Implement movement with the mouse.

src/fmri/RenderingState.cpp

@@ -32,7 +32,8 @@ static float getFPS()
     return fps;
 }
 
-static void updatePointSize(float dir) {
+static void updatePointSize(float dir)
+{
     float size, granularity;
     glGetFloatv(GL_POINT_SIZE, &size);
     glGetFloatv(GL_POINT_SIZE_GRANULARITY, &granularity);
@@ -163,9 +164,12 @@ RenderingState &RenderingState::instance()
 void RenderingState::registerControls()
 {
     reset();
-    glutPassiveMotionFunc([](int x, int y) {
+    auto motionFunc = [](int x, int y) {
         RenderingState::instance().handleMouseAt(x, y);
-    });
+    };
+    glutPassiveMotionFunc(motionFunc);
+    glutMotionFunc(motionFunc);
+
     glutKeyboardFunc([](auto key, auto, auto) {
         RenderingState::instance().handleKey(key);
     });
@@ -174,13 +178,26 @@ void RenderingState::registerControls()
         RenderingState::instance().render(time);
     });
     glutIdleFunc([]() {
-        checkGLErrors();
-        throttleIdleFunc();
-        glutPostRedisplay();
+        RenderingState::instance().idleFunc();
     });
     glutSpecialFunc([](int key, int, int) {
         RenderingState::instance().handleSpecialKey(key);
     });
+    glutMouseFunc([](int button, int state, int, int) {
+        auto& options = RenderingState::instance().options;
+        switch (button) {
+            case GLUT_LEFT_BUTTON:
+                options.mouse_1_pressed = state == GLUT_DOWN;
+                break;
+            case GLUT_RIGHT_BUTTON:
+                options.mouse_2_pressed = state == GLUT_DOWN;
+                break;
+
+            default:
+                // Do nothing.
+                break;
+        }
+    });
 }
 
 void RenderingState::handleMouseAt(int x, int y)
@@ -381,3 +398,17 @@ float RenderingState::layerAlpha() const
 {
     return options.layerAlpha;
 }
+
+void RenderingState::idleFunc()
+{
+    if (options.mouse_1_pressed) {
+        move('w', false);
+    }
+    if (options.mouse_2_pressed) {
+        move('s', false);
+    }
+
+    checkGLErrors();
+    throttleIdleFunc();
+    glutPostRedisplay();
+}

src/fmri/RenderingState.hpp

@@ -68,6 +68,8 @@ namespace fmri
             float layerAlpha;
             float interactionAlpha;
             Color pathColor;
+            bool mouse_1_pressed = false;
+            bool mouse_2_pressed = false;
         } options;
         std::array<float, 3> pos;
         std::array<float, 2> angle;
@@ -83,6 +85,7 @@ namespace fmri
 
         void move(unsigned char key, bool sprint);
         void updateVisualisers();
+        void idleFunc();
 
         std::string debugInfo() const;
         void renderOverlayText() const;