protot/3rdparty/tinygltf/examples/raytrace/gltf-loader.cc

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2018-03-19 23:00:51 +01:00
#include "gltf-loader.h"
#include <iostream>
#include <memory> // c++11
#define TINYGLTF_IMPLEMENTATION
#include <tiny_gltf.h>
namespace example {
static std::string GetFilePathExtension(const std::string &FileName) {
if (FileName.find_last_of(".") != std::string::npos)
return FileName.substr(FileName.find_last_of(".") + 1);
return "";
}
///
/// Loads glTF 2.0 mesh
///
bool LoadGLTF(const std::string &filename, float scale,
std::vector<Mesh<float> > *meshes,
std::vector<Material> *materials,
std::vector<Texture> *textures) {
// TODO(syoyo): Texture
// TODO(syoyo): Material
tinygltf::Model model;
tinygltf::TinyGLTF loader;
std::string err;
const std::string ext = GetFilePathExtension(filename);
bool ret = false;
if (ext.compare("glb") == 0) {
// assume binary glTF.
ret = loader.LoadBinaryFromFile(&model, &err, filename.c_str());
} else {
// assume ascii glTF.
ret = loader.LoadASCIIFromFile(&model, &err, filename.c_str());
}
if (!err.empty()) {
std::cerr << "glTF parse error: " << err << std::endl;
}
if (!ret) {
std::cerr << "Failed to load glTF: " << filename << std::endl;
return false;
}
std::cout << "loaded glTF file has:\n"
<< model.accessors.size() << " accessors\n"
<< model.animations.size() << " animations\n"
<< model.buffers.size() << " buffers\n"
<< model.bufferViews.size() << " bufferViews\n"
<< model.materials.size() << " materials\n"
<< model.meshes.size() << " meshes\n"
<< model.nodes.size() << " nodes\n"
<< model.textures.size() << " textures\n"
<< model.images.size() << " images\n"
<< model.skins.size() << " skins\n"
<< model.samplers.size() << " samplers\n"
<< model.cameras.size() << " cameras\n"
<< model.scenes.size() << " scenes\n"
<< model.lights.size() << " lights\n";
// Iterate through all the meshes in the glTF file
for (const auto &gltfMesh : model.meshes) {
std::cout << "Current mesh has " << gltfMesh.primitives.size()
<< " primitives:\n";
// Create a mesh object
Mesh<float> loadedMesh(sizeof(float) * 3);
// To store the min and max of the buffer (as 3D vector of floats)
v3f pMin = {}, pMax = {};
// Store the name of the glTF mesh (if defined)
loadedMesh.name = gltfMesh.name;
// For each primitive
for (const auto &meshPrimitive : gltfMesh.primitives) {
// Boolean used to check if we have converted the vertex buffer format
bool convertedToTriangleList = false;
// This permit to get a type agnostic way of reading the index buffer
std::unique_ptr<intArrayBase> indicesArrayPtr = nullptr;
{
const auto &indicesAccessor = model.accessors[meshPrimitive.indices];
const auto &bufferView = model.bufferViews[indicesAccessor.bufferView];
const auto &buffer = model.buffers[bufferView.buffer];
const auto dataAddress = buffer.data.data() + bufferView.byteOffset +
indicesAccessor.byteOffset;
const auto byteStride = indicesAccessor.ByteStride(bufferView);
const auto count = indicesAccessor.count;
// Allocate the index array in the pointer-to-base declared in the
// parent scope
switch (indicesAccessor.componentType) {
case TINYGLTF_COMPONENT_TYPE_BYTE:
indicesArrayPtr =
std::unique_ptr<intArray<char> >(new intArray<char>(
arrayAdapter<char>(dataAddress, count, byteStride)));
break;
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE:
indicesArrayPtr = std::unique_ptr<intArray<unsigned char> >(
