vertex-buffer

In my cross platform OpenGL application I want to draw using vertex buffer objects. However I run into problems invoking glDrawRangeElements. glDrawRangeElements(GL_TRIANGLES, start, start + count, count, GL_UNSIGNED_INT, static_cast<GLvoid *> (start * sizeof(unsigned int))); The compiler (CLang on Mac OS X) does not like the last argument "error: cannot cast from type 'unsigned long' to pointer type 'GLvoid *' (aka 'void *')". OpenGL API defines the type of last arguments as const GLvoid * and expects a pointer when this api is used with vertex arrays. However I understand that when vertex

What is the PyOpenGL equivalent of #define BUFFER_OFFSET(i) (reinterpret_cast<void*>(i)) glDrawElements(GL_TRIANGLE_STRIP, count, GL_UNSIGNED_SHORT, BUFFER_OFFSET(offset)) If the offset is 0, then glDrawElements(GL_TRIANGLE_STRIP, count, GL_UNSIGNED_SHORT, None) works, but I can not figure out how to specify a non-zero offset into a buffer object. You're supposed to pass a ctypes void pointer, which can constructed by : ctypes.c_void_p(offset) There seems to be a more PyOpenGL specific option using a VBO class, and gotcha with some versions of PyOpenGL according to this . Mārtiņš Možeiko You

You usually get a speed up when you use interleaved VBOs instead of using multiple VBOs. Is this also valid when using VAOs? Because it's much more convenient to have a VBO for the positions, and one for the normals etc. And you can use one VBO in multiple VAOs. VAOs For sharing larger data sets, a dedicated buffer containing a single vertex (attrib) array is surely a way to go, while one could still interleave specific arrays in another buffer and combine them using a VAO. A VAO handles the binding of all those buffers and the vertex (attrib) array states such as array buffer bindings and