From 0e2b0177163d8f1d0cbec688a877874ec58a6476 Mon Sep 17 00:00:00 2001
From: maverickdgg <danielcyc38@gmail.com>
Date: Mon, 31 Oct 2022 15:39:04 +0800
Subject: [PATCH] View matrix decomposition and set view matrix

View matrix decomposition does not decompose roll yet but there isn't much use case
---
 SHADE_Engine/src/Camera/SHCameraSystem.cpp | 35 ++++++++++++++--------
 SHADE_Engine/src/Camera/SHCameraSystem.h   | 14 ++++-----
 2 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/SHADE_Engine/src/Camera/SHCameraSystem.cpp b/SHADE_Engine/src/Camera/SHCameraSystem.cpp
index be34ecf0..16f651e8 100644
--- a/SHADE_Engine/src/Camera/SHCameraSystem.cpp
+++ b/SHADE_Engine/src/Camera/SHCameraSystem.cpp
@@ -354,7 +354,7 @@ namespace SHADE
     }
   }
 
-  void SHCameraSystem::DecomposeViewMatrix(SHMatrix& viewMatrix, float& pitch, float& yaw, float& roll, SHVec3& pos) noexcept
+  void SHCameraSystem::DecomposeViewMatrix(SHMatrix const& viewMatrix, float& pitch, float& yaw, float& roll, SHVec3& pos) noexcept
   {
 
     float initPitch = pitch;
@@ -362,20 +362,29 @@ namespace SHADE
     SHVec3 translate3, scale;
     SHQuaternion quat;
 
-    SHMatrix viewInverse = viewMatrix;
+    //SHMatrix viewInverse = viewMatrix;
 
-    viewInverse.Decompose(translate3, quat, scale);
+    viewMatrix.Decompose(translate3, quat, scale);
     yaw = 180+ SHMath::RadiansToDegrees(quat.ToEuler().y);
     pitch = -SHMath::RadiansToDegrees(quat.ToEuler().x);
-    SHVec4 translate = (viewMatrix * SHVec4(0.0f, 0.0f, 0.0f,1.0f) );
-    
-    //float forwardLengthXZ = sqrt(viewMatrix(0,2) * viewMatrix(0,2) + viewMatrix(2, 2) * viewMatrix(2, 2));
-    //yaw = SHMath::RadiansToDegrees( atan2f(viewMatrix(2,0), viewMatrix(2, 2)));
-    //pitch = SHMath::RadiansToDegrees( atan2f(viewMatrix(2, 1), forwardLengthXZ ));
-    //roll = SHMath::RadiansToDegrees( atan2f(viewMatrix(0, 1), viewMatrix(0,0)));
-   
-    //std::cout << "Init yaw: " << initPitch<< " , yaw: " << pitch << std::endl;
-    std::cout << "Init pos: " << initPos.x << initPos.y<< initPos.z << " , pos: " << translate.x<<translate.y<<translate.z << std::endl;
-  }
 
+    SHVec4 dotPos{ -viewMatrix(0,3),-viewMatrix(1,3), -viewMatrix(2,3), 1.0f };
+    SHMatrix mtx = viewMatrix;
+    mtx(0, 3) = 0.0f;
+    mtx(1, 3) = 0.0f;
+    mtx(2, 3) = 0.0f;
+    mtx.Transpose();
+    mtx = SHMatrix::Inverse(mtx);
+    SHVec4 translate =  mtx* dotPos;
+
+    pos.x = translate.x;
+    pos.y = translate.y;
+    pos.z = translate.z;
+    
+  }
+  void SHCameraSystem::SetCameraViewMatrix(SHCameraComponent& camera, SHMatrix const& viewMatrix) noexcept
+  {
+    DecomposeViewMatrix(viewMatrix, camera.pitch, camera.yaw, camera.roll, camera.position);
+    camera.dirtyView = true;
+  }
 }
diff --git a/SHADE_Engine/src/Camera/SHCameraSystem.h b/SHADE_Engine/src/Camera/SHCameraSystem.h
index cc522f7c..6f7e7d1f 100644
--- a/SHADE_Engine/src/Camera/SHCameraSystem.h
+++ b/SHADE_Engine/src/Camera/SHCameraSystem.h
@@ -22,6 +22,11 @@ namespace SHADE
 		SHResourceLibrary<SHCameraDirector> directorLibrary;
 		std::vector<DirectorHandle> directorHandleList;
 
+
+    void UpdateCameraComponent(SHCameraComponent& camera) noexcept;
+    void UpdatePivotArmComponent(SHCameraArmComponent& pivot) noexcept;
+
+
 	public:
     SHCameraSystem(void) = default;
     virtual ~SHCameraSystem(void) = default;
@@ -55,13 +60,8 @@ namespace SHADE
 		void ClampCameraRotation(SHCameraComponent& camera) noexcept;
 		void UpdateEditorCamera(double dt) noexcept;
     void SetMainCamera(EntityID eid, size_t directorIndex) noexcept;
-    void DecomposeViewMatrix(SHMatrix& matrix, float& pitch, float& yaw, float& roll, SHVec3& pos) noexcept;
-    
-	protected:
-
-		void UpdateCameraComponent(SHCameraComponent& camera) noexcept;
-    void UpdatePivotArmComponent(SHCameraArmComponent& pivot) noexcept;
-		
+    void DecomposeViewMatrix(SHMatrix const& matrix, float& pitch, float& yaw, float& roll, SHVec3& pos) noexcept;
+    void SetCameraViewMatrix(SHCameraComponent& camera, SHMatrix const& viewMatrix) noexcept;
 
 	};