Spline::InterpolatedPT LoopingCubicHermiteSpline::getTangent(double x) const
{
//use modular arithmetic to bring x into an acceptable range
x = fmod(x, numSegments);
if(x < 0)
x += numSegments;
//find the interpolation data for this t value
InterpolationData segment = segmentData.at(getSegmentIndex(x));
double t = (x - segment.t0) * segment.tDistanceInverse;
return InterpolatedPT(
computePosition(t, segment),
computeTangent(t, segment)
);
}
Spline::InterpolatedPTCW LoopingCubicHermiteSpline::getWiggle(double x) const
{
//use modular arithmetic to bring x into an acceptable range
x = fmod(x, numSegments);
if(x < 0)
x += numSegments;
InterpolationData segment = segmentData.at(getSegmentIndex(x));
double t = (x - segment.t0) * segment.tDistanceInverse;
return InterpolatedPTCW(
computePosition(t, segment),
computeTangent(t, segment),
computeCurvature(t, segment),
computeWiggle(segment)
);
}
void generateTangents(MSubMesh * subMesh)
{
MVector3 * vertices = subMesh->getVertices();
MVector3 * normals = subMesh->getNormals();
MVector2 * texCoords = subMesh->getTexCoords();
if(! (vertices && normals && texCoords))
return;
bool generate = false;
unsigned int mapChannel;
// find normal mapChannel
unsigned int d;
unsigned int dSize = subMesh->getDisplaysNumber();
for(d=0; d<dSize; d++)
{
MDisplay * display = subMesh->getDisplay(d);
MMaterial * material = display->getMaterial();
if(material)
{
if(material->getType() == 1) // standard
{
if(material->getTexturesPassNumber() > 2)
{
MTexturePass * texturePass = material->getTexturePass(2); // Normal map pass
if(texturePass)
{
mapChannel = texturePass->getMapChannel();
generate = true;
}
}
}
else
{
unsigned tSize = material->getTexturesPassNumber();
unsigned int t;
for(t=0; t<tSize; t++)
{
MTexturePass * texturePass = material->getTexturePass(t);
if(texturePass)
{
if(texturePass->getCombineMode() == M_TEX_COMBINE_DOT)
{
mapChannel = texturePass->getMapChannel();
generate = true;
}
}
}
}
}
}
// generate
if(generate)
{
M_TYPES indicesType = subMesh->getIndicesType();
void * indices = subMesh->getIndices();
MVector3 * tangents = subMesh->allocTangents(subMesh->getNormalsSize());
// texCoord offset
unsigned int offset = 0;
if(subMesh->isMapChannelExist(mapChannel))
offset = subMesh->getMapChannelOffset(mapChannel);
texCoords = texCoords + offset;
// scan triangles to generate tangents from vertices and texCoords
for(d=0; d<dSize; d++)
{
MDisplay * display = subMesh->getDisplay(d);
if(display->getPrimitiveType() == M_PRIMITIVE_TRIANGLES)
{
unsigned int begin = display->getBegin();
unsigned int size = display->getSize();
if(! indices)
{
for(unsigned int i=begin; i<(begin+size); i+=3)
{
MVector3 * P1 = &vertices[i];
MVector3 * P2 = &vertices[i+1];
MVector3 * P3 = &vertices[i+2];
MVector3 * N1 = &normals[i];
MVector3 * N2 = &normals[i+1];
MVector3 * N3 = &normals[i+2];
MVector2 * UV1 = &texCoords[i];
MVector2 * UV2 = &texCoords[i+1];
MVector2 * UV3 = &texCoords[i+2];
MVector3 tangent = computeTangent(*P1, *P2, *P3, *UV1, *UV2, *UV3);
tangents[i] = (tangent - ((*N1) * tangent.dotProduct(*N1))).getNormalized();
tangents[i+1] = (tangent - ((*N2) * tangent.dotProduct(*N2))).getNormalized();
tangents[i+2] = (tangent - ((*N3) * tangent.dotProduct(*N3))).getNormalized();
}
}
else if(indicesType == M_USHORT)
{
unsigned short * _indices = (unsigned short *)indices;
for(unsigned int i=begin; i<(begin+size); i+=3)
{
unsigned short A = _indices[i];
unsigned short B = _indices[i+1];
unsigned short C = _indices[i+2];
MVector3 * P1 = &vertices[A];
MVector3 * P2 = &vertices[B];
MVector3 * P3 = &vertices[C];
MVector3 * N1 = &normals[A];
MVector3 * N2 = &normals[B];
MVector3 * N3 = &normals[C];
MVector2 * UV1 = &texCoords[A];
MVector2 * UV2 = &texCoords[B];
MVector2 * UV3 = &texCoords[C];
MVector3 tangent = computeTangent(*P1, *P2, *P3, *UV1, *UV2, *UV3);
tangents[A] = (tangent - ((*N1) * tangent.dotProduct(*N1))).getNormalized();
tangents[B] = (tangent - ((*N2) * tangent.dotProduct(*N2))).getNormalized();
tangents[C] = (tangent - ((*N3) * tangent.dotProduct(*N3))).getNormalized();
}
}
else if(indicesType == M_UINT)
{
unsigned int * _indices = (unsigned int *)indices;
for(unsigned int i=begin; i<(begin+size); i+=3)
{
unsigned int A = _indices[i];
unsigned int B = _indices[i+1];
unsigned int C = _indices[i+2];
MVector3 * P1 = &vertices[A];
MVector3 * P2 = &vertices[B];
MVector3 * P3 = &vertices[C];
MVector3 * N1 = &normals[A];
MVector3 * N2 = &normals[B];
MVector3 * N3 = &normals[C];
MVector2 * UV1 = &texCoords[A];
MVector2 * UV2 = &texCoords[B];
MVector2 * UV3 = &texCoords[C];
MVector3 tangent = computeTangent(*P1, *P2, *P3, *UV1, *UV2, *UV3);
tangents[A] = (tangent - ((*N1) * tangent.dotProduct(*N1))).getNormalized();
tangents[B] = (tangent - ((*N2) * tangent.dotProduct(*N2))).getNormalized();
tangents[C] = (tangent - ((*N3) * tangent.dotProduct(*N3))).getNormalized();
}
}
}
}
}
}
