# DrawDots bug

**URL:** <https://psychtoolbox.discourse.group/t/drawdots-bug/1432>\
**Category:** Uncategorized\
**Created:** [July 15, 2007, 8:37am UTC](https://psychtoolbox.discourse.group/t/drawdots-bug/1432 "2007-07-15T08:37:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [July 15, 2007, 8:37am UTC](https://psychtoolbox.discourse.group/t/drawdots-bug/1432/1 "2007-07-15T08:37:33Z")

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Hi all,  
  
I recently updated to the latest current version of psychtoolbox and  
realized now I cannot draw a circle dot by DrawDots command anymore.  
Here is the syntax in my program:  
  
Screen('BlendFunction', w, GL\_SRC\_ALPHA, GL\_ONE\_MINUS\_SRC\_ALPHA);  
...  
Screen('DrawDots', w, [center(1) center(2)]',LEDradius,[255 0 0]',[],1);  
  
Now it always draws a square dot instead of a circle... I am really  
frustrated with the problem so please, any help is much appreciated!!!  
  
Thanks!

---

<div class="post-metadata">

**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [July 16, 2007, 2:30am UTC](https://psychtoolbox.discourse.group/t/drawdots-bug/1432/2 "2007-07-16T02:30:27Z")

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Actually I found out the problem: It is because of Bootcamp 1.3 with  
it keyboard control program has taken over the alpha-blending screen  
control in Windows. Eventhough I still have no clue how to solve the  
problem, at least it points out that the psychtoolbox DrawDots  
function is not buggy.  
  
Thanks.  
  

> --- In [psychtoolbox@yahoogroups.com](mailto:psychtoolbox@yahoogroups.com), "concuagia" \<concuagia@...\> wrote:  
> \>  
> \> Hi all,  
> \>   
> \> I recently updated to the latest current version of psychtoolbox and  
> \> realized now I cannot draw a circle dot by DrawDots command anymore.  
> \> Here is the syntax in my program:  
> \>   
> \> Screen('BlendFunction', w, GL\_SRC\_ALPHA, GL\_ONE\_MINUS\_SRC\_ALPHA);  
> \> ...  
> \> Screen('DrawDots', w, [center(1) center(2)]',LEDradius,[255 0 0]',[],1);  
> \>   
> \> Now it always draws a square dot instead of a circle... I am really  
> \> frustrated with the problem so please, any help is much appreciated!!!  
> \>   
> \> Thanks!  
> \>