#version 150

out vec4 v;
uniform mat4 proj;
uniform mat4 model;
uniform int gridSize; //cubic, width=height=length=gridSize

int main()
{
    int index = gl_VertexID;
    int zindex = index / (gridSize*gridSize);
    int yindex = (index - zindex*(gridSize*gridSize)) / gridSize;
    int xindex = index % gridSize;

    v = proj * model * vec4(float(xindex), float(yindex), float(zindex), 1.0);
    gl_Position = v;
}