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Converted to use quad strips instead of quad lists.

pull/3/head
Chris Laurel 2001-04-09 18:47:56 +00:00
parent ae51c34435
commit 9a22d0fcb1
1 changed files with 87 additions and 44 deletions
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131
src/spheremesh.cpp
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@ -92,10 +92,13 @@ void SphereMesh::render()
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
glDrawElements(GL_QUADS,
nIndices,
GL_UNSIGNED_SHORT,
indices);
for (int i = 0; i < nRings - 1; i++)
{
glDrawElements(GL_QUAD_STRIP,
(nSlices + 1) * 2,
GL_UNSIGNED_SHORT,
indices + (nSlices + 1) * 2 * i);
}
}
@ -107,7 +110,7 @@ void SphereMesh::createSphere(float radius, int _nRings, int _nSlices)
vertices = new float[nVertices * 3];
normals = new float[nVertices * 3];
texCoords = new float[nVertices * 2];
nIndices = (nRings - 1) * nSlices * 4;
nIndices = (nRings - 1) * (nSlices + 1) * 2;
indices = new unsigned short[nIndices];
int i;
@ -134,13 +137,11 @@ void SphereMesh::createSphere(float radius, int _nRings, int _nSlices)
for (i = 0; i < nRings - 1; i++)
{
for (int j = 0; j < nSlices; j++)
for (int j = 0; j <= nSlices; j++)
{
int n = i * nSlices + j;
indices[n * 4 + 0] = i * (nSlices + 1) + j;
indices[n * 4 + 1] = (i + 1) * (nSlices + 1) + j;
indices[n * 4 + 2] = (i + 1) * (nSlices + 1) + j + 1;
indices[n * 4 + 3] = i * (nSlices + 1) + j + 1;
int n = i * (nSlices + 1) + j;
indices[n * 2 + 0] = i * (nSlices + 1) + j;
indices[n * 2 + 1] = (i + 1) * (nSlices + 1) + j;
}
}
}
@ -150,40 +151,43 @@ void SphereMesh::createSphere(float radius, int _nRings, int _nSlices)
void SphereMesh::generateNormals()
{
Vec3f zero(0, 0, 0);
int nQuads = nIndices / 4;
int nQuads = nSlices * (nRings - 1);
Vec3f* faceNormals = new Vec3f[nQuads];
int i;
// Compute face normals for the mesh
for (i = 0; i < nQuads; i++)
for (i = 0; i < nRings - 1; i++)
{
float* p0 = vertices + indices[i * 4] * 3;
float* p1 = vertices + indices[i * 4 + 1] * 3;
float* p2 = vertices + indices[i * 4 + 2] * 3;
float* p3 = vertices + indices[i * 4 + 3] * 3;
// Compute the face normal. Watch out for degenerate (zero-length)
// edges. If there are two degenerate edges, the entire face must
// be degenerate and we'll handle that later
Vec3f v0(p1[0] - p0[0], p1[1] - p0[1], p1[2] - p0[2]);
Vec3f v1(p2[0] - p1[0], p2[1] - p1[1], p2[2] - p1[2]);
if (v0.length() < 1e-6f)
for (int j = 0; j < nSlices; j++)
{
v0 = Vec3f(p2[0] - p1[0], p2[1] - p1[1], p2[2] - p1[2]);
v1 = Vec3f(p3[0] - p2[0], p3[1] - p2[1], p3[2] - p2[2]);
}
else if (v1.length() < 1e-6f)
{
v0 = Vec3f(p3[0] - p2[0], p3[1] - p2[1], p3[2] - p2[2]);
v1 = Vec3f(p0[0] - p3[0], p0[1] - p3[1], p0[2] - p3[2]);
}
float* p0 = vertices + (i * (nSlices + 1) + j) * 3;
float* p1 = vertices + ((i + 1) * (nSlices + 1) + j) * 3;
float* p2 = vertices + ((i + 1) * (nSlices + 1) + j + 1) * 3;
float* p3 = vertices + (i * (nSlices + 1) + j + 1) * 3;
Vec3f faceNormal = cross(v0, v1);
float length = faceNormal.length();
if (length != 0)
faceNormal *= (1 / length);
// Compute the face normal. Watch out for degenerate (zero-length)
// edges. If there are two degenerate edges, the entire face must
// be degenerate and we'll handle that later
Vec3f v0(p1[0] - p0[0], p1[1] - p0[1], p1[2] - p0[2]);
Vec3f v1(p2[0] - p1[0], p2[1] - p1[1], p2[2] - p1[2]);
if (v0.length() < 1e-6f)
{
v0 = Vec3f(p2[0] - p1[0], p2[1] - p1[1], p2[2] - p1[2]);
v1 = Vec3f(p3[0] - p2[0], p3[1] - p2[1], p3[2] - p2[2]);
}
else if (v1.length() < 1e-6f)
{
v0 = Vec3f(p3[0] - p2[0], p3[1] - p2[1], p3[2] - p2[2]);
v1 = Vec3f(p0[0] - p3[0], p0[1] - p3[1], p0[2] - p3[2]);
}
faceNormals[i] = faceNormal;
Vec3f faceNormal = cross(v0, v1);
float length = faceNormal.length();
if (length != 0)
faceNormal *= (1 / length);
faceNormals[i * nSlices + j] = faceNormal;
}
}
int* faceCounts = new int[nVertices];
@ -195,15 +199,54 @@ void SphereMesh::generateNormals()
normals[i * 3 + 2] = 0;
}
for (i = 0; i < nIndices; i++)
for (i = 1; i < nRings - 1; i++)
{
int face = i / 4;
int vertex = indices[i];
for (int j = 0; j <= nSlices; j++)
{
int vertex = i * (nSlices + 1) + j;
faceCounts[vertex] = 4;
faceCounts[vertex]++;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
int face = (i - 1) * nSlices + j % nSlices;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
face = (i - 1) * nSlices + (j + nSlices - 1) % nSlices;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
face = i * nSlices + (j + nSlices - 1) % nSlices;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
face = i * nSlices + j % nSlices;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
}
}
// Compute normals at the poles
for (i = 0; i <= nSlices; i++)
{
int vertex = i;
faceCounts[vertex] = nSlices;
for (int j = 0; j < nSlices; j++)
{
int face = j;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
}
vertex = (nRings - 1) * (nSlices + 1) + i;
faceCounts[vertex] = nSlices;
for (j = 0; j < nSlices; j++)
{
int face = nQuads - j - 1;
normals[vertex * 3] += faceNormals[face].x;
normals[vertex * 3 + 1] += faceNormals[face].y;
normals[vertex * 3 + 2] += faceNormals[face].z;
}
}
for (i = 0; i < nVertices; i++)