callbacks.py

import mujoco
import sys
import os
import glfw
import imageio
import numpy as np
from threading import Lock


class CallBacks:
    """
    self._key_callback() : key presse handler [on screen info]
    self._scroll_callback() : mouse wheel scrolling handler [Y axis zoom]
    self._mouse_button_callback() : mouse button handler
        [Movement Tracking(pan-scroll-orbit),
        Double-click handling,
        Apply perturbations]
    self._cursor_pos_callback() : context management for perturbation and
                                    movement
    """

    def __init__(self, model, data, vopt, scn, cam, pert, image_dir=None):
        self.model = model
        self.data = data
        self.vopt = vopt
        self.scn = scn
        self.cam = cam
        self.pert = pert

        self._gui_lock = Lock()

        self._button_left_pressed = False
        self._button_right_pressed = False
        self._left_double_click_pressed = False
        self._right_double_click_pressed = False
        self._last_mouse_x = 0
        self._last_mouse_y = 0
        self._paused = False
        self._transparent = False
        self._contacts = False
        self._joints = False
        self._shadows = False
        self._wire_frame = False
        self._convex_hull_rendering = False
        self._inertias = False
        self._com = False
        self._render_every_frame = True
        self._advance_by_one_step = False
        self._run_speed = 1.0
        self._hide_menu = False
        self._hide_graph = False
        # CUSTOM:
        #   ARROW KEYS
        self._key_up = False
        self._key_down = False
        self._key_left = False
        self._key_right = False

        self._image_idx = 0
        if image_dir is None:
            self._image_dir = "/tmp"
        else:
            self._image_dir = image_dir
        self._image_path = "/frame_%07d.png"

        # glfw init
        glfw.init()
        width, height = glfw.get_video_mode(glfw.get_primary_monitor()).size
        self.window = glfw.create_window(
            width // 2, height // 2, "mujoco", None, None
        )
        glfw.make_context_current(self.window)
        glfw.swap_interval(1)

        framebuffer_width, framebuffer_height = glfw.get_framebuffer_size(
            self.window
        )
        window_width, _ = glfw.get_window_size(self.window)
        self._scale = framebuffer_width * 1.0 / window_width

        # set callbacks
        glfw.set_cursor_pos_callback(self.window, self._cursor_pos_callback)
        glfw.set_mouse_button_callback(
            self.window, self._mouse_button_callback
        )
        glfw.set_scroll_callback(self.window, self._scroll_callback)
        glfw.set_key_callback(self.window, self._key_callback)
        self._last_left_click_time = None
        self._last_right_click_time = None

        self.ctx = mujoco.MjrContext(
            self.model, mujoco.mjtFontScale.mjFONTSCALE_150.value
        )

        # get viewport
        self.viewport = mujoco.MjrRect(
            0, 0, framebuffer_width, framebuffer_height
        )

    def get_viewport_width_height(self):
        width, height = glfw.get_framebuffer_size(self.window)
        return width, height

