/*!
\relates QGLCubeSphere
Builds the geometry for \a sphere within the specified
display \a list.
*/
QGLBuilder& operator<<(QGLBuilder& list, const QGLCubeSphere& sphere)
{
/*
A-----H
| |
| |
A-----D-----E-----H-----A
| | | | |
| | | | |
B-----C-----F-----G-----B
| |
| |
B-----G
^ d e
| c f
y
x-->
*/
qreal scale = sphere.diameter();
int depth = sphere.subdivisionDepth();
const qreal offset = 1.0f;
float cube[8][3] = {
{ -offset, offset, -offset}, // A - 0
{ -offset, -offset, -offset }, // B - 1
{ -offset, -offset, offset }, // C - 2
{ -offset, offset, offset }, // D - 3
{ offset, offset, offset }, // E - 4
{ offset, -offset, offset }, // F - 5
{ offset, -offset, -offset }, // G - 6
{ offset, offset, -offset }, // H - 7
};
int face[6][4] = {
{ 0, 1, 2, 3 }, // A-B-C-D
{ 3, 2, 5, 4 }, // D-C-F-E
{ 4, 5, 6, 7 }, // E-F-G-H
{ 7, 6, 1, 0 }, // H-G-B-A
{ 0, 3, 4, 7 }, // A-D-E-H
{ 2, 1, 6, 5 }, // C-B-G-F
};
const float v3 = 0.0f;
const float v2 = 0.333333333f;
const float v1 = 0.666666666f;
const float v0 = 1.0f;
const float u0 = 0.0f;
const float u1 = 0.25f;
const float u2 = 0.5f;
const float u3 = 0.75f;
const float u4 = 1.0f;
float tex[6][4][2] = {
{ {u0, v1}, {u0, v2}, {u1, v2}, {u1, v1} }, // A-B-C-D
{ {u1, v1}, {u1, v2}, {u2, v2}, {u2, v1} }, // D-C-F-E
{ {u2, v1}, {u2, v2}, {u3, v2}, {u3, v1} }, // E-F-G-H
{ {u3, v1}, {u3, v2}, {u4, v2}, {u4, v1} }, // H-G-B-A
{ {u1, v0}, {u1, v1}, {u2, v1}, {u2, v0} }, // A-D-E-H
{ {u1, v2}, {u1, v3}, {u2, v3}, {u2, v2} }, // C-B-G-F
};
// Generate the initial vertex list from a plain cube.
QVector3DArray vertices;
QVector3DArray normals;
QVector2DArray texCoords;
for (int ix = 0; ix < 6; ++ix) {
QVector3D n0(cube[face[ix][0]][0], cube[face[ix][0]][1], cube[face[ix][0]][2]);
QVector3D n1(cube[face[ix][1]][0], cube[face[ix][1]][1], cube[face[ix][1]][2]);
QVector3D n2(cube[face[ix][2]][0], cube[face[ix][2]][1], cube[face[ix][2]][2]);
QVector3D n3(cube[face[ix][3]][0], cube[face[ix][3]][1], cube[face[ix][3]][2]);
QVector2D t0(tex[ix][0][0], tex[ix][0][1]);
QVector2D t1(tex[ix][1][0], tex[ix][1][1]);
QVector2D t2(tex[ix][2][0], tex[ix][2][1]);
QVector2D t3(tex[ix][3][0], tex[ix][3][1]);
n0 = n0.normalized();
n1 = n1.normalized();
n2 = n2.normalized();
n3 = n3.normalized();
QVector3D v0 = n0 * scale / 2.0f;
QVector3D v1 = n1 * scale / 2.0f;
QVector3D v2 = n2 * scale / 2.0f;
QVector3D v3 = n3 * scale / 2.0f;
vertices.append(v0, v1, v2, v3);
normals.append(n0, n1, n2, n3);
texCoords.append(t0, t1, t2, t3);
}
// Subdivide the cube.
