Anyone offer me an example using glMultiDrawArraysIndirect with JOGL? - opengl

Question

I learned the method glMultiDrawArraysIndirect() from OpenGL, and I want to use this method call with JOGL. In the sample code, a C++ struct is used and the data in that struct is stored in a buffer by using glMapBufferRange(). I was wondering how it is down with JOGL? It would be great if there is any example.
Here is the sample code using OpenGL:
struct DrawArraysIndirectCommand
{
GLuint count;
GLuint primCount;
GLuint first;
GLuint baseInstance;
};
load_shaders();
object.load("media/objects/asteroids.sbm");
glGenBuffers(1, &indirect_draw_buffer);
glBindBuffer(GL_DRAW_INDIRECT_BUFFER, indirect_draw_buffer);
glBufferData(GL_DRAW_INDIRECT_BUFFER,
NUM_DRAWS * sizeof(DrawArraysIndirectCommand),
NULL,
GL_STATIC_DRAW);
DrawArraysIndirectCommand * cmd = (DrawArraysIndirectCommand *)
glMapBufferRange(GL_DRAW_INDIRECT_BUFFER,
0,
NUM_DRAWS * sizeof(DrawArraysIndirectCommand),
GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
for (i = 0; i < NUM_DRAWS; i++)
{
object.get_sub_object_info(i % object.get_sub_object_count(),
cmd[i].first,
cmd[i].count);
cmd[i].primCount = 1;
cmd[i].baseInstance = i;
}
glUnmapBuffer(GL_DRAW_INDIRECT_BUFFER);

Answer 1

You can see the struct is just 4 gluint one after the other, you will need to imitate that:
ByteBuffer cmd = gl.glMapBufferRange(GL_DRAW_INDIRECT_BUFFER,
0,
NUM_DRAWS * 4 * 4,
GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
for (int i = 0; i < NUM_DRAWS; i++)
{
int first = object.get_sub_object_info_first(i % object.get_sub_object_count());
int count = object.get_sub_object_info_count(i % object.get_sub_object_count());
int primCount = 1;
int baseInstance = i;
cmd.putInt(count);
cmd.putInt(primCount);
cmd.putInt(first);
cmd.putInt(basInstance);
}