extend to support rendering to RenderTarget/OpenGL texture on Linux

ios/include/FilamentViewer.hpp

@@ -46,7 +46,8 @@ using namespace camutils;
 namespace polyvox {
     class FilamentViewer {
         public:
-            FilamentViewer(void* layer, LoadResource loadResource, FreeResource freeResource);
+            // FilamentViewer(void* layer, LoadResource loadResource, FreeResource freeResource);
+            FilamentViewer(void* context, LoadResource loadResource, FreeResource freeResource);
             ~FilamentViewer();
 
             void loadSkybox(const char* const skyboxUri);
@@ -67,8 +68,11 @@ namespace polyvox {
             
             bool setFirstCamera(SceneAsset* asset);
             bool setCamera(SceneAsset* asset, const char* nodeName);
+            
+            void createSwapChain(void* surface, uint32_t width, uint32_t height);
             void destroySwapChain();
-            void createSwapChain(void* surface);
+
+            void createRenderTarget(uint32_t glTextureId, uint32_t width,uint32_t height);
 
             Renderer* getRenderer();
 
@@ -96,8 +100,6 @@ namespace polyvox {
             void loadResources(std::string relativeResourcePath);
             void cleanup();
             
-            void* _layer;
-
             Manipulator<float>* _manipulator = nullptr;
             math::mat4f _cameraPosition;
             math::mat4f _cameraRotation;
@@ -113,6 +115,9 @@ namespace polyvox {
             Camera* _mainCamera;
 
             Renderer* _renderer;
+            RenderTarget* _rt;
+            Texture* _rtColor;
+            Texture* _rtDepth;
     
             SwapChain* _swapChain = nullptr;
 
@@ -124,12 +129,12 @@ namespace polyvox {
             std::mutex mtx; // mutex to ensure thread safety when removing assets
 
             vector<Entity> _lights;
-            Texture* _skyboxTexture;
-            Skybox* _skybox;
-            Texture* _iblTexture;
-            IndirectLight* _indirectLight;
+            Texture* _skyboxTexture = nullptr;
+            Skybox* _skybox = nullptr;
+            Texture* _iblTexture = nullptr;
+            IndirectLight* _indirectLight = nullptr;
 
-            MaterialProvider* _materialProvider;
+            MaterialProvider* _materialProvider = nullptr;
 
             gltfio::ResourceLoader* _resourceLoader = nullptr;
             gltfio::TextureProvider* _stbDecoder = nullptr;

ios/include/PolyvoxFilamentApi.h

@@ -6,8 +6,9 @@
 typedef struct ResourceBuffer ResourceBuffer;
 
 //ResourceBuffer create_resource_buffer(const void* data, const uint32_t size, const uint32_t id);
-void* filament_viewer_new(void* texture, void* loadResource, void* freeResource);
+void* filament_viewer_new(void* context, ResourceBuffer (*loadResource)(const char*), void (*freeResource)(uint32_t));
 void* filament_viewer_delete(void* viewer);
+void create_render_target(void* viewer, uint32_t textureId, uint32_t width, uint32_t height);
 void set_background_image(void* viewer, const char* path);
 void set_background_image_position(void* viewer, float x, float y, bool clamp);
 void load_skybox(void* viewer, const char* skyboxPath);
@@ -21,6 +22,7 @@ void* load_glb(void* viewer, const char* assetPath);
 void* load_gltf(void* viewer, const char* assetPath, const char* relativePath);
 bool set_camera(void* viewer, void* asset, const char* nodeName);
 void render(void* viewer, uint64_t frameTimeInNanos);
+void create_swap_chain(void* viewer, void* surface = nullptr, uint32_t width = 0, uint32_t height = 0);
 void destroy_swap_chain(void* viewer);
 void set_frame_interval(void* viewer, float interval);
 void* get_renderer(void* viewer);

ios/include/material/UnlitMaterialProvider.hpp

@@ -0,0 +1,47 @@
+#ifndef UNLIT_MATERIAL_PROVIDER
+#define UNLIT_MATERIAL_PROVIDER
+namespace polyvox {
+  class UnlitMaterialProvider : public MaterialProvider {
+
+      const Material* _m;
+      const Material* _ms[1];
+
+      public:
+        UnlitMaterialProvider(Engine* engine) {
+          _m = Material::Builder()
+            .package(	UNLITOPAQUE_UNLIT_OPAQUE_DATA, UNLITOPAQUE_UNLIT_OPAQUE_SIZE)
+            .build(*engine);
+          _ms[0] = _m;
+        }
+
+        filament::MaterialInstance* createMaterialInstance(MaterialKey* config, UvMap* uvmap,
+                const char* label = "material", const char* extras = nullptr) {
+                  MaterialInstance* d = (MaterialInstance*)_m->getDefaultInstance();
+          return d;
+        }
+
+        /**
+        * Gets a weak reference to the array of cached materials.
+        */
+        const filament::Material* const* getMaterials() const noexcept {
+          return _ms;
+        }
+
+        /**
+        * Gets the number of cached materials.
+        */
+        size_t getMaterialsCount() const noexcept {
+          return (size_t)1;
+        }
+
+        void destroyMaterials() {
+
+        }
+
+        bool needsDummyData(filament::VertexAttribute attrib) const noexcept {
+          return true;
+        }
+  };
+}
+
+#endif

ios/include/material/image_material.S

@@ -8,5 +8,5 @@ IMAGE_MATERIAL_PACKAGE:
 IMAGE_MATERIAL_IMAGE_OFFSET:
     .int 0
 IMAGE_MATERIAL_IMAGE_SIZE:
-    .int 29215
+    .int 14141
 

ios/include/material/image_material.apple.S

@@ -8,5 +8,5 @@ _IMAGE_MATERIAL_PACKAGE:
 _IMAGE_MATERIAL_IMAGE_OFFSET:
     .int 0
 _IMAGE_MATERIAL_IMAGE_SIZE:
-    .int 29215
+    .int 14141