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// Copyright (C) 2017 Klaralvdalens Datakonsult AB (KDAB).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "basegeometryloader_p.h"
#include <Qt3DCore/qattribute.h>
#include <Qt3DCore/qbuffer.h>
#include <Qt3DCore/qgeometry.h>
#include <Qt3DRender/private/qaxisalignedboundingbox_p.h>
#include <Qt3DRender/private/renderlogging_p.h>
QT_BEGIN_NAMESPACE
namespace Qt3DRender {
using namespace Qt3DCore;
Q_LOGGING_CATEGORY(BaseGeometryLoaderLog, "Qt3D.BaseGeometryLoader", QtWarningMsg)
BaseGeometryLoader::BaseGeometryLoader()
: m_loadTextureCoords(true)
, m_generateTangents(true)
, m_centerMesh(false)
, m_geometry(nullptr)
{
}
Qt3DCore::QGeometry *BaseGeometryLoader::geometry() const
{
return m_geometry;
}
bool BaseGeometryLoader::load(QIODevice *ioDev, const QString &subMesh)
{
if (!doLoad(ioDev, subMesh))
return false;
if (m_normals.empty())
generateAveragedNormals(m_points, m_normals, m_indices);
if (m_generateTangents && !m_texCoords.empty())
generateTangents(m_points, m_normals, m_indices, m_texCoords, m_tangents);
if (m_centerMesh)
center(m_points);
qCDebug(BaseGeometryLoaderLog) << "Loaded mesh:";
qCDebug(BaseGeometryLoaderLog) << " " << m_points.size() << "points";
qCDebug(BaseGeometryLoaderLog) << " " << m_indices.size() / 3 << "triangles.";
qCDebug(BaseGeometryLoaderLog) << " " << m_normals.size() << "normals";
qCDebug(BaseGeometryLoaderLog) << " " << m_tangents.size() << "tangents ";
qCDebug(BaseGeometryLoaderLog) << " " << m_texCoords.size() << "texture coordinates.";
generateGeometry();
return true;
}
void BaseGeometryLoader::generateAveragedNormals(const std::vector<QVector3D> &points,
std::vector<QVector3D> &normals,
const std::vector<unsigned int> &faces) const
{
for (size_t i = 0; i < points.size(); ++i)
normals.push_back(QVector3D());
for (size_t i = 0; i < faces.size(); i += 3) {
const QVector3D &p1 = points[ faces[i] ];
const QVector3D &p2 = points[ faces[i+1] ];
const QVector3D &p3 = points[ faces[i+2] ];
const QVector3D a = p2 - p1;
const QVector3D b = p3 - p1;
const QVector3D n = QVector3D::crossProduct(a, b).normalized();
normals[ faces[i] ] += n;
normals[ faces[i+1] ] += n;
normals[ faces[i+2] ] += n;
}
for (size_t i = 0; i < normals.size(); ++i)
normals[i].normalize();
}
void BaseGeometryLoader::generateGeometry()
{
QByteArray bufferBytes;
const uint count = uint(m_points.size());
const quint32 elementSize = 3 + (hasTextureCoordinates() ? 2 : 0)
+ (hasNormals() ? 3 : 0)
+ (hasTangents() ? 4 : 0);
const quint32 stride = elementSize * sizeof(float);
bufferBytes.resize(stride * count);
float *fptr = reinterpret_cast<float*>(bufferBytes.data());
for (size_t index = 0; index < count; ++index) {
*fptr++ = m_points.at(index).x();
*fptr++ = m_points.at(index).y();
*fptr++ = m_points.at(index).z();
if (hasTextureCoordinates()) {
*fptr++ = m_texCoords.at(index).x();
*fptr++ = m_texCoords.at(index).y();
}
if (hasNormals()) {
*fptr++ = m_normals.at(index).x();
*fptr++ = m_normals.at(index).y();
*fptr++ = m_normals.at(index).z();
}
if (hasTangents()) {
*fptr++ = m_tangents.at(index).x();
*fptr++ = m_tangents.at(index).y();
*fptr++ = m_tangents.at(index).z();
*fptr++ = m_tangents.at(index).w();
}
} // of buffer filling loop
auto *buf = new Qt3DCore::QBuffer();
buf->setData(bufferBytes);
if (m_geometry)
qDebug(BaseGeometryLoaderLog, "Existing geometry instance getting overridden.");
m_geometry = new QGeometry();
QAttribute *positionAttribute = new QAttribute(buf, QAttribute::defaultPositionAttributeName(), QAttribute::Float, 3, count, 0, stride);
m_geometry->addAttribute(positionAttribute);
quint32 offset = sizeof(float) * 3;
if (hasTextureCoordinates()) {
QAttribute *texCoordAttribute = new QAttribute(buf, QAttribute::defaultTextureCoordinateAttributeName(), QAttribute::Float, 2, count, offset, stride);
m_geometry->addAttribute(texCoordAttribute);
offset += sizeof(float) * 2;
}
if (hasNormals()) {
QAttribute *normalAttribute = new QAttribute(buf, QAttribute::defaultNormalAttributeName(), QAttribute::Float, 3, count, offset, stride);
m_geometry->addAttribute(normalAttribute);
offset += sizeof(float) * 3;
}
if (hasTangents()) {
QAttribute *tangentAttribute = new QAttribute(buf, QAttribute::defaultTangentAttributeName(),QAttribute::Float, 4, count, offset, stride);
m_geometry->addAttribute(tangentAttribute);
offset += sizeof(float) * 4;
}
QByteArray indexBytes;
QAttribute::VertexBaseType ty;
if (m_indices.size() < 65536) {
// we can use USHORT
ty = QAttribute::UnsignedShort;
indexBytes.resize(m_indices.size() * sizeof(quint16));
quint16 *usptr = reinterpret_cast<quint16*>(indexBytes.data());
for (int i = 0; i < int(m_indices.size()); ++i)
*usptr++ = static_cast<quint16>(m_indices.at(i));
} else {
// use UINT - no conversion needed, but let's ensure int is 32-bit!
