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/*****
* bezierpatch.h
* Authors: John C. Bowman and Jesse Frohlich
*
* Render Bezier patches and triangles.
*****/
#ifndef BEZIERPATCH_H
#define BEZIERPATCH_H
#include "drawelement.h"
namespace camp {
#ifdef HAVE_GL
extern int sign;
extern const double Fuzz;
extern const double Fuzz2;
struct BezierPatch
{
static std::vector<GLfloat> buffer;
static std::vector<GLfloat> Buffer;
static std::vector<GLuint> indices;
static std::vector<GLuint> Indices;
static std::vector<GLfloat> tbuffer;
static std::vector<GLuint> tindices;
static std::vector<GLfloat> tBuffer;
static std::vector<GLuint> tIndices;
static GLuint nvertices;
static GLuint ntvertices;
static GLuint Nvertices;
static GLuint Ntvertices;
std::vector<GLuint> *pindices;
triple u,v,w;
double epsilon;
double Epsilon;
double res2;
double Res2; // Reduced resolution for Bezier triangles flatness test.
triple Min,Max;
typedef GLuint vertexFunction(const triple &v, const triple& n);
typedef GLuint VertexFunction(const triple &v, const triple& n, GLfloat *c);
vertexFunction *pvertex;
VertexFunction *pVertex;
BezierPatch() {}
void init(double res, const triple& Min, const triple& Max,
bool transparent, GLfloat *colors=NULL);
// Store the vertex v and its normal vector n in the buffer.
static GLuint vertex(const triple &v, const triple& n) {
buffer.push_back(v.getx());
buffer.push_back(v.gety());
buffer.push_back(v.getz());
buffer.push_back(n.getx());
buffer.push_back(n.gety());
buffer.push_back(n.getz());
return nvertices++;
}
static GLuint tvertex(const triple &v, const triple& n) {
tbuffer.push_back(v.getx());
tbuffer.push_back(v.gety());
tbuffer.push_back(v.getz());
tbuffer.push_back(n.getx());
tbuffer.push_back(n.gety());
tbuffer.push_back(n.getz());
return ntvertices++;
}
// Store the vertex v and its normal vector n and colour c in the buffer.
static GLuint Vertex(const triple& v, const triple& n, GLfloat *c) {
Buffer.push_back(v.getx());
Buffer.push_back(v.gety());
Buffer.push_back(v.getz());
Buffer.push_back(n.getx());
Buffer.push_back(n.gety());
Buffer.push_back(n.getz());
Buffer.push_back(c[0]);
Buffer.push_back(c[1]);
Buffer.push_back(c[2]);
Buffer.push_back(c[3]);
return Nvertices++;
}
static GLuint tVertex(const triple& v, const triple& n, GLfloat *c) {
tBuffer.push_back(v.getx());
tBuffer.push_back(v.gety());
tBuffer.push_back(v.getz());
tBuffer.push_back(n.getx());
tBuffer.push_back(n.gety());
tBuffer.push_back(n.getz());
tBuffer.push_back(c[0]);
tBuffer.push_back(c[1]);
tBuffer.push_back(c[2]);
tBuffer.push_back(c[3]);
return Ntvertices++;
}
triple normal(triple left3, triple left2, triple left1, triple middle,
triple right1, triple right2, triple right3) {
triple rp=right1-middle;
triple lp=left1-middle;
triple n=triple(rp.gety()*lp.getz()-rp.getz()*lp.gety(),
rp.getz()*lp.getx()-rp.getx()*lp.getz(),
rp.getx()*lp.gety()-rp.gety()*lp.getx());
if(abs2(n) > epsilon)
return unit(n);
triple lpp=bezierPP(middle,left1,left2);
triple rpp=bezierPP(middle,right1,right2);
n=cross(rpp,lp)+cross(rp,lpp);
if(abs2(n) > epsilon)
return unit(n);
triple lppp=bezierPPP(middle,left1,left2,left3);
triple rppp=bezierPPP(middle,right1,right2,right3);
return unit(9.0*cross(rpp,lpp)+
3.0*(cross(rp,lppp)+cross(rppp,lp)+
cross(rppp,lpp)+cross(rpp,lppp))+
cross(rppp,lppp));
}
triple derivative(triple p0, triple p1, triple p2, triple p3) {
triple lp=p1-p0;
if(abs2(lp) > epsilon)
return lp;
triple lpp=bezierPP(p0,p1,p2);
if(abs2(lpp) > epsilon)
return lpp;
return bezierPPP(p0,p1,p2,p3);
}
virtual double Distance(const triple *p) {
triple p0=p[0];
triple p3=p[3];
triple p12=p[12];
triple p15=p[15];
// Check the flatness of the quad.
