From 7e3b59b09399bf8da243fb4122caa2c9c10d2624 Mon Sep 17 00:00:00 2001
From: Kelly Rauchenberger <fefferburbia@gmail.com>
Date: Fri, 5 Mar 2021 09:39:31 -0500
Subject: Implemented circle transition effect (for exit area)

---
 src/effect_system.cpp | 16 +++++++++++++++
 src/effect_system.h   | 17 ++++++++++++++++
 src/renderer.cpp      | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/script_system.cpp |  4 +++-
 4 files changed, 90 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/effect_system.cpp b/src/effect_system.cpp
index aeccebb..4dff13c 100644
--- a/src/effect_system.cpp
+++ b/src/effect_system.cpp
@@ -37,6 +37,15 @@ void EffectSystem::tick(double dt) {
       cameraShakeOffset_.y() = 0;
     }
   }
+
+  if (circleEffect_ != circleEffectDest_) {
+    circleEffectThus_ += dt;
+    if (circleEffectThus_ >= circleEffectLength_) {
+      circleEffectThus_ = circleEffectLength_;
+    }
+
+    circleEffect_ = (circleEffectDest_ - circleEffectStart_) / circleEffectLength_ * circleEffectThus_ + circleEffectStart_;
+  }
 }
 
 void EffectSystem::fadeScreen(int length, double amount) {
@@ -64,3 +73,10 @@ void EffectSystem::stopShakingCamera() {
   cameraShaking_ = false;
   cameraShakeOffset_ = { 0, 0 };
 }
+
+void EffectSystem::circleTransition(int length, double amount) {
+  circleEffectStart_ = circleEffect_;
+  circleEffectDest_ = amount;
+  circleEffectLength_ = length;
+  circleEffectThus_ = 0;
+}
diff --git a/src/effect_system.h b/src/effect_system.h
index 12ec7ca..904e6cb 100644
--- a/src/effect_system.h
+++ b/src/effect_system.h
@@ -34,6 +34,11 @@ public:
 
   void stopShakingCamera();
 
+  // Hides or reveals the screen using a circle transition.
+  // - length is the time in milliseconds
+  // - amount is [0,1], where 0 is fully revealed and 1 is fully hidden
+  void circleTransition(int length, double amount);
+
   /* Information */
 
   bool isScreenFaded() const { return screenFade_ > 0.0; }
@@ -52,6 +57,12 @@ public:
 
   bool isCameraShaking() const { return cameraShaking_; }
 
+  bool isCircleTransitionActive() const { return circleEffect_ > 0.0; }
+
+  double getCircleTransitionProgress() const { return circleEffect_; }
+
+  bool isCircleTransitionComplete() const { return circleEffect_ == circleEffectDest_; }
+
 private:
 
   Game& game_;
@@ -72,6 +83,12 @@ private:
   vec2i cameraShakeOffset_ { 0, 0 };
   bool cameraShakeOn_ = false;
   Timer cameraShakeTimer_ { 0 };
+
+  double circleEffect_ = 0.0;
+  double circleEffectDest_ = 0.0;
+  double circleEffectStart_ = 0.0;
+  double circleEffectLength_ = 0.0;
+  double circleEffectThus_ = 0.0;
 };
 
 #endif /* end of include guard: EFFECT_SYSTEM_H_0B497B39 */
diff --git a/src/renderer.cpp b/src/renderer.cpp
index 3007378..5ab623a 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp
@@ -353,6 +353,60 @@ void Renderer::render(Game& game) {
     SDL_RenderFillRect(ren_.get(), nullptr);
   }
 
+  if (effects.isCircleTransitionActive()) {
+    if (effects.getCircleTransitionProgress() == 1.0) {
+      SDL_SetRenderTarget(ren_.get(), cameraTex.get());
+      SDL_SetRenderDrawBlendMode(ren_.get(), SDL_BLENDMODE_NONE);
+      SDL_SetRenderDrawColor(ren_.get(), 0, 0, 0, 255);
+      SDL_RenderClear(ren_.get());
+    } else {
+      texture_ptr circleEffectTex(
+        SDL_CreateTexture(
+          ren_.get(),
+          SDL_PIXELFORMAT_RGBA8888,
+          SDL_TEXTUREACCESS_TARGET,
+          CANVAS_WIDTH,
+          CANVAS_HEIGHT));
+
+      if (!circleEffectTex) {
+        throw sdl_error();
+      }
+
+      SDL_SetRenderTarget(ren_.get(), circleEffectTex.get());
+      SDL_SetRenderDrawBlendMode(ren_.get(), SDL_BLENDMODE_NONE);
+      SDL_SetRenderDrawColor(ren_.get(), 0, 0, 0, 255);
+      SDL_RenderClear(ren_.get());
+
+      int circleDiameter = 290 * (1.0 - effects.getCircleTransitionProgress());
+      SDL_Rect circleSize {
+        CANVAS_WIDTH / 2 - circleDiameter / 2,
+        CANVAS_HEIGHT / 2 - circleDiameter / 2,
+        circleDiameter,
+        circleDiameter
+      };
+
+      SDL_Rect copyFromCamera = circleSize;
+      if (circleDiameter > CANVAS_WIDTH) {
+        copyFromCamera.x = 0;
+        copyFromCamera.w = CANVAS_WIDTH;
+      }
+      if (circleDiameter > CANVAS_HEIGHT) {
+        copyFromCamera.y = 0;
+        copyFromCamera.h = CANVAS_HEIGHT;
+      }
+
+      SDL_RenderCopy(ren_.get(), cameraTex.get(), &copyFromCamera, &copyFromCamera);
+
+      int pinholeTexId = loadImageFromFile("../res/pinhole.png");
+      SDL_SetTextureBlendMode(textures_[pinholeTexId].get(), SDL_BLENDMODE_MOD);
+      SDL_RenderCopy(ren_.get(), textures_[pinholeTexId].get(), nullptr, &circleSize);
+
+      SDL_SetRenderTarget(ren_.get(), cameraTex.get());
+      SDL_SetTextureBlendMode(circleEffectTex.get(), SDL_BLENDMODE_NONE);
+      SDL_RenderCopy(ren_.get(), circleEffectTex.get(), nullptr, nullptr);
+    }
+  }
+
   if (game.getSystem<InputSystem>().isDebugConsoleOpen()) {
     // Not sure why I'm supposed to copy the cached texture to the screen
     // BEFORE rendering it, but we get flickering if we don't, so.
diff --git a/src/script_system.cpp b/src/script_system.cpp
index a3686b4..3325b79 100644
--- a/src/script_system.cpp
+++ b/src/script_system.cpp
@@ -89,7 +89,9 @@ ScriptSystem::ScriptSystem(Game& game) : game_(game) {
     "fadeMap", &EffectSystem::fadeMap,
     "isMapFadeComplete", &EffectSystem::isMapFadeComplete,
     "shakeCamera", &EffectSystem::shakeCamera,
-    "stopShakingCamera", &EffectSystem::stopShakingCamera);
+    "stopShakingCamera", &EffectSystem::stopShakingCamera,
+    "circleTransition", &EffectSystem::circleTransition,
+    "isCircleTransitionComplete", &EffectSystem::isCircleTransitionComplete);
 
   engine_.new_usertype<CameraSystem>(
     "camera",
-- 
cgit 1.4.1