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Building a 3D Ray Tracer  By stevmjon

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Re-sizable Rectangle

Started by kevin, January 24, 2011, 05:56:28 PM

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kevin

  Re-sizable Rectangle

  This example sets up a zone that the user can interact with.  The logic allows the zone to be dragged/sized from any edge or the corners.  


PlayBASIC Code: [Select]
   Type tRect
x1,y1,x2,y2
EndType

Type tScreen
Viewport as tRect
EndType


Dim Screen as tScreen

Screen.Viewport.x1=0
Screen.Viewport.y1=0
Screen.Viewport.x2=GetScreenWidth()-1
Screen.Viewport.y2=GetScreenHeight()-1


Setfps 61.7

Do
Cls $445566

DrawRect(Screen.Viewport,$ff00000)

Mb=MouseButton()
Mx=MouseX()
My=Mousey()


if MB<>1
SelectedEdge=-1
endif

; Looking for an edge selection
if MB=1
if SelectedEdge=-1
ThisEdge=DetectClickedRectEdge(Screen.Viewport,mx,my)
if ThisEdge>0
SelectedEdge=ThisEdge
endif

else
DragEdge(Screen.Viewport,SelectedEdge,Mx,my)
endif
endif




Sync
loop








Psub DrawRect(Rect as tRect pointer,COlour)
linec Rect.x1,Rect.y1,Rect.x2,Rect.y1,COlour
linec Rect.x1,Rect.y2,Rect.x2,Rect.y2,COlour
linec Rect.x1,Rect.y1,Rect.x1,Rect.y2,COlour
linec Rect.x2,Rect.y1,Rect.x2,Rect.y2,COlour
endPsub


psub DetectClickedRectEdge(Rect as tRect pointer, Mx,My)

Edge=0
Radius=4
if LineIntersectCircle(Rect.x1,Rect.y1,Rect.x2,Rect.y1,mx,my,radius,0)
Edge=1
endif

if LineIntersectCircle(Rect.x1,Rect.y2,Rect.x2,Rect.y2,mx,my,radius,0)
Edge=2
endif

if LineIntersectCircle(Rect.x1,Rect.y1,Rect.x1,Rect.y2,mx,my,radius,0)
Edge+=4
endif

if LineIntersectCircle(Rect.x2,Rect.y1,Rect.x2,Rect.y2,mx,my,radius,0)
Edge+=8
endif

EndPsub Edge




psub DragEdge(Rect as tRect pointer,Edge, Mx,My)

Mx=ClipRange(mx,0,GetScreenWidth())
My=ClipRange(my,0,GetScreenHeight())

if Edge & 1
Rect.y1=My
endif

if Edge & 2
Rect.y2=My
endif

if Edge & 4
Rect.X1=Mx
endif

if Edge & 8
Rect.X2=Mx
endif

EndPsub Edge







 Related Examples:

    * Drag Rectangles/ GUI Selection
    * Drag Sprites