/** builds the vertices based on the radius, center and radial and zSamples. */
private void setGeometryData(PApplet pa) {
// allocate vertices
// setVertexCount((zSamples - 2) * (radialSamples + 1) + 2);
// setVertexBuffer(ToolsBuffers.createVector3Buffer(vertBuff,
// getVertexCount()));
int vertexCount = (zSamples - 2) * (radialSamples + 1) + 2;
FloatBuffer vertexBuff = ToolsBuffers.createFloatBuffer(3 * vertexCount);
// allocate normals if requested
// setNormalBuffer(ToolsBuffers.createVector3Buffer(normBuff,
// getVertexCount()));
FloatBuffer normBuff = ToolsBuffers.createFloatBuffer(3 * vertexCount);
// allocate texture coordinates
// setTextureCoords(new TexCoords(ToolsBuffers.createVector2Buffer(getVertexCount())));
FloatBuffer texBuff = ToolsBuffers.createFloatBuffer(2 * vertexCount);
// generate geometry
float fInvRS = 1.0f / radialSamples;
float fZFactor = 2.0f / (zSamples - 1);
// Generate points on the unit circle to be used in computing the mesh
// points on a sphere slice.
float[] afSin = new float[(radialSamples + 1)];
float[] afCos = new float[(radialSamples + 1)];
for (int iR = 0; iR < radialSamples; iR++) {
float fAngle = ToolsMath.TWO_PI * fInvRS * iR;
afCos[iR] = ToolsMath.cos(fAngle);
afSin[iR] = ToolsMath.sin(fAngle);
}
afSin[radialSamples] = afSin[0];
afCos[radialSamples] = afCos[0];
// generate the sphere itself
int i = 0;
for (int iZ = 1; iZ < (zSamples - 1); iZ++) {
float fAFraction = ToolsMath.HALF_PI * (-1.0f + fZFactor * iZ); // in (-pi/2, pi/2)
float fZFraction;
if (useEvenSlices) fZFraction = -1.0f + fZFactor * iZ; // in (-1, 1)
else fZFraction = ToolsMath.sin(fAFraction); // in (-1,1)
float fZ = radius * fZFraction;
// compute center of slice
Vector3D kSliceCenter = tempVb.setValues(center);
kSliceCenter.z += fZ;
// compute radius of slice
float fSliceRadius = ToolsMath.sqrt(ToolsMath.abs(radius * radius - fZ * fZ));
// compute slice vertices with duplication at end point
Vector3D kNormal;
int iSave = i;
for (int iR = 0; iR < radialSamples; iR++) {
float fRadialFraction = iR * fInvRS; // in [0,1)
tempVc.setXYZ(afCos[iR], afSin[iR], 0);
Vector3D kRadial = tempVc;
tempVa = kRadial.getScaled(fSliceRadius);
vertexBuff
.put(kSliceCenter.x + tempVa.x)
.put(kSliceCenter.y + tempVa.y)
.put(kSliceCenter.z + tempVa.z);
ToolsBuffers.populateFromBuffer(tempVa, vertexBuff, i);
kNormal = tempVa.subtractLocal(center);
kNormal.normalizeLocal();
if (true) // later we may allow interior texture vs. exterior
normBuff.put(kNormal.x).put(kNormal.y).put(kNormal.z);
else normBuff.put(-kNormal.x).put(-kNormal.y).put(-kNormal.z);
if (textureMode == TextureMode.Original)
texBuff.put(fRadialFraction).put(0.5f * (fZFraction + 1.0f));
else if (textureMode == TextureMode.Projected)
texBuff
.put(fRadialFraction)
.put(ToolsMath.INV_PI * (ToolsMath.HALF_PI + ToolsMath.asin(fZFraction)));
else if (textureMode == TextureMode.Polar) {
float r = (ToolsMath.HALF_PI - ToolsMath.abs(fAFraction)) / ToolsMath.PI;
float u = r * afCos[iR] + 0.5f;
float v = r * afSin[iR] + 0.5f;
texBuff.put(u).put(v);
}
i++;
}
copyInternalVector3(vertexBuff, iSave, i);
copyInternalVector3(normBuff, iSave, i);
if (textureMode == TextureMode.Original) texBuff.put(1.0f).put(0.5f * (fZFraction + 1.0f));
else if (textureMode == TextureMode.Projected)
texBuff.put(1.0f).put(ToolsMath.INV_PI * (ToolsMath.HALF_PI + ToolsMath.asin(fZFraction)));
else if (textureMode == TextureMode.Polar) {
float r = (ToolsMath.HALF_PI - ToolsMath.abs(fAFraction)) / ToolsMath.PI;
texBuff.put(r + 0.5f).put(0.5f);
}
i++;
}
// south pole
vertexBuff.position(i * 3);
vertexBuff.put(center.x).put(center.y).put(center.z - radius);
normBuff.position(i * 3);
if (true) normBuff.put(0).put(0).put(-1); // allow for inner
// texture orientation
// later.
else normBuff.put(0).put(0).put(1);
texBuff.position(i * 2);
if (textureMode == TextureMode.Polar) {
texBuff.put(0.5f).put(0.5f);
} else {
texBuff.put(0.5f).put(0.0f);
}
i++;
// north pole
vertexBuff.put(center.x).put(center.y).put(center.z + radius);
if (true) normBuff.put(0).put(0).put(1);
else normBuff.put(0).put(0).put(-1);
if (textureMode == TextureMode.Polar) {
texBuff.put(0.5f).put(0.5f);
} else {
texBuff.put(0.5f).put(1.0f);
}
Vertex[] verts = ToolsBuffers.getVertexArray(vertexBuff);
Vector3D[] norms = ToolsBuffers.getVector3DArray(normBuff);
// Set texcoords to vertices
float[] tex = ToolsBuffers.getFloatArray(texBuff);
for (int j = 0; j < tex.length / 2; j++) {
float u = tex[j * 2];
float v = tex[j * 2 + 1];
verts[j].setTexCoordU(u);
verts[j].setTexCoordV(v);
}
// get indices
short[] indices = this.getIndexData();
GeometryInfo geomInfo = new GeometryInfo(pa, verts, norms, indices);
this.setGeometryInfo(geomInfo);
}
