2019独角兽企业重金招聘Python工程师标准>>> 
上图红色路径即为贝塞尔曲线的路线。
核心思路：
获取贝塞尔曲线上的所有的点，然后通过ShapeRenderer画线即可。
代码展示：
package com.oahcfly.chgame.core.ui;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer.ShapeType;
import com.badlogic.gdx.math.Bezier;
import com.badlogic.gdx.math.Vector2;
import com.oahcfly.chgame.core.mvc.CHActor;
/**
*
* 贝塞尔路线 : 使用ShapeRenderer绘制
* @author haocao
*
*/
public class CHBezierLine extends CHActor {
// 以左上角为原点进行绘制的
private ShapeRenderer shapeRenderer;
private Bezier bezier;
// 点列表
private Vector2[] points;
// 线条颜色
private Color lineColor = Color.RED;
public CHBezierLine (Bezier bezier) {
this(bezier, Color.RED);
}
public CHBezierLine (Bezier bezier, Color lineColor) {
updateBezier(bezier);
this.lineColor = lineColor;
shapeRenderer = new ShapeRenderer();
shapeRenderer.setAutoShapeType(true);
}
/**
* 更新贝塞尔曲线参数
* @param bezier
*/
public void updateBezier (Bezier bezier) {
this.bezier = bezier;
// 计算所有点
int dis = (int)(this.bezier.points.get(this.bezier.points.size - 1).x - this.bezier.points.get(0).x);
if (dis == 0) {
dis = (int)(this.bezier.points.get(this.bezier.points.size - 1).y - this.bezier.points.get(0).y);
}
points = new Vector2[dis];
for (int i = 0; i < dis; i++) {
float t = i * 1f / dis;
Vector2 out = new Vector2();
this.bezier.valueAt(out, t);
points[i] = out;
}
}
@Override
public void draw (Batch batch, float parentAlpha) {
batch.flush();
// 设置用于渲染的投影矩阵
getStage().getCamera().update();
shapeRenderer.setProjectionMatrix(getStage().getCamera().combined);
shapeRenderer.begin(ShapeType.Line);
shapeRenderer.setColor(this.lineColor);
for (int i = 0, l = points.length - 1; i < l; i++) {
Vector2 cur = points[i];
Vector2 next = points[i + 1];
shapeRenderer.line(cur, next);
}
shapeRenderer.end();
// 结束本次绘制
batch.end();
// 重新开始新的
batch.begin();
}
@Override
public boolean remove () {
// TODO Auto-generated method stub
shapeRenderer.dispose();
return super.remove();
}
} 关联代码：
package com.oahcfly.chgame.core.mvc;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.TextureAtlas.AtlasRegion;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.utils.Align;
import com.badlogic.gdx.utils.Array;
import com.badlogic.gdx.utils.Pool;
import com.badlogic.gdx.utils.Pool.Poolable;
import com.badlogic.gdx.utils.Pools;
import com.oahcfly.chgame.core.Chao;
/**
* 二次封装的actor
*
* date: 2014-12-11
*
*
* @author caohao */
public class CHActor extends Actor implements Poolable {
private int tag;
private Texture bgTexture;
private TextureRegion bgTextureRegion;
private Sprite sprite;
public CHActor () {
}
/**
* 绑定一个精灵，此时CHActor的属性会同步到精灵上。
* @param sprite
*/
public void bindSprite (Sprite sprite) {
this.sprite = sprite;
setSize(this.sprite.getWidth(), this.sprite.getHeight());
setOrigin(Align.center);
}
@Override
public void draw (Batch batch, float parentAlpha) {
if (clipRectangleArr.size > 0) {
for (Rectangle cRectangle : clipRectangleArr) {
this.drawCore(batch, parentAlpha, cRectangle);
}
} else {
this.drawCore(batch, parentAlpha, null);
}
}
/**
* 核心绘制
* @param batch
* @param parentAlpha
* @param clipRectangle
*/
private void drawCore (Batch batch, float parentAlpha, Rectangle clipRectangle) {
boolean clipok = false;
// 开始裁剪
if (clipRectangle != null) {
batch.flush(); // 绘制之前添加的元素，如果不添加此处代码，后面的裁剪会导致之前的纹理也会被裁剪
clipok = clipBegin(getX() + clipRectangle.x, getY() + clipRectangle.y, clipRectangle.width, clipRectangle.height);
}
Color color = getColor();
batch.setColor(color.r, color.g, color.b, color.a);
float x = getX();
float y = getY();
float scaleX = getScaleX();
float scaleY = getScaleY();
