The changes are:
- The shader now is passed as a parameter of the batch `draw` method (batch.draw(shader)). Since the batch always has to set a shader before drawing;
- The batch methods to specify a value to a uniform have been removed. Uniforms are parameters of the program (here called shader). If you change a uniform, it changes in all batchs that use the same program;
- New methods were added to set uniforms by the shader;
- The `batch.program_set_builtin` was removed. It is a duplicate of `program_set` but without a shader object. We need the shader object to configure the uniform;
Differential Revision: https://developer.blender.org/D3752
Maybe it's still early to set the new drawing api for python.
But joining these two modules is an initial step.
```
>>> gpu.
matrix
select
types
```
```
>>> gpu.types.GPU
Batch(
OffScreen(
VertBuf(
VertFormat(
```
The creation of a new offscreen object is now done by the `GPUOffscreen.__new__` method.
Reviewers: campbellbarton, dfelinto
Reviewed By: campbellbarton, dfelinto
Tags: #bf_blender_2.8
Differential Revision: https://developer.blender.org/D3667
