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Changed circle calculation to match sphere tessellation; makes example022 look better

stl_dim
Marius Kintel 2011-04-13 14:30:55 +02:00
parent 95c2fdcabf
commit 8c95ac4462
1 changed files with 20 additions and 32 deletions
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52
src/primitives.cc
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@ -219,6 +219,19 @@ int get_fragments_from_r(double r, double fn, double fs, double fa)
return (int)ceil(fmax(fmin(360.0 / fa, r*M_PI / fs), 5));
}
struct point2d {
double x, y;
};
static void generate_circle(point2d *circle, double r, int fragments)
{
for (int i=0; i<fragments; i++) {
double phi = (M_PI*2* (i + 0.5)) / fragments;
circle[i].x = r*cos(phi);
circle[i].y = r*sin(phi);
}
}
PolySet *PrimitiveNode::render_polyset(render_mode_e) const
{
PolySet *p = new PolySet();
@ -279,10 +292,6 @@ PolySet *PrimitiveNode::render_polyset(render_mode_e) const
if (type == SPHERE && r1 > 0)
{
struct point2d {
double x, y;
};
struct ring_s {
point2d *points;
double z;
@ -290,21 +299,19 @@ PolySet *PrimitiveNode::render_polyset(render_mode_e) const
int fragments = get_fragments_from_r(r1, fn, fs, fa);
int rings = fragments/2;
if(rings<=0)
rings=1;
// Uncomment the following three lines to enable experimental sphere tesselation
// if (rings % 2 == 0) rings++; // To ensure that the middle ring is at phi == 0 degrees
ring_s *ring = new ring_s[rings];
// double offset = 0.5 * ((fragments / 2) % 2);
for (int i = 0; i < rings; i++) {
// double phi = (M_PI * (i + offset)) / (fragments/2);
double phi = (M_PI * (i + 0.5)) / rings;
double r = r1 * sin(phi);
ring[i].z = r1 * cos(phi);
ring[i].points = new point2d[fragments];
for (int j = 0; j < fragments; j++) {
phi = (M_PI*2*j) / fragments;
ring[i].points[j].x = r * cos(phi);
ring[i].points[j].y = r * sin(phi);
}
generate_circle(ring[i].points, r, fragments);
}
p->append_poly();
@ -363,30 +370,11 @@ sphere_next_r2:
z2 = h;
}
struct point2d {
double x, y;
};
point2d *circle1 = new point2d[fragments];
point2d *circle2 = new point2d[fragments];
for (int i=0; i<fragments; i++) {
double phi = (M_PI*2*i) / fragments;
if (r1 > 0) {
circle1[i].x = r1*cos(phi);
circle1[i].y = r1*sin(phi);
} else {
circle1[i].x = 0;
circle1[i].y = 0;
}
if (r2 > 0) {
circle2[i].x = r2*cos(phi);
circle2[i].y = r2*sin(phi);
} else {
circle2[i].x = 0;
circle2[i].y = 0;
}
}
generate_circle(circle1, r1, fragments);
generate_circle(circle2, r2, fragments);
for (int i=0; i<fragments; i++) {
int j = (i+1) % fragments;