From d78f70ac504af196efd1f1e9834b6369dcbca5bc Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Thu, 25 Aug 2022 19:01:04 +1000
Subject: [PATCH] setRotation/setPosition from center

---
 ios/src/FilamentViewer.cpp     | 10 ++++++++++
 ios/src/FilamentViewer.hpp     |  3 +++
 ios/src/PolyvoxFilamentApi.cpp |  8 ++++++++
 ios/src/PolyvoxFilamentApi.hpp |  4 ++++
 ios/src/SceneAsset.cpp         | 23 ++++++++++++++++++-----
 ios/src/SceneAsset.hpp         |  9 ++++++++-
 6 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/ios/src/FilamentViewer.cpp b/ios/src/FilamentViewer.cpp
index a846295a..862c2b0b 100644
--- a/ios/src/FilamentViewer.cpp
+++ b/ios/src/FilamentViewer.cpp
@@ -597,4 +597,14 @@ void FilamentViewer::updateViewportAndCameraProjection(
       contentScaleFactor);
 }
 
+void FilamentViewer::setCameraPosition(float x, float y, float z) {
+  Camera& cam =_view->getCamera();
+  auto &tm = _engine->getTransformManager();
+  // tm.setTransform(tm.getInstance(_asset->getRoot()), math::mat4f::translation(math::float3(x,y,z)) * _cameraRotation);
+}
+
+void FilamentViewer::setCameraRotation(float rads, float x, float y, float z) {
+  Camera& cam =_view->getCamera();
+}
+
 } // namespace polyvox
diff --git a/ios/src/FilamentViewer.hpp b/ios/src/FilamentViewer.hpp
index 6b726047..1fb2c3bf 100644
--- a/ios/src/FilamentViewer.hpp
+++ b/ios/src/FilamentViewer.hpp
@@ -74,6 +74,9 @@ namespace polyvox {
 
             void setBackgroundImage(const char* resourcePath);
 
+            void setCameraPosition(float x, float y, float z);
+            void setCameraRotation(float rads, float x, float y, float z);
+
         private:
             void createImageRenderable();
             void loadResources(std::string relativeResourcePath);
diff --git a/ios/src/PolyvoxFilamentApi.cpp b/ios/src/PolyvoxFilamentApi.cpp
index 0b4ca5f9..12aa21a9 100644
--- a/ios/src/PolyvoxFilamentApi.cpp
+++ b/ios/src/PolyvoxFilamentApi.cpp
@@ -56,6 +56,14 @@ extern "C" {
     return ((FilamentViewer*)viewer)->setCamera((SceneAsset*)asset, nodeName);
   }
 
+  void set_camera_position(void* viewer, float x, float y, float z) {
+    return ((FilamentViewer*)viewer)->setCameraPosition(x, y, z);
+  }
+
+  void set_camera_rotation(void* viewer, float rads, float x, float y, float z) {
+    return ((FilamentViewer*)viewer)->setCameraRotation(rads, x, y, z);
+  }
+
   void render(
     void* viewer
   ) {
diff --git a/ios/src/PolyvoxFilamentApi.hpp b/ios/src/PolyvoxFilamentApi.hpp
index a5710f29..37db0cde 100644
--- a/ios/src/PolyvoxFilamentApi.hpp
+++ b/ios/src/PolyvoxFilamentApi.hpp
@@ -56,5 +56,9 @@ void set_position(void* asset, float x, float y, float z);
 void set_rotation(void* asset, float rads, float x, float y, float z);
 
 void stop_animation(void* asset, int index);
+
+void set_camera_position(void* viewer, float x, float y, float z);
+
+void set_camera_rotation(void* viewer, float rads, float x, float y, float z);
       
 #endif
diff --git a/ios/src/SceneAsset.cpp b/ios/src/SceneAsset.cpp
index 4756fcda..95798f89 100644
--- a/ios/src/SceneAsset.cpp
+++ b/ios/src/SceneAsset.cpp
@@ -27,7 +27,6 @@ using namespace filament;
 using namespace filament::gltfio;
 using namespace image;
 using namespace utils;
-using namespace filament::math;
 
 SceneAsset::SceneAsset(FilamentAsset *asset, Engine *engine,
                        NameComponentManager *ncm, LoadResource loadResource, FreeResource freeResource)
@@ -294,15 +293,29 @@ void SceneAsset::transformToUnitCube() {
 void SceneAsset::setPosition(float x, float y, float z) {
   Log("Setting position to %f %f %f", x, y, z);
   auto &tm = _engine->getTransformManager();
-  auto transform = tm.getTransform(tm.getInstance(_asset->getRoot()));
-  tm.setTransform(tm.getInstance(_asset->getRoot()), transform * math::mat4f::translation(math::float3(x,y,z)));
+  _position = math::mat4f::translation(math::float3(x,y,z));
+  auto aabb = _asset->getBoundingBox();
+  auto center = aabb.center();
+  auto halfExtent = aabb.extent();
+  auto maxExtent = max(halfExtent) * 2;
+  auto scaleFactor = 2.0f / maxExtent;
+  auto transform =
+      math::mat4f::scaling(scaleFactor) * math::mat4f::translation(-center) * _position * _rotation;
+  tm.setTransform(tm.getInstance(_asset->getRoot()), transform);
 }
 
 void SceneAsset::setRotation(float rads, float x, float y, float z) {
   Log("Rotating %f radians around axis %f %f %f", x, y, z);
   auto &tm = _engine->getTransformManager();
-  auto transform = tm.getTransform(tm.getInstance(_asset->getRoot()));
-  tm.setTransform(tm.getInstance(_asset->getRoot()), transform * math::mat4f::rotation(rads, math::float3(x,y,z)));
+  _rotation = math::mat4f::rotation(rads, math::float3(x,y,z));
+  auto aabb = _asset->getBoundingBox();
+  auto center = aabb.center();
+  auto halfExtent = aabb.extent();
+  auto maxExtent = max(halfExtent) * 2;
+  auto scaleFactor = 2.0f / maxExtent;
+  auto transform =
+      math::mat4f::scaling(scaleFactor) * math::mat4f::translation(-center) * _position * _rotation;
+  tm.setTransform(tm.getInstance(_asset->getRoot()), transform);
 }
 
 
diff --git a/ios/src/SceneAsset.hpp b/ios/src/SceneAsset.hpp
index a0692662..186e3f50 100644
--- a/ios/src/SceneAsset.hpp
+++ b/ios/src/SceneAsset.hpp
@@ -6,11 +6,15 @@
 #include <filament/Scene.h>
 #include <filament/Texture.h>
 
+#include <math/vec3.h>
+#include <math/vec4.h>
+#include <math/mat3.h>
+#include <math/norm.h>
+
 #include <gltfio/AssetLoader.h>
 #include <gltfio/FilamentAsset.h>
 #include <gltfio/ResourceLoader.h>
 
-
 #include <utils/NameComponentManager.h>
 
 #include "SceneResources.hpp"
@@ -102,5 +106,8 @@ namespace polyvox {
             // a slot to preload textures
             filament::Texture* _texture = nullptr;
 
+            math::mat4f _position;
+            math::mat4f _rotation;
+
     };
 }
\ No newline at end of file