while (depth-- > 1) {
QVector3DArray newVertices;
QVector3DArray newNormals;
QVector2DArray newTexCoords;
int count = vertices.count();
for (int i = 0; i < count; i+= 4) {
QVector3D v0 = vertices.at(i);
QVector3D v1 = vertices.at(i+1);
QVector3D v2 = vertices.at(i+2);
QVector3D v3 = vertices.at(i+3);
QVector3D n0 = normals.at(i);
QVector3D n1 = normals.at(i+1);
QVector3D n2 = normals.at(i+2);
QVector3D n3 = normals.at(i+3);
QVector2D t0 = texCoords.at(i);
QVector2D t1 = texCoords.at(i+1);
QVector2D t2 = texCoords.at(i+2);
QVector2D t3 = texCoords.at(i+3);
QVector3D n01 = (v0 + v1).normalized();
QVector3D n12 = (v1 + v2).normalized();
QVector3D n23 = (v2 + v3).normalized();
QVector3D n30 = (v3 + v0).normalized();
QVector3D nc = (v0 + v1 + v2 + v3).normalized();
QVector3D v01 = n01 * scale / 2.0f;
QVector3D v12 = n12 * scale / 2.0f;
QVector3D v23 = n23 * scale / 2.0f;
QVector3D v30 = n30 * scale / 2.0f;
QVector3D vc = nc * scale / 2.0f;
QVector2D t01 = (t0 + t1) / 2;
QVector2D t12 = (t1 + t2) / 2;
QVector2D t23 = (t2 + t3) / 2;
QVector2D t30 = (t3 + t0) / 2;
QVector2D tc = (t2 + t0) / 2;
newVertices.append(v0, v01, vc, v30);
newNormals.append(n0, n01, nc, n30);
newTexCoords.append(t0, t01, tc, t30);
newVertices.append(v01, v1, v12, vc);
newNormals.append(n01, n1, n12, nc);
newTexCoords.append(t01, t1, t12, tc);
newVertices.append(vc, v12, v2, v23);
newNormals.append(nc, n12, n2, n23);
newTexCoords.append(tc, t12, t2, t23);
newVertices.append(v30, vc, v23, v3);
newNormals.append(n30, nc, n23, n3);
newTexCoords.append(t30, tc, t23, t3);
}
vertices = newVertices;
normals = newNormals;
texCoords = newTexCoords;
}
// Add the final vertices to the display list.
QGeometryData prim;
prim.appendVertexArray(vertices);
prim.appendNormalArray(normals);
prim.appendTexCoordArray(texCoords);
list.addTriangles(prim);
return list;
}
QT_BEGIN_NAMESPACE
/*!
\class QGLCylinder
\brief The QGLCylinder class represents the geometry of a simple cylinder/cone in 3D space.
\since 4.8
\ingroup qt3d
\ingroup qt3d::geometry
The following example creates a cone with a top diameter of 1 unit,
a bottom diameter of 2 units in diameter and height of 3 units.
It then draws it at (10, 25, 0) in a QGLPainter:
\code
QGLBuilder builder;
builder << QGLCylinder(1.0,2.0,3.0);
QGLSceneNode *node = builder.finalizedSceneNode();
painter.translate(10, 25, 0);
node->draw(&painter);
\endcode
Note that the bottom circle of the cylinder will always be centred at (0,0,0)
unless otherwise transformed after cylinder creation.
The QGLCylinder class specifies positions, normals and 2D texture
co-ordinates for all of the vertices that make up the cylinder.
The texture co-ordinates are fixed at construction time. This
is because constructing the cylinder can involve generating additional
vertices which need to interpolate the texture co-ordinates of their
neighboring vertices.
The QGLCylinder is divided into slices and layers. The slices value
indicate number of triangular sections into which the top and bottom
circles of the cylinder are broken into. Consequently it also sets the
number of facets which run the length of the cylinder. More slices
results in a smoother circumference.
The layers value indicates the number of longitudinal sections the
cylinder is broken into. Fewer layers means that the side facets of the
cylinder will be made up of fewer, very long, triangles, while a higher
number of layers will produce many and smaller triangles. Often it is
desirable to avoid large triangles as they may cause inefficiencies in
texturing/lighting on certain platforms.
