From f873f7da668b7ea9df26d4a4f1b12f218e59977a Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Tue, 17 Dec 2024 16:36:53 +0800
Subject: [PATCH] feat: add setTransparencyMode to Dart Material class

---
 .../src/viewer/src/ffi/src/ffi_material.dart  |  9 ++++++-
 .../src/viewer/src/shared_types/material.dart | 26 +++++++++++++++++--
 .../native/include/c_api/TMaterialInstance.h  | 23 ++++++++++++++--
 .../native/src/c_api/TMaterialInstance.cpp    |  8 ++++++
 4 files changed, 61 insertions(+), 5 deletions(-)

diff --git a/thermion_dart/lib/src/viewer/src/ffi/src/ffi_material.dart b/thermion_dart/lib/src/viewer/src/ffi/src/ffi_material.dart
index c40a2819..a7eb653e 100644
--- a/thermion_dart/lib/src/viewer/src/ffi/src/ffi_material.dart
+++ b/thermion_dart/lib/src/viewer/src/ffi/src/ffi_material.dart
@@ -139,7 +139,14 @@ class FFIMaterialInstance extends MaterialInstance {
 
   Future dispose() async {
     await withVoidCallback((cb) {
-      SceneManager_destroyMaterialInstanceRenderThread(sceneManager, pointer, cb);
+      SceneManager_destroyMaterialInstanceRenderThread(
+          sceneManager, pointer, cb);
     });
   }
+
+  @override
+  Future setTransparencyMode(TransparencyMode mode) async {
+    MaterialInstance_setTransparencyMode(
+        pointer, TTransparencyMode.values[mode.index]);
+  }
 }
diff --git a/thermion_dart/lib/src/viewer/src/shared_types/material.dart b/thermion_dart/lib/src/viewer/src/shared_types/material.dart
index 4aa4eda1..3fd207b3 100644
--- a/thermion_dart/lib/src/viewer/src/shared_types/material.dart
+++ b/thermion_dart/lib/src/viewer/src/shared_types/material.dart
@@ -70,7 +70,28 @@ enum StencilFace {
   FRONT_AND_BACK
 }
 
-enum AlphaMode { OPAQUE, MASK, BLEND }
+enum AlphaMode { 
+  OPAQUE, 
+  MASK, 
+  BLEND 
+}
+
+enum TransparencyMode { 
+  	//! the transparent object is drawn honoring the raster state
+		DEFAULT,
+		/**
+		 * the transparent object is first drawn in the depth buffer,
+		 * then in the color buffer, honoring the culling mode, but ignoring the depth test function
+		 */
+		TWO_PASSES_ONE_SIDE,
+
+		/**
+		 * the transparent object is drawn twice in the color buffer,
+		 * first with back faces only, then with front faces; the culling
+		 * mode is ignored. Can be combined with two-sided lighting
+		 */
+		TWO_PASSES_TWO_SIDES
+}
 
 abstract class Material {
   Future<MaterialInstance> createInstance();
@@ -115,6 +136,7 @@ abstract class MaterialInstance {
   Future setStencilReadMask(int mask);
   Future setStencilWriteMask(int mask);
 
-  Future dispose();
+  Future setTransparencyMode(TransparencyMode mode);
 
+  Future dispose();
 }
diff --git a/thermion_dart/native/include/c_api/TMaterialInstance.h b/thermion_dart/native/include/c_api/TMaterialInstance.h
index f348a4f2..bc794fdc 100644
--- a/thermion_dart/native/include/c_api/TMaterialInstance.h
+++ b/thermion_dart/native/include/c_api/TMaterialInstance.h
@@ -35,7 +35,6 @@ extern "C"
 		INVERT	   // Invert the current value
 	};
 
-	// StencilFace equivalent
 	enum TStencilFace
 	{
 		STENCIL_FACE_FRONT = 1,
@@ -43,7 +42,6 @@ extern "C"
 		STENCIL_FACE_FRONT_AND_BACK = 3
 	};
 
-	// Add these enum definitions at the top with the other enums
 	enum TCullingMode
 	{
 		CULLING_MODE_NONE = 0,
@@ -52,6 +50,23 @@ extern "C"
 		CULLING_MODE_FRONT_AND_BACK
 	};
 
+	enum TTransparencyMode { 
+		//! the transparent object is drawn honoring the raster state
+		DEFAULT,
+		/**
+		 * the transparent object is first drawn in the depth buffer,
+		 * then in the color buffer, honoring the culling mode, but ignoring the depth test function
+		 */
+		TWO_PASSES_ONE_SIDE,
+
+		/**
+		 * the transparent object is drawn twice in the color buffer,
+		 * first with back faces only, then with front faces; the culling
+		 * mode is ignored. Can be combined with two-sided lighting
+		 */
+		TWO_PASSES_TWO_SIDES
+	};
+
 	EMSCRIPTEN_KEEPALIVE TMaterialInstance *Material_createInstance(TMaterial *tMaterial);
 	EMSCRIPTEN_KEEPALIVE bool MaterialInstance_isStencilWriteEnabled(TMaterialInstance *materialInstance);
 	EMSCRIPTEN_KEEPALIVE void MaterialInstance_setStencilWrite(TMaterialInstance *materialInstance, bool enabled);
@@ -98,6 +113,10 @@ extern "C"
 		TMaterialInstance *materialInstance,
 		uint8_t mask);
 
+	EMSCRIPTEN_KEEPALIVE void MaterialInstance_setTransparencyMode(
+            TMaterialInstance *materialInstance,
+            TTransparencyMode transparencyMode);
+
 
 #ifdef __cplusplus
 }
diff --git a/thermion_dart/native/src/c_api/TMaterialInstance.cpp b/thermion_dart/native/src/c_api/TMaterialInstance.cpp
index 19f51115..65594e3b 100644
--- a/thermion_dart/native/src/c_api/TMaterialInstance.cpp
+++ b/thermion_dart/native/src/c_api/TMaterialInstance.cpp
@@ -139,6 +139,14 @@ namespace thermion
             auto *instance = reinterpret_cast<::filament::MaterialInstance *>(materialInstance);
             instance->setStencilWriteMask(mask);
         }
+
+        EMSCRIPTEN_KEEPALIVE void MaterialInstance_setTransparencyMode(
+            TMaterialInstance *materialInstance,
+            TTransparencyMode transparencyMode)
+        {
+            auto *instance = reinterpret_cast<::filament::MaterialInstance *>(materialInstance);
+            instance->setTransparencyMode((filament::TransparencyMode)transparencyMode);
+        }
 #ifdef __cplusplus
     }
 }