void GeometryGenerator::CreateSphere(float radius, UINT sliceCount, UINT stackCount, MeshData& meshData)
{
meshData.Vertices.clear();
meshData.Indices.clear();
//
// Compute the vertices stating at the top pole and moving down the stacks.
//
// Poles: note that there will be texture coordinate distortion as there is
// not a unique point on the texture map to assign to the pole when mapping
// a rectangular texture onto a sphere.
Vertex topVertex(0.0f, +radius, 0.0f, 0.0f, +1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f);
Vertex bottomVertex(0.0f, -radius, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f);
meshData.Vertices.push_back( topVertex );
float phiStep = XM_PI/stackCount;
float thetaStep = 2.0f*XM_PI/sliceCount;
// Compute vertices for each stack ring (do not count the poles as rings).
for(UINT i = 1; i <= stackCount-1; ++i)
{
float phi = i*phiStep;
// Vertices of ring.
for(UINT j = 0; j <= sliceCount; ++j)
{
float theta = j*thetaStep;
Vertex v;
// spherical to cartesian
v.Position.x = radius*sinf(phi)*cosf(theta);
v.Position.y = radius*cosf(phi);
v.Position.z = radius*sinf(phi)*sinf(theta);
// Partial derivative of P with respect to theta
v.TangentU.x = -radius*sinf(phi)*sinf(theta);
v.TangentU.y = 0.0f;
v.TangentU.z = +radius*sinf(phi)*cosf(theta);
XMVECTOR T = XMLoadFloat3(&v.TangentU);
XMStoreFloat3(&v.TangentU, XMVector3Normalize(T));
XMVECTOR p = XMLoadFloat3(&v.Position);
XMStoreFloat3(&v.Normal, XMVector3Normalize(p));
v.TexC.x = theta / XM_2PI;
v.TexC.y = phi / XM_PI;
meshData.Vertices.push_back( v );
}
}
meshData.Vertices.push_back( bottomVertex );
//
// Compute indices for top stack. The top stack was written first to the vertex buffer
// and connects the top pole to the first ring.
//
for(UINT i = 1; i <= sliceCount; ++i)
{
meshData.Indices.push_back(0);
meshData.Indices.push_back(i+1);
meshData.Indices.push_back(i);
}
//
// Compute indices for inner stacks (not connected to poles).
//
// Offset the indices to the index of the first vertex in the first ring.
// This is just skipping the top pole vertex.
UINT baseIndex = 1;
UINT ringVertexCount = sliceCount+1;
for(UINT i = 0; i < stackCount-2; ++i)
{
for(UINT j = 0; j < sliceCount; ++j)
{
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j+1);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j+1);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j+1);
}
}
//
// Compute indices for bottom stack. The bottom stack was written last to the vertex buffer
// and connects the bottom pole to the bottom ring.
//
// South pole vertex was added last.
UINT southPoleIndex = (UINT)meshData.Vertices.size()-1;
// Offset the indices to the index of the first vertex in the last ring.
baseIndex = southPoleIndex - ringVertexCount;
for(UINT i = 0; i < sliceCount; ++i)
{
meshData.Indices.push_back(southPoleIndex);
meshData.Indices.push_back(baseIndex+i);
meshData.Indices.push_back(baseIndex+i+1);
}
}
void CreateSphere(float radius, UINT sliceCount, UINT stackCount, std::vector<XMFLOAT3>* Positions, std::vector<WORD>* Indices, std::vector<XMFLOAT2>* UVs) //From Frank D. Luna's book but edited a little bit
{
//
// Compute the vertices stating at the top pole and moving down the stacks.
//
// Poles: note that there will be texture coordinate distortion as there is
// not a unique point on the texture map to assign to the pole when mapping
// a rectangular texture onto a sphere.
XMFLOAT3 topVertex(0.0f, +radius, 0.0f);
XMFLOAT3 bottomVertex(0.0f, -radius, 0.0f);
Positions->push_back(topVertex);
float phiStep = XM_PI / stackCount;
float thetaStep = 2.0f*XM_PI / sliceCount;
// Compute vertices for each stack ring (do not count the poles as rings).
for (UINT i = 1; i <= stackCount - 1; ++i)
{
float phi = i*phiStep;
// Vertices of ring.
for (UINT j = 0; j <= sliceCount; ++j)
{
float theta = j*thetaStep;
XMFLOAT3 v;
// spherical to cartesian
v.x = radius*sinf(phi)*cosf(theta);
v.y = radius*cosf(phi);
v.z = radius*sinf(phi)*sinf(theta);
//// Partial derivative of P with respect to theta
//v.TangentU.x = -radius*sinf(phi)*sinf(theta);
//v.TangentU.y = 0.0f;
//v.TangentU.z = +radius*sinf(phi)*cosf(theta);
//XMVECTOR T = XMLoadFloat3(&v.TangentU);
//XMStoreFloat3(&v.TangentU, XMVector3Normalize(T));
//XMVECTOR p = XMLoadFloat3(&v.Position);
//XMStoreFloat3(&v.Normal, XMVector3Normalize(p));
XMFLOAT2 uv;
uv.x = theta / XM_2PI;
uv.y = phi / XM_PI;
Positions->push_back(v);
UVs->push_back(uv);
}
}
Positions->push_back(bottomVertex);
//
// Compute indices for top stack. The top stack was written first to the vertex buffer
// and connects the top pole to the first ring.