The end-caps and sides of the cylinder are independent sections of the
scene-graph, and so may be textured separately.
Textures are wrapped around the sides of thecylinder in such a way that
the texture may distort across the x axis if the top and bottom diameters
of the cylinder differ (ie. the cylinder forms a truncated cone). Textures
begin and end at the centre points of the top and bottom end-caps of the
cylinder. This wrapping means that textures on either end-cap may be
distorted.
Texture coordinates are assigned as shown below.
\image cylinder-texture-coords.png
It is worth noting that the cylinder class can, in fact, be used to generate
any regular solid polygonal prism. A rectangular prism can be created, for
example, by creating a 4 sided cylinder. Likewise a hexagonal prism is
simply a 6 sided cylinder.
With this knowledge, and an understanding of the texture coordinate mapping,
it is possible to make custom textures which will be usable with these
three dimensional objects.
\sa QGLBuilder
*/
/*!
\fn QGLCylinder::QGLCylinder(float diameterTop, float diameterBase , float height, int slices, int layers, bool top, bool base)
Constructs the geometry for a cylinder with top of diameter \a diameterTop,
a base of diameter \a diameterBase, and a height of \a height.
The resultant mesh will be divided around the vertical axis of the cylinder
into \a slices individual wedges, and shall be formed of \a layers stacked
to form the cylinder.
If the values for \a top or \a base are true, then the cylinder will be
created with solid endcaps. Otherwise, it shall form a hollow pipe.
units on a side.
*/
/*!
\fn float QGLCylinder::diameterTop() const
Returns the diameter of the top of the cylinder.
The default value is 1.
\sa setDiameterTop()
*/
/*!
\fn void QGLCylinder::setDiameterTop(float diameter)
Sets the diameter of the top of this cylinder to \a diameter.
\sa diameterTop()
*/
/*!
\fn float QGLCylinder::diameterBottom() const
Returns the diameter of the bottom of the cylinder.
The default value is 1.
\sa setDiameterBottom()
*/
/*!
\fn void QGLCylinder::setDiameterBottom(float diameter)
Sets the diameter of the bottom of this cylinder to \a diameter.
\sa diameterBottom()
*/
/*!
\fn float QGLCylinder::height() const
Returns the height of the cylinder.
The default value is 1.0
\sa setDiameterBottom()
*/
/*!
\fn void QGLCylinder::setHeight(float height)
Sets the height of this cylinder to \a height.
\sa diameterBottom()
*/
/*!
\fn int QGLCylinder::slices() const
Returns the number of triangular slices the cylinder is divided into
around its polar axis.
The default is 6.
\sa setSlices()
*/
/*!
\fn int QGLCylinder::setSlices(int slices)
Sets the number of triangular \a slices the cylinder is divided into
around its polar axis.
\sa slices()
*/
/*!
\fn int QGLCylinder::layers() const
Returns the number of cylindrical layers the cylinder is divided into
along its height.
The default is 3.
\sa setLayers()
*/
/*!
\fn int QGLCylinder::setLayers(int layers)
Sets the number of stacked \a layers the cylinder is divided into
along its height.
\sa layers()
*/
/*!
\fn bool QGLCylinder::topEnabled() const
Returns true if the top of the cyclinder will be created when
building the mesh.
The default is true.
\sa setTopEnabled()
*/
/*!
\fn void QGLCylinder::setTopEnabled(bool top)
Set whether the top end-cap of the cylinder will be created when
building the mesh. If \a top is true, the end-cap will be created.
\sa topEnabled()
*/
/*!
\fn bool QGLCylinder::baseEnabled() const
Returns true if the base of the cyclinder will be created when
building the mesh.
The default is true.
\sa setBaseEnabled()
*/
/*!
\fn void QGLCylinder::setBaseEnabled(bool base)
Set whether the base end-cap of the cylinder will be created when
building the mesh. If \a base is true, the end-cap will be created.
\sa baseEnabled()
*/
/*!
\relates QGLCylinder
Builds the geometry for \a cylinder within the specified
geometry \a builder.
