qt5base-lts/examples/opengl/shared/qtlogo.cpp
Jason McDonald 5635823e17 Remove "All rights reserved" line from license headers.
As in the past, to avoid rewriting various autotests that contain
line-number information, an extra blank line has been inserted at the
end of the license text to ensure that this commit does not change the
total number of lines in the license header.

Change-Id: I311e001373776812699d6efc045b5f742890c689
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
2012-01-30 03:54:59 +01:00

412 lines
12 KiB
C++

/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use 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 Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** 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."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <QGLWidget>
#include <QMatrix4x4>
#include <QVector3D>
#include <qmath.h>
#include "qtlogo.h"
static const qreal tee_height = 0.311126;
static const qreal cross_width = 0.25;
static const qreal bar_thickness = 0.113137;
static const qreal inside_diam = 0.20;
static const qreal outside_diam = 0.30;
static const qreal logo_depth = 0.10;
static const int num_divisions = 32;
//! [0]
struct Geometry
{
QVector<GLushort> faces;
QVector<QVector3D> vertices;
QVector<QVector3D> normals;
void appendSmooth(const QVector3D &a, const QVector3D &n, int from);
void appendFaceted(const QVector3D &a, const QVector3D &n);
void finalize();
void loadArrays() const;
};
//! [0]
//! [1]
class Patch
{
public:
enum Smoothing { Faceted, Smooth };
Patch(Geometry *);
void setSmoothing(Smoothing s) { sm = s; }
void translate(const QVector3D &t);
void rotate(qreal deg, QVector3D axis);
void draw() const;
void addTri(const QVector3D &a, const QVector3D &b, const QVector3D &c, const QVector3D &n);
void addQuad(const QVector3D &a, const QVector3D &b, const QVector3D &c, const QVector3D &d);
GLushort start;
GLushort count;
GLushort initv;
GLfloat faceColor[4];
QMatrix4x4 mat;
Smoothing sm;
Geometry *geom;
};
//! [1]
static inline void qSetColor(float colorVec[], QColor c)
{
colorVec[0] = c.redF();
colorVec[1] = c.greenF();
colorVec[2] = c.blueF();
colorVec[3] = c.alphaF();
}
void Geometry::loadArrays() const
{
glVertexPointer(3, GL_FLOAT, 0, vertices.constData());
glNormalPointer(GL_FLOAT, 0, normals.constData());
}
void Geometry::finalize()
{
// TODO: add vertex buffer uploading here
// Finish smoothing normals by ensuring accumulated normals are returned
// to length 1.0.
for (int i = 0; i < normals.count(); ++i)
normals[i].normalize();
}
void Geometry::appendSmooth(const QVector3D &a, const QVector3D &n, int from)
{
// Smooth normals are acheived by averaging the normals for faces meeting
// at a point. First find the point in geometry already generated
// (working backwards, since most often the points shared are between faces
// recently added).
int v = vertices.count() - 1;
for ( ; v >= from; --v)
if (qFuzzyCompare(vertices[v], a))
break;
if (v < from)
{
// The vert was not found so add it as a new one, and initialize
// its corresponding normal
v = vertices.count();
vertices.append(a);
normals.append(n);
}
else
{
// Vert found, accumulate normals into corresponding normal slot.
// Must call finalize once finished accumulating normals
normals[v] += n;
}
// In both cases (found or not) reference the vert via its index
faces.append(v);
}
void Geometry::appendFaceted(const QVector3D &a, const QVector3D &n)
{
// Faceted normals are achieved by duplicating the vert for every
// normal, so that faces meeting at a vert get a sharp edge.
int v = vertices.count();
vertices.append(a);
normals.append(n);
faces.append(v);
}
Patch::Patch(Geometry *g)
: start(g->faces.count())
, count(0)
, initv(g->vertices.count())
, sm(Patch::Smooth)
, geom(g)
{
qSetColor(faceColor, QColor(Qt::darkGray));
}
void Patch::rotate(qreal deg, QVector3D axis)
{
mat.rotate(deg, axis);
}
void Patch::translate(const QVector3D &t)
{
mat.translate(t);
}
static inline void qMultMatrix(const QMatrix4x4 &mat)
{
if (sizeof(qreal) == sizeof(GLfloat))
glMultMatrixf((GLfloat*)mat.constData());
#ifndef QT_OPENGL_ES
else if (sizeof(qreal) == sizeof(GLdouble))
glMultMatrixd((GLdouble*)mat.constData());
#endif
else
{
GLfloat fmat[16];
qreal const *r = mat.constData();
for (int i = 0; i < 16; ++i)
fmat[i] = r[i];
glMultMatrixf(fmat);
}
}
//! [2]
void Patch::draw() const
{
glPushMatrix();
qMultMatrix(mat);
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, faceColor);
const GLushort *indices = geom->faces.constData();
glDrawElements(GL_TRIANGLES, count, GL_UNSIGNED_SHORT, indices + start);
glPopMatrix();
}
//! [2]
void Patch::addTri(const QVector3D &a, const QVector3D &b, const QVector3D &c, const QVector3D &n)
{
