Support for zooming from scripting (#1560)

* Support for zooming from scripting

* Fixed build errors (Camera zooming/scaling)

* Improved code quality

Co-authored-by: Semphris <semphris@protonmail.com>

src/object/camera.cpp

@@ -137,7 +137,13 @@ Camera::Camera(const std::string& name) :
   m_scroll_goal(),
   m_scroll_to_pos(),
   m_scrollspeed(),
-  m_config(std::make_unique<CameraConfig>())
+  m_config(std::make_unique<CameraConfig>()),
+  m_scale(1.f),
+  m_scale_origin(1.f),
+  m_scale_target(1.f),
+  m_scale_time_total(0.f),
+  m_scale_time_remaining(0.f),
+  m_scale_easing()
 {
   reload_config();
 }
@@ -162,7 +168,13 @@ Camera::Camera(const ReaderMapping& reader) :
   m_scroll_goal(),
   m_scroll_to_pos(),
   m_scrollspeed(),
-  m_config(std::make_unique<CameraConfig>())
+  m_config(std::make_unique<CameraConfig>()),
+  m_scale(1.f),
+  m_scale_origin(1.f),
+  m_scale_target(1.f),
+  m_scale_time_total(0.f),
+  m_scale_time_remaining(0.f),
+  m_scale_easing()
 {
   std::string modename;
 
@@ -232,10 +244,11 @@ Camera::after_editor_set()
   }
 }
 
-const Vector&
+const Vector
 Camera::get_translation() const
 {
-  return m_translation;
+  Vector screen_size = Sizef(m_screen_size).as_vector();
+  return m_translation + ((screen_size * (m_scale - 1.f)) / 2.f);
 }
 
 void
@@ -305,6 +318,7 @@ Camera::update(float dt_sec)
     default:
       break;
   }
+  update_scale(dt_sec);
   shake();
 }
 
@@ -594,6 +608,13 @@ Camera::update_scroll_normal(float dt_sec)
       }
     }
 
+    if (m_lookahead_pos.x > RIGHTEND) {
+      m_lookahead_pos.x = RIGHTEND;
+    }
+    if (m_lookahead_pos.x < LEFTEND) {
+      m_lookahead_pos.x = LEFTEND;
+    }
+
     // adjust for level ends
     if (player_pos.x < LEFTEND) {
       m_lookahead_pos.x = LEFTEND;
@@ -676,6 +697,50 @@ Camera::update_scroll_to(float dt_sec)
   m_translation = m_scroll_from + (m_scroll_goal - m_scroll_from) * m_scroll_to_pos;
 }
 
+void
+Camera::update_scale(float dt_sec)
+{
+  if (m_scale_time_remaining > 0.f)
+  {
+    m_scale_time_remaining -= dt_sec;
+
+    if (m_scale_time_remaining <= 0.f)
+    {
+      m_scale = m_scale_target;
+      m_scale_time_remaining = 0.f;
+    }
+    else
+    {
+      float progress = (m_scale_time_total - m_scale_time_remaining)
+                                                          / m_scale_time_total;
+      float true_progress = static_cast<float>(m_scale_easing(
+                                               static_cast<double>(progress)));
+      m_scale = m_scale_origin +
+                             (m_scale_target - m_scale_origin) * true_progress;
+    }
+
+    // Re-center camera when zooming
+    m_lookahead_pos /= 1.01f;
+  }
+
+  Vector screen_size = Sizef(m_screen_size).as_vector();
+  m_translation += screen_size * (1.f - m_scale) / 2.f;
+}
+
+void
+Camera::ease_scale(float scale, float time, easing ease)
+{
+  if (time <= 0.f) {
+    m_scale = scale;
+  } else {
+    m_scale_origin = m_scale;
+    m_scale_target = scale;
+    m_scale_time_total = time;
+    m_scale_time_remaining = time;
+    m_scale_easing = ease;
+  }
+}
+
 Vector
 Camera::get_center() const
 {

src/object/camera.hpp

@@ -79,7 +79,7 @@ class Camera final : public GameObject,
   void reset(const Vector& tuxpos);
 
   /** return camera position */
-  const Vector& get_translation() const;
+  const Vector get_translation() const;
   void set_translation(const Vector& translation) { m_translation = translation; }
 
   /** shake camera in a direction 1 time */
@@ -97,12 +97,22 @@ class Camera final : public GameObject,
   Vector get_center() const;
 
   void set_mode(Mode mode_) { m_mode = mode_; }
+
+  /** get the exact scale at this exact moment */
+  float get_current_scale() const { return m_scale; }
+
+  /** get the scale towards which the camera is moving */
+  float get_target_scale() const { return m_scale_target; }
+
+  /** smoothly slide the scale of the camera towards a new value */
+  void ease_scale(float scale, float time, easing ease);
   /** @} */
 
 private:
   void update_scroll_normal(float dt_sec);
   void update_scroll_autoscroll(float dt_sec);
   void update_scroll_to(float dt_sec);
+  void update_scale(float dt_sec);
   void keep_in_bounds(Vector& vector);
   void shake();
 
@@ -135,6 +145,13 @@ class Camera final : public GameObject,
 
   std::unique_ptr<CameraConfig> m_config;
 
+  float m_scale,
+        m_scale_origin,
+        m_scale_target,
+        m_scale_time_total,
+        m_scale_time_remaining;
+  easing m_scale_easing;
+
 private:
   Camera(const Camera&) = delete;
   Camera& operator=(const Camera&) = delete;

src/scripting/camera.cpp

@@ -70,6 +70,42 @@ Camera::scroll_to(float x, float y, float scrolltime)
   object.scroll_to(Vector(x, y), scrolltime);
 }
 
+float
+Camera::get_current_scale()
+{
+  SCRIPT_GUARD_DEFAULT;
+  BIND_SECTOR(::Sector::get());
+  return object.get_current_scale();
+}
+
+float
+Camera::get_target_scale()
+{
+  SCRIPT_GUARD_DEFAULT;
+  BIND_SECTOR(::Sector::get());
+  return object.get_target_scale();
+}
+
+void
+Camera::set_scale(float scale)
+{
+  ease_scale(scale, 0, "");
+}
+
+void
+Camera::scale(float scale, float time)
+{
+  ease_scale(scale, time, "");
+}
+
+void
+Camera::ease_scale(float scale, float time, std::string ease)
+{
+  SCRIPT_GUARD_VOID;
+  BIND_SECTOR(::Sector::get());
+  object.ease_scale(scale, time, getEasingByName(EasingMode_from_string(ease)));
+}
+
 } // namespace scripting
 
 /* EOF */

src/scripting/camera.hpp

@@ -51,6 +51,16 @@ class Camera final
   void set_mode(const std::string& mode);
   /** Scroll camera to position x,y in scrolltime seconds */
   void scroll_to(float x, float y, float scrolltime);
+  /** Get the curent scale factor of the camera */
+  float get_current_scale();
+  /** Get the scale factor the camera is fading towards */
+  float get_target_scale();
+  /** Set the scale factor */
+  void set_scale(float scale);
+  /** Fade the scale factor over time */
+  void scale(float scale, float time);
+  /** Fade the scale factor over time with easing (smooth movement) */
+  void ease_scale(float scale, float time, std::string ease);
 };
 
 } // namespace scripting

src/scripting/sector.cpp

@@ -16,6 +16,7 @@
 
 #include "scripting/sector.hpp"
 
+#include "math/easing.hpp"
 #include "object/ambient_light.hpp"
 #include "object/music_object.hpp"
 #include "supertux/sector.hpp"