From 856a6567a155afe84e2d14aabe343b6de447ae82 Mon Sep 17 00:00:00 2001
From: Alexey Pelykh <alexey.pelykh@gmail.com>
Date: Sun, 23 May 2021 07:04:50 +0200
Subject: [PATCH] LightManager: cone angles API (#3979)

---
 .../src/main/cpp/LightManager.cpp                | 14 ++++++++++++++
 .../google/android/filament/LightManager.java    | 10 ++++++++++
 filament/include/filament/LightManager.h         | 16 ++++++++++++++++
 filament/src/components/LightManager.cpp         | 12 ++++++++++++
 filament/src/components/LightManager.h           |  2 ++
 5 files changed, 54 insertions(+)

diff --git a/android/filament-android/src/main/cpp/LightManager.cpp b/android/filament-android/src/main/cpp/LightManager.cpp
index 8cc37f69d7..72bf5dfa4e 100644
--- a/android/filament-android/src/main/cpp/LightManager.cpp
+++ b/android/filament-android/src/main/cpp/LightManager.cpp
@@ -379,3 +379,17 @@ Java_com_google_android_filament_LightManager_nIsShadowCaster(JNIEnv*, jclass,
     LightManager *lm = (LightManager *) nativeLightManager;
     return (jboolean)lm->isShadowCaster((LightManager::Instance) i);
 }
+
+extern "C" JNIEXPORT jfloat JNICALL
+Java_com_google_android_filament_LightManager_nGetOuterConeAngle(JNIEnv*, jclass,
+        jlong nativeLightManager, jint i) {
+    LightManager *lm = (LightManager *) nativeLightManager;
+    return (jfloat)lm->getSpotLightOuterCone((LightManager::Instance) i);
+}
+
+extern "C" JNIEXPORT jfloat JNICALL
+Java_com_google_android_filament_LightManager_nGetInnerConeAngle(JNIEnv*, jclass,
+        jlong nativeLightManager, jint i) {
+    LightManager *lm = (LightManager *) nativeLightManager;
+    return (jfloat)lm->getSpotLightInnerCone((LightManager::Instance) i);
+}
diff --git a/android/filament-android/src/main/java/com/google/android/filament/LightManager.java b/android/filament-android/src/main/java/com/google/android/filament/LightManager.java
index ea537cf2e7..02fff3614b 100644
--- a/android/filament-android/src/main/java/com/google/android/filament/LightManager.java
+++ b/android/filament-android/src/main/java/com/google/android/filament/LightManager.java
@@ -1065,6 +1065,14 @@ public class LightManager {
         return nIsShadowCaster(mNativeObject, i);
     }
 
+    public float getOuterConeAngle(@EntityInstance int i) {
+        return nGetOuterConeAngle(mNativeObject, i);
+    }
+
+    public float getInnerConeAngle(@EntityInstance int i) {
+        return nGetInnerConeAngle(mNativeObject, i);
+    }
+
     public long getNativeObject() {
         return mNativeObject;
     }
@@ -1118,4 +1126,6 @@ public class LightManager {
     private static native float nGetSunHaloFalloff(long nativeLightManager, int i);
     private static native void nSetShadowCaster(long nativeLightManager, int i, boolean shadowCaster);
     private static native boolean nIsShadowCaster(long nativeLightManager, int i);
+    private static native float nGetOuterConeAngle(long nativeLightManager, int i);
+    private static native float nGetInnerConeAngle(long nativeLightManager, int i);
 }
diff --git a/filament/include/filament/LightManager.h b/filament/include/filament/LightManager.h
index dd5127267f..64d3211885 100644
--- a/filament/include/filament/LightManager.h
+++ b/filament/include/filament/LightManager.h
@@ -787,8 +787,24 @@ public:
      */
     void setSpotLightCone(Instance i, float inner, float outer) noexcept;
 
+    /**
+     * returns the outer cone angle in *radians* between inner and pi/2.
+     * @param i     Instance of the component obtained from getInstance().
+     * @return the outer cone angle of this light.
+     */
     float getSpotLightOuterCone(Instance i) const noexcept;
 
+    /**
+     * returns the inner cone angle in *radians* between 0 and pi/2.
+     * 
+     * The value is recomputed from the initial values, thus is not precisely
+     * the same as the one passed to setSpotLightCone() or Builder.spotLightCone().
+     * 
+     * @param i     Instance of the component obtained from getInstance().
+     * @return the inner cone angle of this light.
+     */
+    float getSpotLightInnerCone(Instance i) const noexcept;
+
     /**
      * Dynamically updates the angular radius of a Type.SUN light
      *
diff --git a/filament/src/components/LightManager.cpp b/filament/src/components/LightManager.cpp
index e96f8eeead..612ad51a7b 100644
--- a/filament/src/components/LightManager.cpp
+++ b/filament/src/components/LightManager.cpp
@@ -370,6 +370,14 @@ void FLightManager::setShadowCaster(Instance i, bool shadowCaster) noexcept {
     }
 }
 
+float FLightManager::getSpotLightInnerCone(Instance i) const noexcept {
+    const auto& spotParams = getSpotParams(i);
+    float cosOuter = std::cos(spotParams.outerClamped);
+    float scale = spotParams.scaleOffset.x;
+    float inner = std::acos((1.0f / spotParams.scaleOffset.x) + cosOuter);
+    return inner;
+}
+
 // ------------------------------------------------------------------------------------------------
 // ShadowCascades utility methods
 // ------------------------------------------------------------------------------------------------
@@ -482,6 +490,10 @@ float LightManager::getSpotLightOuterCone(Instance i) const noexcept {
     return upcast(this)->getSpotParams(i).outerClamped;
 }
 
+float LightManager::getSpotLightInnerCone(Instance i) const noexcept {
+    return upcast(this)->getSpotLightInnerCone(i);
+}
+
 void LightManager::setSunAngularRadius(Instance i, float angularRadius) noexcept {
     upcast(this)->setSunAngularRadius(i, angularRadius);
 }
diff --git a/filament/src/components/LightManager.h b/filament/src/components/LightManager.h
index c262cd4ce3..fda5064d91 100644
--- a/filament/src/components/LightManager.h
+++ b/filament/src/components/LightManager.h
@@ -191,6 +191,8 @@ public:
         return mManager[i].spotParams;
     }
 
+    float getSpotLightInnerCone(Instance i) const noexcept;
+
     float getCosOuterSquared(Instance i) const noexcept {
         return getSpotParams(i).cosOuterSquared;
     }