QVector3D norm = n.isNull() ? QVector3D::normal(a, b, c) : n;
if (sm == Smooth)
{
geom->appendSmooth(a, norm, initv);
geom->appendSmooth(b, norm, initv);
geom->appendSmooth(c, norm, initv);
}
else
{
geom->appendFaceted(a, norm);
geom->appendFaceted(b, norm);
geom->appendFaceted(c, norm);
}
count += 3;
}
void Patch::addQuad(const QVector3D &a, const QVector3D &b, const QVector3D &c, const QVector3D &d)
{
QVector3D norm = QVector3D::normal(a, b, c);
if (sm == Smooth)
{
addTri(a, b, c, norm);
addTri(a, c, d, norm);
}
else
{
// If faceted share the two common verts
addTri(a, b, c, norm);
int k = geom->vertices.count();
geom->appendSmooth(a, norm, k);
geom->appendSmooth(c, norm, k);
geom->appendFaceted(d, norm);
count += 3;
}
}
static inline QVector<QVector3D> extrude(const QVector<QVector3D> &verts, qreal depth)
{
QVector<QVector3D> extr = verts;
for (int v = 0; v < extr.count(); ++v)
extr[v].setZ(extr[v].z() - depth);
return extr;
}
class Rectoid
{
public:
void translate(const QVector3D &t)
{
for (int i = 0; i < parts.count(); ++i)
parts[i]->translate(t);
}
void rotate(qreal deg, QVector3D axis)
{
for (int i = 0; i < parts.count(); ++i)
parts[i]->rotate(deg, axis);
}
// No special Rectoid destructor - the parts are fetched out of this member
// variable, and destroyed by the new owner
QList<Patch*> parts;
};
class RectPrism : public Rectoid
{
public:
RectPrism(Geometry *g, qreal width, qreal height, qreal depth);
};
RectPrism::RectPrism(Geometry *g, qreal width, qreal height, qreal depth)
{
enum { bl, br, tr, tl };
Patch *fb = new Patch(g);
fb->setSmoothing(Patch::Faceted);
// front face
QVector<QVector3D> r(4);
r[br].setX(width);
r[tr].setX(width);
r[tr].setY(height);
r[tl].setY(height);
QVector3D adjToCenter(-width / 2.0, -height / 2.0, depth / 2.0);
for (int i = 0; i < 4; ++i)
r[i] += adjToCenter;
fb->addQuad(r[bl], r[br], r[tr], r[tl]);
// back face
QVector<QVector3D> s = extrude(r, depth);
fb->addQuad(s[tl], s[tr], s[br], s[bl]);
// side faces
Patch *sides = new Patch(g);
sides->setSmoothing(Patch::Faceted);
sides->addQuad(s[bl], s[br], r[br], r[bl]);
sides->addQuad(s[br], s[tr], r[tr], r[br]);
sides->addQuad(s[tr], s[tl], r[tl], r[tr]);
sides->addQuad(s[tl], s[bl], r[bl], r[tl]);
parts << fb << sides;
}
class RectTorus : public Rectoid
{
public:
RectTorus(Geometry *g, qreal iRad, qreal oRad, qreal depth, int numSectors);
};
RectTorus::RectTorus(Geometry *g, qreal iRad, qreal oRad, qreal depth, int k)
{
QVector<QVector3D> inside;
QVector<QVector3D> outside;
for (int i = 0; i < k; ++i) {
qreal angle = (i * 2 * M_PI) / k;
inside << QVector3D(iRad * qSin(angle), iRad * qCos(angle), depth / 2.0);
outside << QVector3D(oRad * qSin(angle), oRad * qCos(angle), depth / 2.0);
}
inside << QVector3D(0.0, iRad, 0.0);
outside << QVector3D(0.0, oRad, 0.0);
QVector<QVector3D> in_back = extrude(inside, depth);
QVector<QVector3D> out_back = extrude(outside, depth);
// Create front, back and sides as separate patches so that smooth normals
// are generated for the curving sides, but a faceted edge is created between
// sides and front/back
Patch *front = new Patch(g);
for (int i = 0; i < k; ++i)
front->addQuad(outside[i], inside[i],
inside[(i + 1) % k], outside[(i + 1) % k]);
Patch *back = new Patch(g);
for (int i = 0; i < k; ++i)
back->addQuad(in_back[i], out_back[i],
out_back[(i + 1) % k], in_back[(i + 1) % k]);
Patch *is = new Patch(g);
for (int i = 0; i < k; ++i)
is->addQuad(in_back[i], in_back[(i + 1) % k],
inside[(i + 1) % k], inside[i]);
Patch *os = new Patch(g);
for (int i = 0; i < k; ++i)
os->addQuad(out_back[(i + 1) % k], out_back[i],
outside[i], outside[(i + 1) % k]);
parts << front << back << is << os;
}
QtLogo::QtLogo(QObject *parent, int divisions, qreal scale)
: QObject(parent)
, geom(new Geometry())
{
buildGeometry(divisions, scale);
}
QtLogo::~QtLogo()
{
qDeleteAll(parts);
delete geom;
}
void QtLogo::setColor(QColor c)
{
for (int i = 0; i < parts.count(); ++i)
qSetColor(parts[i]->faceColor, c);
}
//! [3]
void QtLogo::buildGeometry(int divisions, qreal scale)
{
qreal cw = cross_width * scale;
qreal bt = bar_thickness * scale;
qreal ld = logo_depth * scale;
qreal th = tee_height *scale;
RectPrism cross(geom, cw, bt, ld);
RectPrism stem(geom, bt, th, ld);
QVector3D z(0.0, 0.0, 1.0);
cross.rotate(45.0, z);
stem.rotate(45.0, z);
qreal stem_downshift = (th + bt) / 2.0;
stem.translate(QVector3D(0.0, -stem_downshift, 0.0));
RectTorus body(geom, 0.20, 0.30, 0.1, divisions);
parts << stem.parts << cross.parts << body.parts;
geom->finalize();
}
//! [3]
//! [4]
void QtLogo::draw() const
{
geom->loadArrays();
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
for (int i = 0; i < parts.count(); ++i)
parts[i]->draw();
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
}
//! [4]