Java 如何在libgdx中将触摸坐标转换为本地对象坐标?
我想将用户触摸时接收到的点坐标转换为本地对象坐标 触地时,我得到屏幕坐标中的(x,y):Java 如何在libgdx中将触摸坐标转换为本地对象坐标?,java,android,libgdx,transformation,Java,Android,Libgdx,Transformation,我想将用户触摸时接收到的点坐标转换为本地对象坐标 触地时,我得到屏幕坐标中的(x,y): left-top=(0,0), bottom-right=(SCREEN_WIDTH,SCREEN_HEIGHT). 然后我做camera.unproject(…)并在世界坐标(视口)中获取(x,y),但我不知道如何将获取的点转换为局部对象坐标。我尝试了一些操作(请参见MyRect.unproject(..))中的注释),但都不起作用 public class MyLibgdxGame extends G
left-top=(0,0), bottom-right=(SCREEN_WIDTH,SCREEN_HEIGHT).
然后我做camera.unproject(…)
并在世界坐标(视口)中获取(x,y),但我不知道如何将获取的点转换为局部对象坐标。我尝试了一些操作(请参见MyRect.unproject(..)
)中的注释),但都不起作用
public class MyLibgdxGame extends Game implements InputProcessor {
private MyRect obj;
...
public void render() {
camera.update();
Gdx.gl.glClearColor(.1f,.1f,.1f,1);
Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
renderer.setProjectionMatrix(camera.combined);
renderer.begin(ShapeRenderer.ShapeType.Line);
renderer.setColor(Color.GREEN);
renderer.line(0,0, 0, 30);
renderer.setColor(Color.BLUE);
renderer.line(0,0, 30, 0);
renderer.end();
obj.render(renderer);
}
public void resize(int width, int height) {
float units = 100f;
float aspectRatio = (float) width / (float) height;
camera = new OrthographicCamera(units * aspectRatio, units);
camera.update();
}
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
Gdx.app.log("my", String.format("[Touch] x: %d, y: %d", screenX, screenY));
Vector3 v = new Vector3(screenX, screenY, 0);
camera.unproject(v);
Gdx.app.log("my", String.format("[S to VP] x: %.1f, y: %.1f", v.x, v.y));
// !! convert world coordinate "v" to local object coordinate
obj.unproject(v);
Gdx.app.log("my", String.format("[VP to Object] x: %.1f, y: %.1f", v.x, v.y));
return false;
}
...
}
public class MyRect {
private Rectangle rect;
private float angle;
private Matrix4 transform;
public MyRect(float x, float y, float w, float h, float angle) {
this.rect = new Rectangle(x, y, w, h);
this.angle = angle;
transform = new Matrix4().translate(x,y,0).rotate(0,0,1,angle);
}
public void render(ShapeRenderer renderer) {
renderer.identity();
renderer.setTransformMatrix(transform);
renderer.begin(ShapeRenderer.ShapeType.Rectangle);
renderer.setColor(Color.RED);
renderer.rect(0, 0, rect.width, rect.height);
renderer.end();
r.begin(ShapeRenderer.ShapeType.Line);
r.setColor(Color.GREEN);
r.line(0,0, 0, 30);
r.setColor(Color.BLUE);
r.line(0,0, 30, 0);
r.end();
renderer.identity();
}
public Vector3 unproject(Vector3 v) {
// return v.mul(transform); // 1
// return v.prj(transform); // 2
return v.rotate(0,0,1,angle).sub(new Vector3(rect.x, rect.y, 0)); //3
}
}
最快的方法是使用
MyRect
扩展Actor
并使用Actor.stageToLocalCoordinates()
。如果您不想子类化Actor
,请获取libgdx源代码并查看上述方法
你完全弄错了
camera.unproject(v);
Gdx.app.log("my", String.format("[S to VP] x: %.1f, y: %.1f", v.x, v.y));
// !! convert world coordinate "v" to local object coordinate
obj.unproject(v);
Gdx.app.log("my", String.format("[VP to Object] x: %.1f, y: %.1f", v.x, v.y));
你说的“局部坐标”是摄像机坐标。当您取消投影触摸时,您将屏幕坐标转换为相机坐标。但你想要的是世界坐标。不需要取消对象的投影,因为这样会得到一个无用的向量。只需将相机坐标转换为世界坐标,然后使用以下坐标:
camera.unproject(v);
Gdx.app.log("my", String.format("[S to VP] x: %.1f, y: %.1f", v.x, v.y));
x = camera.position.x-camera.viewportWidth+v.x;
y = camera.position.y-camera.viewportHeight+v.y;