feat(QGl): basic window with camera

using qt + openGL

.gitignore

@@ -30,3 +30,6 @@
 *.exe
 *.out
 *.app
+
+# Directories
+build/

CMakeLists.txt

@@ -0,0 +1,18 @@
+project(qt5test)
+cmake_minimum_required(VERSION 2.8.12)
+set (CMAKE_CXX_STANDARD 11)
+
+# Qt library
+find_package(Qt5Widgets)
+find_package(Qt5OpenGL)
+# Eigen
+find_package(Eigen3 REQUIRED)
+# OpenGL & GLEW library
+find_package(OpenGL)
+
+include_directories(${EIGEN3_INCLUDE_DIR})
+
+# executable
+add_executable(qt5test src/main.cpp)
+qt5_use_modules(qt5test Widgets OpenGL)
+target_link_libraries(qt5test ${QT_LIBRARIES} ${OPENGL_LIBRARIES})

src/main.cpp

@@ -0,0 +1,215 @@
+#include <QApplication>
+#include <QGLWidget>
+#include <QDebug>
+#include <QMouseEvent>
+#include <QTimer>
+#include <cmath>
+#include <GL/glu.h>
+#include <iostream>
+#include <chrono>
+#include <Eigen/Dense>
+
+using Eigen::Vector3d;
+using Eigen::Matrix4d;
+
+#define PI 3.14159265
+
+class GLWidget : public QGLWidget{
+    void initializeGL(){
+
+        glEnable(GL_DEPTH_TEST);
+        glEnable(GL_CULL_FACE);
+
+        last_update_ = std::chrono::steady_clock::now();
+        update_timer_ = new QTimer(this);
+        connect(update_timer_, SIGNAL(timeout()), this, SLOT(update()));
+        update_timer_->start(0.017);
+        is_dragging_ = false;
+        last_dragging_x_ = 0.0;
+        last_dragging_y_ = 0.0;
+        trans_ << 1.0, 0.0, 0.0, 0.0,
+                 0.0, 1.0, 0.0, 0.0,
+                 0.0, 0.0, 1.0, 0.0,
+                 0.0, 0.0, 0.0, 1.0;
+    }
+
+/// @note camera decides renderer size
+    void resizeGL(int width, int height){
+        if (height==0) height=1;
+        glViewport(0,0,width,height);
+        glMatrixMode(GL_PROJECTION);
+        glLoadIdentity();
+        gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
+     }
+
+//void updateAngles(){
+//    std::chrono::steady_clock::time_point current_time;
+//    current_time = std::chrono::steady_clock::now();
+//    double ellapsed_time = std::chrono::duration_cast<std::chrono::microseconds>(current_time - last_update_).count();
+//    //angle_z_ += 0.00005 * ellapsed_time;
+//    //angle_y_ += 0.00005 * ellapsed_time;
+//    last_update_ = current_time;
+//}
+
+
+    void mouseMoveEvent(QMouseEvent *event){
+
+        if (event->buttons() & Qt::LeftButton) {
+           if(is_dragging_) {
+               trans_tmp_ << 1.0, 0.0, 0.0, (event->x() - last_dragging_x_) * 0.005,
+                             0.0, 1.0, 0.0, -(event->y() - last_dragging_y_) * 0.005,
+                             0.0, 0.0, 1.0, 0.0,
+                             0.0, 0.0, 0.0, 1.0;
+               trans_ = trans_tmp_ * trans_;
+
+           }
+           else{
+                is_dragging_ = true;
+
+           }
+        }
+        else if (event->buttons() & Qt::RightButton) {
+           if(is_dragging_) {
+               double tmp_rot_y_ = (event->x() - last_dragging_x_) * 0.003;
+               double tmp_rot_x_ = (event->y() - last_dragging_y_) * 0.003;
+               trans_tmp_ << cos(tmp_rot_y_),  0.0, sin(tmp_rot_y_), 0.0,
+                             0.0            ,  1.0,             0.0, 0.0,
+                             -sin(tmp_rot_y_), 0.0, cos(tmp_rot_y_), 0.0,
+                             0.0             , 0.0,             0.0, 1.0;
+               trans_ = trans_tmp_ * trans_;
+               trans_tmp_ << 1.0,             0.0,              0.0, 0.0,
