assimp.assimp/code/glTFExporter.cpp

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2016, assimp team
All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
following conditions are met:

* Redistributions of source code must retain the above
copyright notice, this list of conditions and the
following disclaimer.

* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other
materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
contributors may be used to endorse or promote products
derived from this software without specific prior
written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/



#ifndef ASSIMP_BUILD_NO_EXPORT
#ifndef ASSIMP_BUILD_NO_GLTF_EXPORTER

#include "glTFExporter.h"

#include "Exceptional.h"
#include "StringComparison.h"
#include "ByteSwapper.h"

#include "SplitLargeMeshes.h"
#include "SceneCombiner.h"

#include <assimp/version.h>
#include <assimp/IOSystem.hpp>
#include <assimp/Exporter.hpp>
#include <assimp/material.h>
#include <assimp/scene.h>

// Header files, standart library.
#include <memory>
#include <inttypes.h>

#include "glTFAssetWriter.h"

#ifdef ASSIMP_IMPORTER_GLTF_USE_OPEN3DGC
	// Header files, Open3DGC.
#	include <Open3DGC/o3dgcSC3DMCEncoder.h>
#endif

using namespace rapidjson;

using namespace Assimp;
using namespace glTF;

namespace Assimp {

    // ------------------------------------------------------------------------------------------------
    // Worker function for exporting a scene to GLTF. Prototyped and registered in Exporter.cpp
    void ExportSceneGLTF(const char* pFile, IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties)
    {

        // invoke the exporter
        glTFExporter exporter(pFile, pIOSystem, pScene, pProperties, false);
    }

    // ------------------------------------------------------------------------------------------------
    // Worker function for exporting a scene to GLB. Prototyped and registered in Exporter.cpp
    void ExportSceneGLB(const char* pFile, IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties)
    {
        // invoke the exporter
        glTFExporter exporter(pFile, pIOSystem, pScene, pProperties, true);
    }

} // end of namespace Assimp



glTFExporter::glTFExporter(const char* filename, IOSystem* pIOSystem, const aiScene* pScene,
                           const ExportProperties* pProperties, bool isBinary)
    : mFilename(filename)
    , mIOSystem(pIOSystem)
    , mProperties(pProperties)
{
    aiScene* sceneCopy_tmp;
    SceneCombiner::CopyScene(&sceneCopy_tmp, pScene);
    std::unique_ptr<aiScene> sceneCopy(sceneCopy_tmp);

    SplitLargeMeshesProcess_Triangle tri_splitter;
    tri_splitter.SetLimit(0xffff);
    tri_splitter.Execute(sceneCopy.get());

    SplitLargeMeshesProcess_Vertex vert_splitter;
    vert_splitter.SetLimit(0xffff);
    vert_splitter.Execute(sceneCopy.get());

    mScene = sceneCopy.get();

    std::unique_ptr<Asset> asset();
    mAsset.reset( new glTF::Asset( pIOSystem ) );

    if (isBinary) {
        mAsset->SetAsBinary();
    }

    ExportMetadata();

    //for (unsigned int i = 0; i < pScene->mNumAnimations; ++i) {}

    //for (unsigned int i = 0; i < pScene->mNumCameras; ++i) {}

    //for (unsigned int i = 0; i < pScene->mNumLights; ++i) {}


    ExportMaterials();

    ExportMeshes();

    //for (unsigned int i = 0; i < pScene->mNumTextures; ++i) {}


    if (mScene->mRootNode) {
        ExportNode(mScene->mRootNode);
    }

    ExportScene();

    glTF::AssetWriter writer(*mAsset);

    if (isBinary) {
        writer.WriteGLBFile(filename);
    } else {
        writer.WriteFile(filename);
    }
}


static void CopyValue(const aiMatrix4x4& v, glTF::mat4& o)
{
    o[ 0] = v.a1; o[ 1] = v.b1; o[ 2] = v.c1; o[ 3] = v.d1;
    o[ 4] = v.a2; o[ 5] = v.b2; o[ 6] = v.c2; o[ 7] = v.d2;
    o[ 8] = v.a3; o[ 9] = v.b3; o[10] = v.c3; o[11] = v.d3;
    o[12] = v.a4; o[13] = v.b4; o[14] = v.c4; o[15] = v.d4;
}

inline Ref<Accessor> ExportData(Asset& a, std::string& meshName, Ref<Buffer>& buffer,
    unsigned int count, void* data, AttribType::Value typeIn, AttribType::Value typeOut, ComponentType compType, bool isIndices = false)
{
    if (!count || !data) return Ref<Accessor>();

    unsigned int numCompsIn = AttribType::GetNumComponents(typeIn);
    unsigned int numCompsOut = AttribType::GetNumComponents(typeOut);
    unsigned int bytesPerComp = ComponentTypeSize(compType);

    size_t offset = buffer->byteLength;
    size_t length = count * numCompsOut * bytesPerComp;
    buffer->Grow(length);

