[Newbies] How to draw a single pixel with permanence?

[Lawson English]

Bert Freudenberg wrote:
> On 29.04.2010, at 14:44, Lawson English wrote:
>   
>> Bert Freudenberg wrote:
>>     
>>> On 29.04.2010, at 13:15, Lawson English wrote:
>>>  
>>>       
>>>> I'm trying to go back to beginnings with my own ManelBrot morph because I can quite grok how the one I have works.
>>>>
>>>> Mostly because I still dont grok morphs.
>>>>
>>>> Example: I'm trying to plot points on a morph using the drawOn message below:
>>>>    
>>>>         
>>> Paint into a Form. Draw the form in #drawOn:.
>>>
>>>
>>>  
>>>       
>> I'm sorry, I don't understand.
>>
>> Isn't this "painting" into a Form?
>>
>> aCanvas  form  colorAt: 30 at 30 put: Color black.
>>     
>
> No, that's painting directly onto the Display (a.k.a. the canvas's form), which is considered bad style in Morphic. 
>
>   
>> My problem is that the pixel doesn't stay set.
>>     
>
> 30 at 30 would be in the upper-left corner of the Display. Unless your morph covers that, you won't see it.
>   
well, when I'm dragging the morph around it draws next to the cursor and 
when I release, it doesn't draw in the upper-left corner of the display.


> You might try "self topLeft + (30 at 30)" but again, that's bad style.
>
> In any case, I thought your question was about displaying the Mandelbrot set. It would be wise to paint that into a form, preferably in a background process. Then just update the display (by drawing the form) once a second until it's finished.
>
> - Bert -
>
>   

My  point is, how do I "paint it" into a form and then display it? If 
somehow I'm misinterpreting what I'm seeing: that it DOES draw within 
the bounds of the morph, then I'm quite happy to use

aCanvas form colarAt: (self topLeft + (30 at 30) ) put: Color black.


my question concerns getting what I've poked into the form to stay on 
the screen after I've released the mouse. Obviously I'm not caching the 
results as I thought I was.


Lawson