/**
* @param group an empty group to be the parent
* @return the group with the current selection
*/
public Group createGroup(Group group) {
// New group has the same transformation as this
group.setBounds(getX(), getY(), getWidth(), getHeight());
group.setOrigin(getOriginX(), getOriginY());
group.setRotation(getRotation());
group.setScale(getScaleX(), getScaleY());
// Each children in the group must be contained by the new group
Array<Actor> children = getChildren();
children.sort(
new Comparator<Actor>() {
@Override
public int compare(Actor actor, Actor actor2) {
return ((SelectionGhost) actor).getRepresentedActor().getZIndex()
- ((SelectionGhost) actor2).getRepresentedActor().getZIndex();
}
});
for (Actor actor : children) {
SelectionGhost ghost = (SelectionGhost) actor;
Actor representedActor = ghost.getRepresentedActor();
representedActor.setPosition(ghost.getX(), ghost.getY());
representedActor.setRotation(ghost.getRotation());
representedActor.setScale(ghost.getScaleX(), ghost.getScaleY());
group.addActor(representedActor);
}
return group;
}
/** Sets position, rotation, scale and origin in actor to meet the 3 given points */
public static void applyTransformation(
Actor actor, Vector2 origin, Vector2 tangent, Vector2 normal) {
/*
* We are going to calculate the affine transformation for the actor to
* fit the bounds represented by the handles. The affine transformation
* is defined as follows:
*/
// |a b tx|
// |c d ty|=|Translation Matrix| x |Scale Matrix| x |Rotation
// Matrix|
// |0 0 1 |
/*
* More info about affine transformations:
* https://people.gnome.org/~mathieu
* /libart/libart-affine-transformation-matrices.html, To obtain the
* matrix, we want to resolve the following equation system:
*/
// | a b tx| |0| |o.x|
// | c d ty|*|0|=|o.y|
// | 0 0 1 | |1| | 1 |
//
// | a b tx| |w| |t.x|
// | c d ty|*|0|=|t.y|
// | 0 0 1 | |1| | 1 |
//
// | a b tx| |0| |n.x|
// | c d ty|*|h|=|n.y|
// | 0 0 1 | |1| | 1 |
/*
* where o is handles[0] (origin), t is handles[2] (tangent) and n is
* handles[6] (normal), w is actor.getWidth() and h is
* actor.getHeight().
*
* This matrix defines that the 3 points defining actor bounds are
* transformed to the 3 points defining modifier bounds. E.g., we want
* that actor origin (0,0) is transformed to (handles[0].x,
* handles[0].y), and that is expressed in the first equation.
*
* Resolving these equations is obtained:
*/
// a = (t.x - o.y) / w
// b = (t.y - o.y) / w
// c = (n.x - o.x) / h
// d = (n.y - o.y) / h
/*
* Values for translation, scale and rotation contained by the matrix
* can be obtained directly making operations over a, b, c and d:
*/
// tx = o.x
// ty = o.y
// sx = sqrt(a^2+b^2)
// sy = sqrt(c^2+d^2)
// rotation = atan(c/d)
// or
// rotation = atan(-b/a)
/*
* Rotation can give two different values (this happens when there is
* more than one way of obtaining the same transformation). To avoid
* that, we ignore the rotation to obtain the final values.
*/
Vector2 tmp1 = Pools.obtain(Vector2.class);
Vector2 tmp2 = Pools.obtain(Vector2.class);
Vector2 tmp3 = Pools.obtain(Vector2.class);
Vector2 tmp4 = Pools.obtain(Vector2.class);
Vector2 tmp5 = Pools.obtain(Vector2.class);
Vector2 o = tmp1.set(origin.x, origin.y);
Vector2 t = tmp2.set(tangent.x, tangent.y);
Vector2 n = tmp3.set(normal.x, normal.y);
Vector2 vt = tmp4.set(t).sub(o);
Vector2 vn = tmp5.set(n).sub(o);
// Ignore rotation
float rotation = actor.getRotation();
vt.rotate(-rotation);
vn.rotate(-rotation);
t.set(vt).add(o);
n.set(vn).add(o);
Vector2 bottomLeft = Pools.obtain(Vector2.class);
Vector2 size = Pools.obtain(Vector2.class);
calculateBounds(actor, bottomLeft, size);
float a = (t.x - o.x) / size.x;
float c = (t.y - o.y) / size.x;
float b = (n.x - o.x) / size.y;
float d = (n.y - o.y) / size.y;
Pools.free(tmp1);
Pools.free(tmp2);
Pools.free(tmp3);
Pools.free(tmp4);
Pools.free(tmp5);
Pools.free(bottomLeft);
Pools.free(size);
// Math.sqrt gives a positive value, but it also have a negatives.
// The
// signum is calculated computing the current rotation
float signumX = vt.angle() > 90.0f && vt.angle() < 270.0f ? -1.0f : 1.0f;
float signumY = vn.angle() > 180.0f ? -1.0f : 1.0f;
float scaleX = (float) Math.sqrt(a * a + b * b) * signumX;
float scaleY = (float) Math.sqrt(c * c + d * d) * signumY;
actor.setScale(scaleX, scaleY);
/*
* To obtain the correct translation value we need to subtract the
* amount of translation due to the origin.
*/
tmpMatrix.setToTranslation(actor.getOriginX(), actor.getOriginY());
tmpMatrix.rotate(actor.getRotation());
tmpMatrix.scale(actor.getScaleX(), actor.getScaleY());
tmpMatrix.translate(-actor.getOriginX(), -actor.getOriginY());
/*
* Now, the matrix has how much translation is due to the origin
* involved in the rotation and scaling operations
*/
float x = o.x - tmpMatrix.getValues()[Matrix3.M02];
float y = o.y - tmpMatrix.getValues()[Matrix3.M12];
actor.setPosition(x, y);
}
@Override
public void render() {
Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
Gdx.gl.glClearColor(0.2f, 0.2f, 0.2f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
if (Gdx.input.isTouched()) {
stage.screenToStageCoordinates(stageCoords.set(Gdx.input.getX(), Gdx.input.getY()));
Actor actor = stage.hit(stageCoords.x, stageCoords.y, true);
if (actor != null)
actor.setColor(
(float) Math.random(),
(float) Math.random(),
(float) Math.random(),
0.5f + 0.5f * (float) Math.random());
}
Array<Actor> actors = stage.getActors();
int len = actors.size;
if (rotateSprites) {
for (int i = 0; i < len; i++) actors.get(i).rotateBy(Gdx.graphics.getDeltaTime() * 10);
}
scale += vScale * Gdx.graphics.getDeltaTime();
if (scale > 1) {
scale = 1;
vScale = -vScale;
}
if (scale < 0.5f) {
scale = 0.5f;
vScale = -vScale;
}
len = sprites.size;
for (int i = 0; i < len; i++) {
Actor sprite = sprites.get(i);
if (rotateSprites) sprite.rotateBy(-40 * Gdx.graphics.getDeltaTime());
else sprite.setRotation(0);
if (scaleSprites) {
sprite.setScale(scale);
} else {
sprite.setScale(1);
}
}
stage.draw();
renderer.begin(ShapeType.Point);
renderer.setColor(1, 0, 0, 1);
len = actors.size;
for (int i = 0; i < len; i++) {
Group group = (Group) actors.get(i);
renderer.point(group.getX() + group.getOriginX(), group.getY() + group.getOriginY(), 0);
}
renderer.end();
fps.setText(
"fps: "
+ Gdx.graphics.getFramesPerSecond()
+ ", actors "
+ sprites.size
+ ", groups "
+ sprites.size);
ui.draw();
}