cup_edit/thermion_dart/native/src/CustomGeometry.cpp

#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 {

using namespace filament;

CustomGeometry::CustomGeometry(
    float* vertices, 
    uint32_t numVertices, 
    float* normals,
    uint32_t numNormals,
    float* uvs,
    uint32_t numUvs,
    uint16_t* indices, 
    uint32_t numIndices, 
    RenderableManager::PrimitiveType primitiveType, 
    Engine* engine)
    : numVertices(numVertices), numIndices(numIndices), _engine(engine) {
    this->primitiveType = primitiveType;
    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));
    } else { 
        Log("no normals");
    }

    if(numUvs > 0) {
        Log("numUvs %d", numUvs);
        this->uvs = new float[numUvs];
        std::memcpy(this->uvs, uvs, numUvs * sizeof(float));
    } else {
        this->uvs = nullptr;
    }

    this->indices = new uint16_t[numIndices];
    std::memcpy(this->indices, indices, numIndices * sizeof(uint16_t));  

    computeBoundingBox();
}

IndexBuffer* CustomGeometry::indexBuffer() const { 
    IndexBuffer::BufferDescriptor::Callback indexCallback = [](void *buf, size_t,
                                                               void *data)
    {
    //   free((void *)buf);
    };

    auto indexBuffer = IndexBuffer::Builder()
        .indexCount(numIndices)
        .bufferType(IndexBuffer::IndexType::USHORT)
        .build(*_engine);

    indexBuffer->setBuffer(*_engine, IndexBuffer::BufferDescriptor(
        this->indices, indexBuffer->getIndexCount() * sizeof(uint16_t), indexCallback));
    return indexBuffer;
}

VertexBuffer* CustomGeometry::vertexBuffer() const { 
    VertexBuffer::BufferDescriptor::Callback vertexCallback = [](void *buf, size_t,
                                                                 void *data)
    {
    //   free((void *)buf);
    };

    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);

    // Use provided UVs or create dummy UV data
    std::vector<filament::math::float2>* uvData;
    if (this->uvs != nullptr) {
        uvData = new std::vector<filament::math::float2>((filament::math::float2*)this->uvs, (filament::math::float2*)(this->uvs + numVertices * 2));
    } else {
        uvData = 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)
        .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(
        uvData->data(), uvData->size() * sizeof(math::float2), 
        [](void* buf, size_t, void* data) {
            delete static_cast<std::vector<math::float2>*>(data);
        }, uvData));

    // Set UV1 buffer (reusing UV0 data)
    vertexBuffer->setBufferAt(*_engine, 2, VertexBuffer::BufferDescriptor(
        uvData->data(), uvData->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;
}

CustomGeometry::~CustomGeometry() {
    delete[] vertices;
    delete[] indices;
    if (normals) delete[] normals;
    if (uvs) delete[] uvs;
}

void CustomGeometry::computeBoundingBox() {
    float minX = FLT_MAX, minY = FLT_MAX, minZ = FLT_MAX;
    float maxX = -FLT_MAX, maxY = -FLT_MAX, maxZ = -FLT_MAX;

    for (uint32_t i = 0; i < numVertices; i += 3) {
        minX = std::min(vertices[i], minX);
        minY = std::min(vertices[i + 1], minY);
        minZ = std::min(vertices[i + 2], minZ);
        maxX = std::max(vertices[i], maxX);
        maxY = std::max(vertices[i + 1], maxY);
        maxZ = std::max(vertices[i + 2], maxZ);
    }

    boundingBox = Box{{minX, minY, minZ}, {maxX, maxY, maxZ}};
}

Box CustomGeometry::getBoundingBox() const {
    return boundingBox;
}

}