//
for (UINT i = 1; i <= sliceCount; ++i)
{
Indices->push_back(0);
Indices->push_back(i + 1);
Indices->push_back(i);
}
//
// Compute indices for inner stacks (not connected to poles).
//
// Offset the indices to the index of the first vertex in the first ring.
// This is just skipping the top pole vertex.
UINT baseIndex = 1;
UINT ringVertexCount = sliceCount + 1;
for (UINT i = 0; i < stackCount - 2; ++i)
{
for (UINT j = 0; j < sliceCount; ++j)
{
Indices->push_back(baseIndex + i*ringVertexCount + j);
Indices->push_back(baseIndex + i*ringVertexCount + j + 1);
Indices->push_back(baseIndex + (i + 1)*ringVertexCount + j);
Indices->push_back(baseIndex + (i + 1)*ringVertexCount + j);
Indices->push_back(baseIndex + i*ringVertexCount + j + 1);
Indices->push_back(baseIndex + (i + 1)*ringVertexCount + j + 1);
}
}
//
// Compute indices for bottom stack. The bottom stack was written last to the vertex buffer
// and connects the bottom pole to the bottom ring.
//
// South pole vertex was added last.
UINT southPoleIndex = (UINT)Positions->size() - 1;
// Offset the indices to the index of the first vertex in the last ring.
baseIndex = southPoleIndex - ringVertexCount;
for (UINT i = 0; i < sliceCount; ++i)
{
Indices->push_back(southPoleIndex);
Indices->push_back(baseIndex + i);
Indices->push_back(baseIndex + i + 1);
}
}
void GeometryGenerator::CreateSphere(float radius, UINT sliceCount, UINT stackCount, MeshData& meshData)
{
meshData.Vertices.clear();
meshData.Indices.clear();
Vertex topVertex(0.0f, +radius, 0.0f, 0.0f, +1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f);
Vertex bottomVertex(0.0f, -radius, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f);
meshData.Vertices.push_back( topVertex );
float phiStep = XM_PI/stackCount;
float thetaStep = 2.0f*XM_PI/sliceCount;
for(UINT i = 1; i <= stackCount-1; ++i)
{
float phi = i*phiStep;
for(UINT j = 0; j <= sliceCount; ++j)
{
float theta = j*thetaStep;
Vertex v;
v.Position.x = radius*sinf(phi)*cosf(theta);
v.Position.y = radius*cosf(phi);
v.Position.z = radius*sinf(phi)*sinf(theta);
v.TangentU.x = -radius*sinf(phi)*sinf(theta);
v.TangentU.y = 0.0f;
v.TangentU.z = +radius*sinf(phi)*cosf(theta);
v.TangentU = glm::normalize(v.TangentU);
v.Normal = glm::normalize(v.Position);
v.TexC.x = theta / (2.0f * glm::pi<float>());
v.TexC.y = phi / XM_PI;
meshData.Vertices.push_back( v );
}
}
meshData.Vertices.push_back( bottomVertex );
for(UINT i = 1; i <= sliceCount; ++i)
{
meshData.Indices.push_back(0);
meshData.Indices.push_back(i+1);
meshData.Indices.push_back(i);
}
UINT baseIndex = 1;
UINT ringVertexCount = sliceCount+1;
for(UINT i = 0; i < stackCount-2; ++i)
{
for(UINT j = 0; j < sliceCount; ++j)
{
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j+1);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j);
meshData.Indices.push_back(baseIndex + i*ringVertexCount + j+1);
meshData.Indices.push_back(baseIndex + (i+1)*ringVertexCount + j+1);
}
}
UINT southPoleIndex = (UINT)meshData.Vertices.size()-1;
baseIndex = southPoleIndex - ringVertexCount;
for(UINT i = 0; i < sliceCount; ++i)
{
meshData.Indices.push_back(southPoleIndex);
meshData.Indices.push_back(baseIndex+i);
meshData.Indices.push_back(baseIndex+i+1);
}
}
void Geometry::createSphere(float radius, UINT sliceCount, UINT stackCount, OGLMeshData& meshData)
{
//
// Compute the vertices stating at the top pole and moving down the stacks.
//
// Poles: note that there will be texture coordinate distortion as there is
// not a unique point on the texture map to assign to the pole when mapping
// a rectangular texture onto a sphere.
