Implement moving camera

main_bounce.cpp

@@ -56,7 +56,8 @@ int main(int argc, char** argv) {
 
     render.set_idle_func(periodic_update);
     render.add_kb_handler(periodic_kb_handler);
-    init_periodic_static(&ball);
+    render.add_kb_up_handler(periodic_kb_up_handler);
+    init_periodic_static(&ball, &render);
     render.run();
 
     return 0;

periodic_updates.cpp

@@ -1,20 +1,66 @@
 #include "periodic_updates.hpp"
 
 #include <ctime>
+#include <cmath>
 #include <chrono>
 #include <GL/glut.h>
 
+struct Movement {
+    Movement()  :
+        fwd(false),
+        bck(false),
+        left(false),
+        right(false),
+        turn_l(false),
+        turn_r(false),
+        sight_angle(0.)
+    {}
+
+    bool
+        fwd,
+        bck,
+        left,
+        right,
+        turn_l,
+        turn_r;
+
+    double sight_angle;
+
+    void tick() {
+        sight_angle += (turn_l - turn_r) * .05;
+    }
+
+    Point movement() {
+        Point front_dir = Point(-sin(sight_angle), 0, -cos(sight_angle)),
+              left_dir = Point(-cos(sight_angle), 0, sin(sight_angle));
+        return (fwd - bck) * front_dir
+            + (left - right) * left_dir;
+    }
+    Point sight() {
+        return Point(-sin(sight_angle), 0., -cos(sight_angle));
+    }
+};
+
 static Ball* _ball = nullptr;
 static std::chrono::time_point<std::chrono::steady_clock>
     _last_time, _init_clocks;
 
 static bool is_paused = false;
 static double speed_factor = 1.;
+static KeyMappings _keymap = KeyMappings::qwerty();
+static Movement _movement;
+static Point _position(0., 2.5, -10.);
+static GlutRender* _render = nullptr;
 
-void init_periodic_static(Ball* ball) {
+void init_periodic_static(Ball* ball, GlutRender* render) {
     _last_time = std::chrono::steady_clock::now();
     _init_clocks = std::chrono::steady_clock::now();
     _ball = ball;
+    _render = render;
+}
+
+void set_key_mapping(const KeyMappings& mapping) {
+    _keymap = mapping;
 }
 
 double ellapsed_double(
@@ -26,23 +72,38 @@ double ellapsed_double(
 }
 
 void periodic_update() {
-    if(is_paused)
-        return;
-
-    printf("%lf\n", speed_factor);
     auto now = std::chrono::steady_clock::now();
+
+    if(!is_paused)
         _ball->update_pos(speed_factor * ellapsed_double(_last_time, now));
 
+    _movement.tick();
+    _position += _movement.movement();
+
+    _render->set_camera(_position, _position + _movement.sight());
+
     _last_time = now;
     glutPostRedisplay();
 }
 
-void periodic_kb_handler(unsigned char key, int, int) {
+void mvt_keys_update(bool up, unsigned key) {
-    if(key == ' ') {
+    if(key == _keymap.mv_fwd)
-        if(is_paused)
+        _movement.fwd = !up;
-            _last_time = std::chrono::steady_clock::now();
+    else if(key == _keymap.mv_bck)
-        is_paused = !is_paused;
+        _movement.bck = !up;
+    else if(key == _keymap.mv_left)
+        _movement.left = !up;
+    else if(key == _keymap.mv_right)
+        _movement.right = !up;
+    else if(key == _keymap.turn_left)
+        _movement.turn_l = !up;
+    else if(key == _keymap.turn_right)
+        _movement.turn_r = !up;
 }
+
+void periodic_kb_handler(unsigned char key, int, int) {
+    if(key == ' ')
+        is_paused = !is_paused;
     else if(key == '<') {
         speed_factor -= .1;
         if(speed_factor <= 0.05)
@@ -54,4 +115,9 @@ void periodic_kb_handler(unsigned char key, int, int) {
     else if(key == '0') {
         speed_factor = 1.;
     }
+    mvt_keys_update(false, key);
+}
+
+void periodic_kb_up_handler(unsigned char key, int, int) {
+    mvt_keys_update(true, key);
 }

periodic_updates.hpp

@@ -1,8 +1,45 @@
 #pragma once
 
 #include "Ball.hpp"
+#include "render/GlutRender.hpp"
 
-void init_periodic_static(Ball* ball);
+struct KeyMappings {
+    static KeyMappings qwerty() {
+        return KeyMappings('w', 's', 'a', 'd', 'q', 'e');
+    }
+    static KeyMappings azerty() {
+        return KeyMappings('z', 's', 'q', 'd', 'a', 'e');
+    }
+
+    KeyMappings(
+            unsigned char mv_fwd,
+            unsigned char mv_bck,
+            unsigned char mv_left,
+            unsigned char mv_right,
+            unsigned char turn_left,
+            unsigned char turn_right)
+        :
+            mv_fwd(mv_fwd),
+            mv_bck(mv_bck),
+            mv_left(mv_left),
+            mv_right(mv_right),
+            turn_left(turn_left),
+            turn_right(turn_right)
+    {}
+
+
+    unsigned char
+        mv_fwd,
+        mv_bck,
+        mv_left,
+        mv_right,
+        turn_left,
+        turn_right;
+};
+
+void init_periodic_static(Ball* ball, GlutRender* render);
+void set_key_mapping(const KeyMappings& mapping);
 void periodic_update();
 
 void periodic_kb_handler(unsigned char key, int, int);
+void periodic_kb_up_handler(unsigned char key, int, int);

render/GlutRender.cpp

@@ -12,7 +12,11 @@ GlutRender& GlutRender::get_instance() {
     return instance;
 }
 