*/
QGLBuilder& operator<<(QGLBuilder& builder, const QGLCylinder& cylinder)
{
int nCaps = (cylinder.topEnabled()?1:0) + (cylinder.baseEnabled()?1:0);
Q_ASSERT(cylinder.layers() >= 1 + nCaps);
float numSlices = float(cylinder.slices());
float numLayers = float(cylinder.layers() - nCaps); // minus top and base caps
float topRadius = cylinder.diameterTop() / 2.0f;
float bottomRadius = cylinder.diameterBottom() / 2.0f;
float angle = 0.0f;
float angleIncrement = (2.0f * M_PI) / numSlices;
float radius = topRadius;
float radiusIncrement = float(bottomRadius-topRadius) / numLayers;
float height = float(cylinder.height());
float heightDecrement = height / numLayers;
height *= 0.5f;
float textureHeight = 1.0f;
float textureDecrement = 1.0f / numLayers;
QGeometryData oldLayer;
// layer 0: Top cap
{
QGeometryData newLayer;
//Generate a circle of vertices for this layer.
for (int i=0; i<cylinder.slices(); i++) {
newLayer.appendVertex(QVector3D(radius * cosf(angle), radius * sinf(angle), height));
angle+=angleIncrement;
}
angle = 0.0f;
QVector3D center = newLayer.center();
// Generate texture coordinates (including an extra seam vertex for textures).
newLayer.appendVertex(newLayer.vertex(0));
newLayer.generateTextureCoordinates();
for (int i = 0; i < newLayer.count(); ++i)
newLayer.texCoord(i).setY(textureHeight);
if (cylinder.topEnabled()) {
QGeometryData top;
builder.newSection();
builder.currentNode()->setObjectName(QStringLiteral("Cylinder Top"));
top.appendVertex(center);
top.appendVertexArray(newLayer.vertices());
//Generate a circle of texture vertices for this layer.
top.appendTexCoord(QVector2D(0.5f, 0.5f));
for (int i=1; i<top.count(); i++) {
top.appendTexCoord(QVector2D(0.5f * cosf(angle) + 0.5f, 0.5f * sinf(angle) + 0.5f));
angle+=angleIncrement;
}
angle = 0;
builder.addTriangulatedFace(top);
}
oldLayer.clear();
oldLayer.appendGeometry(newLayer);
}
// intermediate layers
for (int layerCount=0; layerCount<(cylinder.layers()-nCaps); ++layerCount) {
radius+=radiusIncrement;
height-=heightDecrement;
textureHeight-=textureDecrement;
QGeometryData newLayer;
//Generate a circle of vertices for this layer.
for (int i=0; i<cylinder.slices(); ++i) {
newLayer.appendVertex(QVector3D(radius * cosf(angle), radius * sinf(angle), height));
angle+=angleIncrement;
}
angle = 0.0f;
// Generate texture coordinates (including an extra seam vertex for textures).
newLayer.appendVertex(newLayer.vertex(0));
newLayer.generateTextureCoordinates();
for (int i = 0; i < newLayer.count(); ++i)
newLayer.texCoord(i).setY(textureHeight);
if (layerCount==0) {
builder.newSection();
builder.currentNode()->setObjectName(QStringLiteral("Cylinder Sides"));
}
builder.addQuadsInterleaved(oldLayer, newLayer);
oldLayer.clear();
oldLayer.appendGeometry(newLayer);
}
// last layer: Base cap
if (cylinder.baseEnabled()) {
builder.newSection();
builder.currentNode()->setObjectName(QStringLiteral("Cylinder Base"));
QGeometryData base;
{
QVector3DArray vvv = oldLayer.vertices();
for (int i=0; i<vvv.size()-1; ++i)
base.appendVertex(vvv.at(i));
QVector3D center = base.center();
base.appendVertex(vvv.at(0));
base.appendVertex(center);
}
//Generate a circle of texture vertices for this layer.
for (int i=1; i<base.count(); i++) {
base.appendTexCoord(QVector2D(0.5f * cosf(angle) + 0.5f, 0.5f * sinf(angle) + 0.5f));
angle+=angleIncrement;
}
base.appendTexCoord(QVector2D(0.5f, 0.5f));
angle = 0.0f;
//we need to reverse the above to draw it properly - windings!
builder.addTriangulatedFace(base.reversed());
}
return builder;
}
/*!
