/*!
Construct a new QuadPlane with \a size, subdivided \a level times. By default
the plane is 100.0f x 100.0f, and is subdivided 3 times - that is into an
8 x 8 grid.
It is centered on the origin, and lies in the z = 0 plane.
*/
QuadPlane::QuadPlane(QObject *parent, QSizeF size, int level)
: QGLSceneNode(parent)
{
setObjectName(QLatin1String("QuadPlane"));
if (level > 8)
level = 8;
if (level < 1)
level = 1;
int divisions = 1;
for ( ; level--; divisions *= 2) {} // integer 2**n
QSizeF div = size / float(divisions);
QSizeF half = size / 2.0f;
QGLBuilder builder;
QGeometryData zip;
QGeometryData zip2;
for (int yy = 0; yy <= divisions; ++yy)
{
float y = half.height() - float(yy) * div.height();
float texY = float(yy) / divisions;
for (int xx = 0; xx <= divisions; ++xx)
{
float x = half.width() - float(xx) * div.width();
float texX = float(xx) / divisions;
zip.appendVertex(QVector3D(x, y, 0));
zip.appendTexCoord(QVector2D(1.0f - texX, 1.0f - texY));
}
if (yy > 0)
builder.addQuadsInterleaved(zip, zip2);
zip2 = zip;
zip2.detach();
zip.clear();
}
QGLSceneNode *n = builder.finalizedSceneNode();
addNode(n);
}
