Vertex Array Sample??

OpenGL Development JOGL Development
#1

Hi to all …
have someone some example of usign java.nio.buffer for this opengl calls?

gl.glVertexPointer(int p1, gl.GL_FLOAT, 0, Buffer);
gl.glTexCoordPointer(2, gl.GL_FLOAT, 0, Buffer);

how do i can fills the buffers?
and … when i must do it?

#2

  1. allocate a direct, native ordered {Byte, Float, Int}Buffer per data set using net.java.games.jogl.util.BufferUtils

  2. fill each buffer with data (using put(int[]) for example)

  3. enable GL states with glEnableClientState(GL_VERTEX_ARRAY) and glEnableClientState(GL_TEXTURE_COORD_ARRAY)

  4. bind buffers :
    glVertexPointer(3, GL_INT, 0, vertices);
    glColorPointer(3, GL_FLOAT, 0, colors);

  5. draw with glDrawArrays (draw everything) or glDrawElements (draw only a subset)

Some comments :

  • even though you can use a single buffer to store all your vertex, texture coord, color and normal data, it is IMO easier to keep them in separate buffers

  • usually you’ll only need to enable vertex array states once, in the init method

  • when you bind a buffer, data can be copied but it is not a requirement ; therefore when you modify your buffer you must rebind it