492 lines
20 KiB
C++
492 lines
20 KiB
C++
#include "gltf-loader.h"
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#include <iostream>
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#include <memory> // c++11
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#define TINYGLTF_IMPLEMENTATION
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#include <tiny_gltf.h>
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namespace example {
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static std::string GetFilePathExtension(const std::string &FileName) {
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if (FileName.find_last_of(".") != std::string::npos)
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return FileName.substr(FileName.find_last_of(".") + 1);
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return "";
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}
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///
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/// Loads glTF 2.0 mesh
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///
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bool LoadGLTF(const std::string &filename, float scale,
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std::vector<Mesh<float> > *meshes,
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std::vector<Material> *materials,
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std::vector<Texture> *textures) {
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// TODO(syoyo): Texture
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// TODO(syoyo): Material
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tinygltf::Model model;
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tinygltf::TinyGLTF loader;
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std::string err;
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const std::string ext = GetFilePathExtension(filename);
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bool ret = false;
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if (ext.compare("glb") == 0) {
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// assume binary glTF.
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ret = loader.LoadBinaryFromFile(&model, &err, filename.c_str());
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} else {
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// assume ascii glTF.
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ret = loader.LoadASCIIFromFile(&model, &err, filename.c_str());
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}
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if (!err.empty()) {
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std::cerr << "glTF parse error: " << err << std::endl;
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}
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if (!ret) {
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std::cerr << "Failed to load glTF: " << filename << std::endl;
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return false;
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}
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std::cout << "loaded glTF file has:\n"
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<< model.accessors.size() << " accessors\n"
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<< model.animations.size() << " animations\n"
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<< model.buffers.size() << " buffers\n"
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<< model.bufferViews.size() << " bufferViews\n"
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<< model.materials.size() << " materials\n"
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<< model.meshes.size() << " meshes\n"
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<< model.nodes.size() << " nodes\n"
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<< model.textures.size() << " textures\n"
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<< model.images.size() << " images\n"
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<< model.skins.size() << " skins\n"
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<< model.samplers.size() << " samplers\n"
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<< model.cameras.size() << " cameras\n"
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<< model.scenes.size() << " scenes\n"
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<< model.lights.size() << " lights\n";
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// Iterate through all the meshes in the glTF file
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for (const auto &gltfMesh : model.meshes) {
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std::cout << "Current mesh has " << gltfMesh.primitives.size()
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<< " primitives:\n";
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// Create a mesh object
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Mesh<float> loadedMesh(sizeof(float) * 3);
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// To store the min and max of the buffer (as 3D vector of floats)
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v3f pMin = {}, pMax = {};
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// Store the name of the glTF mesh (if defined)
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loadedMesh.name = gltfMesh.name;
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// For each primitive
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for (const auto &meshPrimitive : gltfMesh.primitives) {
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// Boolean used to check if we have converted the vertex buffer format
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bool convertedToTriangleList = false;
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// This permit to get a type agnostic way of reading the index buffer
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std::unique_ptr<intArrayBase> indicesArrayPtr = nullptr;
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{
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const auto &indicesAccessor = model.accessors[meshPrimitive.indices];
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const auto &bufferView = model.bufferViews[indicesAccessor.bufferView];
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const auto &buffer = model.buffers[bufferView.buffer];
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const auto dataAddress = buffer.data.data() + bufferView.byteOffset +
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indicesAccessor.byteOffset;
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const auto byteStride = indicesAccessor.ByteStride(bufferView);
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const auto count = indicesAccessor.count;
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// Allocate the index array in the pointer-to-base declared in the
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// parent scope
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switch (indicesAccessor.componentType) {
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case TINYGLTF_COMPONENT_TYPE_BYTE:
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indicesArrayPtr =
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std::unique_ptr<intArray<char> >(new intArray<char>(
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arrayAdapter<char>(dataAddress, count, byteStride)));
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break;
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case TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE:
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indicesArrayPtr = std::unique_ptr<intArray<unsigned char> >(
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new intArray<unsigned char>(arrayAdapter<unsigned char>(
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dataAddress, count, byteStride)));
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break;
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case TINYGLTF_COMPONENT_TYPE_SHORT:
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indicesArrayPtr =
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std::unique_ptr<intArray<short> >(new intArray<short>(
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arrayAdapter<short>(dataAddress, count, byteStride)));
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break;
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case TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT:
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indicesArrayPtr = std::unique_ptr<intArray<unsigned short> >(
