viewer.cpp

//
//  main.cpp
//  MuJoCoViewer
//
//  Created by Adam Rojík on 21/05/2019.
//  Copyright © 2019 Adam Rojík. All rights reserved.
//

/*  Copyright © 2018, Roboti LLC

 This file is licensed under the MuJoCo Resource License (the "License").
 You may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 https://www.roboti.us/resourcelicense.txt
 */


#include "mujoco.h"
#include "glfw3.h"
#include "stdio.h"
#include "stdlib.h"
#include <string>
#include <iostream>
#include <sstream>
#include <fstream>

// MuJoCo data structures
mjModel* m = NULL;                  // MuJoCo model
mjData* d = NULL;                   // MuJoCo data
mjvCamera cam;                      // abstract camera
mjvOption opt;                      // visualization options
mjvScene scn;                       // abstract scene
mjrContext con;                     // custom GPU context

// mouse interaction
bool button_left = false;
bool button_middle = false;
bool button_right =  false;
double lastx = 0;
double lasty = 0;

// keyboard callback
void keyboard(GLFWwindow* window, int key, int scancode, int act, int mods)
{
    // backspace: reset simulation
    if( act==GLFW_PRESS && key==GLFW_KEY_BACKSPACE )
    {
        mj_resetData(m, d);
        mj_forward(m, d);
    }
}


// mouse button callback
void mouse_button(GLFWwindow* window, int button, int act, int mods)
{
    // update button state
    button_left =   (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_LEFT)==GLFW_PRESS);
    button_middle = (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_MIDDLE)==GLFW_PRESS);
    button_right =  (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_RIGHT)==GLFW_PRESS);

    // update mouse position
    glfwGetCursorPos(window, &lastx, &lasty);
}


// mouse move callback
void mouse_move(GLFWwindow* window, double xpos, double ypos)
{
    // no buttons down: nothing to do
    if( !button_left && !button_middle && !button_right )
        return;

    // compute mouse displacement, save
    double dx = xpos - lastx;
    double dy = ypos - lasty;
    lastx = xpos;
    lasty = ypos;

    // get current window size
    int width, height;
    glfwGetWindowSize(window, &width, &height);

    // get shift key state
    bool mod_shift = (glfwGetKey(window, GLFW_KEY_LEFT_SHIFT)==GLFW_PRESS ||
                      glfwGetKey(window, GLFW_KEY_RIGHT_SHIFT)==GLFW_PRESS);

    // determine action based on mouse button
    mjtMouse action;
    if( button_right )
        action = mod_shift ? mjMOUSE_MOVE_H : mjMOUSE_MOVE_V;
    else if( button_left )
        action = mod_shift ? mjMOUSE_ROTATE_H : mjMOUSE_ROTATE_V;
    else
        action = mjMOUSE_ZOOM;

    // move camera
    mjv_moveCamera(m, action, dx/height, dy/height, &scn, &cam);
}


// scroll callback
void scroll(GLFWwindow* window, double xoffset, double yoffset)
{
    // emulate vertical mouse motion = 5% of window height
    mjv_moveCamera(m, mjMOUSE_ZOOM, 0, -0.05*yoffset, &scn, &cam);
}


// main function
int main(int argc, const char** argv)
{
    // check command-line arguments
    if( argc != 3 )
    {
        printf(" USAGE:  basic modelfile & simulation data\n");
        return 0;
    }

    // activate software
    mj_activate("mjkey.txt");

    // load and compile model
    char error[1000] = "Could not load binary model";
    if( strlen(argv[1])>4 && !strcmp(argv[1]+strlen(argv[1])-4, ".mjb") )
        m = mj_loadModel(argv[1], 0);
    else
        m = mj_loadXML(argv[1], 0, error, 1000);
    if( !m )
        mju_error_s("Load model error: %s", error);

    // make data
    d = mj_makeData(m);

    // init GLFW
    if( !glfwInit() )
        mju_error("Could not initialize GLFW");

    // create window, make OpenGL context current, request v-sync
    GLFWwindow* window = glfwCreateWindow(1200, 900, "Simulation (space for reset)", NULL, NULL);
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1);

    // initialize visualization data structures
    mjv_defaultCamera(&cam);
    mjv_defaultOption(&opt);
    mjv_defaultScene(&scn);
    mjr_defaultContext(&con);

    // create scene and context
    mjv_makeScene(m, &scn, 2000);
    mjr_makeContext(m, &con, mjFONTSCALE_150);

    // install GLFW mouse and keyboard callbacks
    glfwSetKeyCallback(window, keyboard);
    glfwSetCursorPosCallback(window, mouse_move);
    glfwSetMouseButtonCallback(window, mouse_button);
    glfwSetScrollCallback(window, scroll);

    std::ifstream file(argv[2]);
    std::string loadedData;

    // run main loop
    while( !glfwWindowShouldClose(window))
    {
        if (std::getline(file, loadedData)) {
            std::stringstream ss;
            ss.str(loadedData);

            std::string parsed;
            for(int i=0; i<m->nq;i++) {
                if (std::getline(ss, parsed,',')) {
                    d->qpos[i] = (mjtNum)std::stod(parsed);
                }
            }
            mj_forward(m, d);

        }

        // get framebuffer viewport
        mjrRect viewport = {0, 0, 0, 0};

        int state = glfwGetKey(window, GLFW_KEY_SPACE);
        if (state == GLFW_PRESS)
        {
            file.close();
            file.open(argv[2]);
        }

        glfwGetFramebufferSize(window, &viewport.width, &viewport.height);

        // update scene and render
        mjv_updateScene(m, d, &opt, NULL, &cam, mjCAT_ALL, &scn);
        mjr_render(viewport, &scn, &con);

        // swap OpenGL buffers (blocking call due to v-sync)
        glfwSwapBuffers(window);

        // process pending GUI events, call GLFW callbacks
        glfwPollEvents();
    }

    //free visualization storage
    mjv_freeScene(&scn);
    mjr_freeContext(&con);

    // free MuJoCo model and data, deactivate
    mj_deleteData(d);
    mj_deleteModel(m);
    mj_deactivate();

    // terminate GLFW (crashes with Linux NVidia drivers)
#if defined(__APPLE__) || defined(_WIN32)
    glfwTerminate();
#endif

    return 1;
}