[PD] GEM mapping units to pixels

[cyrille henry]

altern a écrit :
> hi
> 
> just tested it under linux and it does work, 
test2 or test3 work?

cyrille

>so this seems to be either 
> a windows issue or my laptop graphics card. any ideas?
> 
> enrike
> 
> cyrille henry(e)k dio:
>> hello,
>>
>> altern a écrit :
>>> hi
>>>
>>> do you mean something like the example attached?
>> yes, exactly.
>>
>>> This doesnt work ok for me, the shape should be 10x10 px and is not, 
>> a [rectangle 10 10] should be 20 pixel.
>>
>>> also x and y pos are dont match with window size. Translating to 400, 
>>> 300 should place the rect in top right corner but I get that with only 
>>> 320, 190,  so the units are not mapped to pixels
>> translating to 400 300 should move the center of the rectangle in the 
>> top right corner.
>> if your rectangle is 100 100, then you just have to move it 300 200 in 
>> order to have the corner of the rectangle in the corner of the gem window.
>>
>> your patch work that way here.
>>
>>
>>> but maybe i am missing something from what you describe?
>>>
>>> In opengl to achieve this 2D like-pixels to units effect i would
>>> set the perspective to be orthographical with glOrtho command, is 
>>> something like this possible in Gem?
>> yes, insert an [ortho] after the gemhead
>>
>>
>> cyrille
>>
>>> thanks!!
>>>
>>> enrike
>>>
>>> cyrille henry(e)k dio:
>>>> hello,
>>>>
>>>> i tried with :
>>>> dimen 400 300
>>>> view 0 0 1000 // 1000 is in order to put the camera far from the view 
>>>> point, to reduce space distortion
>>>> perspec 0 400 0 300 999 1001 // 999 and 1001 limit the render to 
>>>> primitive position is between -1 and 1 (because camera is at 1000)
>>>>
>>>>
>>>> and everything is working as expected.
>>>> i just have 1 strange thing : i need to set the [dimen<, [create<  , 
>>>> then [reset< and last [view< and [perspec< if i did not do a reset, a 
>>>> square is not rendered as a square but a rectangle.
>>>>
>>>> anyway, it's working.
>>>>
>>>> cyrille
>>>>
>>>>
>>>> altern a écrit :
>>>>> i tried to pass different view values to gemwin. I can see that in 
>>>>> order to be able to specify location or with with pixels i should 
>>>>> set view to
>>>>> view 0 0 2
>>>>> but as soon as i set that the shape is not there any more. This is 
>>>>> an example i am using to test. If i ser view to
>>>>> view 0 0 2.01
>>>>> it is almost there but if i set it to 0 0 2 it is not there any 
>>>>> more. I guess it might be because it is either beyond the back limit 
>>>>> y or behind the camera?
>>>>>
>>>>> thanks
>>>>>
>>>>> enrike
>>>>>
>>>>>
>>>>> altern(e)k dio:
>>>>>> hi
>>>>>>
>>>>>> I am trying to map GEM units to pixels so that i can position some
>>>>>> videos in the GEM window using pixels values. For this I understand 
>>>>>> that
>>>>>> i must match the projection values with the window size. So i am doing
>>>>>>
>>>>>> dimen 400 300
>>>>>> perspect 0 400 0 300 1 20
>>>>>>
>>>>>> and i render all objects at z position 1
>>>>>>
>>>>>> translateXYZ 100 100 1
>>>>>>
>>>>>> However I am getting a weird result, the units are far smaller that
>>>>>> pixels, so to move a video 100px in the x i need to change it x 
>>>>>> position
>>>>>> by 300 units or something like this. So I am not sure about what i am
>>>>>> doing wrong, I am familiar with OpenGL but i never played too much 
>>>>>> with
>>>>>> GEM before so I am still getting into it.
>>>>>>
>>>>>> Another small issue is that I would also like to reverse the Y so that
>>>>>> upper left is 0,0 and bottom left would be 0,200 for example, not sure
>>>>>> about how to change this. I guess it is to do with the gemwin settings
>>>>>> but i dont get it right.
>>>>>>
>>>>>> thanks
>>>>>>
>>>>>> enrike
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>>
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> #N canvas 393 156 429 320 10;
>>> #X obj 84 210 gemwin;
>>> #X obj 245 163 gemhead;
>>> #X msg 173 82 create \, 1;
>>> #X msg 293 106 0 \, destroy;
>>> #X floatatom 309 164 5 0 0 0 - - -;
>>> #X floatatom 347 164 5 0 0 0 - - -;
>>> #X floatatom 288 215 5 0 0 0 - - -;
>>> #X floatatom 332 215 5 0 0 0 - - -;
>>> #X obj 245 190 translateXYZ 10 10 1;
>>> #X msg 215 50 dimen 400 300;
>>> #X msg 48 73 view 0 0 1000;
>>> #X msg 9 48 perspec 0 400 0 300 999 1001;
>>> #X msg 110 99 reset;
>>> #X obj 50 -8 bng 15 250 50 0 empty empty empty 0 -6 0 10 -262144 -1
>>> -1;
>>> #X obj 50 13 t b b b b b;
>>> #X obj 245 234 rectangle 10 10;
>>> #X connect 1 0 8 0;
>>> #X connect 2 0 0 0;
>>> #X connect 3 0 0 0;
>>> #X connect 4 0 8 1;
>>> #X connect 5 0 8 2;
>>> #X connect 6 0 15 1;
>>> #X connect 7 0 15 2;
>>> #X connect 8 0 15 0;
>>> #X connect 9 0 0 0;
>>> #X connect 10 0 0 0;
>>> #X connect 11 0 0 0;
>>> #X connect 12 0 0 0;
>>> #X connect 13 0 14 0;
>>> #X connect 14 0 11 0;
>>> #X connect 14 1 10 0;
>>> #X connect 14 2 12 0;
>>> #X connect 14 3 2 0;
>>> #X connect 14 4 9 0;
>>>
> 
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