    // bufferView
    Ref<BufferView> bv = a.bufferViews.Create(a.FindUniqueID(meshName, "view"));
    bv->buffer = buffer;
    bv->byteOffset = unsigned(offset);
    bv->byteLength = length; //! The target that the WebGL buffer should be bound to.
    bv->target = isIndices ? BufferViewTarget_ELEMENT_ARRAY_BUFFER : BufferViewTarget_ARRAY_BUFFER;

    // accessor
    Ref<Accessor> acc = a.accessors.Create(a.FindUniqueID(meshName, "accessor"));
    acc->bufferView = bv;
    acc->byteOffset = 0;
    acc->byteStride = 0;
    acc->componentType = compType;
    acc->count = count;
    acc->type = typeOut;

    // copy the data
    acc->WriteData(count, data, numCompsIn*bytesPerComp);

    return acc;
}

namespace {
    void GetMatScalar(const aiMaterial* mat, float& val, const char* propName, int type, int idx) {
        if (mat->Get(propName, type, idx, val) == AI_SUCCESS) {}
    }
}

void glTFExporter::GetMatColorOrTex(const aiMaterial* mat, glTF::TexProperty& prop, const char* propName, int type, int idx, aiTextureType tt)
{
    aiString tex;
    aiColor4D col;
    if (mat->GetTextureCount(tt) > 0) {
        if (mat->Get(AI_MATKEY_TEXTURE(tt, 0), tex) == AI_SUCCESS) {
            std::string path = tex.C_Str();

            if (path.size() > 0) {
                if (path[0] != '*') {
                    std::map<std::string, unsigned int>::iterator it = mTexturesByPath.find(path);
                    if (it != mTexturesByPath.end()) {
                        prop.texture = mAsset->textures.Get(it->second);
                    }
                }

                if (!prop.texture) {
                    std::string texId = mAsset->FindUniqueID("", "texture");
                    prop.texture = mAsset->textures.Create(texId);
                    mTexturesByPath[path] = prop.texture.GetIndex();

                    std::string imgId = mAsset->FindUniqueID("", "image");
                    prop.texture->source = mAsset->images.Create(imgId);

                    if (path[0] == '*') { // embedded
                        aiTexture* tex = mScene->mTextures[atoi(&path[1])];

                        uint8_t* data = reinterpret_cast<uint8_t*>(tex->pcData);
                        prop.texture->source->SetData(data, tex->mWidth, *mAsset);

                        if (tex->achFormatHint[0]) {
                            std::string mimeType = "image/";
                            mimeType += (memcmp(tex->achFormatHint, "jpg", 3) == 0) ? "jpeg" : tex->achFormatHint;
                            prop.texture->source->mimeType = mimeType;
                        }
                    }
                    else {
                        prop.texture->source->uri = path;
                    }
                }
            }
        }
    }

    if (mat->Get(propName, type, idx, col) == AI_SUCCESS) {
        prop.color[0] = col.r; prop.color[1] = col.g; prop.color[2] = col.b; prop.color[3] = col.a;
    }
}

void glTFExporter::ExportMaterials()
{
    aiString aiName;
    for (unsigned int i = 0; i < mScene->mNumMaterials; ++i) {
        const aiMaterial* mat = mScene->mMaterials[i];


        std::string name;
        if (mat->Get(AI_MATKEY_NAME, aiName) == AI_SUCCESS) {
            name = aiName.C_Str();
        }
        name = mAsset->FindUniqueID(name, "material");

        Ref<Material> m = mAsset->materials.Create(name);

        GetMatColorOrTex(mat, m->ambient, AI_MATKEY_COLOR_AMBIENT, aiTextureType_AMBIENT);
        GetMatColorOrTex(mat, m->diffuse, AI_MATKEY_COLOR_DIFFUSE, aiTextureType_DIFFUSE);
        GetMatColorOrTex(mat, m->specular, AI_MATKEY_COLOR_SPECULAR, aiTextureType_SPECULAR);
        GetMatColorOrTex(mat, m->emission, AI_MATKEY_COLOR_EMISSIVE, aiTextureType_EMISSIVE);