-GlutRender::GlutRender() : followed_implicit(nullptr) {
+GlutRender::GlutRender()
+    : followed_implicit(nullptr),
+    camera_position(0., 2.5, -10.),
+    camera_sight(0, 2.5, 0)
+{
     std::default_random_engine rand_engine(time(NULL));
     std::uniform_real_distribution<double> distribution;
     rand_color = std::bind(distribution, rand_engine);
@@ -30,6 +34,7 @@ void GlutRender::init(int* argc, char** argv,
     glutDisplayFunc(display_handle);
     glutReshapeFunc(reshape_handle);
     glutKeyboardFunc(kb_evt_handle);
+    glutKeyboardUpFunc(kb_evt_up_handle);
 
     // ==== Lighting ====
     GLfloat light0_pos[] = {30., 35., 20., 0.};
@@ -97,10 +102,19 @@ void GlutRender::add_kb_handler(GlutRender::kb_handler_t handler) {
     kb_handlers.push_back(handler);
 }
 
+void GlutRender::add_kb_up_handler(GlutRender::kb_handler_t handler) {
+    kb_up_handlers.push_back(handler);
+}
+
 void GlutRender::follow_implicit_position(const ImplicitSurface* surf) {
     followed_implicit = surf;
 }
 
+void GlutRender::set_camera(const Point& location, const Point& sight) {
+    camera_position = location;
+    camera_sight = sight;
+}
+
 void GlutRender::reshape(int wid, int hei) {
     if (hei == 0)
         hei = 1;
@@ -192,16 +206,15 @@ void GlutRender::display() {
     // Camera position and orientation
     glLoadIdentity();
 
-    Point look_from(0, 2.5, -10);
     if(followed_implicit != nullptr) {
         const Point& look_at = followed_implicit->getCenter();
-        gluLookAt(look_from.x, look_from.y, look_from.z,
+        gluLookAt(camera_position.x, camera_position.y, camera_position.z,
-                look_at.x, look_from.y, look_at.z,
+                look_at.x, camera_position.y, look_at.z,
                 0, 1, 0);
     }
     else {
-        gluLookAt(look_from.x, look_from.y, look_from.z,
+        gluLookAt(camera_position.x, camera_position.y, camera_position.z,
-                0, 2.5, 0,
+                camera_sight.x, camera_position.y, camera_sight.z,
                 0, 1, 0);
     }
 
@@ -220,8 +233,9 @@ void GlutRender::display() {
     glutSwapBuffers();
 }
 
-void GlutRender::on_kb_evt(unsigned char key, int x, int y) {
+void GlutRender::on_kb_evt(bool up, unsigned char key, int x, int y) {
-    for(auto& handler: kb_handlers) {
+    std::vector<kb_handler_t>& handlers = up? kb_up_handlers : kb_handlers;
+    for(auto& handler: handlers) {
         handler(key, x, y);
     }
 }
@@ -233,5 +247,8 @@ void GlutRender::display_handle() {
     get_instance().display();
 }
 void GlutRender::kb_evt_handle(unsigned char key, int x, int y) {
-    get_instance().on_kb_evt(key, x, y);
+    get_instance().on_kb_evt(false, key, x, y);
+}
+void GlutRender::kb_evt_up_handle(unsigned char key, int x, int y) {
+    get_instance().on_kb_evt(true, key, x, y);
 }

render/GlutRender.hpp

@@ -29,9 +29,12 @@ class GlutRender {
         void set_idle_func(void (*func)(void));
 
         void add_kb_handler(kb_handler_t handler);
+        void add_kb_up_handler(kb_handler_t handler);
 
         void follow_implicit_position(const ImplicitSurface* surf);
 
+        void set_camera(const Point& location, const Point& sight);
+
     private:
         struct SurfaceDetails {
             SurfaceDetails(ImplicitSurface* surf, const Cuboid& box,
@@ -56,12 +59,13 @@ class GlutRender {
     protected:
         void reshape(int wid, int hei);
         void display();
-        void on_kb_evt(unsigned char key, int x, int y);
+        void on_kb_evt(bool up, unsigned char key, int x, int y);
 
         static void reshape_handle(int wid, int hei);
         static void display_handle();
 
         static void kb_evt_handle(unsigned char key, int x, int y);
+        static void kb_evt_up_handle(unsigned char key, int x, int y);
 
     private: //attr
         std::function<double()> rand_color;
@@ -70,6 +74,9 @@ class GlutRender {
         std::set<SurfaceDetails> surfaces;
 
         std::vector<kb_handler_t> kb_handlers;
+        std::vector<kb_handler_t> kb_up_handlers;
 
         const ImplicitSurface* followed_implicit;
+
+        Point camera_position, camera_sight;
 };