Source code for simvx.core.nodes_3d.text

"""Text3D -- 3D-projected text node."""

from __future__ import annotations

import numpy as np

from ..descriptors import Property
from .node3d import Node3D




class Text3D(Node3D):
    """Text that floats at a 3D world position, projected to screen."""

    text = Property("", hint="Text to display")
    font_scale = Property(1.0, range=(0.1, 100.0), hint="Font size")
    font_colour = Property((1.0, 1.0, 1.0, 1.0), hint="RGBA colour (0.0-1.0)")



    def draw(self, renderer):
        if not self.text:
            return
        vp = getattr(renderer, '_view_proj', None)
        if vp is None:
            return
        pos = self.world_position
        pos4 = np.array([pos.x, pos.y, pos.z, 1.0], dtype=np.float32)
        clip = vp @ pos4
        if clip[3] <= 0:
            return  # behind camera
        ndc_x = clip[0] / clip[3]
        ndc_y = clip[1] / clip[3]
        sx = (ndc_x * 0.5 + 0.5) * renderer.width
        sy = (1.0 - (ndc_y * 0.5 + 0.5)) * renderer.height
        colour = tuple(self.font_colour)
        renderer.draw_text(self.text, (sx, sy),
                           scale=self.font_scale, colour=colour)