How do I change blend modes with gpu.state.blend_set()?

Archive Python API
1

I’ve been trying to use blend_set() with no success if I select any option other than “ALPHA” it simply displays nothing and I cant figure out why.

I took the simplest example from the documentation, and trying to call blend_set breaks it.
how am I supposed to use this function?

import bpy
import gpu
from gpu_extras.batch import batch_for_shader

coords = [(1, 1, 1), (-2, 0, 0), (-2, -1, 3), (0, 1, 1)]
shader = gpu.shader.from_builtin('3D_UNIFORM_COLOR')
batch = batch_for_shader(shader, 'LINES', {"pos": coords})


def draw():
    gpu.state.blend_set('MULTIPLY') # adding this line breaks rendering
    shader.bind()
    shader.uniform_float("color", (1, 1, 0, 1))
    batch.draw(shader)

bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_VIEW')

I’d really like to draw lines in multiply blend mode for an addon I’m working on because they are more visible on a wider range of conditions.

2

After googling for a while i cant even find examples of using this function for anything other than “ALPHA” blend.
Does it even work?