GPUBatch.draw supports basic drawing methods. Although all
supported GPU backends support range based and instance based drawing.
This patch adds 2 methods to GPUBatch to add support to range based and
instance based drawing.
my_batch.draw_range(my_shader, elem_start=10, elem_count=5)
Will draw my_batch using my_shader. From the attached index buffer
elements 10-14 will be drawn.
my_batch.draw_instance_range(my_shader, instance_start=0, instance_count=10)
will draw my_batch using my_shader 10 times. Inside the vertex
shader the current instance number is held by gl_InstanceID.
Pull Request #104457