    def _key_callback(self, window, key, scancode, action, mods):
        if action != glfw.RELEASE:
            return
        # Switch cameras
        elif key == glfw.KEY_TAB:
            self.cam.fixedcamid += 1
            self.cam.type = mujoco.mjtCamera.mjCAMERA_FIXED
            if self.cam.fixedcamid >= self.model.ncam:
                self.cam.fixedcamid = -1
                self.cam.type = mujoco.mjtCamera.mjCAMERA_FREE
        # Pause simulation
        elif key == glfw.KEY_SPACE and self._paused is not None:
            self._paused = not self._paused
        # Advances simulation by one step.
        elif key == glfw.KEY_RIGHT and self._paused is not None:
            self._advance_by_one_step = True
            self._paused = True
        # Slows down simulation
        elif key == glfw.KEY_S:
            self._run_speed /= 2.0
        # Speeds up simulation
        elif key == glfw.KEY_F:
            self._run_speed *= 2.0
        # Capture screenshot
        elif key == glfw.KEY_T:
            img = np.zeros(
                (
                    glfw.get_framebuffer_size(self.window)[1],
                    glfw.get_framebuffer_size(self.window)[0],
                    3,
                ),
                dtype=np.uint8,
            )
            mujoco.mjr_readPixels(img, None, self.viewport, self.ctx)
            MYDIR = str(os.getcwd()) + str(self._image_dir)
            print(MYDIR)
            CHECK_FOLDER = os.path.isdir(MYDIR)
            if not CHECK_FOLDER:
                os.makedirs(MYDIR)
                print("created folder : ", MYDIR)
            else:
                print(MYDIR, "folder already exists.")
            image_path = MYDIR + self._image_path
            imageio.imwrite(image_path % self._image_idx, np.flipud(img))
            self._image_idx += 1
        # Display joints
        elif key == glfw.KEY_J:
            self._joints = not self._joints
            self.vopt.flags[mujoco.mjtVisFlag.mjVIS_JOINT] = self._joints
        # Display coordinate frames
        elif key == glfw.KEY_E:
            self.vopt.frame = 1 - self.vopt.frame
        # Display contact forces
        elif key == glfw.KEY_C:
            self._contacts = not self._contacts
            self.vopt.flags[
                mujoco.mjtVisFlag.mjVIS_CONTACTPOINT
            ] = self._contacts
            self.vopt.flags[
                mujoco.mjtVisFlag.mjVIS_CONTACTFORCE
            ] = self._contacts
        # Turn off / turn on rendering every frame.
        elif key == glfw.KEY_D:
            self._render_every_frame = not self._render_every_frame
        # Shadow Rendering
        elif key == glfw.KEY_O:
            self._shadows = not self._shadows
            self.scn.flags[mujoco.mjtRndFlag.mjRND_SHADOW] = self._shadows
        # Display PID
        elif key == glfw.KEY_G:
            self._hide_graph = not self._hide_graph
        # Hide overlay menu
        elif key == glfw.KEY_H:
            self._hide_menu = not self._hide_menu
        # Display inertia
        elif key == glfw.KEY_I:
            self._inertias = not self._inertias
            self.vopt.flags[mujoco.mjtVisFlag.mjVIS_INERTIA] = self._inertias
        # Display center of mass
        elif key == glfw.KEY_M:
            self._com = not self._com
            self.vopt.flags[mujoco.mjtVisFlag.mjVIS_COM] = self._com
        # Make transparent
        elif key == glfw.KEY_R:
            self._transparent = not self._transparent
            if self._transparent:
                self.model.geom_rgba[:, 3] /= 5.0
            else:
                self.model.geom_rgba[:, 3] *= 5.0
        # Convex-Hull rendering
        elif key == glfw.KEY_V:
            self.vopt.flags[
                mujoco.mjtVisFlag.mjVIS_CONVEXHULL
            ] = self._convex_hull_rendering
            self._convex_hull_rendering = not self._convex_hull_rendering
        # Wireframe Rendering
        elif key == glfw.KEY_W:
            self._wire_frame = not self._wire_frame
            self.scn.flags[
                mujoco.mjtRndFlag.mjRND_WIREFRAME
            ] = self._wire_frame
        # ARROW KEYS
        elif key == glfw.KEY_UP:
            self._key_up = not self._key_up
        elif key == glfw.KEY_DOWN:
            self._key_down = not self._key_down
        elif key == glfw.KEY_K:
            self._key_left = not self._key_left
        elif key == glfw.KEY_L:
            self._key_right = not self._key_right
        # Geom group visibility
        elif key in (
            glfw.KEY_0,
            glfw.KEY_1,
            glfw.KEY_2,
            glfw.KEY_3,
            glfw.KEY_4,
        ):
            self.vopt.geomgroup[key - glfw.KEY_0] ^= 1
        # Quit
        if key == glfw.KEY_ESCAPE:
            print("Pressed ESC")
            print("Quitting.")
            glfw.terminate()
            sys.exit(0)

    def _scroll_callback(self, window, x_offset, y_offset):
        with self._gui_lock:
            mujoco.mjv_moveCamera(
                self.model,
                mujoco.mjtMouse.mjMOUSE_ZOOM,
                0,
                -0.05 * y_offset,
                self.scn,
                self.cam,
            )

    def _mouse_button_callback(self, window, button, act, mods):
        self._button_left_pressed = (
            button == glfw.MOUSE_BUTTON_LEFT and act == glfw.PRESS
        )
        self._button_right_pressed = (
            button == glfw.MOUSE_BUTTON_RIGHT and act == glfw.PRESS
        )

        x, y = glfw.get_cursor_pos(window)
        self._last_mouse_x = int(self._scale * x)
        self._last_mouse_y = int(self._scale * y)

        # detect a left- or right- doubleclick
        self._left_double_click_pressed = False
        self._right_double_click_pressed = False
        time_now = glfw.get_time()

        if self._button_left_pressed:
            if self._last_left_click_time is None:
                self._last_left_click_time = glfw.get_time()

            time_diff = time_now - self._last_left_click_time
            if time_diff > 0.01 and time_diff < 0.3:
                self._left_double_click_pressed = True
            self._last_left_click_time = time_now

        if self._button_right_pressed:
            if self._last_right_click_time is None:
                self._last_right_click_time = glfw.get_time()

            time_diff = time_now - self._last_right_click_time
            if time_diff > 0.01 and time_diff < 0.2:
                self._right_double_click_pressed = True
            self._last_right_click_time = time_now