\relates QGLIcoSphere
Builds the geometry for \a sphere within the specified
display \a list.
*/
QGLBuilder& operator<<(QGLBuilder& list, const QGLIcoSphere& sphere)
{
qreal scale = sphere.diameter();
int depth = sphere.subdivisionDepth();
qreal tiny= 1.0f;
qreal large = phi*tiny;
float ico[12][3] = {
{ 0.0f, tiny, large }, // A - 0
{ 0.0f, tiny, -large }, // B - 1
{ 0.0f, -tiny, large }, // C - 2
{ 0.0f, -tiny, -large }, // D - 3
{ tiny, large, 0.0f }, // E - 4
{ tiny, -large, 0.0f }, // F - 5
{ -tiny, large, 0.0f }, // G - 6
{ -tiny, -large, 0.0f }, // H - 7
{ large, 0.0f, tiny}, // I - 8
{ large, 0.0f, -tiny}, // J - 9
{ -large, 0.0f, tiny}, // K - 10
{ -large, 0.0f, -tiny} // L - 11
};
int face[20][3] = {
{ 4, 0, 8 }, // E-A-I
{ 6, 0, 4 }, // G-A-E
{ 6, 10, 0 }, // G-K-A
{ 11, 10, 6 }, // L-K-G
{ 0, 2, 8 }, // A-C-I
{ 10, 2, 0 }, // K-C-A
{ 10, 7, 2 }, // K-H-C
{ 11, 7, 10 }, // L-H-K
{ 2, 5, 8 }, // C-F-I
{ 7, 5, 2 }, // H-F-C
{ 7, 3, 5 }, // H-D-F
{ 11, 3, 7 }, // L-D-H
{ 5, 9, 8 }, // F-J-I
{ 3, 9, 5 }, // D-J-F
{ 3, 1, 9 }, // D-B-J
{ 11, 1, 3 }, // L-B-D
{ 9, 4, 8 }, // J-E-I
{ 1, 4, 9 }, // B-E-J
{ 1, 6, 4 }, // B-G-E
{ 11, 6, 1 } // L-G-B
};
const float u0 = 0.0f;
const float u1 = 0.173205081f;
const float u2 = 0.346410162f;
const float u3 = 0.519615242f;
const float u4 = 0.692820323f;
const float u5 = 0.866025402f;
const float v9 = 0.0f;
const float v8 = 0.111111111f;
const float v7 = 0.222222222f;
const float v6 = 0.333333333f;
const float v5 = 0.444444444f;
const float v4 = 0.555555555f;
const float v3 = 0.666666666f;
const float v2 = 0.777777777f;
const float v1 = 0.888888888f;
const float v0 = 1.0f;
float tex[20][3][2] = {
{ { u0, v1 }, { u1, v2 }, { u1, v0 } }, // E-A-I
{ { u0, v3 }, { u1, v2 }, { u0, v1 } }, // G-A-E
{ { u0, v3 }, { u1, v4 }, { u1, v2 } }, // G-K-A
{ { u0, v5 }, { u1, v4 }, { u0, v3 } }, // L-K-G
{ { u1, v2 }, { u2, v3 }, { u2, v1 } }, // A-C-I
{ { u1, v4 }, { u2, v3 }, { u1, v2 } }, // K-C-A
{ { u1, v4 }, { u2, v5 }, { u2, v3 } }, // K-H-C
{ { u1, v6 }, { u2, v5 }, { u1, v4 } }, // L-H-K
{ { u2, v3 }, { u3, v4 }, { u3, v2 } }, // C-F-I
{ { u2, v5 }, { u3, v4 }, { u2, v3 } }, // H-F-C
{ { u2, v5 }, { u3, v6 }, { u3, v4 } }, // H-D-F
{ { u2, v7 }, { u3, v6 }, { u2, v5 } }, // L-D-H
{ { u3, v4 }, { u4, v5 }, { u4, v3 } }, // F-J-I
{ { u3, v6 }, { u4, v5 }, { u3, v4 } }, // D-J-F
{ { u3, v6 }, { u4, v7 }, { u4, v5 } }, // D-B-J
{ { u3, v8 }, { u4, v7 }, { u3, v6 } }, // L-B-D
{ { u4, v5 }, { u5, v6 }, { u5, v4 } }, // J-E-I
{ { u4, v7 }, { u5, v6 }, { u4, v5 } }, // B-E-J
{ { u4, v7 }, { u5, v8 }, { u5, v6 } }, // B-G-E
{ { u4, v9 }, { u5, v8 }, { u4, v7 } } // L-G-B
};
// Generate the initial vertex list from a plain icosahedron.
