How to call pdb.gimp_pencil in Gimp Python-fu plugin - gimp

Question

I'm trying to automate the task of drawing lines with Gimp.
So I tried the scripting feature with no luck so far.
>>>from pprint import pprint
>>>img = gimp.Image(200, 200, RGB)
>>>pprint (pdb.gimp_pencil.params)
((16, 'drawable', 'The affected drawable'),
(0,
'num-strokes',
'Number of stroke control points (count each coordinate as 2 points) (num-strokes >= 2)'),
(8,
'strokes',
'Array of stroke coordinates: { s1.x, s1.y, s2.x, s2.y, ..., sn.x, sn.y }'))
>>>pdb.gimp_pencil(img, 4, [0,0,200,200] )
Traceback (most recent call last):
File "<input>", line 1, in <module>
TypeError: wrong parameter type
I couldn't find any example of passing a vector (Array of stroke coordinates) in Python for Gimp
What's wrong here?

Answer 1

Ok my mistake, I assumed the TypeError was on the last array argument. As it happens img is not the drawable, hence the TypeError.
You have to:
create an image
create a layer
add the layer to the image
set the layer active
obtain the active drawable of the image
Then only you can use this drawable in the gimp_pencil() method.
img = gimp.Image(200, 200, RGB)
layer = gimp.Layer(img, "Test", 200, 200, RGBA_IMAGE, 100, NORMAL_MODE)
img.add_layer(layer, -1)
pdb.gimp_image_set_active_layer(img, layer)
draw = pdb.gimp_image_get_active_drawable(img)
pdb.gimp_pencil(draw, 4, [0,0,100,100])
disp1 = gimp.Display(img)