        # set perturbation
        key = mods == glfw.MOD_CONTROL
        newperturb = 0
        if key and self.pert.select > 0:
            # right: translate, left: rotate
            if self._button_right_pressed:
                newperturb = mujoco.mjtPertBit.mjPERT_TRANSLATE
            if self._button_left_pressed:
                newperturb = mujoco.mjtPertBit.mjPERT_ROTATE

            # perturbation onste: reset reference
            if newperturb and not self.pert.active:
                mujoco.mjv_initPerturb(
                    self.model, self.data, self.scn, self.pert
                )
        self.pert.active = newperturb

        # handle doubleclick
        if self._left_double_click_pressed or self._right_double_click_pressed:
            # determine selection mode
            selmode = 0
            if self._left_double_click_pressed:
                selmode = 1
            if self._right_double_click_pressed:
                selmode = 2
            if self._right_double_click_pressed and key:
                selmode = 3

            # find geom and 3D click point, get corresponding body
            width, height = self.viewport.width, self.viewport.height
            aspectratio = width / height
            relx = x / width
            rely = (self.viewport.height - y) / height
            selpnt = np.zeros((3, 1), dtype=np.float64)
            selgeom = np.zeros((1, 1), dtype=np.int32)
            selskin = np.zeros((1, 1), dtype=np.int32)
            selbody = mujoco.mjv_select(
                self.model,
                self.data,
                self.vopt,
                aspectratio,
                relx,
                rely,
                self.scn,
                selpnt,
                selgeom,
                selskin,
            )

            # set lookat point, start tracking is requested
            if selmode == 2 or selmode == 3:
                # set cam lookat
                if selbody >= 0:
                    self.cam.lookat = selpnt.flatten()
                # switch to tracking camera if dynamic body clicked
                if selmode == 3 and selbody > 0:
                    self.cam.type = mujoco.mjtCamera.mjCAMERA_TRACKING
                    self.cam.trackbodyid = selbody
                    self.cam.fixedcamid = -1
            # set body selection
            else:
                if selbody >= 0:
                    # record selection
                    self.pert.select = selbody
                    self.pert.skinselect = selskin
                    # compute localpos
                    vec = selpnt.flatten() - self.data.xpos[selbody]
                    mat = self.data.xmat[selbody].reshape(3, 3)
                    self.pert.localpos = (
                        self.data.xmat[selbody].reshape(3, 3).dot(vec)
                    )
                else:
                    self.pert.select = 0
                    self.pert.skinselect = -1
            # stop perturbation on select
            self.pert.active = 0

        # 3D release
        if act == glfw.RELEASE:
            self.pert.active = 0

    def _cursor_pos_callback(self, window, xpos, ypos):
        if not (self._button_left_pressed or self._button_right_pressed):
            return

        mod_shift = (
            glfw.get_key(window, glfw.KEY_LEFT_SHIFT) == glfw.PRESS
            or glfw.get_key(window, glfw.KEY_RIGHT_SHIFT) == glfw.PRESS
        )
        if self._button_right_pressed:
            action = (
                mujoco.mjtMouse.mjMOUSE_MOVE_H
                if mod_shift
                else mujoco.mjtMouse.mjMOUSE_MOVE_V
            )
        elif self._button_left_pressed:
            action = (
                mujoco.mjtMouse.mjMOUSE_ROTATE_H
                if mod_shift
                else mujoco.mjtMouse.mjMOUSE_ROTATE_V
            )
        else:
            action = mujoco.mjtMouse.mjMOUSE_ZOOM

        dx = int(self._scale * xpos) - self._last_mouse_x
        dy = int(self._scale * ypos) - self._last_mouse_y
        width, height = glfw.get_framebuffer_size(window)

        with self._gui_lock:
            if self.pert.active:
                mujoco.mjv_movePerturb(
                    self.model,
                    self.data,
                    action,
                    dx / height,
                    dy / height,
                    self.scn,
                    self.pert,
                )
            else:
                mujoco.mjv_moveCamera(
                    self.model,
                    action,
                    dx / height,
                    dy / height,
                    self.scn,
                    self.cam,
                )

        self._last_mouse_x = int(self._scale * xpos)
        self._last_mouse_y = int(self._scale * ypos)

    def _swap_buffers(self):
        glfw.swap_buffers(self.window)

    def _poll_events(self):
        glfw.poll_events()

    def close(self):
        glfw.terminate()