QVector3DArray vertices;
QVector3DArray normals;
QVector2DArray texCoords;
for (int ix = 0; ix < 20; ++ix) {
QVector3D n0(ico[face[ix][0]][0], ico[face[ix][0]][1], ico[face[ix][0]][2]);
QVector3D n1(ico[face[ix][1]][0], ico[face[ix][1]][1], ico[face[ix][1]][2]);
QVector3D n2(ico[face[ix][2]][0], ico[face[ix][2]][1], ico[face[ix][2]][2]);
QVector2D t0(tex[ix][0][0], tex[ix][0][1]);
QVector2D t1(tex[ix][1][0], tex[ix][1][1]);
QVector2D t2(tex[ix][2][0], tex[ix][2][1]);
n0 = n0.normalized();
n1 = n1.normalized();
n2 = n2.normalized();
QVector3D v0 = n0 * scale / 2.0f;
QVector3D v1 = n1 * scale / 2.0f;
QVector3D v2 = n2 * scale / 2.0f;
vertices.append(v0, v1, v2);
normals.append(n0, n1, n2);
texCoords.append(t0, t1, t2);
}
// Subdivide the icosahedron.
while (depth-- > 1) {
QVector3DArray newVertices;
QVector3DArray newNormals;
QVector2DArray newTexCoords;
int count = vertices.count();
for (int i = 0; i < count; i+= 3) {
QVector3D v0 = vertices.at(i);
QVector3D v1 = vertices.at(i+1);
QVector3D v2 = vertices.at(i+2);
QVector3D n0 = normals.at(i);
QVector3D n1 = normals.at(i+1);
QVector3D n2 = normals.at(i+2);
QVector2D t0 = texCoords.at(i);
QVector2D t1 = texCoords.at(i+1);
QVector2D t2 = texCoords.at(i+2);
QVector3D n01 = (v0 + v1).normalized();
QVector3D n12 = (v1 + v2).normalized();
QVector3D n20 = (v2 + v0).normalized();
QVector3D v01 = n01 * scale / 2.0f;
QVector3D v12 = n12 * scale / 2.0f;
QVector3D v20 = n20 * scale / 2.0f;
QVector2D t01 = (t0 + t1) / 2;
QVector2D t12 = (t1 + t2) / 2;
QVector2D t20 = (t2 + t0) / 2;
newVertices.append(v0, v01, v20);
newNormals.append(n0, n01, n20);
newTexCoords.append(t0, t01, t20);
newVertices.append(v01, v1, v12);
newNormals.append(n01, n1, n12);
newTexCoords.append(t01, t1, t12);
newVertices.append(v01, v12, v20);
newNormals.append(n01, n12, n20);
newTexCoords.append(t01, t12, t20);
newVertices.append(v20, v12, v2);
newNormals.append(n20, n12, n2);
newTexCoords.append(t20, t12, t2);
}
vertices = newVertices;
normals = newNormals;
texCoords = newTexCoords;
}
// Add the final vertices to the builder.
QGeometryData prim;
prim.appendVertexArray(vertices);
prim.appendNormalArray(normals);
prim.appendTexCoordArray(texCoords);
list.addTriangles(prim);
return list;
}