        GetMatScalar(mat, m->shininess, AI_MATKEY_SHININESS);
    }
}

void glTFExporter::ExportMeshes()
{
    // Not for
    //     using IndicesType = decltype(aiFace::mNumIndices);
    // But yes for
    //     using IndicesType = unsigned short;
    // because "ComponentType_UNSIGNED_SHORT" used for indices. And it's a maximal type according to glTF specification.
    typedef unsigned short IndicesType;

    // Variables needed for compression. BEGIN.
    // Indices, not pointers - because pointer to buffer is changin while writing to it.
    size_t idx_srcdata_begin;// Index of buffer before writing mesh data. Also, index of begin of coordinates array in buffer.
    size_t idx_srcdata_normal = SIZE_MAX;// Index of begin of normals array in buffer. SIZE_MAX - mean that mesh has no normals.
    std::vector<size_t> idx_srcdata_tc;// Array of indices. Every index point to begin of texture coordinates array in buffer.
    size_t idx_srcdata_ind;// Index of begin of coordinates indices array in buffer.
    bool comp_allow;// Point that data of current mesh can be compressed.
    // Variables needed for compression. END.

    std::string fname = std::string(mFilename);
    std::string bufferIdPrefix = fname.substr(0, fname.find("."));
    std::string bufferId = mAsset->FindUniqueID("", bufferIdPrefix.c_str());

    Ref<Buffer> b = mAsset->GetBodyBuffer();
    if (!b) {
       b = mAsset->buffers.Create(bufferId);
    }

	for (unsigned int idx_mesh = 0; idx_mesh < mScene->mNumMeshes; ++idx_mesh) {
		const aiMesh* aim = mScene->mMeshes[idx_mesh];

		// Check if compressing requested and mesh can be encoded.
#ifdef ASSIMP_IMPORTER_GLTF_USE_OPEN3DGC
		comp_allow = mProperties->GetPropertyBool("extensions.Open3DGC.use", false);
#else
		comp_allow = false;
#endif

		if(comp_allow && (aim->mPrimitiveTypes == aiPrimitiveType_TRIANGLE) && (aim->mNumVertices > 0) && (aim->mNumFaces > 0))
		{
			idx_srcdata_tc.clear();
			idx_srcdata_tc.reserve(AI_MAX_NUMBER_OF_TEXTURECOORDS);
		}
		else
		{
			std::string msg;

			if(aim->mPrimitiveTypes != aiPrimitiveType_TRIANGLE)
				msg = "all primitives of the mesh must be a triangles.";
			else
				msg = "mesh must has vertices and faces.";

			DefaultLogger::get()->warn("GLTF: can not use Open3DGC-compression: " + msg);
            comp_allow = false;
		}

        std::string meshId = mAsset->FindUniqueID(aim->mName.C_Str(), "mesh");
        Ref<Mesh> m = mAsset->meshes.Create(meshId);
        m->primitives.resize(1);
        Mesh::Primitive& p = m->primitives.back();

        p.material = mAsset->materials.Get(aim->mMaterialIndex);

		/******************* Vertices ********************/
		// If compression is used then you need parameters of uncompressed region: begin and size. At this step "begin" is stored.
		if(comp_allow) idx_srcdata_begin = b->byteLength;

        Ref<Accessor> v = ExportData(*mAsset, meshId, b, aim->mNumVertices, aim->mVertices, AttribType::VEC3, AttribType::VEC3, ComponentType_FLOAT);
		if (v) p.attributes.position.push_back(v);

		/******************** Normals ********************/
		if(comp_allow && (aim->mNormals > 0)) idx_srcdata_normal = b->byteLength;// Store index of normals array.

		Ref<Accessor> n = ExportData(*mAsset, meshId, b, aim->mNumVertices, aim->mNormals, AttribType::VEC3, AttribType::VEC3, ComponentType_FLOAT);
		if (n) p.attributes.normal.push_back(n);

		/************** Texture coordinates **************/
        for (int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
            // Flip UV y coords
            if (aim -> mNumUVComponents[i] > 1) {
                for (unsigned int j = 0; j < aim->mNumVertices; ++j) {
                    aim->mTextureCoords[i][j].y = 1 - aim->mTextureCoords[i][j].y;
                }
            }

            if (aim->mNumUVComponents[i] > 0) {
                AttribType::Value type = (aim->mNumUVComponents[i] == 2) ? AttribType::VEC2 : AttribType::VEC3;

				if(comp_allow) idx_srcdata_tc.push_back(b->byteLength);// Store index of texture coordinates array.

