table and how
; *   does this looks like for doing the rotations of our tunnel. Dont forget to enable
; *   inline assembler. Otherwise as you see, you will see nothing. :D
; *
; *   Source and Tutorial (c) by Thorsten Will aka va!n
; *   All rigths reserved.
; *
; *************************************************************************************

#image=0

Procedure.d ATan2(y.d, x.d)
  !FLD qword[P.v_y]
  !FLD qword[P.v_x]
  !FPATAN
  ProcedureReturn
EndProcedure

; -------- Init Code --------

lTextureSize.l  = 256
lScreenWidth.l  = 640
lScreenHeight.l = 480

CreateImage (0, lScreenWidth, lScreenHeight)

; -------- Generating Angle Table / Texture --------

StartDrawing(ImageOutput(#image))
 
  dParts.d = 0.5
 
  For x = 0 To lScreenWidth -1             
    For y = 0 To lScreenHeight -1
      dAngle.d = (dParts * lTextureSize * ATan2(y-lScreenHeight/2, x-lScreenWidth/2) / #PI)
      lColor = Int (256 - dAngle) & 255
      Plot (x, y, RGB(lColor, lColor, lColor) )
    Next
  Next
 
StopDrawing()

; -------- Saving Table as Texture --------

SaveImage (0, "c:\TunnelFx_Angle.bmp")


; *************** ecran minimum **********************************
If InitSprite() = 0 Or InitKeyboard() = 0
  MessageRequester("Error", "Can't open DirectX 7 or later", 0)
  End
EndIf

OpenScreen(1024,768,32,"texture")



Repeat
 
  If StartDrawing(ScreenOutput()) 
      DrawText(10,10,"ok")
      DrawImage(ImageID(#image),100,100,256,256)
    StopDrawing()
  EndIf
 
  ; Inverse the buffers (the back become the front (visible)... And we can do the rendering on the back)
 
 
  FlipBuffers()
 
  ; ClearScreen(RGB(0,0,0)) 
 
  ExamineKeyboard()
Until  KeyboardPushed(#PB_Key_Escape)

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