qt5base-lts/examples/opengl/pbuffers/cube.cpp
Sean Harmer 51d40d7e9b Make gui/math3d classes use float rather than qreal
This corrects the mismatch between using floats for internal storage
and qreal in the API of QVector*D which leads to lots of implicit
casts between double and float.

This change also stops users from being surprised by the loss of
precision when using these classes on desktop platforms and removes
the need for the private constructors taking a dummy int as the final
argument.

The QMatrix4x4 and QQuaternion classes have been changed to use float
for their internal storage since these are meant to be used in
conjunction with the QVector*D classes. This is to prevent unexpected
loss of precision and to improve performance.

The on-disk format has also been changed from double to float thereby
reducing the storage required when streaming vectors and matrices. This
is potentially a large saving when working with complex 3D meshes etc.

This also has a significant performance improvement when passing
matrices to QOpenGLShaderProgram (and QGLShaderProgram) as we no
longer have to iterate and convert the data to floats. This is
an operation that could easily be needed many times per frame.

This change also opens the door for further optimisations of these
classes to be implemented by using SIMD intrinsics.

This needs to be applied in conjunction with

https://codereview.qt-project.org/#change,33548

Task-number: QTBUG-21035
Task-number: QTBUG-20661
Change-Id: I9321b06040ffb93ae1cbd72fd2013267ac901b2e
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
2012-09-07 13:27:38 +02:00

