Thanks Igor , yes I was aware of String Cr because I have done some googling
around and it did find information on the subject. Apparently it failed
because I had an error in my source.
So for our next challenge is learning how to fetch data that a pointer
points to.
in this case I have an array that contains my vertex positions , called
vertexPositions
vertexPositions
"the positions of vertices to be passed to opengl"
^ #( 0.75 0.75 0.0 1.0
0.75 -0.75 0.0 1.0
-0.75 -0.75 0.0 1.0 )
so far so good
so I create a pointer for that array
vptrsize := (NBExternalType sizeOf: 'float')* self vertexPositions size.
and then take that pointer and insert in each position the individual values
from vertexPositions
vertexPositions withIndexDo: [:each :i |
"using nbUInt32AtOffset because we know pointer is 4 bytes :) "
vpos nbFloat32AtOffset: (i-1)*(NBExternalType sizeOf: 'float') put:
each value.
Transcript show: ' I am putting to vpos in index: '; show: i-1; show:'
value: '; show: each value; cr.
].
so far so good.
now the tricky part is that I have a function that expects that Array , not
the smalltalk version but the C version we just created
gl bufferData_target: GL_ARRAY_BUFFER size: vptrsize data: ....... usage:
GL_STATIC_DRAW.
where you see the dots is where I should pass the data, in this case the C
array
I could do a vpo nbFloat32AtOffset: but that will return me only the
individual value at the specific point (index) of the array, while I want to
pass the entire array.
So how I do that ?
I explored NBExternalAdress and I cant find something that would return an
array. Am I missing something obvious here ?
NBExternalAdress value , returns the number of the address and not that data
contained in that address.
I also see a NBExternalArray but I am not sure if it is what I should be
using .
Igor Stasenko wrote
> On 30 June 2013 21:11, kilon <
> [email protected]
> > wrote:
>> I am not going to post my code here cause it has become too big , you can
>> find it here
>>
>> http://www.smalltalkhub.com/#!/~kilon/GLTutorial
>> <http://www.smalltalkhub.com/#!/~kilon/GLTutorial>
>>
>> I tried adding newlines with String cr to my shaders strings, but
>> apparently
>> opengl is not convinced. It looks like smalltalk cr is not converted to C
>> "\n" newlines. So how I do that ?
>>
>
> simply replace all occurences of
> Character cr
> with
> Character lf
> (or crlf, if it wants that)
>
>> --
>> View this message in context:
>> http://forum.world.st/Understanding-NBOpenGL-tp4686514p4696465.html
>> Sent from the Pharo Smalltalk Developers mailing list archive at
>> Nabble.com.
>>
>
>
>
> --
> Best regards,
> Igor Stasenko.
--
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