new intArray<unsigned char>(arrayAdapter<unsigned char>(
dataAddress, count, byteStride)));
break;
case TINYGLTF_COMPONENT_TYPE_SHORT:
indicesArrayPtr =
std::unique_ptr<intArray<short> >(new intArray<short>(
arrayAdapter<short>(dataAddress, count, byteStride)));
break;
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT:
indicesArrayPtr = std::unique_ptr<intArray<unsigned short> >(
new intArray<unsigned short>(arrayAdapter<unsigned short>(
dataAddress, count, byteStride)));
break;
case TINYGLTF_COMPONENT_TYPE_INT:
indicesArrayPtr = std::unique_ptr<intArray<int> >(new intArray<int>(
arrayAdapter<int>(dataAddress, count, byteStride)));
break;
case TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT:
indicesArrayPtr = std::unique_ptr<intArray<unsigned int> >(
new intArray<unsigned int>(arrayAdapter<unsigned int>(
dataAddress, count, byteStride)));
break;
default:
break;
}
}
const auto &indices = *indicesArrayPtr;
if (indicesArrayPtr) {
std::cout << "indices: ";
for (size_t i(0); i < indicesArrayPtr->size(); ++i) {
std::cout << indices[i] << " ";
loadedMesh.faces.push_back(indices[i]);
}
std::cout << '\n';
}
switch (meshPrimitive.mode) {
// We re-arrange the indices so that it describe a simple list of
// triangles
case TINYGLTF_MODE_TRIANGLE_FAN:
if (!convertedToTriangleList) {
std::cout << "TRIANGLE_FAN\n";
// This only has to be done once per primitive
convertedToTriangleList = true;
// We steal the guts of the vector
auto triangleFan = std::move(loadedMesh.faces);
loadedMesh.faces.clear();
// Push back the indices that describe just one triangle one by one
for (size_t i{2}; i < triangleFan.size(); ++i) {
loadedMesh.faces.push_back(triangleFan[0]);
loadedMesh.faces.push_back(triangleFan[i - 1]);
loadedMesh.faces.push_back(triangleFan[i]);
}
}
case TINYGLTF_MODE_TRIANGLE_STRIP:
if (!convertedToTriangleList) {
std::cout << "TRIANGLE_STRIP\n";
// This only has to be done once per primitive
convertedToTriangleList = true;
auto triangleStrip = std::move(loadedMesh.faces);
loadedMesh.faces.clear();
for (size_t i{2}; i < triangleStrip.size(); ++i) {
loadedMesh.faces.push_back(triangleStrip[i - 2]);
loadedMesh.faces.push_back(triangleStrip[i - 1]);
loadedMesh.faces.push_back(triangleStrip[i]);
}
}
case TINYGLTF_MODE_TRIANGLES: // this is the simpliest case to handle
{
std::cout << "TRIANGLES\n";
for (const auto &attribute : meshPrimitive.attributes) {
const auto attribAccessor = model.accessors[attribute.second];
const auto &bufferView =
model.bufferViews[attribAccessor.bufferView];
const auto &buffer = model.buffers[bufferView.buffer];
const auto dataPtr = buffer.data.data() + bufferView.byteOffset +
attribAccessor.byteOffset;
const auto byte_stride = attribAccessor.ByteStride(bufferView);
const auto count = attribAccessor.count;
std::cout << "current attribute has count " << count
<< " and stride " << byte_stride << " bytes\n";
std::cout << "attribute string is : " << attribute.first << '\n';
if (attribute.first == "POSITION") {
std::cout << "found position attribute\n";
// get the position min/max for computing the boundingbox
pMin.x = attribAccessor.minValues[0];
pMin.y = attribAccessor.minValues[1];
pMin.z = attribAccessor.minValues[2];
pMax.x = attribAccessor.maxValues[0];
pMax.y = attribAccessor.maxValues[1];
pMax.z = attribAccessor.maxValues[2];
switch (attribAccessor.type) {
case TINYGLTF_TYPE_VEC3: {
switch (attribAccessor.componentType) {
