PureBasic Forums - English

Posted: **Sun Aug 15, 2004 11:23 pm**

A) When I am using examinemouse(), I always have the problem of the mouse disappearing, and not being able to leave the window boundaries. Is it possible to correct these?

B) Would there happen to be a method to draw a smooth circle, or would I have to make an image?

Posted: **Mon Aug 16, 2004 12:01 am**

In answer to your first question, you could try using WindowMouseX() /WindowMouseY() instead of the ExamineMouse() and MouseX()/MouseY() commands.

Posted: **Mon Aug 16, 2004 1:04 am**

GreenGiant wrote:In answer to your first question, you could try using WindowMouseX() /WindowMouseY() instead of the ExamineMouse() and MouseX()/MouseY() commands.

Ah! Very good, thank you.

With what I'm going to do, the new set of coordinates will be easy to work with, too.

Posted: **Mon Aug 16, 2004 1:14 pm**

And in answer to your second question, here's something I wrote that will draw a smoothed ellipse. It will however, also anti-alias whatever is in the background square where it draws. But it should be fine to use on plain backgrounds, and maybe elsewhere too, you'd have to try it.

Code: Select all

Procedure SmoothEllipse(ImNum,x,y,width,height,colour)
  tempimg=CreateImage(#PB_any,width*4,height*4)
  tempimg2=GrabImage(ImNum,#PB_Any,x,y,width,height)
  UseImage(tempimg2)
  ResizeImage(tempimg2,ImageWidth()*4,ImageHeight()*4)
  
  UseImage(tempimg)
  StartDrawing(ImageOutput())
    DrawingMode(4)
    UseImage(tempimg2)
    DrawImage(ImageID(),0,0)
    Ellipse(width*2,height*2,width*2,height*2,colour)
    Ellipse(width*2,height*2,width*2-1,height*2-1,colour)
    Ellipse(width*2,height*2,width*2-2,height*2-2,colour)
    Ellipse(width*2,height*2,width*2-3,height*2-3,colour)
    Ellipse(width*2,height*2,width*2-4,height*2-4,colour)
    Ellipse(width*2,height*2,width*2-5,height*2-5,colour)
  StopDrawing()
  
  ResizeImage(tempimg,width,height)
  UseImage(ImNum)
  StartDrawing(ImageOutput())
    UseImage(tempimg)
    DrawImage(ImageID(),x,y)
  StopDrawing()
  FreeImage(tempimg)
  FreeImage(tempimg2)
EndProcedure


OpenWindow(0,0,0,400,400,#PB_Window_SystemMenu | #PB_Window_ScreenCentered,"test")

UseJPEGImageDecoder()

CreateImage(1,400,400)
StartDrawing(ImageOutput())
  DrawingMode(0)
  Box(0,0,400,400,$0000FF)
  DrawingMode(4)
  For temp=0 To 400 Step 20
    Line(0,temp,temp,-temp,$FF0000)
    Line(temp,400,400-temp,temp-400)
    Line(temp,0,400-temp,400-temp)
    Line(0,temp,400-temp,400-temp)
  Next
  Ellipse(280,280,100,100,$00FF00)
StopDrawing()


SmoothEllipse(1,84,87,200,200,$00FF00)

CreateGadgetList(WindowID())
ImageGadget(0,0,0,400,400,UseImage(1))

Repeat
Until WaitWindowEvent()=#PB_Event_CloseWindow

Its making use of the fact that resizing in PB will anti-alias automatically. The example lets you compare it to a normally drawn ellipse, and I think it is an improvement.

Posted: **Tue Aug 17, 2004 12:49 am**

Thank you, although it generates errors for me because you're using variables for UseImage(), etc. I'll see if I can learn anything from it, though.

I didn't know PB antialiased when resizing, I'm happy that you told me that.

Posted: **Tue Aug 17, 2004 10:47 am**

Hmm I dont know why it would generate an error, it runs fine for me. Are you running the latest version of PB?

Posted: **Tue Aug 17, 2004 12:15 pm**

Actually, if that other one doesnt work for you, I have one you can try. I decided I would try to write a set of anti-aliased shape commands. Here's my first attempt at an ellipse one. Two problems: firstly, its far too slow to be used in realtime and secondly, it produces bad results when the ellipse is too thin. I think I know how to fix this, and I will hopefully make a whole set of anti-aliased shape commands and release them, but in the meantime, here's something to use.