+                             0.0, cos(tmp_rot_x_), -sin(tmp_rot_x_), 0.0,
+                             0.0, sin(tmp_rot_x_),  cos(tmp_rot_x_), 0.0,
+                             0.0,             0.0,              0.0, 1.0;
+               trans_ = trans_tmp_ * trans_;
+           }
+           else{
+                is_dragging_ = true;
+
+           }
+
+        }
+        last_dragging_x_ = event->x();
+        last_dragging_y_ = event->y();
+
+    }
+
+    void mouseReleaseEvent(QMouseEvent* event){
+            is_dragging_ = false;
+    }
+
+    void paintGrid(){
+            glLineWidth(5.0);
+            glBegin(GL_LINES);
+            glColor3ub(220,220,220);
+        for(int i=-100; i<100; i=i+5){
+            glVertex3d(i, 100.0, 0.0);
+            glVertex3d(i, -100.0, 0.0);
+
+            glVertex3d(100.0, i, 0.0);
+            glVertex3d(-100.0, i, 0.0);
+        }
+            glEnd();
+
+    }
+
+    Vector3d MToEulerAngles(const Matrix4d& m){
+
+        double sy = sqrt(m(0, 0) * m(0, 0) +  m(1,0) * m(1,0));
+
+        bool singular = sy < 1e-6; // If
+
+        double x, y, z;
+        if (!singular)
+        {
+            x = atan2(m(2,1) , m(2,2));
+            y = atan2(-m(2,0), sy);
+            z = atan2(m(1,0), m(0,0));
+        }
+        else
+        {
+            x = atan2(-m(1,2), m(1,1));
+            y = atan2(-m(2,0), sy);
+            z = 0;
+        }
+        return Vector3d(x, y, z);
+    }
+
+    void paintGL(){
+        glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+        glMatrixMode( GL_MODELVIEW );
+        glLoadIdentity( );
+
+        gluLookAt(0, 0, 10,0,0,0,0,1,0);
+
+        glTranslated(trans_(0,3), trans_(1,3), trans_(2,3));
+        Vector3d xyz = MToEulerAngles(trans_);
+        glRotated(xyz(2)* 180 / PI,0,0,1);
+        glRotated(xyz(1)* 180 / PI,0,1,0);
+        glRotated(xyz(0)* 180 / PI,1,0,0);
+
+        paintGrid();
+
+        glBegin(GL_QUADS);
+
+        glColor3ub(255,0,0); // Red
+
+        glVertex3d(1,1,1);
+
+        glVertex3d(1,1,-1);
+        glVertex3d(-1,1,-1);
+        glVertex3d(-1,1,1);
+
+        glColor3ub(0,255,0); // Green
+        glVertex3d(1,-1,1);
+        glVertex3d(1,-1,-1);
+        glVertex3d(1,1,-1);
+        glVertex3d(1,1,1);
+
+        glColor3ub(0,0,255); // Blue
+        glVertex3d(-1,-1,1);
+        glVertex3d(-1,-1,-1);
+        glVertex3d(1,-1,-1);
+        glVertex3d(1,-1,1);
+
+        glColor3ub(255,255,0); // Yellow
+        glVertex3d(-1,1,1);
+        glVertex3d(-1,1,-1);
+        glVertex3d(-1,-1,-1);
+        glVertex3d(-1,-1,1);
+
+        glColor3ub(0,255,255); // Cyan
+        glVertex3d(1,1,-1);
+        glVertex3d(1,-1,-1);
+        glVertex3d(-1,-1,-1);
+        glVertex3d(-1,1,-1);
+
+        glColor3ub(255,0,255); // Magenta
+        glVertex3d(1,-1,1);
+        glVertex3d(1,1,1);
+        glVertex3d(-1,1,1);
+        glVertex3d(-1,-1,1);
+
+        glEnd();
+
+        glFlush();
+    }
+    private:
+        std::chrono::steady_clock::time_point last_update_;
+        QTimer* update_timer_;
+        bool is_dragging_;
+        double last_dragging_x_;
+        double last_dragging_y_;
+        Matrix4d trans_tmp_;
+        Matrix4d trans_;
+};
+
+int main(int argc, char *argv[]){
+    QApplication app(argc, argv);
+    GLWidget widget;
+    widget.resize(800,600);
+    widget.show();
+    return app.exec();
+}
+