So my goal is to draw a spline similar to this one (where the line goes through each point):
But the spline loops around (from the end point 2 back to the start point):
I tried changing the "continuous" boolean in the catmullromspline, but that resulted in only a dot being drawn in the center of the screen.
I also ended the line drawing when it hit the last point, but the result was ugly because the line was still curving at the start and end points.
I looked everywhere in the source code, and could not find a function that could prevent it from looping.
And as far as i know, bezier splines don't go through all the points (they only pass near them).
So what should I do?
Here's my code:
...
public class GameScreen implements Screen {
final game game;
float w=800;
float h=480;
OrthographicCamera camera;
long startTime;
Texture baseTexture=new Texture(Gdx.files.internal("white.png"));
public GameScreen(final game gam) {
this.game = gam;
startTime = TimeUtils.millis();
camera = new OrthographicCamera();
camera.setToOrtho(false, w, h);
setup();
}
//https://github.com/libgdx/libgdx/wiki/Path-interface-&-Splines
int k = 10000; //increase k for more fidelity to the spline
Vector2[] points = new Vector2[k];
Vector2 cp[] = new Vector2[]{
new Vector2(w/2, h), new Vector2(w/2, h/2),new Vector2(50, 50)
};
ShapeRenderer rope=new ShapeRenderer();
public void setup(){
CatmullRomSpline<Vector2> myCatmull = new CatmullRomSpline<Vector2>( cp, true);
for(int i = 0; i < k; ++i)
{
points[i] = new Vector2();
myCatmull.valueAt(points[i], ((float)i)/((float)k-1));
}
}
@Override
public void render(float delta) {
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
Gdx.gl20.glLineWidth(50);
game.batch.begin();
rope.setAutoShapeType(true);
rope.begin();
for(int i = 0; i < k-1; ++i)
{
//rope.line(points[i], points[i+1]);
//shaper.line(myCatmull.valueAt(points[i], ((float)i)/((float)k-1)), myCatmull.valueAt(points[i+1], ((float)i)/((float)k-1)));
game.batch.draw(baseTexture, points[i].x, points[i].y, 5, 5);
}
rope.end();
for(int i=0;i<cp.length;i++){//draw the location of each point
game.font.draw(game.batch, "point "+i, cp[i].x, cp[i].y);
}
//logging systems
for(int i=0;i<20;i++){
if(Gdx.input.isTouched(i))
game.font.draw(game.batch, "x:"+Gdx.input.getX(i)+" y:"+Gdx.input.getY(i), 0, (game.font.getCapHeight()+10)*(i+1));
}
game.font.draw(game.batch, "fps:"+Gdx.graphics.getFramesPerSecond()+" log:"+log, 0, h-game.font.getCapHeight());
game.batch.end();
}
...
来源:https://stackoverflow.com/questions/29198881/drawing-a-catmullromspline-in-libgdx-with-an-endpoint-and-startpoint