Pte *
walkpgmap(Pml4e *pgmap, void *va, int alloc)
{
Pdpe *pdirpt;
Pde *pgdir;
Pte *pgtab;
pdirpt = pgmapget(pgmap, pmx(va), alloc);
if (pdirpt == nil)
return nil;
pgdir = pgmapget(pdirpt, pdpx(va), alloc);
if (pgdir == nil)
return nil;
pgtab = pgmapget(pgdir, pdx(va), alloc);
if (pgtab == nil)
return nil;
return &pgtab[ptx(va)];
}
void manifold(Mesh<Vertex3d> &mesh)
{
const int N = 11;
const int M = N - 1;
const double L = ((double)N) / 2.0;
Vertex3d vertices[N * N];
int indices[M * M * 6];
int index = 0;
for (int ix = 0; ix < N; ++ix)
{
for (int iy = 0; iy < N; ++iy)
{
double x = (1.0 * ix - L + 0.5) / L;
double y = (1.0 * iy - L + 0.5) / L;
double z = manifoldFunction(x,y);
double xdx = x + 0.01;
double ydy = y + 0.01;
double zdx = manifoldFunction(xdx, y);
double zdy = manifoldFunction(x, ydy);
GAL::P3d p0(x,y,z);
GAL::P3d pdx(xdx, y, zdx);
GAL::P3d pdy(x, ydy, zdy);
GAL::P3d nor = GAL::Cross(pdx - p0, pdy - p0);
vertices[index].position = p0;
vertices[index].normal = nor / GAL::Len(nor);
++index;
}
}
index = 0;
for (int n = 0; n < M; ++n)
{
for (int m = 0; m < M; ++m)
{
int i0 = n * N + m;
int i1 = i0 + 1;
int i2 = i0 + N;
int i3 = i0 + N + 1;
indices[index++] = i0;
indices[index++] = i2;
indices[index++] = i1;
indices[index++] = i1;
indices[index++] = i2;
indices[index++] = i3;
}
}
mesh.addVertices(vertices, sizeof(vertices) / sizeof(GAL::P3d));
mesh.addIndices(indices, sizeof(indices) / sizeof(int));
}