From d1235174157bd498d0c148325d7c8066e3ab6ac7 Mon Sep 17 00:00:00 2001
From: Kelly Rauchenberger <fefferburbia@gmail.com>
Date: Mon, 15 Feb 2021 12:05:18 -0500
Subject: Added camera shake to lightning event

---
 src/effect_system.cpp | 28 ++++++++++++++++++++++++++++
 src/effect_system.h   | 17 +++++++++++++++++
 src/renderer.cpp      |  6 ++++--
 src/script_system.cpp |  4 +++-
 4 files changed, 52 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/effect_system.cpp b/src/effect_system.cpp
index 3a0afe4..74fc8f3 100644
--- a/src/effect_system.cpp
+++ b/src/effect_system.cpp
@@ -18,6 +18,22 @@ void EffectSystem::tick(double dt) {
 
     mapFade_ = (mapFadeDest_ - mapFadeStart_) / mapFadeLength_ * mapFadeThus_ + mapFadeStart_;
   }
+
+  if (cameraShaking_) {
+    cameraShakeTimer_.accumulate(dt);
+
+    while (cameraShakeTimer_.step()) {
+      cameraShakeOn_ = !cameraShakeOn_;
+    }
+
+    if (cameraShakeOn_) {
+      cameraShakeOffset_.x() = 8;
+      cameraShakeOffset_.y() = 8;
+    } else {
+      cameraShakeOffset_.x() = 0;
+      cameraShakeOffset_.y() = 0;
+    }
+  }
 }
 
 void EffectSystem::fadeScreen(int length, double amount) {
@@ -33,3 +49,15 @@ void EffectSystem::fadeMap(int length, double amount) {
   mapFadeLength_ = length;
   mapFadeThus_ = 0;
 }
+
+void EffectSystem::shakeCamera(int period) {
+  cameraShaking_ = true;
+  cameraShakeOffset_ = { 0, 0 };
+  cameraShakeOn_ = false;
+  cameraShakeTimer_ = Timer(period);
+}
+
+void EffectSystem::stopShakingCamera() {
+  cameraShaking_ = false;
+  cameraShakeOffset_ = { 0, 0 };
+}
diff --git a/src/effect_system.h b/src/effect_system.h
index 2cdcb10..12ec7ca 100644
--- a/src/effect_system.h
+++ b/src/effect_system.h
@@ -2,6 +2,8 @@
 #define EFFECT_SYSTEM_H_0B497B39
 
 #include "system.h"
+#include "timer.h"
+#include "vector.h"
 
 class Game;
 
@@ -26,6 +28,12 @@ public:
   // - amount is [0,1]
   void fadeMap(int length, double amount);
 
+  // Shakes the viewport by 1 tile in both directions.
+  // - period is in milliseconds, it's actually a half period
+  void shakeCamera(int period);
+
+  void stopShakingCamera();
+
   /* Information */
 
   bool isScreenFaded() const { return screenFade_ > 0.0; }
@@ -40,6 +48,10 @@ public:
 
   bool isMapFadeComplete() const { return mapFade_ == mapFadeDest_; }
 
+  const vec2i& getCameraShakeOffset() const { return cameraShakeOffset_; }
+
+  bool isCameraShaking() const { return cameraShaking_; }
+
 private:
 
   Game& game_;
@@ -55,6 +67,11 @@ private:
   double mapFadeStart_ = 0.0;
   double mapFadeLength_ = 0.0;
   double mapFadeThus_ = 0.0;
+
+  bool cameraShaking_ = false;
+  vec2i cameraShakeOffset_ { 0, 0 };
+  bool cameraShakeOn_ = false;
+  Timer cameraShakeTimer_ { 0 };
 };
 
 #endif /* end of include guard: EFFECT_SYSTEM_H_0B497B39 */
diff --git a/src/renderer.cpp b/src/renderer.cpp
index c80b0d3..5aeb232 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp
@@ -194,9 +194,11 @@ void Renderer::render(Game& game) {
     renderSprite(sprite);
   }
 
+  vec2i viewport = game.getSystem<CameraSystem>().getCameraPosition() + effects.getCameraShakeOffset();
+
   SDL_Rect cameraField {
-    game.getSystem<CameraSystem>().getCameraPosition().x(),
-    game.getSystem<CameraSystem>().getCameraPosition().y(),
+    viewport.x(),
+    viewport.y(),
     game.getSystem<CameraSystem>().getFieldOfView().w(),
     game.getSystem<CameraSystem>().getFieldOfView().h()
   };
diff --git a/src/script_system.cpp b/src/script_system.cpp
index 7109d98..cbbd473 100644
--- a/src/script_system.cpp
+++ b/src/script_system.cpp
@@ -59,7 +59,9 @@ ScriptSystem::ScriptSystem(Game& game) : game_(game) {
     "fadeScreen", &EffectSystem::fadeScreen,
     "isScreenFadeComplete", &EffectSystem::isScreenFadeComplete,
     "fadeMap", &EffectSystem::fadeMap,
-    "isMapFadeComplete", &EffectSystem::isMapFadeComplete);
+    "isMapFadeComplete", &EffectSystem::isMapFadeComplete,
+    "shakeCamera", &EffectSystem::shakeCamera,
+    "stopShakingCamera", &EffectSystem::stopShakingCamera);
 
   engine_.new_usertype<Mixer>(
     "mixer",
-- 
cgit 1.4.1