331 lines
9.0 KiB
C++

/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
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**
** This file is part of the examples of the Qt Toolkit.
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#include "cube.h"
#include "glwidget.h"
#include <QtGui/QImage>
#include <QtCore/QPropertyAnimation>
static const qreal FACE_SIZE = 0.4;
static const qreal speeds[] = { 3.8f, 4.4f, 5.6f };
static const qreal amplitudes[] = { 2.0f, 2.5f, 3.0f };
static inline void qSetColor(float colorVec[], QColor c)
{
colorVec[0] = c.redF();
colorVec[1] = c.greenF();
colorVec[2] = c.blueF();
colorVec[3] = c.alphaF();
}
int Geometry::append(const QVector3D &a, const QVector3D &n, const QVector2D &t)
{
int v = vertices.count();
vertices.append(a);
normals.append(n);
texCoords.append(t);
faces.append(v);
colors.append(QVector4D(0.6f, 0.6f, 0.6f, 1.0f));
return v;
}
void Geometry::addQuad(const QVector3D &a, const QVector3D &b,
const QVector3D &c, const QVector3D &d,
const QVector<QVector2D> &tex)
{
QVector3D norm = QVector3D::normal(a, b, c);
// append first triangle
int aref = append(a, norm, tex[0]);
append(b, norm, tex[1]);
int cref = append(c, norm, tex[2]);
// append second triangle
faces.append(aref);
faces.append(cref);
append(d, norm, tex[3]);
}
void Geometry::loadArrays() const
{
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, vertices.constData());
glNormalPointer(GL_FLOAT, 0, normals.constData());
glTexCoordPointer(2, GL_FLOAT, 0, texCoords.constData());
glColorPointer(4, GL_FLOAT, 0, colors.constData());
}
void Geometry::setColors(int start, GLfloat colorArray[4][4])
{
int off = faces[start];
for (int i = 0; i < 4; ++i)
colors[i + off] = QVector4D(colorArray[i][0],
colorArray[i][1],
colorArray[i][2],
colorArray[i][3]);
}
Tile::Tile(const QVector3D &loc)
: location(loc)
, start(0)
, count(0)
, useFlatColor(false)
, geom(0)
{
qSetColor(faceColor, QColor(Qt::darkGray));
}
void Tile::setColors(GLfloat colorArray[4][4])
{
useFlatColor = true;
geom->setColors(start, colorArray);
}
void Tile::draw() const
{
QMatrix4x4 mat;
mat.translate(location);
mat.rotate(orientation);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glMultMatrixf(mat.constData());
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, faceColor);
glDrawElements(GL_TRIANGLES, count, GL_UNSIGNED_SHORT, geom->indices() + start);
glPopMatrix();
}
TileBuilder::TileBuilder(Geometry *g, qreal depth, qreal size)
: verts(4)
, tex(4)
, start(g->count())
, count(0)
, geom(g)
{
// front face - make a square with bottom-left at origin
verts[br].setX(size);
verts[tr].setX(size);
verts[tr].setY(size);
verts[tl].setY(size);
// these vert numbers are good for the tex-coords
for (int i = 0; i < 4; ++i)
tex[i] = verts[i].toVector2D();
// now move verts half cube width across so cube is centered on origin
for (int i = 0; i < 4; ++i)
verts[i] -= QVector3D(size / 2.0f, size / 2.0f, -depth);
// add the front face
g->addQuad(verts[bl], verts[br], verts[tr], verts[tl], tex);
count = g->count() - start;
}
void TileBuilder::initialize(Tile *tile) const
{
tile->start = start;
tile->count = count;
tile->geom = geom;
qSetColor(tile->faceColor, color);
}
Tile *TileBuilder::newTile(const QVector3D &loc) const
{
Tile *tile = new Tile(loc);
initialize(tile);
return tile;
}
Cube::Cube(const QVector3D &loc)
: Tile(loc)
, rot(0.0f)
, r(0)
, animGroup(0)
{
}
Cube::~Cube()
{
}
void Cube::setAltitude(qreal a)
{
if (location.y() != a)
{
location.setY(a);
emit changed();
}
}
void Cube::setRange(qreal r)
{
if (location.x() != r)
{
location.setX(r);
emit changed();
}
}
void Cube::setRotation(qreal r)
{
if (r != rot)
{
orientation = QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 1.0f, 1.0f), r);
emit changed();
}
}
void Cube::removeBounce()
{
delete animGroup;
animGroup = 0;
delete r;
r = 0;
}
void Cube::startAnimation()
{
if (r)
{
r->start();
r->setCurrentTime(startx);
}
if (animGroup)
animGroup->start();
if (rtn)
rtn->start();
}
void Cube::setAnimationPaused(bool paused)
{
if (paused)
{
if (r)
r->pause();
if (animGroup)
animGroup->pause();
if (rtn)
rtn->pause();
}
else
{
if (r)
r->resume();
if (animGroup)
animGroup->resume();
if (rtn)
rtn->resume();
}
}
CubeBuilder::CubeBuilder(Geometry *g, qreal depth, qreal size)
: TileBuilder(g, depth)
, ix(0)
{
for (int i = 0; i < 4; ++i)
verts[i].setZ(size / 2.0f);
// back face - "extrude" verts down
QVector<QVector3D> back(verts);
for (int i = 0; i < 4; ++i)
back[i].setZ(-size / 2.0f);
// add the back face
g->addQuad(back[br], back[bl], back[tl], back[tr], tex);
// add the sides
g->addQuad(back[bl], back[br], verts[br], verts[bl], tex);
g->addQuad(back[br], back[tr], verts[tr], verts[br], tex);
g->addQuad(back[tr], back[tl], verts[tl], verts[tr], tex);
g->addQuad(back[tl], back[bl], verts[bl], verts[tl], tex);
count = g->count() - start;
}
Cube *CubeBuilder::newCube(const QVector3D &loc) const
{
Cube *c = new Cube(loc);
initialize(c);
qreal d = 4000.0f;
qreal d3 = d / 3.0f;
// Animate movement from left to right
c->r = new QPropertyAnimation(c, "range");
c->r->setStartValue(-1.3f);
c->r->setEndValue(1.3f);
c->startx = ix * d3 * 3.0f;
c->r->setDuration(d * 4.0f);
c->r->setLoopCount(-1);
c->r->setEasingCurve(QEasingCurve(QEasingCurve::CosineCurve));
c->animGroup = new QSequentialAnimationGroup(c);
// Animate movement from bottom to top
QPropertyAnimation *a_up = new QPropertyAnimation(c, "altitude", c->animGroup);
a_up->setEndValue(loc.y());
a_up->setStartValue(loc.y() + amplitudes[ix]);
a_up->setDuration(d / speeds[ix]);
a_up->setLoopCount(1);
a_up->setEasingCurve(QEasingCurve(QEasingCurve::InQuad));
// Animate movement from top to bottom
QPropertyAnimation *a_down = new QPropertyAnimation(c, "altitude", c->animGroup);
a_down->setEndValue(loc.y() + amplitudes[ix]);
a_down->setStartValue(loc.y());
a_down->setDuration(d / speeds[ix]);
a_down->setLoopCount(1);
a_down->setEasingCurve(QEasingCurve(QEasingCurve::OutQuad));
c->animGroup->addAnimation(a_up);
c->animGroup->addAnimation(a_down);
c->animGroup->setLoopCount(-1);
// Animate rotation
c->rtn = new QPropertyAnimation(c, "rotation");
c->rtn->setStartValue(c->rot);
c->rtn->setEndValue(359.0f);
c->rtn->setDuration(d * 2.0f);
c->rtn->setLoopCount(-1);
c->rtn->setDuration(d / 2);
ix = (ix + 1) % 3;
return c;
}