case TINYGLTF_COMPONENT_TYPE_FLOAT:
std::cout << "Type is FLOAT\n";
// 3D vector of float
v3fArray positions(
arrayAdapter<v3f>(dataPtr, count, byte_stride));
std::cout << "positions's size : " << positions.size()
<< '\n';
for (size_t i{0}; i < positions.size(); ++i) {
const auto v = positions[i];
std::cout << "positions[" << i << "]: (" << v.x << ", "
<< v.y << ", " << v.z << ")\n";
loadedMesh.vertices.push_back(v.x * scale);
loadedMesh.vertices.push_back(v.y * scale);
loadedMesh.vertices.push_back(v.z * scale);
}
}
break;
case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
std::cout << "Type is DOUBLE\n";
switch (attribAccessor.type) {
case TINYGLTF_TYPE_VEC3: {
v3dArray positions(
arrayAdapter<v3d>(dataPtr, count, byte_stride));
for (size_t i{0}; i < positions.size(); ++i) {
const auto v = positions[i];
std::cout << "positions[" << i << "]: (" << v.x
<< ", " << v.y << ", " << v.z << ")\n";
loadedMesh.vertices.push_back(v.x * scale);
loadedMesh.vertices.push_back(v.y * scale);
loadedMesh.vertices.push_back(v.z * scale);
}
} break;
default:
// TODO Handle error
break;
}
break;
default:
break;
}
} break;
}
}
if (attribute.first == "NORMAL") {
std::cout << "found normal attribute\n";
switch (attribAccessor.type) {
case TINYGLTF_TYPE_VEC3: {
std::cout << "Normal is VEC3\n";
switch (attribAccessor.componentType) {
case TINYGLTF_COMPONENT_TYPE_FLOAT: {
std::cout << "Normal is FLOAT\n";
v3fArray normals(
arrayAdapter<v3f>(dataPtr, count, byte_stride));
// IMPORTANT: We need to reorder normals (and texture
// coordinates into "facevarying" order) for each face
// For each triangle :
for (size_t i{0}; i < indices.size() / 3; ++i) {
// get the i'th triange's indexes
auto f0 = indices[3 * i + 0];
auto f1 = indices[3 * i + 1];
auto f2 = indices[3 * i + 2];
// get the 3 normal vectors for that face
v3f n0, n1, n2;
n0 = normals[f0];
n1 = normals[f1];
n2 = normals[f2];
// Put them in the array in the correct order
loadedMesh.facevarying_normals.push_back(n0.x);
loadedMesh.facevarying_normals.push_back(n0.y);
loadedMesh.facevarying_normals.push_back(n0.z);
loadedMesh.facevarying_normals.push_back(n1.x);
loadedMesh.facevarying_normals.push_back(n1.y);
loadedMesh.facevarying_normals.push_back(n2.z);
loadedMesh.facevarying_normals.push_back(n2.x);
loadedMesh.facevarying_normals.push_back(n2.y);
loadedMesh.facevarying_normals.push_back(n2.z);
}
} break;
case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
std::cout << "Normal is DOUBLE\n";
v3dArray normals(
arrayAdapter<v3d>(dataPtr, count, byte_stride));
// IMPORTANT: We need to reorder normals (and texture
// coordinates into "facevarying" order) for each face
// For each triangle :
for (size_t i{0}; i < indices.size() / 3; ++i) {
// get the i'th triange's indexes
auto f0 = indices[3 * i + 0];
auto f1 = indices[3 * i + 1];
auto f2 = indices[3 * i + 2];
// get the 3 normal vectors for that face
v3d n0, n1, n2;
n0 = normals[f0];
n1 = normals[f1];
n2 = normals[f2];
// Put them in the array in the correct order
loadedMesh.facevarying_normals.push_back(n0.x);
loadedMesh.facevarying_normals.push_back(n0.y);
loadedMesh.facevarying_normals.push_back(n0.z);
loadedMesh.facevarying_normals.push_back(n1.x);
loadedMesh.facevarying_normals.push_back(n1.y);
loadedMesh.facevarying_normals.push_back(n2.z);
loadedMesh.facevarying_normals.push_back(n2.x);
loadedMesh.facevarying_normals.push_back(n2.y);