				Ref<Accessor> tc = ExportData(*mAsset, meshId, b, aim->mNumVertices, aim->mTextureCoords[i], AttribType::VEC3, type, ComponentType_FLOAT, true);
				if (tc) p.attributes.texcoord.push_back(tc);
			}
		}

		/*************** Vertices indices ****************/
		idx_srcdata_ind = b->byteLength;// Store index of indices array.

		if (aim->mNumFaces > 0) {
			std::vector<IndicesType> indices;
			unsigned int nIndicesPerFace = aim->mFaces[0].mNumIndices;
            indices.resize(aim->mNumFaces * nIndicesPerFace);
            for (size_t i = 0; i < aim->mNumFaces; ++i) {
                for (size_t j = 0; j < nIndicesPerFace; ++j) {
                    indices[i*nIndicesPerFace + j] = uint16_t(aim->mFaces[i].mIndices[j]);
                }
            }

			p.indices = ExportData(*mAsset, meshId, b, unsigned(indices.size()), &indices[0], AttribType::SCALAR, AttribType::SCALAR, ComponentType_UNSIGNED_SHORT, true);
		}

        switch (aim->mPrimitiveTypes) {
            case aiPrimitiveType_POLYGON:
                p.mode = PrimitiveMode_TRIANGLES; break; // TODO implement this
            case aiPrimitiveType_LINE:
                p.mode = PrimitiveMode_LINES; break;
            case aiPrimitiveType_POINT:
                p.mode = PrimitiveMode_POINTS; break;
            default: // aiPrimitiveType_TRIANGLE
                p.mode = PrimitiveMode_TRIANGLES;
        }

		/****************** Compression ******************/
		///TODO: animation: weights, joints.
		if(comp_allow)
		{
#ifdef ASSIMP_IMPORTER_GLTF_USE_OPEN3DGC
			// Only one type of compression supported at now - Open3DGC.
			//
			o3dgc::BinaryStream bs;
			o3dgc::SC3DMCEncoder<IndicesType> encoder;
			o3dgc::IndexedFaceSet<IndicesType> comp_o3dgc_ifs;
			o3dgc::SC3DMCEncodeParams comp_o3dgc_params;

			//
			// Fill data for encoder.
			//
			// Quantization
			unsigned quant_coord = mProperties->GetPropertyInteger("extensions.Open3DGC.quantization.POSITION", 12);
			unsigned quant_normal = mProperties->GetPropertyInteger("extensions.Open3DGC.quantization.NORMAL", 10);
			unsigned quant_texcoord = mProperties->GetPropertyInteger("extensions.Open3DGC.quantization.TEXCOORD", 10);

			// Prediction
			o3dgc::O3DGCSC3DMCPredictionMode prediction_position = o3dgc::O3DGC_SC3DMC_PARALLELOGRAM_PREDICTION;
			o3dgc::O3DGCSC3DMCPredictionMode prediction_normal =  o3dgc::O3DGC_SC3DMC_SURF_NORMALS_PREDICTION;
			o3dgc::O3DGCSC3DMCPredictionMode prediction_texcoord = o3dgc::O3DGC_SC3DMC_PARALLELOGRAM_PREDICTION;

			// IndexedFacesSet: "Crease angle", "solid", "convex" are set to default.
			comp_o3dgc_ifs.SetCCW(true);
			comp_o3dgc_ifs.SetIsTriangularMesh(true);
			comp_o3dgc_ifs.SetNumFloatAttributes(0);
			// Coordinates
			comp_o3dgc_params.SetCoordQuantBits(quant_coord);
			comp_o3dgc_params.SetCoordPredMode(prediction_position);
			comp_o3dgc_ifs.SetNCoord(aim->mNumVertices);
			comp_o3dgc_ifs.SetCoord((o3dgc::Real* const)&b->GetPointer()[idx_srcdata_begin]);
			// Normals
			if(idx_srcdata_normal != SIZE_MAX)
			{
				comp_o3dgc_params.SetNormalQuantBits(quant_normal);
				comp_o3dgc_params.SetNormalPredMode(prediction_normal);
				comp_o3dgc_ifs.SetNNormal(aim->mNumVertices);
				comp_o3dgc_ifs.SetNormal((o3dgc::Real* const)&b->GetPointer()[idx_srcdata_normal]);
			}