OGLVertex topVertex(0.0f, +radius, 0.0f, 0.0f, +1.0f, 0.0f, 0.0f, 0.0f);
OGLVertex bottomVertex(0.0f, -radius, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f);
meshData.VertexData.push_back(topVertex);
float phiStep = XM_PI / stackCount;
float thetaStep = 2.0f*XM_PI / sliceCount;
// Compute vertices for each stack ring (do not count the poles as rings).
for (UINT i = 1; i <= stackCount - 1; ++i)
{
float phi = i*phiStep;
// Vertices of ring.
for (UINT j = 0; j <= sliceCount; ++j)
{
float theta = j*thetaStep;
OGLVertex v;
// spherical to cartesian
v.position.x = radius * sinf(phi) * cosf(theta);
v.position.y = radius * cosf(phi);
v.position.z = radius * sinf(phi) * sinf(theta);
v.normal = v.position;
glm::normalize(v.normal);
v.texcoord.x = theta / XM_2PI;
v.texcoord.y = phi / XM_PI;
meshData.VertexData.push_back(v);
}
}
// Compute indices for top stack. The top stack was written first to the vertex buffer
// and connects the top pole to the first ring.
//
for (UINT i = 1; i <= sliceCount; ++i)
{
meshData.IndexData.push_back(0);
meshData.IndexData.push_back(i + 1);
meshData.IndexData.push_back(i);
}
//
// Compute indices for inner stacks (not connected to poles).
//
// Offset the indices to the index of the first vertex in the first ring.
// This is just skipping the top pole vertex.
UINT baseIndex = 1;
UINT ringVertexCount = sliceCount + 1;
for (UINT i = 0; i < stackCount - 2; ++i)
{
for (UINT j = 0; j < sliceCount; ++j)
{
meshData.IndexData.push_back(baseIndex + i*ringVertexCount + j);
meshData.IndexData.push_back(baseIndex + i*ringVertexCount + j + 1);
meshData.IndexData.push_back(baseIndex + (i + 1)*ringVertexCount + j);
meshData.IndexData.push_back(baseIndex + (i + 1)*ringVertexCount + j);
meshData.IndexData.push_back(baseIndex + i*ringVertexCount + j + 1);
meshData.IndexData.push_back(baseIndex + (i + 1)*ringVertexCount + j + 1);
}
}
//
// Compute indices for bottom stack. The bottom stack was written last to the vertex buffer
// and connects the bottom pole to the bottom ring.
//
// South pole vertex was added last.
UINT southPoleIndex = (UINT)meshData.VertexData.size() - 1;
// Offset the indices to the index of the first vertex in the last ring.
baseIndex = southPoleIndex - ringVertexCount;
for (UINT i = 0; i < sliceCount; ++i)
{
meshData.IndexData.push_back(southPoleIndex);
meshData.IndexData.push_back(baseIndex + i);
meshData.IndexData.push_back(baseIndex + i + 1);
}
}
//
// Create a sphere with the given radius and center point. 'numStacks' is
// the number of layers along the Z axis and 'numSlices' is the number
// of radial divisions.
//
STShape* CreateSphere(
float radius, const STPoint3& center,
unsigned int numSlices, unsigned int numStacks)
{
STShape* result = new STShape();
float PI_Stacks = float(M_PI) / float(numStacks);
float PI2_Slices = 2.0f * float(M_PI) / float(numSlices);
//
// Add the interior vertices
//
for (unsigned int ii = 1; ii < numStacks; ++ii) {
float phi = float(ii) * PI_Stacks;
float cosPhi = cosf(phi);
float sinPhi = sinf(phi);
for(unsigned int jj = 0; jj < numSlices; ++jj) {
float theta = float(jj) * PI2_Slices;
STPoint3 position = center +
STVector3(radius * cosf(theta) * sinPhi,
radius * sinf(theta) * sinPhi,
radius * cosPhi);
result->AddVertex(STShape::Vertex(
position,
STVector3::Zero,
STPoint2::Origin));
}
}
//
// Add the pole vertices
//
STShape::Vertex topVertex(
center + STVector3(0,0,radius),
STVector3::Zero,
STPoint2::Origin);
STShape::Index topVertexIndex = result->AddVertex(topVertex);
STShape::Vertex bottomVertex(
center + STVector3(0,0,-radius),
STVector3::Zero, STPoint2::Origin);
STShape::Index bottomVertexIndex = result->AddVertex(bottomVertex);
//
// Add the top and bottom triangles (all triangles involving the pole vertices)
//
for( unsigned int ii = 0; ii < numSlices; ii++) {
unsigned int iiPlus1 = (ii + 1) % numSlices;
result->AddFace(
STShape::Face(ii, iiPlus1, topVertexIndex));
result->AddFace(STShape::Face(
iiPlus1 + (numStacks - 2) * numSlices,
ii + (numStacks - 2) * numSlices,
bottomVertexIndex));
}
//
// Add all the interior triangles
//
for(unsigned int ii = 0; ii < numStacks - 2; ++ii) {
for(unsigned int jj = 0; jj < numSlices; ++jj) {
unsigned int jjPlus1 = (jj + 1) % numSlices;
result->AddFace(STShape::Face(
(ii + 1)*numSlices + jj,
(ii + 0)*numSlices + jjPlus1,
(ii + 0)*numSlices + jj));
result->AddFace(STShape::Face(
(ii + 1)*numSlices + jj,
(ii + 1)*numSlices + jjPlus1,
(ii + 0)*numSlices + jjPlus1));
}
}
result->GenerateNormals();
return result;
}
