/* Java2DModel.java Representation of a 3D model as a wire frame of line
segments tailored for use in a Java2D environment.
History:
10 Jun 2008 Extracted and adapted from Model3D class in JTwoD.java.
*/
import java.io.*;
/**
The representation of a 3D model. Used by JTwoD.
@see JTwoD
*/
class Java2DModel extends Model3D {
/**
Class for storing LineSegment data.
*/
static class LineSegment {
public final int m_p1, m_p2; // end points (indices into m_points)
public final int m_type;
LineSegment(int p1, int p2, int type)
{
m_p1 = p1;
m_p2 = p2;
m_type = type;
}
}
/**
Average x value (in model coordinates) for the figure.
*/
float m_xmean;
/**
Average y value (in model coordinates) for the figure.
*/
float m_ymean;
/**
Average z value (in model coordinates) for the figure.
*/
float m_zmean;
/**
Radius (in model coordinates) of the figure's bounding sphere.
*/
float m_radius;
/**
Untransformed (model) coordinates for all points.
*/
private tuple3d m_verts[];
/**
Size of used portion of vertex array.
*/
private int m_nverts;
/**
Minimum size of vertex and line arrays.
*/
static final int M_MIN_BUFFSIZE = 50;
/**
Lines in the model.
*/
private LineSegment m_lines[];
/**
Indicates how many of the values in m_lines are valid.
Incremented by addLine().
@see #m_lines
@see #addLine
*/
private int m_nlines;
Java2DModel() { }
/**
Zero vertex and line counts.
*/
public void reset()
{
m_nverts = 0;
m_nlines = 0;
}
/**
See how many vertices are in the current model -- can also be
used to check if a model has been loaded.
*/
int nverts() { return m_nverts; }
/**
Get vertices for the current model.
*/
tuple3d[] verts() { return m_verts; }
/**
See how many lines are in the current model.
*/
int nlines() { return m_nlines; }
/**
Index of first end point for given line.
*/
int p1(int index) { return m_lines[index].m_p1; }
/**
Index of second end point for given line.
*/
int p2(int index) { return m_lines[index].m_p2; }
/**
Type value for given line.
*/
int type(int index) { return m_lines[index].m_type; }
/**
Add a point to this model. Implements abstract method.
@param x x coordinate of point
@param y y coordinate of point
@param z z coordinate of point
*/
void addPoint(double x, double y, double z) {
if (m_verts == null) m_verts = new tuple3d[M_MIN_BUFFSIZE];
else if (m_nverts >= m_verts.length) {
tuple3d nv[] = new tuple3d[m_verts.length*2];
System.arraycopy(m_verts, 0, nv, 0, m_verts.length);
m_verts = nv;
}
if (m_verts[m_nverts] == null)
m_verts[m_nverts] = new tuple3d((float)x, (float)y, (float)z);
else m_verts[m_nverts].set((float)x, (float)y, (float)z);
m_nverts++;
}
/**
Add a line segment from vertex p1 to vertex p2 to the model's geometry.
Implements abstract method.
@param p1 zero-based index of first endpoint
@param p2 zero-based index of second endpoint
@param type type value for this line segment
*/
void addLineSegment(int p1, int p2, int type) {
if (p1 >= m_nverts || p2 >= m_nverts) return;
if (m_lines == null) m_lines = new LineSegment[M_MIN_BUFFSIZE];
else if (m_nlines >= m_lines.length) {
LineSegment lines[] = new LineSegment[m_lines.length*2];
System.arraycopy(m_lines, 0, lines, 0, m_lines.length);
m_lines = lines;
}
m_lines[m_nlines] = new LineSegment(p1, p2, type);
m_nlines++;
}
/**
Compute the bounding sphere (in model coordinates) of this model.
Implements abstract method.
@see #m_xmean
@see #m_ymean
@see #m_zmean
@see #m_radius
*/
void computeBoundingSphere() {
if (m_nverts <= 0) return;
// find center
m_xmean = 0f;
m_ymean = 0f;
m_zmean = 0f;
for (int i = 0; i < m_nverts; i++) {
m_xmean += m_verts[i].x();
m_ymean += m_verts[i].y();
m_zmean += m_verts[i].z();
}
m_xmean /= m_nverts;
m_ymean /= m_nverts;
m_zmean /= m_nverts;
// find radius
m_radius = 0;
for (int i = 0; i < m_nverts; i++) {
float dx = m_verts[i].x() - m_xmean;
float dy = m_verts[i].y() - m_ymean;
float dz = m_verts[i].z() - m_zmean;
float radius = dx*dx + dy*dy + dz*dz;
if (radius > m_radius) m_radius = radius;
}
m_radius = (float)Math.sqrt(m_radius);
}
}