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new intArray<unsigned short>(arrayAdapter<unsigned short>(
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dataAddress, count, byteStride)));
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break;
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case TINYGLTF_COMPONENT_TYPE_INT:
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indicesArrayPtr = std::unique_ptr<intArray<int> >(new intArray<int>(
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arrayAdapter<int>(dataAddress, count, byteStride)));
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break;
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case TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT:
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indicesArrayPtr = std::unique_ptr<intArray<unsigned int> >(
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new intArray<unsigned int>(arrayAdapter<unsigned int>(
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dataAddress, count, byteStride)));
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break;
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default:
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break;
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}
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}
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const auto &indices = *indicesArrayPtr;
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if (indicesArrayPtr) {
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std::cout << "indices: ";
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for (size_t i(0); i < indicesArrayPtr->size(); ++i) {
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std::cout << indices[i] << " ";
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loadedMesh.faces.push_back(indices[i]);
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}
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std::cout << '\n';
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}
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switch (meshPrimitive.mode) {
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// We re-arrange the indices so that it describe a simple list of
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// triangles
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case TINYGLTF_MODE_TRIANGLE_FAN:
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if (!convertedToTriangleList) {
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std::cout << "TRIANGLE_FAN\n";
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// This only has to be done once per primitive
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convertedToTriangleList = true;
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// We steal the guts of the vector
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auto triangleFan = std::move(loadedMesh.faces);
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loadedMesh.faces.clear();
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// Push back the indices that describe just one triangle one by one
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for (size_t i{2}; i < triangleFan.size(); ++i) {
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loadedMesh.faces.push_back(triangleFan[0]);
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loadedMesh.faces.push_back(triangleFan[i - 1]);
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loadedMesh.faces.push_back(triangleFan[i]);
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}
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}
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case TINYGLTF_MODE_TRIANGLE_STRIP:
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if (!convertedToTriangleList) {
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std::cout << "TRIANGLE_STRIP\n";
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// This only has to be done once per primitive
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convertedToTriangleList = true;
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auto triangleStrip = std::move(loadedMesh.faces);
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loadedMesh.faces.clear();
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for (size_t i{2}; i < triangleStrip.size(); ++i) {
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loadedMesh.faces.push_back(triangleStrip[i - 2]);
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loadedMesh.faces.push_back(triangleStrip[i - 1]);
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loadedMesh.faces.push_back(triangleStrip[i]);
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}
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}
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case TINYGLTF_MODE_TRIANGLES: // this is the simpliest case to handle
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{
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std::cout << "TRIANGLES\n";
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for (const auto &attribute : meshPrimitive.attributes) {
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const auto attribAccessor = model.accessors[attribute.second];
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const auto &bufferView =
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model.bufferViews[attribAccessor.bufferView];
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const auto &buffer = model.buffers[bufferView.buffer];
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const auto dataPtr = buffer.data.data() + bufferView.byteOffset +
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attribAccessor.byteOffset;
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const auto byte_stride = attribAccessor.ByteStride(bufferView);
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const auto count = attribAccessor.count;
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std::cout << "current attribute has count " << count
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<< " and stride " << byte_stride << " bytes\n";
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std::cout << "attribute string is : " << attribute.first << '\n';
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if (attribute.first == "POSITION") {
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std::cout << "found position attribute\n";
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// get the position min/max for computing the boundingbox
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pMin.x = attribAccessor.minValues[0];
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pMin.y = attribAccessor.minValues[1];
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pMin.z = attribAccessor.minValues[2];
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pMax.x = attribAccessor.maxValues[0];
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pMax.y = attribAccessor.maxValues[1];
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pMax.z = attribAccessor.maxValues[2];
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switch (attribAccessor.type) {
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case TINYGLTF_TYPE_VEC3: {
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switch (attribAccessor.componentType) {
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case TINYGLTF_COMPONENT_TYPE_FLOAT:
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std::cout << "Type is FLOAT\n";
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// 3D vector of float
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v3fArray positions(
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arrayAdapter<v3f>(dataPtr, count, byte_stride));
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std::cout << "positions's size : " << positions.size()
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<< '\n';
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for (size_t i{0}; i < positions.size(); ++i) {
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const auto v = positions[i];
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std::cout << "positions[" << i << "]: (" << v.x << ", "
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<< v.y << ", " << v.z << ")\n";
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loadedMesh.vertices.push_back(v.x * scale);
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loadedMesh.vertices.push_back(v.y * scale);
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loadedMesh.vertices.push_back(v.z * scale);
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}
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}
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break;
