From 33f2c5fbf72daa4de698861ec8329737f87cf33c Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Wed, 11 Sep 2024 18:08:48 +0800
Subject: [PATCH] add normals to CustomGeometry implementation

---
 thermion_dart/native/src/CustomGeometry.cpp | 95 ++++++++++++++++++++-
 1 file changed, 91 insertions(+), 4 deletions(-)

diff --git a/thermion_dart/native/src/CustomGeometry.cpp b/thermion_dart/native/src/CustomGeometry.cpp
index a8799de5..48d7aa91 100644
--- a/thermion_dart/native/src/CustomGeometry.cpp
+++ b/thermion_dart/native/src/CustomGeometry.cpp
@@ -1,10 +1,16 @@
+#include <vector> 
+
+#include "math.h"
+
 #include <filament/Engine.h>
 #include <filament/TransformManager.h>
 #include <filament/Texture.h>
 #include <filament/RenderableManager.h>
 #include <filament/Viewport.h>
 #include <filament/Frustum.h>
+#include <filament/geometry/SurfaceOrientation.h>
 
+#include "Log.hpp"
 #include "CustomGeometry.hpp"
 
 namespace thermion_filament {
@@ -14,6 +20,8 @@ using namespace filament;
 CustomGeometry::CustomGeometry(
     float* vertices, 
     uint32_t numVertices, 
+    float* normals,
+    uint32_t numNormals,
     uint16_t* indices, 
     uint32_t numIndices, 
     RenderableManager::PrimitiveType primitiveType, 
@@ -23,13 +31,19 @@ CustomGeometry::CustomGeometry(
     this->vertices = new float[numVertices];
     std::memcpy(this->vertices, vertices, numVertices * sizeof(float));
 
+    if(numNormals > 0) {
+        Log("numNormals %d", numNormals);
+        this->normals = new float[numNormals];
+        std::memcpy(this->normals, normals, numNormals * sizeof(float));
+    }
+
     this->indices = new uint16_t[numIndices];
     std::memcpy(this->indices, indices, numIndices * sizeof(uint16_t));  
 
     computeBoundingBox();
 }
 
-IndexBuffer* CustomGeometry::indexBuffer() { 
+IndexBuffer* CustomGeometry::indexBuffer() const { 
     IndexBuffer::BufferDescriptor::Callback indexCallback = [](void *buf, size_t,
                                                                void *data)
     {
@@ -46,21 +60,94 @@ IndexBuffer* CustomGeometry::indexBuffer() {
     return indexBuffer;
 }
 
-VertexBuffer* CustomGeometry::vertexBuffer() { 
+VertexBuffer* CustomGeometry::vertexBuffer() const { 
     VertexBuffer::BufferDescriptor::Callback vertexCallback = [](void *buf, size_t,
                                                                  void *data)
     {
     //   free((void *)buf);
     };
 
-    auto vertexBuffer = VertexBuffer::Builder()
+    std::vector<filament::math::ushort3> triangles;
+    for(int i=0; i < numIndices; i+=3) {
+        filament::math::ushort3 triangle;
+        triangle.x = this->indices[i];
+        triangle.y = this->indices[i+1];
+        triangle.z = this->indices[i+2];
+        triangles.push_back(triangle);
+    }
+    
+
+    // Create a SurfaceOrientation builder
+    geometry::SurfaceOrientation::Builder builder;
+    builder.vertexCount(numVertices)
+           .normals((filament::math::float3*)normals)
+           .positions((filament::math::float3*)this->vertices)
+           .triangleCount(triangles.size())
+           .triangles(triangles.data());
+        
+    // Build the SurfaceOrientation object
+    auto orientation = builder.build();
+
+    // Retrieve the quaternions
+    auto quats = new std::vector<filament::math::quatf>(numVertices);
+    orientation->getQuats(quats->data(), numVertices);
+
+    // Create dummy UV data
+    auto dummyUVs = new std::vector<filament::math::float2>(numVertices, filament::math::float2{0.0f, 0.0f});
+
+    // Create dummy vertex color data (white color for all vertices)
+    auto dummyColors = new std::vector<filament::math::float4>(numVertices, filament::math::float4{1.0f, 1.0f, 1.0f, 1.0f});
+
+    auto vertexBufferBuilder = VertexBuffer::Builder()
         .vertexCount(numVertices)
-        .bufferCount(1)
         .attribute(VertexAttribute::POSITION, 0, VertexBuffer::AttributeType::FLOAT3)
+        .attribute(VertexAttribute::UV0, 1, VertexBuffer::AttributeType::FLOAT2)
+        .attribute(VertexAttribute::UV1, 2, VertexBuffer::AttributeType::FLOAT2)
+        .attribute(VertexAttribute::COLOR, 3, VertexBuffer::AttributeType::FLOAT4);
+   
+    if(this->normals) {
+        vertexBufferBuilder
+            .bufferCount(5)
+            .attribute(VertexAttribute::TANGENTS, 4, filament::VertexBuffer::AttributeType::FLOAT4);
+    } else {
+        vertexBufferBuilder = vertexBufferBuilder.bufferCount(4);
+    }
+    auto vertexBuffer = vertexBufferBuilder
         .build(*_engine);
 
     vertexBuffer->setBufferAt(*_engine, 0, VertexBuffer::BufferDescriptor(
         this->vertices, vertexBuffer->getVertexCount() * sizeof(math::float3), vertexCallback));
+
+
+      // Set UV0 buffer
+    vertexBuffer->setBufferAt(*_engine, 1, VertexBuffer::BufferDescriptor(
+        dummyUVs->data(), dummyUVs->size() * sizeof(math::float2), 
+        [](void* buf, size_t, void* data) {
+            delete static_cast<std::vector<math::float2>*>(data);
+        }, dummyUVs));
+
+    // Set UV1 buffer
+    vertexBuffer->setBufferAt(*_engine, 2, VertexBuffer::BufferDescriptor(
+        dummyUVs->data(), dummyUVs->size() * sizeof(math::float2), 
+        [](void* buf, size_t, void* data) {
+            // Do nothing here, as we're reusing the same data as UV0
+        }, nullptr));
+
+      // Set vertex color buffer
+    vertexBuffer->setBufferAt(*_engine, 3, VertexBuffer::BufferDescriptor(
+        dummyColors->data(), dummyColors->size() * sizeof(math::float4),
+        [](void* buf, size_t, void* data) {
+            delete static_cast<std::vector<math::float4>*>(data);
+        }, dummyColors));
+    
+    if(this->normals) {
+        vertexBuffer->setBufferAt(*_engine, 4, VertexBuffer::BufferDescriptor(
+            quats->data(), quats->size() * sizeof(math::quatf), [] (void *buf, size_t,
+                                                                    void *data)
+        {
+        delete (std::vector<math::quatf>*)data;
+        }, (void*)quats));
+    }
     return vertexBuffer;
 }