Added scriptable camera panning

3 files changed, 79 insertions, 14 deletions

@@ -6,26 +6,39 @@
 void CameraSystem::tick(double dt) {
   if (!locked_ && followingSprite_ != -1) {
     const Sprite& follow = game_.getSprite(followingSprite_);
-    const Map& map = game_.getMap();
-    vec2i mapBounds = map.getMapSize() * map.getTileSize();
 
-    pos_ = follow.loc - vec2i{0, 16} - (fov_ / 2);
+    pos_ = calculatePosWithCenter(follow.loc - vec2i{0, 16});
+  }
 
-    if (pos_.x() < 0) {
-      pos_.x() = 0;
-    }
-    if (pos_.y() < 0) {
-      pos_.y() = 0;
-    }
-    if (pos_.x() + fov_.w() >= mapBounds.w()) {
-      pos_.x() = mapBounds.w() - fov_.w() - 1;
-    }
-    if (pos_.y() + fov_.h() >= mapBounds.h()) {
-      pos_.y() = mapBounds.h() - fov_.h() - 1;
+  if (panning_) {
+    panThus_ += dt;
+
+    if (panThus_ >= panLength_) {
+      panning_ = false;
+      pos_ = panEnd_;
+    } else {
+      pos_.x() = static_cast<double>((panEnd_ - panStart_).x()) / panLength_ * panThus_ + panStart_.x();
+      pos_.y() = static_cast<double>((panEnd_ - panStart_).y()) / panLength_ * panThus_ + panStart_.y();
     }
   }
 }
 
+void CameraSystem::panToSprite(int targetId, int length) {
+  locked_ = true;
+
+  const Sprite& target = game_.getSprite(targetId);
+
+  if (length > 0) {
+    panning_ = true;
+    panStart_ = pos_;
+    panEnd_ = calculatePosWithCenter(target.loc - vec2i{0, 16});
+    panLength_ = length;
+    panThus_ = 0.0;
+  } else {
+    pos_ = calculatePosWithCenter(target.loc - vec2i{0, 16});
+  }
+}
+
 void CameraSystem::destroySprite(int spriteId) {
   if (followingSprite_ == spriteId) {
     followingSprite_ = -1;
@@ -35,3 +48,25 @@ void CameraSystem::destroySprite(int spriteId) {
 void CameraSystem::clearSpriteCache() {
   followingSprite_ = -1;
 }
+
+vec2i CameraSystem::calculatePosWithCenter(vec2i center) const {
+  const Map& map = game_.getMap();
+  vec2i mapBounds = map.getMapSize() * map.getTileSize();
+
+  vec2i result = center - (fov_ / 2);
+
+  if (result.x() < 0) {
+    result.x() = 0;
+  }
+  if (result.y() < 0) {
+    result.y() = 0;
+  }
+  if (result.x() + fov_.w() >= mapBounds.w()) {
+    result.x() = mapBounds.w() - fov_.w() - 1;
+  }
+  if (result.y() + fov_.h() >= mapBounds.h()) {
+    result.y() = mapBounds.h() - fov_.h() - 1;
+  }
+
+  return result;
+}
@@ -24,6 +24,13 @@ public:
 
   void unlockCamera() { locked_ = false; }
 
+  // Pans over to the provided sprite over the provided amount of time.
+  // - length is in milliseconds
+  // Automatically locks the camera.
+  void panToSprite(int targetId, int length);
+
+  bool isPanning() const { return panning_; }
+
   void tick(double dt) override;
 
   void destroySprite(int spriteId) override;
@@ -31,12 +38,21 @@ public:
   void clearSpriteCache() override;
 
 private:
+
+  vec2i calculatePosWithCenter(vec2i center) const;
+
   Game& game_;
 
   vec2i pos_;
   vec2i fov_ { CANVAS_WIDTH, CANVAS_HEIGHT };
   int followingSprite_ = -1;
   bool locked_ = true;
+
+  bool panning_ = false;
+  vec2i panStart_;
+  vec2i panEnd_;
+  double panLength_ = 0.0;
+  double panThus_ = 0.0;
 };
 
 #endif /* end of include guard: CAMERA_SYSTEM_H_D52ADAD3 */
@@ -6,6 +6,7 @@
 #include "character_system.h"
 #include "transform_system.h"
 #include "effect_system.h"
+#include "camera_system.h"
 #include "vector.h"
 
 ScriptSystem::ScriptSystem(Game& game) : game_(game) {
@@ -63,6 +64,13 @@ ScriptSystem::ScriptSystem(Game& game) : game_(game) {
     "shakeCamera", &EffectSystem::shakeCamera,
     "stopShakingCamera", &EffectSystem::stopShakingCamera);
 
+  engine_.new_usertype<CameraSystem>(
+    "camera",
+    "panToSprite", &CameraSystem::panToSprite,
+    "isPanning", &CameraSystem::isPanning,
+    "unlockCamera", &CameraSystem::unlockCamera,
+    "setFollowingSprite", &CameraSystem::setFollowingSprite);
+
   engine_.new_usertype<Mixer>(
     "mixer",
     "playSound", &Mixer::playSound,
@@ -100,6 +108,12 @@ ScriptSystem::ScriptSystem(Game& game) : game_(game) {
     });
 
   engine_.set_function(
+    "camera",
+    [&] () -> CameraSystem& {
+      return game_.getSystem<CameraSystem>();
+    });
+
+  engine_.set_function(
     "mixer",
     [&] () -> Mixer& {
       return game_.getMixer();