			// Texture coordinates
			for(size_t num_tc = 0; num_tc < idx_srcdata_tc.size(); num_tc++)
			{
				size_t num = comp_o3dgc_ifs.GetNumFloatAttributes();

				comp_o3dgc_params.SetFloatAttributeQuantBits(num, quant_texcoord);
				comp_o3dgc_params.SetFloatAttributePredMode(num, prediction_texcoord);
				comp_o3dgc_ifs.SetNFloatAttribute(num, aim->mNumVertices);// number of elements.
				comp_o3dgc_ifs.SetFloatAttributeDim(num, aim->mNumUVComponents[num_tc]);// components per element: aiVector3D => x * float
				comp_o3dgc_ifs.SetFloatAttributeType(num, o3dgc::O3DGC_IFS_FLOAT_ATTRIBUTE_TYPE_TEXCOORD);
				comp_o3dgc_ifs.SetFloatAttribute(num, (o3dgc::Real* const)&b->GetPointer()[idx_srcdata_tc[num_tc]]);
				comp_o3dgc_ifs.SetNumFloatAttributes(num + 1);
			}

			// Coordinates indices
			comp_o3dgc_ifs.SetNCoordIndex(aim->mNumFaces);
			comp_o3dgc_ifs.SetCoordIndex((IndicesType* const)&b->GetPointer()[idx_srcdata_ind]);
			// Prepare to enconding
			comp_o3dgc_params.SetNumFloatAttributes(comp_o3dgc_ifs.GetNumFloatAttributes());
			if(mProperties->GetPropertyBool("extensions.Open3DGC.binary", true))
				comp_o3dgc_params.SetStreamType(o3dgc::O3DGC_STREAM_TYPE_BINARY);
			else
				comp_o3dgc_params.SetStreamType(o3dgc::O3DGC_STREAM_TYPE_ASCII);

			comp_o3dgc_ifs.ComputeMinMax(o3dgc::O3DGC_SC3DMC_MAX_ALL_DIMS);
			//
			// Encoding
			//
			encoder.Encode(comp_o3dgc_params, comp_o3dgc_ifs, bs);
			// Replace data in buffer.
			b->ReplaceData(idx_srcdata_begin, b->byteLength - idx_srcdata_begin, bs.GetBuffer(), bs.GetSize());
			//
			// Add information about extension to mesh.
			//
			// Create extension structure.
			Mesh::SCompression_Open3DGC* ext = new Mesh::SCompression_Open3DGC;

			// Fill it.
			ext->Buffer = b->id;
			ext->Offset = idx_srcdata_begin;
			ext->Count = b->byteLength - idx_srcdata_begin;
			ext->Binary = mProperties->GetPropertyBool("extensions.Open3DGC.binary");
			ext->IndicesCount = comp_o3dgc_ifs.GetNCoordIndex() * 3;
			ext->VerticesCount = comp_o3dgc_ifs.GetNCoord();
			// And assign to mesh.
			m->Extension.push_back(ext);
#endif
		}// if(comp_allow)
	}// for (unsigned int i = 0; i < mScene->mNumMeshes; ++i) {
}

unsigned int glTFExporter::ExportNode(const aiNode* n)
{
    Ref<Node> node = mAsset->nodes.Create(mAsset->FindUniqueID(n->mName.C_Str(), "node"));

    if (!n->mTransformation.IsIdentity()) {
        node->matrix.isPresent = true;
        CopyValue(n->mTransformation, node->matrix.value);
    }

    for (unsigned int i = 0; i < n->mNumMeshes; ++i) {
        node->meshes.push_back(mAsset->meshes.Get(n->mMeshes[i]));
    }

    for (unsigned int i = 0; i < n->mNumChildren; ++i) {
        unsigned int idx = ExportNode(n->mChildren[i]);
        node->children.push_back(mAsset->nodes.Get(idx));
    }

    return node.GetIndex();
}


void glTFExporter::ExportScene()
{
    const char* sceneName = "defaultScene";
    Ref<Scene> scene = mAsset->scenes.Create(sceneName);

    // root node will be the first one exported (idx 0)
    if (mAsset->nodes.Size() > 0) {
        scene->nodes.push_back(mAsset->nodes.Get(0u));
    }

    // set as the default scene
    mAsset->scene = scene;
}

void glTFExporter::ExportMetadata()
{
    glTF::AssetMetadata& asset = mAsset->asset;
    asset.version = 1;

    char buffer[256];
    ai_snprintf(buffer, 256, "Open Asset Import Library (assimp v%d.%d.%d)",
        aiGetVersionMajor(), aiGetVersionMinor(), aiGetVersionRevision());

    asset.generator = buffer;
}







#endif // ASSIMP_BUILD_NO_GLTF_EXPORTER
#endif // ASSIMP_BUILD_NO_EXPORT