ty = QAttribute::UnsignedInt;
Q_ASSERT(sizeof(int) == sizeof(quint32));
indexBytes.resize(m_indices.size() * sizeof(quint32));
memcpy(indexBytes.data(), reinterpret_cast<const char*>(m_indices.data()), indexBytes.size());
}
auto *indexBuffer = new Qt3DCore::QBuffer();
indexBuffer->setData(indexBytes);
QAttribute *indexAttribute = new QAttribute(indexBuffer, ty, 1, uint(m_indices.size()));
indexAttribute->setAttributeType(QAttribute::IndexAttribute);
m_geometry->addAttribute(indexAttribute);
}
void BaseGeometryLoader::generateTangents(const std::vector<QVector3D> &points,
const std::vector<QVector3D> &normals,
const std::vector<unsigned int> &faces,
const std::vector<QVector2D> &texCoords,
std::vector<QVector4D> &tangents) const
{
tangents.clear();
std::vector<QVector3D> tan1Accum;
std::vector<QVector3D> tan2Accum;
tan1Accum.resize(points.size());
tan2Accum.resize(points.size());
tangents.resize(points.size());
// Compute the tangent vector
for (size_t i = 0; i < faces.size(); i += 3) {
const QVector3D &p1 = points[ faces[i] ];
const QVector3D &p2 = points[ faces[i+1] ];
const QVector3D &p3 = points[ faces[i+2] ];
const QVector2D &tc1 = texCoords[ faces[i] ];
const QVector2D &tc2 = texCoords[ faces[i+1] ];
const QVector2D &tc3 = texCoords[ faces[i+2] ];
const QVector3D q1 = p2 - p1;
const QVector3D q2 = p3 - p1;
const float s1 = tc2.x() - tc1.x(), s2 = tc3.x() - tc1.x();
const float t1 = tc2.y() - tc1.y(), t2 = tc3.y() - tc1.y();
const float r = 1.0f / (s1 * t2 - s2 * t1);
const QVector3D tan1((t2 * q1.x() - t1 * q2.x()) * r,
(t2 * q1.y() - t1 * q2.y()) * r,
(t2 * q1.z() - t1 * q2.z()) * r);
const QVector3D tan2((s1 * q2.x() - s2 * q1.x()) * r,
(s1 * q2.y() - s2 * q1.y()) * r,
(s1 * q2.z() - s2 * q1.z()) * r);
tan1Accum[ faces[i] ] += tan1;
tan1Accum[ faces[i+1] ] += tan1;
tan1Accum[ faces[i+2] ] += tan1;
tan2Accum[ faces[i] ] += tan2;
tan2Accum[ faces[i+1] ] += tan2;
tan2Accum[ faces[i+2] ] += tan2;
}
for (size_t i = 0; i < points.size(); ++i) {
const QVector3D &n = normals[i];
const QVector3D &t1 = tan1Accum[i];
const QVector3D &t2 = tan2Accum[i];
// Gram-Schmidt orthogonalize
tangents[i] = QVector4D(QVector3D(t1 - QVector3D::dotProduct(n, t1) * n).normalized(), 0.0f);
// Store handedness in w
tangents[i].setW((QVector3D::dotProduct(QVector3D::crossProduct(n, t1), t2) < 0.0f) ? -1.0f : 1.0f);
}
}
void BaseGeometryLoader::center(std::vector<QVector3D> &points)
{
if (points.empty())
return;
const QAxisAlignedBoundingBox bb(points);
const QVector3D center = bb.center();
// Translate center of the AABB to the origin
for (size_t i = 0; i < points.size(); ++i) {
QVector3D &point = points[i];
point = point - center;
}
}
} // namespace Qt3DRender
QT_END_NAMESPACE
#include "moc_basegeometryloader_p.cpp"