gui_direct.py

"""
Direct integration of glfw and wgpu-py without using the
wgpu.gui Canvas abstraction/class hierarchy.

Demonstration for hardcore users that need total low-level control.

"""

# run_example = false

import time
import atexit

import glfw

from wgpu.backends.wgpu_native import GPUCanvasContext
from wgpu.gui.glfw import get_glfw_present_methods, poll_glfw_briefly

# from triangle import setup_drawing_sync
from cube import setup_drawing_sync

# Setup glfw
glfw.init()
atexit.register(glfw.terminate)


class MinimalGlfwCanvas:  # implements WgpuCanvasInterface
    """Minimal canvas interface required by wgpu."""

    def __init__(self, title):
        # disable automatic API selection, we are not using opengl
        glfw.window_hint(glfw.CLIENT_API, glfw.NO_API)
        glfw.window_hint(glfw.RESIZABLE, True)

        self.window = glfw.create_window(640, 480, title, None, None)
        self.context = GPUCanvasContext(self, get_glfw_present_methods(self.window))

    def get_physical_size(self):
        """get framebuffer size in integer pixels"""
        psize = glfw.get_framebuffer_size(self.window)
        return int(psize[0]), int(psize[1])

    def get_context(self, kind="wgpu"):
        return self.context


def main():
    # create canvas
    canvas = MinimalGlfwCanvas("wgpu gui direct")
    draw_frame = setup_drawing_sync(canvas)

    last_frame_time = time.perf_counter()
    frame_count = 0

    # render loop
    while not glfw.window_should_close(canvas.window):
        # process inputs
        glfw.poll_events()
        # draw a frame
        draw_frame()
        # present the frame to the screen
        canvas.context.present()
        # stats
        frame_count += 1
        etime = time.perf_counter() - last_frame_time
        if etime > 1:
            print(f"{frame_count / etime:0.1f} FPS")
            last_frame_time, frame_count = time.perf_counter(), 0

    # dispose resources
    glfw.destroy_window(canvas.window)
    poll_glfw_briefly()


if __name__ == "__main__":
    main()