Code: Select all

Procedure.f Dist(x1,y1,x2,y2)
  ProcedureReturn Sqr(Pow(x2-x1,2)+Pow(y2-y1,2))
EndProcedure 

Procedure SmoothEllipse(ImNum,x,y,radiusX,radiusY,colour)
  UseImage(ImNum)
  StartDrawing(ImageOutput())
    For tempx = -radiusX To RadiusX
      For tempy = -radiusY To radiusY
        rdist.f=Dist(0,0,tempx,tempy)
        tempang.f=ATan(tempx/tempy)
        pdist.f=Sqr((Pow(radiusY,2)*Pow(radiusX,2))/(Pow(radiusX,2)*Pow(Cos(tempang),2)+Pow(radiusY,2)*Pow(Sin(tempang),2)))
        tempnear.f=(pdist-rdist-(1.5))/(1.5)
        If tempnear>-1 And tempnear<1
          xpos=tempx+x
          ypos=tempy+y
          tempred=Red(colour)+((Red(Point(xpos,ypos))-Red(colour))*(Abs(tempnear)))
          tempblue=Blue(colour)+((Blue(Point(xpos,ypos))-Blue(colour))*(Abs(tempnear)))
          tempgreen=Green(colour)+((Green(Point(xpos,ypos))-Green(colour))*(Abs(tempnear)))
          If xpos>-1 And xpos<ImageWidth() And ypos>-1 And ypos<ImageHeight()
            Plot(xpos,ypos,RGB(tempred,tempgreen,tempblue))
          EndIf
        EndIf
      Next
    Next
  StopDrawing()
EndProcedure

OpenWindow(0,0,0,400,400,#PB_Window_SystemMenu | #PB_Window_ScreenCentered,"test")
CreateImage(0,400,400)
SmoothEllipse(0,190,190,170,130,$A0BF9F)
SmoothEllipse(0,200,200,30,30,$FF0000)

CreateGadgetList(WindowID(0))
ImageGadget(0,0,0,400,400,UseImage(0))

Repeat
Until WaitWindowEvent()=#PB_Event_CloseWindow

Dont forget to turn off the debugger, or it really is very slow.

Posted: **Tue Aug 17, 2004 8:54 pm**

GreenGiant wrote:Hmm I dont know why it would generate an error, it runs fine for me. Are you running the latest version of PB?

3.90, probably not the latest... Where might I see what changes have been made to consider downloading an update?

Posted: **Tue Aug 17, 2004 8:56 pm**

GreenGiant wrote:Actually, if that other one doesnt work for you, I have one you can try. I decided I would try to write a set of anti-aliased shape commands. Here's my first attempt at an ellipse one. Two problems: firstly, its far too slow to be used in realtime and secondly, it produces bad results when the ellipse is too thin. I think I know how to fix this, and I will hopefully make a whole set of anti-aliased shape commands and release them, but in the meantime, here's something to use.

Code: Select all

Procedure.f Dist(x1,y1,x2,y2)
  ProcedureReturn Sqr(Pow(x2-x1,2)+Pow(y2-y1,2))
EndProcedure 

Procedure SmoothEllipse(ImNum,x,y,radiusX,radiusY,colour)
  UseImage(ImNum)
  StartDrawing(ImageOutput())
    For tempx = -radiusX To RadiusX
      For tempy = -radiusY To radiusY
        rdist.f=Dist(0,0,tempx,tempy)
        tempang.f=ATan(tempx/tempy)
        pdist.f=Sqr((Pow(radiusY,2)*Pow(radiusX,2))/(Pow(radiusX,2)*Pow(Cos(tempang),2)+Pow(radiusY,2)*Pow(Sin(tempang),2)))
        tempnear.f=(pdist-rdist-(1.5))/(1.5)
        If tempnear>-1 And tempnear<1
          xpos=tempx+x
          ypos=tempy+y
          tempred=Red(colour)+((Red(Point(xpos,ypos))-Red(colour))*(Abs(tempnear)))
          tempblue=Blue(colour)+((Blue(Point(xpos,ypos))-Blue(colour))*(Abs(tempnear)))
          tempgreen=Green(colour)+((Green(Point(xpos,ypos))-Green(colour))*(Abs(tempnear)))
          If xpos>-1 And xpos<ImageWidth() And ypos>-1 And ypos<ImageHeight()
            Plot(xpos,ypos,RGB(tempred,tempgreen,tempblue))
          EndIf
        EndIf
      Next
    Next
  StopDrawing()
EndProcedure

OpenWindow(0,0,0,400,400,#PB_Window_SystemMenu | #PB_Window_ScreenCentered,"test")
CreateImage(0,400,400)
SmoothEllipse(0,190,190,170,130,$A0BF9F)
SmoothEllipse(0,200,200,30,30,$FF0000)

CreateGadgetList(WindowID(0))
ImageGadget(0,0,0,400,400,UseImage(0))

Repeat
Until WaitWindowEvent()=#PB_Event_CloseWindow

Dont forget to turn off the debugger, or it really is very slow.

I'm sorry, I would really prefer to use it in realtime, and I haven't been able to buy PB, so the debugger is forced. The other script will be much more useful to me. :-/

PureBasic Forums - English

Mouse / Window Boundaries and Smooth Circle

Mouse / Window Boundaries and Smooth Circle