/*
* Draw patch
*
* patch = set of point numbers
* Sx = x reflection (+/-1)
* Sy = y reflection (+/-1)
* Sz = z reflection (+/-1)
*/
static void Patch(int patch[4][4],float Sx,float Sy,float Sz)
{
int i,j,k;
Point p[4][4],P[MAXN+1][MAXN+1],N[MAXN+1][MAXN+1],T[MAXN+1][MAXN+1];
// Copy data with reflection
for (k=0;k<4;k++)
{
int K = Sx*Sy*Sz<0 ? 3-k : k;
for (j=0;j<4;j++)
{
int l = patch[j][K];
p[j][k].x = +Sx*data[l].x;
p[j][k].z = -Sy*data[l].y;
p[j][k].y = +Sz*data[l].z;
}
}
// Evaluate vertexes
for (i=0;i<=n;i++)
for (j=0;j<=n;j++)
{
float u = (float)i/n;
float v = (float)j/n;
// Vertex coordinates
P[i][j] = Bezier2D(p,u,v);
// Normal
N[i][j] = Normal2D(p,u,v);
// Texture coordinates
T[i][j].x = 1-u;
T[i][j].y = 1-v;
T[i][j].z = 0;
}
// Draw quads
for (i=0;i<n;i++)
for (j=0;j<n;j++)
{
Point p[4] = {P[i][j],P[i+1][j],P[i+1][j+1],P[i][j+1]};
Point n[4] = {N[i][j],N[i+1][j],N[i+1][j+1],N[i][j+1]};
Point t[4] = {T[i][j],T[i+1][j],T[i+1][j+1],T[i][j+1]};
DrawPolyShadow(p,n,t,4);
}
}
/*
* Draw patch
*/
static void Patch(int patch[4][4],float Sx,float Sy,int n)
{
Point p[4][4],P[MAXN+1][MAXN+1],N[MAXN+1][MAXN+1],T[MAXN+1][MAXN+1];
// Copy data with reflection
for (int k=0;k<4;k++)
{
int K = Sx*Sy<0 ? 3-k : k;
for (int j=0;j<4;j++)
{
int l = patch[j][K];
p[j][k].x = Sx*data[l].x;
p[j][k].y = Sy*data[l].y;
p[j][k].z = data[l].z;
}
}
// Evaluate grid points
for (int i=0;i<=n;i++)
for (int j=0;j<=n;j++)
{
float u = (float)i/n;
float v = (float)j/n;
P[i][j] = Bezier2D(p,u,v);
N[i][j] = Normal2D(p,u,v);
T[i][j].x = 1-u;
T[i][j].y = 1-v;
T[i][j].z = 0;
}
// Draw quads
for (int i=0;i<n;i++)
{
glBegin(GL_QUAD_STRIP);
for (int j=0;j<=n;j++)
{
// Draw normals and vertexes
glNormal3fv((float*)&N[i ][j]); glTexCoord2fv((float*)&T[i ][j]); glVertex3fv((float*)&P[i ][j]);
glNormal3fv((float*)&N[i+1][j]); glTexCoord2fv((float*)&T[i+1][j]); glVertex3fv((float*)&P[i+1][j]);
}
glEnd();
}
}