loadedMesh.facevarying_normals.push_back(n2.z);
}
} break;
default:
std::cerr << "Unhandeled componant type for normal\n";
}
} break;
default:
std::cerr << "Unhandeled vector type for normal\n";
}
// Face varying comment on the normals is also true for the UVs
if (attribute.first == "TEXCOORD_0") {
std::cout << "Found texture coordinates\n";
switch (attribAccessor.type) {
case TINYGLTF_TYPE_VEC2: {
std::cout << "TEXTCOORD is VEC2\n";
switch (attribAccessor.componentType) {
case TINYGLTF_COMPONENT_TYPE_FLOAT: {
std::cout << "TEXTCOORD is FLOAT\n";
v2fArray uvs(
arrayAdapter<v2f>(dataPtr, count, byte_stride));
for (size_t i{0}; i < indices.size() / 3; ++i) {
// get the i'th triange's indexes
auto f0 = indices[3 * i + 0];
auto f1 = indices[3 * i + 1];
auto f2 = indices[3 * i + 2];
// get the texture coordinates for each triangle's
// vertices
v2f uv0, uv1, uv2;
uv0 = uvs[f0];
uv1 = uvs[f1];
uv2 = uvs[f2];
// push them in order into the mesh data
loadedMesh.facevarying_uvs.push_back(uv0.x);
loadedMesh.facevarying_uvs.push_back(uv0.y);
loadedMesh.facevarying_uvs.push_back(uv1.x);
loadedMesh.facevarying_uvs.push_back(uv1.y);
loadedMesh.facevarying_uvs.push_back(uv2.x);
loadedMesh.facevarying_uvs.push_back(uv2.y);
}
} break;
case TINYGLTF_COMPONENT_TYPE_DOUBLE: {
std::cout << "TEXTCOORD is DOUBLE\n";
v2dArray uvs(
arrayAdapter<v2d>(dataPtr, count, byte_stride));
for (size_t i{0}; i < indices.size() / 3; ++i) {
// get the i'th triange's indexes
auto f0 = indices[3 * i + 0];
auto f1 = indices[3 * i + 1];
auto f2 = indices[3 * i + 2];
v2d uv0, uv1, uv2;
uv0 = uvs[f0];
uv1 = uvs[f1];
uv2 = uvs[f2];
loadedMesh.facevarying_uvs.push_back(uv0.x);
loadedMesh.facevarying_uvs.push_back(uv0.y);
loadedMesh.facevarying_uvs.push_back(uv1.x);
loadedMesh.facevarying_uvs.push_back(uv1.y);
loadedMesh.facevarying_uvs.push_back(uv2.x);
loadedMesh.facevarying_uvs.push_back(uv2.y);
}
} break;
default:
std::cerr << "unrecognized vector type for UV";
}
} break;
default:
std::cerr << "unreconized componant type for UV";
}
}
}
}
break;
default:
std::cerr << "primitive mode not implemented";
break;
// These aren't triangles:
case TINYGLTF_MODE_POINTS:
case TINYGLTF_MODE_LINE:
case TINYGLTF_MODE_LINE_LOOP:
std::cerr << "primitive is not triangle based, ignoring";
}
}
// bbox :
v3f bCenter;
bCenter.x = 0.5f * (pMax.x - pMin.x) + pMin.x;
bCenter.y = 0.5f * (pMax.y - pMin.y) + pMin.y;
bCenter.z = 0.5f * (pMax.z - pMin.z) + pMin.z;
for (size_t v = 0; v < loadedMesh.vertices.size() / 3; v++) {
loadedMesh.vertices[3 * v + 0] -= bCenter.x;
loadedMesh.vertices[3 * v + 1] -= bCenter.y;
loadedMesh.vertices[3 * v + 2] -= bCenter.z;
}
loadedMesh.pivot_xform[0][0] = 1.0f;
loadedMesh.pivot_xform[0][1] = 0.0f;
loadedMesh.pivot_xform[0][2] = 0.0f;
loadedMesh.pivot_xform[0][3] = 0.0f;
loadedMesh.pivot_xform[1][0] = 0.0f;
loadedMesh.pivot_xform[1][1] = 1.0f;
loadedMesh.pivot_xform[1][2] = 0.0f;
loadedMesh.pivot_xform[1][3] = 0.0f;
loadedMesh.pivot_xform[2][0] = 0.0f;
loadedMesh.pivot_xform[2][1] = 0.0f;
loadedMesh.pivot_xform[2][2] = 1.0f;
loadedMesh.pivot_xform[2][3] = 0.0f;
loadedMesh.pivot_xform[3][0] = bCenter.x;
loadedMesh.pivot_xform[3][1] = bCenter.y;
loadedMesh.pivot_xform[3][2] = bCenter.z;
loadedMesh.pivot_xform[3][3] = 1.0f;
// TODO handle materials
for (size_t i{0}; i < loadedMesh.faces.size(); ++i)
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;
}
} // namespace example