Sending data to the shader

OpenGL
1

Let’s assume that I have a structure:

struct Points
{
float r,g,b;
float a,b,c;
float x[9],y[9],z[9];

};
Points Table[100];

I am sending first and second data from this structure to the shader as follows

positionLoc = glGetAttribLocation( shader, “inPosition” );
positionLoc2 = glGetAttribLocation( shader, “inPosition2” );

glVertexAttribPointer(positionLoc ,3,GL_FLOAT,0,sizeof(Points),BUFFER_OFFSET(sizeof(float) * 0));
glVertexAttribPointer(positionLoc2 ,3,GL_FLOAT,0,sizeof(Points),BUFFER_OFFSET(sizeof(float) * 3));

My question is: how send last data ( float x[9],y[9],z[9] ) from the struct to the shader ?

2

Well, a first question would be… what is this data?

OK, a first-first question is this: do you mean “float x[9],y[9],z[9];” as you said the first time, or “int x[9],y[9],z[9]” as you said the second?

Either way, it’s not a good idea to transfer this kind of data. If you want to transfer an array of 9 XYZs (for some reason), then you need to provide it that way: an array of 9 XYZs. Not an array of 9 Xs, 9 Ys, and 9 Zs.

You can send it that way, but it’ll be a big pain to access in your shader.

3

It can sometimes be easier to access big data structures like this via texture buffer objects and access the buffer object in the vertex shader via a vertex texture fetch.

4

I changed the array how you advised but still I don’t know how to send this array from the structure to the shader.

struct Points
{
float r,g,b;
float a,b,c;
float xyz[18];

};

5

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