initial work to re-implement FFI with background thread render loop

ios/include/PolyvoxFilamentFFIApi.h

@@ -0,0 +1,83 @@
+#ifndef _POLYVOX_FILAMENT_FFI_API_H
+#define _POLYVOX_FILAMENT_FFI_API_H
+
+#include "PolyvoxFilamentApi.h"
+
+/// 
+/// This header replicates most of the methods in PolyvoxFilamentApi.h, and is only intended to be used to generate client FFI bindings.
+/// The intention is that calling one of these methods will call its respective method in PolyvoxFilamentApi.h, but wrapped in some kind of thread runner to ensure thread safety. 
+/// 
+
+typedef int32_t EntityId;
+
+const void* create_filament_viewer_ffi(void* const context, const ResourceLoaderWrapper* const loader);
+void destroy_filament_viewer_ffi(void* const viewer);
+void render_ffi(void* const viewer);
+void set_rendering_ffi(void* const viewer, bool rendering);
+void set_frame_interval_ffi(float frameInterval);
+void update_viewport_and_camera_projection_ffi(void* const viewer, const uint32_t width, const uint32_t height, const float scaleFactor);
+void create_render_target_ffi(void* const viewer, uint32_t textureId, uint32_t width, uint32_t height);
+void set_background_color_ffi(void* const viewer, const float r, const float g, const float b, const float a);
+void clear_background_image_ffi(void* const viewer);
+void set_background_image_ffi(void* const viewer, const char *path, bool fillHeight);
+void set_background_image_position_ffi(void* const viewer, float x, float y, bool clamp);
+void set_background_color_ffi(void* const viewer, const float r, const float g, const float b, const float a);
+void set_tone_mapping_ffi(void* const viewer, int toneMapping);
+void set_bloom_ffi(void* const viewer, float strength);
+void load_skybox_ffi(void* const viewer, const char *skyboxPath);
+void load_ibl_ffi(void* const viewer, const char *iblPath, float intensity);
+void remove_skybox_ffi(void* const viewer);
+void remove_ibl_ffi(void* const viewer);
+EntityId add_light_ffi(void* const viewer, uint8_t type, float colour, float intensity, float posX, float posY, float posZ, float dirX, float dirY, float dirZ, bool shadows);
+void remove_light_ffi(void* const viewer, EntityId entityId);
+void clear_lights_ffi(void* const viewer);
+EntityId load_glb_ffi(void* const assetManager, const char *assetPath, bool unlit);
+EntityId load_gltf_ffi(void* const assetManager, const char *assetPath, const char *relativePath);
+void remove_asset_ffi(const void* const viewer, EntityId asset);
+void clear_assets_ffi(const void* const viewer);
+bool set_camera_ffi(void* const viewer, EntityId asset, const char *nodeName);
+void apply_weights_ffi(
+    void* assetManager,
+    EntityId asset, 
+    const char *const entityName, 
+    float *const weights, 
+    int count
+);
+void set_morph_target_weights_ffi(
+    void* assetManager,
+    EntityId asset,
+    const char *const entityName,
+    const float *const morphData,
+    int numWeights
+);
+bool set_morph_animation_ffi(
+    void* assetManager,
+    EntityId asset,
+    const char *const entityName,
+    const float *const morphData,
+    const int* const morphIndices,
+    int numMorphTargets,
+    int numFrames,
+    float frameLengthInMs);
+
+void set_bone_animation_ffi(
+    void* assetManager,
+    EntityId asset, 
+    const float* const frameData,
+    int numFrames, 
+    int numBones,
+    const char** const boneNames,
+    const char** const meshName,
+    int numMeshTargets,
+    float frameLengthInMs);
+
+void play_animation_ffi(void* assetManager, EntityId asset, int index, bool loop, bool reverse, bool replaceActive, float crossfade);
+void set_animation_frame_ffi(void* assetManager, EntityId asset, int animationIndex, int animationFrame);
+void stop_animation_ffi(void* assetManager, EntityId asset, int index);
+int get_animation_count_ffi(void* assetManager, EntityId asset);
+void get_animation_name_ffi(void* assetManager, EntityId asset, char *const outPtr, int index);
+float get_animation_duration_ffi(void* assetManager, EntityId asset, int index);
+void get_morph_target_name_ffi(void* assetManager, EntityId asset, const char *meshName, char *const outPtr, int index);
+int get_morph_target_name_count_ffi(void* assetManager, EntityId asset, const char *meshName);
+
+#endif // _POLYVOX_FILAMENT_FFI_API_H