tex scaling that works

tex_scaling_working.py

"""
texture that scales over time.
Thanks go rdb for help
"""
import numpy as np 
from direct.showbase.ShowBase import ShowBase
from panda3d.core import Texture, CardMaker, TextureStage
from direct.task import Task
from panda3d.core import TransformState

def make_circle_tex(texture_size = 512, circle_center = (0, 0), circle_radius = 50):
    x = np.linspace(-texture_size/2, texture_size/2, texture_size)
    y = np.linspace(-texture_size/2, texture_size/2, texture_size)
    X, Y = np.meshgrid(x, y)
    circle_texture = np.zeros((texture_size, texture_size), dtype = np.uint8)
    circle_mask = (X - circle_center[0])**2 + (Y - circle_center[1])**2 <= circle_radius**2
    circle_texture[circle_mask] = 255
    return np.uint8(circle_texture)


class TexScaler(ShowBase):
    """
    Show a single full-field texture that scales up or down in time, starting after 1 second.
    """
    def __init__(self, texture_array, scale = 0.2, window_size = 512, texture_size = 512):
        super().__init__()
        self.scale = scale       
        self.current_scale = 1
        self.texture_array = texture_array
        self.texture_dtype = type(self.texture_array.flat[0])
        self.ndims = self.texture_array.ndim
        self.center_shift = TransformState.make_pos2d((-0.5, -0.5))
        self.shift_back = TransformState.make_pos2d((0.5, 0.5))
       
        #Create texture stage
        self.texture = Texture("Stimulus")
        self.texture.setup2dTexture(texture_size, texture_size, 
                               Texture.T_unsigned_byte, Texture.F_luminance)  
        self.texture.setWrapU(Texture.WM_clamp)
        self.texture.setWrapV(Texture.WM_clamp)
        self.texture.setRamImageAs(self.texture_array, "L")        
        self.textureStage = TextureStage("Stimulus")
                                                                    
        #Create scenegraph
        cm = CardMaker('card1')
        cm.setFrameFullscreenQuad()
        self.card1 = self.aspect2d.attachNewNode(cm.generate())  
        self.card1.setTexture(self.textureStage, self.texture)  #ts, tx
              
        if self.scale != 0:
            self.taskMgr.add(self.scaleTextureTask, "scaleTextureTask")
        
    #Scale the texture
    def scaleTextureTask(self, task):
        if task.time > 1:
            self.current_scale *= 1/self.scale
            scale_transform = TransformState.make_scale2d(self.current_scale)
            full_transform = self.shift_back.compose(scale_transform.compose(self.center_shift))
            self.card1.setTexTransform(self.textureStage, full_transform)
            
        return Task.cont       
           
if __name__ == '__main__':
    circle_texture = make_circle_tex()
    #Try scale < 1: expect (single) circle to shrink
    circle_scaling = TexScaler(circle_texture, scale = 0.99)
    #Try scale > 1: expect circle to dilate
    #circle_scaling = TexScaler(circle_texture, scale = 1.02)
    circle_scaling.run()