private void setGeometryData() {
// generate geometry
final double inverseRadial = 1.0 / _radialSamples;
final double inverseAxisLess = 1.0 / (_closed ? _axisSamples - 3 : _axisSamples - 1);
final double inverseAxisLessTexture = 1.0 / (_axisSamples - 1);
final double halfHeight = 0.5 * _height;
// Generate points on the unit circle to be used in computing the mesh
// points on a cylinder slice.
final double[] sin = new double[_radialSamples + 1];
final double[] cos = new double[_radialSamples + 1];
for (int radialCount = 0; radialCount < _radialSamples; radialCount++) {
final double angle = MathUtils.TWO_PI * inverseRadial * radialCount;
cos[radialCount] = MathUtils.cos(angle);
sin[radialCount] = MathUtils.sin(angle);
}
sin[_radialSamples] = sin[0];
cos[_radialSamples] = cos[0];
// generate the cylinder itself
final Vector3 tempNormal = new Vector3();
for (int axisCount = 0, i = 0; axisCount < _axisSamples; axisCount++) {
double axisFraction;
double axisFractionTexture;
int topBottom = 0;
if (!_closed) {
axisFraction = axisCount * inverseAxisLess; // in [0,1]
axisFractionTexture = axisFraction;
} else {
if (axisCount == 0) {
topBottom = -1; // bottom
axisFraction = 0;
axisFractionTexture = inverseAxisLessTexture;
} else if (axisCount == _axisSamples - 1) {
topBottom = 1; // top
axisFraction = 1;
axisFractionTexture = 1 - inverseAxisLessTexture;
} else {
axisFraction = (axisCount - 1) * inverseAxisLess;
axisFractionTexture = axisCount * inverseAxisLessTexture;
}
}
final double z = -halfHeight + _height * axisFraction;
// compute center of slice
final Vector3 sliceCenter = new Vector3(0, 0, z);
// compute slice vertices with duplication at end point
final int save = i;
for (int radialCount = 0; radialCount < _radialSamples; radialCount++) {
final double radialFraction = radialCount * inverseRadial; // in [0,1)
tempNormal.set(cos[radialCount], sin[radialCount], 0);
if (topBottom == 0) {
if (!_inverted) {
_meshData
.getNormalBuffer()
.put(tempNormal.getXf())
.put(tempNormal.getYf())
.put(tempNormal.getZf());
} else {
_meshData
.getNormalBuffer()
.put(-tempNormal.getXf())
.put(-tempNormal.getYf())
.put(-tempNormal.getZf());
}
} else {
_meshData.getNormalBuffer().put(0).put(0).put(topBottom * (_inverted ? -1 : 1));
}
tempNormal
.multiplyLocal((_radius - _radius2) * axisFraction + _radius2)
.addLocal(sliceCenter);
_meshData
.getVertexBuffer()
.put(tempNormal.getXf())
.put(tempNormal.getYf())
.put(tempNormal.getZf());
_meshData
.getTextureCoords(0)
.getBuffer()
.put((float) (_inverted ? 1 - radialFraction : radialFraction))
.put((float) axisFractionTexture);
i++;
}
BufferUtils.copyInternalVector3(_meshData.getVertexBuffer(), save, i);
BufferUtils.copyInternalVector3(_meshData.getNormalBuffer(), save, i);
_meshData
.getTextureCoords(0)
.getBuffer()
.put((_inverted ? 0.0f : 1.0f))
.put((float) axisFractionTexture);
i++;
}
if (_closed) {
_meshData.getVertexBuffer().put(0).put(0).put((float) -halfHeight); // bottom center
_meshData.getNormalBuffer().put(0).put(0).put(-1 * (_inverted ? -1 : 1));
_meshData.getTextureCoords(0).getBuffer().put(0.5f).put(0);
_meshData.getVertexBuffer().put(0).put(0).put((float) halfHeight); // top center
_meshData.getNormalBuffer().put(0).put(0).put(1 * (_inverted ? -1 : 1));
_meshData.getTextureCoords(0).getBuffer().put(0.5f).put(1);
}
}