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case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
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std::cout << "Type is DOUBLE\n";
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switch (attribAccessor.type) {
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case TINYGLTF_TYPE_VEC3: {
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v3dArray positions(
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arrayAdapter<v3d>(dataPtr, count, byte_stride));
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for (size_t i{0}; i < positions.size(); ++i) {
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const auto v = positions[i];
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std::cout << "positions[" << i << "]: (" << v.x
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<< ", " << v.y << ", " << v.z << ")\n";
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loadedMesh.vertices.push_back(v.x * scale);
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loadedMesh.vertices.push_back(v.y * scale);
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loadedMesh.vertices.push_back(v.z * scale);
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}
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} break;
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default:
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// TODO Handle error
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break;
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}
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break;
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default:
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break;
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}
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} break;
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}
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}
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if (attribute.first == "NORMAL") {
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std::cout << "found normal attribute\n";
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switch (attribAccessor.type) {
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case TINYGLTF_TYPE_VEC3: {
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std::cout << "Normal is VEC3\n";
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switch (attribAccessor.componentType) {
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case TINYGLTF_COMPONENT_TYPE_FLOAT: {
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std::cout << "Normal is FLOAT\n";
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v3fArray normals(
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arrayAdapter<v3f>(dataPtr, count, byte_stride));
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// IMPORTANT: We need to reorder normals (and texture
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// coordinates into "facevarying" order) for each face
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// For each triangle :
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for (size_t i{0}; i < indices.size() / 3; ++i) {
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// get the i'th triange's indexes
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auto f0 = indices[3 * i + 0];
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auto f1 = indices[3 * i + 1];
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auto f2 = indices[3 * i + 2];
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// get the 3 normal vectors for that face
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v3f n0, n1, n2;
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n0 = normals[f0];
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n1 = normals[f1];
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n2 = normals[f2];
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// Put them in the array in the correct order
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loadedMesh.facevarying_normals.push_back(n0.x);
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loadedMesh.facevarying_normals.push_back(n0.y);
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loadedMesh.facevarying_normals.push_back(n0.z);
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loadedMesh.facevarying_normals.push_back(n1.x);
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loadedMesh.facevarying_normals.push_back(n1.y);
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loadedMesh.facevarying_normals.push_back(n2.z);
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loadedMesh.facevarying_normals.push_back(n2.x);
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loadedMesh.facevarying_normals.push_back(n2.y);
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loadedMesh.facevarying_normals.push_back(n2.z);
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}
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} break;
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case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
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std::cout << "Normal is DOUBLE\n";
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v3dArray normals(
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arrayAdapter<v3d>(dataPtr, count, byte_stride));
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// IMPORTANT: We need to reorder normals (and texture
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// coordinates into "facevarying" order) for each face
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// For each triangle :
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for (size_t i{0}; i < indices.size() / 3; ++i) {
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// get the i'th triange's indexes
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auto f0 = indices[3 * i + 0];
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auto f1 = indices[3 * i + 1];
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auto f2 = indices[3 * i + 2];
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// get the 3 normal vectors for that face
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v3d n0, n1, n2;
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n0 = normals[f0];
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n1 = normals[f1];
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n2 = normals[f2];
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// Put them in the array in the correct order
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loadedMesh.facevarying_normals.push_back(n0.x);
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loadedMesh.facevarying_normals.push_back(n0.y);
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loadedMesh.facevarying_normals.push_back(n0.z);
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loadedMesh.facevarying_normals.push_back(n1.x);
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loadedMesh.facevarying_normals.push_back(n1.y);
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loadedMesh.facevarying_normals.push_back(n2.z);
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loadedMesh.facevarying_normals.push_back(n2.x);
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loadedMesh.facevarying_normals.push_back(n2.y);
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loadedMesh.facevarying_normals.push_back(n2.z);
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}
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} break;
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default:
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std::cerr << "Unhandeled componant type for normal\n";
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}
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} break;
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default:
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std::cerr << "Unhandeled vector type for normal\n";
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}
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// Face varying comment on the normals is also true for the UVs
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if (attribute.first == "TEXCOORD_0") {
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std::cout << "Found texture coordinates\n";
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switch (attribAccessor.type) {
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case TINYGLTF_TYPE_VEC2: {
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std::cout << "TEXTCOORD is VEC2\n";
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switch (attribAccessor.componentType) {