double d=Distance2(p15,p0,normal(p3,p[2],p[1],p0,p[4],p[8],p12));
// Determine how straight the edges are.
d=max(d,Straightness(p0,p[1],p[2],p3));
d=max(d,Straightness(p0,p[4],p[8],p12));
d=max(d,Straightness(p3,p[7],p[11],p15));
d=max(d,Straightness(p12,p[13],p[14],p15));
// Determine how straight the interior control curves are.
d=max(d,Straightness(p[4],p[5],p[6],p[7]));
d=max(d,Straightness(p[8],p[9],p[10],p[11]));
d=max(d,Straightness(p[1],p[5],p[9],p[13]));
return max(d,Straightness(p[2],p[6],p[10],p[14]));
}
struct Split3 {
triple m0,m2,m3,m4,m5;
Split3() {}
Split3(triple z0, triple c0, triple c1, triple z1) {
m0=0.5*(z0+c0);
triple m1=0.5*(c0+c1);
m2=0.5*(c1+z1);
m3=0.5*(m0+m1);
m4=0.5*(m1+m2);
m5=0.5*(m3+m4);
}
};
// Approximate bounds by bounding box of control polyhedron.
bool offscreen(size_t n, const triple *v) {
double x,y,z;
double X,Y,Z;
boundstriples(x,y,z,X,Y,Z,n,v);
return
X < Min.getx() || x > Max.getx() ||
Y < Min.gety() || y > Max.gety() ||
Z < Min.getz() || z > Max.getz();
}
void clear() {
nvertices=ntvertices=Nvertices=Ntvertices=0;
buffer.clear();
indices.clear();
Buffer.clear();
Indices.clear();
tbuffer.clear();
tindices.clear();
tBuffer.clear();
tIndices.clear();
}
~BezierPatch() {}
void render(const triple *p,
GLuint I0, GLuint I1, GLuint I2, GLuint I3,
triple P0, triple P1, triple P2, triple P3,
bool flat0, bool flat1, bool flat2, bool flat3,
GLfloat *C0=NULL, GLfloat *C1=NULL, GLfloat *C2=NULL,
GLfloat *C3=NULL);
virtual void render(const triple *p, bool straight, GLfloat *c0=NULL);
void queue(const triple *g, bool straight, double ratio,
const triple& Min, const triple& Max, bool transparent,
GLfloat *colors=NULL) {
init(pixel*ratio,Min,Max,transparent,colors);
render(g,straight,colors);
}
void draw();
void draw(const triple *g, bool straight, double ratio,
const triple& Min, const triple& Max, bool transparent,
GLfloat *colors=NULL) {
queue(g,straight,ratio,Min,Max,transparent,colors);
draw();
}
};
struct BezierTriangle : public BezierPatch {
public:
BezierTriangle() : BezierPatch() {}
double Distance(const triple *p) {
triple p0=p[0];
triple p6=p[6];
triple p9=p[9];
// Check how far the internal point is from the centroid of the vertices.
double d=abs2((p0+p6+p9)*third-p[4]);
// Determine how straight the edges are.
d=max(d,Straightness(p0,p[1],p[3],p6));
d=max(d,Straightness(p0,p[2],p[5],p9));
return max(d,Straightness(p6,p[7],p[8],p9));
}
void render(const triple *p,
GLuint I0, GLuint I1, GLuint I2,
triple P0, triple P1, triple P2,
bool flat0, bool flat1, bool flat2,
GLfloat *C0=NULL, GLfloat *C1=NULL, GLfloat *C2=NULL);
void render(const triple *p, bool straight, GLfloat *c0=NULL);
};
#endif
} //namespace camp
#endif
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