load txt.file in meshlib demo
in
Contributed Library Questions
•
2 years ago
hello, i have a small problem.
i want to load a txt file with the coordinates of some points into
the meshlib demo from Lee Byron
txtfile with points:
2;6
100;3
20;2
120;233
10;31
I tried but failed to load the data. Things i added: "//_ ADDED:"
everytime i try i get a NullPointerException.
any suggestions? would be nice.
// MeshLibDemo.pde - Demo of Lee Byron's Mesh library for
// calculating and drawing Voronoi, Delaunay and Convex Hull
// diagrams.
// Uses a set of random points to calculate all
// three diagrams, with one point responding to the mouse
// position. Press space to reset points, press '1', '2' and
// '3' to toggle display of the different diagrams.
//
// The library is included in this sketch, see the "libraries"
// subfolder See
http://leebyron.com/else/mesh/ for more
// information about the library.
//
// Marius Watz -
http://workshop.evolutionzone.com/
import megamu.mesh.*;
Voronoi myVoronoi;
Delaunay myDelaunay;
Hull myHull;
float[][] points;
float[][] myEdges;
MPolygon myRegions[],myHullRegion;
int col[];
int index=0;// _ ADDED: FOR LOADING TXTFILE
String[] lines; // _ ADDED: FOR LOADING TXTFILE
float startX,startY,endX,endY;
float[][] regionCoordinates;
boolean showVoronoi=true;
boolean showDelaunay=false;
boolean showHull=false;
void setup() {
size(500,250);
// initialize points and calculate diagrams
initMesh();
smooth();
lines = loadStrings("list.txt"); // _ ADDED: FOR LOADING TXT.FILE
}
void draw() {
background(200);
if(myRegions==null) return;
// draw Voronoi
if(showVoronoi) {
strokeWeight(1);
stroke(0);
for(int i=0; i<myRegions.length; i++) {
fill(col[i]); // use random color for each region
regionCoordinates = myRegions[i].getCoords();
myRegions[i].draw(this); // draw this shape
}
}
// draw Voronoi as lines
if(showDelaunay) {
strokeWeight(2);
stroke(255,0,0);
for(int i=0; i<myEdges.length; i++) {
startX = myEdges[i][0];
startY = myEdges[i][1];
endX = myEdges[i][2];
endY = myEdges[i][3];
line(startX, startY, endX, endY);
}
}
// draw Hull in semi-transparent yellow
if(showHull) {
strokeWeight(1);
stroke(0);
fill(255,255,0, 150);
myHullRegion.draw(this);
}
}
void initMesh() {
// is points array is null then initialize it
if(points==null) initPoints();
// save the current number of regions, so that
// we can check if it's the same after the Voronoi
// has been recalculated.
int oldlength=0;
if(myRegions!=null) oldlength=myRegions.length;
myVoronoi = new Voronoi( points );
myHull = new Hull( points );
myDelaunay = new Delaunay( points );
myRegions = myVoronoi.getRegions();
myHullRegion = myHull.getRegion();
myEdges = myDelaunay.getEdges();
// if the number of regions is different than
// before then recalculate the random colors
if(oldlength!=myRegions.length) {
col=new int[myRegions.length];
for(int i=0; i<myRegions.length; i++) {
float prob=random(100);
if(prob>60) col[i]=color(random(30,100));
else col[i]=color(random(200,255));
}
col[0]=color(255,0,0);
}
}
void initPoints() {
/*
points = new float[(int)random(5,30)][2];
for(int i=0; i<points.length; i++) {
points[i][0] = random(width); // first point, x
points[i][1] = random(height); // first point, y
}
*/
// _ ADDED: TO LOAD POINTS FROM TXT.FILE
points = new float[lines.length][2];
if (index < lines.length) {
String[] pieces = split(lines[index], ';');
if (pieces.length == 2) {
points[index][0] = int(pieces[0]);
points[index][1] = int(pieces[1]);
}
// Go to the next line for the next run through draw()
index = index + 1;
}
}
void keyPressed() {
// reset points and mesh when spacebar is pressed
if(key==' ') {
initPoints();
initMesh();
}
// use keys '1'-'3' to toggle display
if(key=='1') showVoronoi=!showVoronoi;
if(key=='2') showDelaunay=!showDelaunay;
if(key=='3') showHull=!showHull;
}
void mouseMoved() {
// if myRegions is null then mesh is not ready
if(myRegions==null) return;
// set first point to mouse position and recalculate
points[0][0]=mouseX;
points[0][1]=mouseY;
initMesh();
}
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