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case TINYGLTF_COMPONENT_TYPE_FLOAT: {
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std::cout << "TEXTCOORD is FLOAT\n";
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v2fArray uvs(
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arrayAdapter<v2f>(dataPtr, count, byte_stride));
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for (size_t i{0}; i < indices.size() / 3; ++i) {
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// get the i'th triange's indexes
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auto f0 = indices[3 * i + 0];
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auto f1 = indices[3 * i + 1];
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auto f2 = indices[3 * i + 2];
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// get the texture coordinates for each triangle's
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// vertices
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v2f uv0, uv1, uv2;
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uv0 = uvs[f0];
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uv1 = uvs[f1];
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uv2 = uvs[f2];
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// push them in order into the mesh data
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loadedMesh.facevarying_uvs.push_back(uv0.x);
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loadedMesh.facevarying_uvs.push_back(uv0.y);
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loadedMesh.facevarying_uvs.push_back(uv1.x);
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loadedMesh.facevarying_uvs.push_back(uv1.y);
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loadedMesh.facevarying_uvs.push_back(uv2.x);
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loadedMesh.facevarying_uvs.push_back(uv2.y);
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}
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} break;
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case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
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std::cout << "TEXTCOORD is DOUBLE\n";
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v2dArray uvs(
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arrayAdapter<v2d>(dataPtr, count, byte_stride));
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for (size_t i{0}; i < indices.size() / 3; ++i) {
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// get the i'th triange's indexes
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auto f0 = indices[3 * i + 0];
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auto f1 = indices[3 * i + 1];
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auto f2 = indices[3 * i + 2];
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v2d uv0, uv1, uv2;
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uv0 = uvs[f0];
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uv1 = uvs[f1];
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uv2 = uvs[f2];
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loadedMesh.facevarying_uvs.push_back(uv0.x);
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loadedMesh.facevarying_uvs.push_back(uv0.y);
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loadedMesh.facevarying_uvs.push_back(uv1.x);
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loadedMesh.facevarying_uvs.push_back(uv1.y);
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loadedMesh.facevarying_uvs.push_back(uv2.x);
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loadedMesh.facevarying_uvs.push_back(uv2.y);
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}
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} break;
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default:
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std::cerr << "unrecognized vector type for UV";
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}
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} break;
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default:
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std::cerr << "unreconized componant type for UV";
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}
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}
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}
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}
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break;
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default:
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std::cerr << "primitive mode not implemented";
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break;
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// These aren't triangles:
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case TINYGLTF_MODE_POINTS:
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case TINYGLTF_MODE_LINE:
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case TINYGLTF_MODE_LINE_LOOP:
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std::cerr << "primitive is not triangle based, ignoring";
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}
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}
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// bbox :
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v3f bCenter;
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bCenter.x = 0.5f * (pMax.x - pMin.x) + pMin.x;
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bCenter.y = 0.5f * (pMax.y - pMin.y) + pMin.y;
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bCenter.z = 0.5f * (pMax.z - pMin.z) + pMin.z;
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for (size_t v = 0; v < loadedMesh.vertices.size() / 3; v++) {
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loadedMesh.vertices[3 * v + 0] -= bCenter.x;
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loadedMesh.vertices[3 * v + 1] -= bCenter.y;
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loadedMesh.vertices[3 * v + 2] -= bCenter.z;
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}
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loadedMesh.pivot_xform[0][0] = 1.0f;
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loadedMesh.pivot_xform[0][1] = 0.0f;
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loadedMesh.pivot_xform[0][2] = 0.0f;
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loadedMesh.pivot_xform[0][3] = 0.0f;
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loadedMesh.pivot_xform[1][0] = 0.0f;
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loadedMesh.pivot_xform[1][1] = 1.0f;
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loadedMesh.pivot_xform[1][2] = 0.0f;
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loadedMesh.pivot_xform[1][3] = 0.0f;
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loadedMesh.pivot_xform[2][0] = 0.0f;
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loadedMesh.pivot_xform[2][1] = 0.0f;
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loadedMesh.pivot_xform[2][2] = 1.0f;
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loadedMesh.pivot_xform[2][3] = 0.0f;
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loadedMesh.pivot_xform[3][0] = bCenter.x;
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loadedMesh.pivot_xform[3][1] = bCenter.y;
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loadedMesh.pivot_xform[3][2] = bCenter.z;
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loadedMesh.pivot_xform[3][3] = 1.0f;
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// TODO handle materials
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for (size_t i{0}; i < loadedMesh.faces.size(); ++i)
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|
loadedMesh.material_ids.push_back(materials->at(0).id);
|
|
|
|
meshes->push_back(loadedMesh);
|
|
ret = true;
|
|
}
|
|
}
|
|
|
|
// Iterate through all texture declaration in glTF file
|
|
for (const auto &gltfTexture : model.textures) {
|
|
std::cout << "Found texture!";
|
|
Texture loadedTexture;
|
|
const auto &image = model.images[gltfTexture.source];
|
|
loadedTexture.components = image.component;
|
|
loadedTexture.width = image.width;
|
|
loadedTexture.height = image.height;
|
|
|
|
const auto size =
|
|
image.component * image.width * image.height * sizeof(unsigned char);
|
|
loadedTexture.image = new unsigned char[size];
|
|
memcpy(loadedTexture.image, image.image.data(), size);
|
|
textures->push_back(loadedTexture);
|
|
}
|
|
return ret;
|
|
}
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|
} // namespace example
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