float width = getWidth();
float height = getHeight();
if (bgTexture != null) {
batch.draw(bgTexture, x, y, getOriginX(), getOriginY(), getWidth(), getHeight(), scaleX, scaleY, getRotation(), 0, 0,
(int)width, (int)height, false, false);
}
if (bgTextureRegion != null) {
if (bgTextureRegion instanceof Sprite) {
Sprite sprite = (Sprite)bgTextureRegion;
sprite.setColor(batch.getColor());
sprite.setOrigin(getOriginX(), getOriginY());
sprite.setPosition(x, y);
sprite.setScale(scaleX, scaleY);
sprite.setSize(width, height);
sprite.setRotation(getRotation());
sprite.draw(batch);
} else {
batch.draw(bgTextureRegion, x, y, getOriginX(), getOriginY(), width, height, scaleX, scaleY, getRotation());
}
}
if (sprite != null) {
sprite.setColor(color);
sprite.setOrigin(getOriginX(), getOriginY());
sprite.setPosition(x, y);
sprite.setScale(scaleX, scaleY);
sprite.setSize(width, height);
sprite.setRotation(getRotation());
sprite.draw(batch);
}
// 绘制完背景后进行其他内容绘制
drawAfterBg(batch);
// 提交裁剪内容
if (clipok) {
batch.flush();
clipEnd();
}
}
public void drawAfterBg (Batch batch) {
};
public void setBgTexture (Texture bgTexture) {
this.bgTexture = bgTexture;
if (bgTexture != null) {
setSize(bgTexture.getWidth(), bgTexture.getHeight());
}
setOrigin(Align.center);
}
/**
* 使用缓存池
*
* date: 2015-1-3
*
*
* @author caohao
* @return */
@SuppressWarnings("unchecked")
public static T obtain (Class type) {
Pool pool = (Pool)Pools.get(type);
CHActor actor = pool.obtain();
actor.setBgTexture(null);
return (T)actor;
}
public static CHActor obtain () {
return obtain(CHActor.class);
}
@Override
public void reset () {
this.bgTexture = null;
this.bgTextureRegion = null;
clipRectangleArr.clear();
setScale(1);
setRotation(0);
clear();
setUserObject(null);
this.setColor(new Color(1, 1, 1, 1));
setStage(null);
setParent(null);
setVisible(true);
setName(null);
setOrigin(Align.center);
setPosition(0, 0);
}
public Texture getBgTexture () {
return bgTexture;
}
public TextureRegion getBgTextureRegion () {
return bgTextureRegion;
}
public void setBgTextureRegion (TextureRegion textureRegion) {
this.bgTextureRegion = textureRegion;
if (bgTextureRegion != null) {
if (bgTextureRegion instanceof Sprite) {
Sprite sprite = (Sprite)bgTextureRegion;
setSize(sprite.getWidth(), sprite.getHeight());
} else if (bgTextureRegion instanceof AtlasRegion) {
AtlasRegion atlasRegion = (AtlasRegion)bgTextureRegion;
bgTextureRegion = Chao.plistCenter.createSprite(atlasRegion);
Sprite sprite = (Sprite)bgTextureRegion;
setSize(sprite.getWidth(), sprite.getHeight());
} else {
setSize(bgTextureRegion.getRegionWidth(), bgTextureRegion.getRegionHeight());
}
}
setOrigin(Align.center);
}
@Override
public boolean remove () {
boolean remove = super.remove();
if (remove) {
Pools.free(this);
}
return remove;
}
public int getTag () {
return tag;
}
public void setTag (int tag) {
this.tag = tag;
}
private Array clipRectangleArr = new Array();
/**
* 添加裁剪矩形，范围为当前Actor的显示区域即：(0,0)~(w,h) 左下角
* @param rectangle
*/
public void addClipRectangle (Rectangle rectangle) {
clipRectangleArr.add(rectangle);
}
public Sprite getSprite () {
return sprite;
}
private Rectangle boundsRectangle;
@Override
protected void sizeChanged () {
if (boundsRectangle == null) {
boundsRectangle = new Rectangle();
}
boundsRectangle.width = getWidth();
boundsRectangle.height = getHeight();
}
/**
* 用于碰撞检测的矩形区域
* @return
*/
public Rectangle getBoundsRectangle () {
boundsRectangle.x = getX();
boundsRectangle.y = getY();
return boundsRectangle;
}
} 基于Libgdx开发的开源游戏框架CHGame：
http://git.oschina.net/oahcfly/CHGameFrame