Sorry I forgot to paste how i create the vpos pointer vpos := NativeBoost allocate: vptrsize.
My questions on how to pass the contents of a C array to a C function as can be seen in quoted message remains :) kilon wrote > 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 < >> thekilon@.co >> > 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. -- View this message in context: http://forum.world.st/Understanding-NBOpenGL-tp4686514p4696667.html Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.
