vispy_minimal.py

import time

import threading
import atexit
import numpy as np

from vispy import app, scene, gloo, visuals


rolling_tex = """
float rolling_texture(vec2 pos) {
    if( pos.x < 0 || pos.x > 1 || pos.y < 0 || pos.y > 1) {
        return 0.0f;
    }
    vec2 uv = vec2(mod(pos.x, 1), pos.y);
    return texture2D($texture, uv).r;
}
"""

cmap = """
vec4 colormap(float x) {
    if(x == 1){
        return vec4(0,255,0,1);
    } if(x == 12345) {  // TODO: VERY VERY VERY DIRTY HACK
        return vec4(255,0,0,1);
    }
    return vec4(x,x,x,1);
}
"""


class ScrollingImage(scene.Image):
    def __init__(self, shape, parent):
        self._shape = shape
        self._color_fn = visuals.shaders.Function(rolling_tex)
        self._ctex = gloo.Texture2D(np.zeros(shape+(1,), dtype='float32'),
                                    format='luminance', internalformat='r32f')
        self._color_fn['texture'] = self._ctex
#        self._color_fn['shift'] = 0
        self.ptr = 0
        scene.Image.__init__(self, method='impostor', parent=parent)
        # self.set_gl_state('additive', cull_face=False)
        self.shared_program.frag['get_data'] = self._color_fn
        cfun = visuals.shaders.Function(cmap)
        self.shared_program.frag['color_transform'] = cfun

    @property
    def size(self):
        return self._shape

    def add_bar(self, bar_height):
        print(bar_height, end=',')
        bar = np.zeros((self._shape[0],1,1), dtype=np.float32)
        bar[0:bar_height] = 1
        
        self._ctex[:, self.ptr] = bar

        self.ptr = (self.ptr + 1) % self._shape[1]
        self.update()

    def _prepare_draw(self, view):
        # hacky progressbar
        from_ = (self.ptr + 1) % self._shape[1]
        to_ = (self.ptr + 3) % self._shape[1]
        if(to_ > from_):
            self._ctex[:, from_:to_] = np.full((self._shape[0], 1,1), 12345, dtype=np.float32)

        if self._need_vertex_update:
            self._build_vertex_data()

        if view._need_method_update:
            self._update_method(view)


HEIGHT = 750
WIDTH = 500

GRID_COLS = 8
GRID_ROWS = 5

def visualize():

    win = scene.SceneCanvas(keys='interactive', show=True, fullscreen=False)
    grid = win.central_widget.add_grid()

    view3 = grid.add_view(
                row=0,
                col=1,
                row_span=GRID_ROWS,
                col_span=GRID_COLS,
                camera='panzoom',
                border_color='grey')

    #image = ScrollingImage((SAMPLES_PER_SECOND*5, HEIGHT), parent=view3.scene)
    image = ScrollingImage((HEIGHT, WIDTH), parent=view3.scene)
    view3.camera.rect = (0, 0, image.size[1], image.size[0])
    gridlines = scene.GridLines(color=(1, 1, 1, 1), parent=image)

    print(image.size)

    # Add axes                                                                  
    yax = scene.AxisWidget(orientation='left', axis_label="Counts")             
    ##yax.stretch = (0.05, 1)                                                   
    grid.add_widget(yax, 0, 0, row_span=GRID_ROWS)                              
    yax.link_view(view3)

    xax = scene.AxisWidget(orientation='bottom', tick_label_margin=15)
    grid.add_widget(xax, GRID_ROWS, 1, col_span=GRID_COLS)                      
    xax.link_view(view3)

    last_height = 0
    def update(ev):
        nonlocal last_height
        height = (last_height + 10) % HEIGHT
        image.add_bar(height)
        last_height = height

    timer = app.Timer(interval='auto', connect=update)
    timer.start()
    app.run()

if __name__ == '__main__':
    visualize()