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#include "model.h"
#include <QFile>
#include <QSet>
#include <QTextStream>
#include <QVarLengthArray>
#include "GL/gl.h"
struct Edge
{
Edge() : pointA(0), pointB(0) {}
Edge(int pa, int pb) : pointA(pa), pointB(pb) {}
int pointA;
int pointB;
};
uint qHash(const Edge &edge)
{
return qHash(edge.pointA) ^ qHash(edge.pointB);
}
bool operator==(const Edge &a, const Edge &b)
{
return (a.pointA == b.pointA && a.pointB == b.pointB)
|| (a.pointA == b.pointB && a.pointB == b.pointA);
}
Model::Model(const QString &filename)
{
QFile file(filename);
if (!file.open(QIODevice::ReadOnly))
return;
// use a set to avoid duplicate edges
QSet<Edge> edges;
Point3d min( 1e9, 1e9, 1e9);
Point3d max(-1e9,-1e9,-1e9);
QTextStream in(&file);
while (!in.atEnd()) {
QString input = in.readLine();
// empty or comment?
if (input.isEmpty() || input[0] == '#')
continue;
QTextStream ts(&input);
QString id;
ts >> id;
if (id == "v") {
Point3d p;
ts >> p.x >> p.y >> p.z;
m_points << p;
for (int i = 0; i < 3; ++i) {
min[i] = qMin(min[i], p[i]);
max[i] = qMax(max[i], p[i]);
}
} else if (id == "f" || id == "fo") {
QVarLengthArray<int, 4> p;
while (!ts.atEnd()) {
QString vertex;
ts >> vertex;
int index;
QTextStream vertexStream(&vertex);
vertexStream >> index;
if (vertexStream.status() == QTextStream::Ok)
p.append(index - 1);
}
for (int i = 0; i < p.size(); ++i)
edges << Edge(p[i], p[(i + 1) % p.size()]);
for (int i = 0; i < 3; ++i)
m_pointIndices << p[i];
if (p.size() == 4)
for (int i = 0; i < 3; ++i)
m_pointIndices << p[(i + 2) % 4];
}
}
const Point3d bounds = max - min;
const qreal scale = 1 / qMax(bounds.x, qMax(bounds.y, bounds.z));
for (int i = 0; i < m_points.size(); ++i)
m_points[i] = (m_points[i] - (min + bounds * 0.5)) * scale;
m_normals.resize(m_points.size());
for (int i = 0; i < m_pointIndices.size(); i += 3) {
const Point3d a = m_points.at(m_pointIndices.at(i));
const Point3d b = m_points.at(m_pointIndices.at(i+1));
const Point3d c = m_points.at(m_pointIndices.at(i+2));
const Point3d normal = cross(b - a, c - a).normalize();
for (int j = 0; j < 3; ++j) {
Point3d &n = m_normals[m_pointIndices.at(i + j)];
n = n + normal;
}
}
for (int i = 0; i < m_normals.size(); ++i)
m_normals[i] = m_normals[i].normalize();
foreach (const Edge &edge, QVector<Edge>::fromList(edges.toList()))
m_edges << m_points.at(edge.pointA) << m_points.at(edge.pointB);
}
void Model::render(bool wireframe, bool normals) const
{
glEnable(GL_DEPTH_TEST);
glEnableClientState(GL_VERTEX_ARRAY);
if (wireframe) {
glVertexPointer(3, GL_FLOAT, 0, m_edges.data());
glDrawArrays(GL_LINES, 0, m_edges.size());
} else {
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_COLOR_MATERIAL);
glShadeModel(GL_SMOOTH);
glEnableClientState(GL_NORMAL_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, (float *)m_points.data());
glNormalPointer(GL_FLOAT, 0, (float *)m_normals.data());
glDrawElements(GL_TRIANGLES, m_pointIndices.size(), GL_UNSIGNED_INT, m_pointIndices.data());
glDisableClientState(GL_NORMAL_ARRAY);
glDisable(GL_COLOR_MATERIAL);
glDisable(GL_LIGHT0);
glDisable(GL_LIGHTING);
}
glDisableClientState(GL_VERTEX_ARRAY);
if (normals) {
glColor3f(1, 0, 0);
glBegin(GL_LINES);
for (int i = 0; i < m_normals.size(); ++i) {
Point3d a = m_points.at(i);
Point3d b = m_points.at(i) + m_normals.at(i) * 0.02;
glVertex3f(a.x, a.y, a.z);
glVertex3f(b.x, b.y, b.z);
}
glEnd();
}
glDisable(GL_DEPTH_TEST);
}
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