2d grid drawing GL_QUADS

gl quads.py

"""
in   in_colors  v  d=[[]]  n=0
out  dummy_out  s
"""
import math

import bgl
import bpy

from sverchok.data_structure import node_id
from sverchok.ui import nodeview_bgl_viewer_draw_mk2 as nvBGL2


def get_location(i):
    items_wide = 40
    offset_x = 5
    offset_y = 5
    x = offset_x * (i % items_wide)
    y = offset_y * math.floor(i / items_wide)
    return [x, y]


self.n_id = node_id(self)
nvBGL2.callback_disable(self.n_id)


def simple_color_viewer_nvBGL(x, y, args):

    colors = args[0]
    size = 10.0
    
    bgl.glEnable(bgl.GL_POINT_SMOOTH)
    bgl.glPointSize(size)
    bgl.glBlendFunc(bgl.GL_SRC_ALPHA, bgl.GL_ONE_MINUS_SRC_ALPHA)
    
    for color_list in colors:

        bgl.glBegin(bgl.GL_QUADS)
        for idx, color in enumerate(color_list):
            bgl.glColor4f(*color)
            coord = get_location(idx)
            tx = coord[0] + x
            ty = coord[1] + y

            w = size//2
            h = size//2        
            coords = [(tx, ty), (tx+w, ty), (w+tx, ty-h), (tx, ty-h)]
            for coord in coords:
                bgl.glVertex2f(*coord)            
            
        bgl.glEnd()

    
    bgl.glDisable(bgl.GL_POINT_SMOOTH)
    bgl.glDisable(bgl.GL_POINTS)
        
socket = self.inputs['in_colors']
if socket.links:

    draw_data = {
        'tree_name': self.id_data.name[:],
        'mode': 'custom_function',
        'custom_function': simple_color_viewer_nvBGL,    
        'loc': (self.location[:]),
        'args': (socket.sv_get(),)
    }

    nvBGL2.callback_enable(self.n_id, draw_data)