/************************************************************************
* Object2D.js
************************************************************************
* Copyright (c) 2021 Pedro Tonini Rosenberg Schneider.
*
* This file is part of Pandora.
*
* Pandora is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Pandora is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Pandora. If not, see <https://www.gnu.org/licenses/>.
*************************************************************************/
/**
* The {@code Object2D} class represents a GameObject that has a transform,
* comprised of a position, a rotation in degrees and a scale. All parameters
* of this transform are relative to the parent of this GameObject, if it has one.
*
* ! All GameObjects need to be inside the tree to do anything (can be added as a child
* ! of another GameObject on the tree or as a root).
*
* @author Pedro Schneider
*
* @class
*/
class Object2D extends GameObject
{
/**
* Initializes an empty Object2D GameObject.
*
* @param {String} name name of the Object2D GameObject.
*
* @constructor
*/
constructor(name)
{
super(name);
this.position = Vector2.ZERO(); // This Object2D's position on the secondary buffer.
this.rotationDegrees = 0; // This Object2D's rotation degrees on the secondary buffer.
this.scale = Vector2.ONE(); // This Object2D's scale on the secondary buffer.
this.visible = true; // Is this Object2D visible at the moment?
this.globalPosition = Vector2.ZERO(); // This Object2D's global position on the secondary buffer.
this.globalRotationDegrees = 0; // This Object2D's global rotation degrees on the secondary buffer.
this.globalScale = Vector2.ONE(); // This Object2D's global scale on the secondary buffer.
}
/**
* Sets this Object2D's position.
*
* @param {number} x new position on the x axis for this Object2D.
* @param {number} y new positoin on the y axis for this Object2D.
*/
setPosition(x, y)
{
this.position.x = x;
this.position.y = y;
}
/**
* Sets the visibility flag of this Object2D and all of its children
* that have a visibility flag to true.
*/
show()
{
this.visible = true;
for (let i = 0; i < this.children.length; i++)
{
if (!this.children[i].show) continue;
this.children[i].show();
}
}
/**
* Sets the visibility flag of this Object2D and all of its children
* that have a visibility flag to false.
*/
hide()
{
this.visible = false;
for (let i = 0; i < this.children.length; i++)
{
if (!this.children[i].hide) continue;
this.children[i].hide();
}
}
/**
* Sets the visibility flag of this Object2D and all of its children that have a visibility
* flag to the provided value.
*
* @param {boolean} val value to set the flag to.
*/
setVisibility(val)
{
this.visible = val;
for (let i = 0; i < this.children.length; i++)
{
if (!this.children[i].setVisibility) continue;
this.children[i].setVisibility(val);
}
}
/**
* Returns this Object2D's visibility flag.
*
* @returns {boolean} true if this Object2D is visible, false if not.
*/
getVisibility()
{
return this.visible;
}
/**
* Translates this Object2D by (x, y).
*
* @param {number} x X-axis translation.
* @param {number} y Y-axis translation.
*/
translate(x, y)
{
this.position.x += x;
this.position.y += y;
}
/**
* Rotates this Object2D by a degrees.
*
* @param {number} a rotation in degrees.
*/
rotate(a)
{
this.rotationDegrees += a;
}
/**
* Scales this Object2D by (x, y).
*
* @param {number} x X-axis scale.
* @param {number} y Y-axis scale.
*/
addScale(x, y)
{
this.scale.x *= x;
this.scale.y *= y;
}
/**
* Updates this Object2D's global transform.
*
* ! This method only exists to modularize the code, and should not be used by the user.
*/
udpateGlobalTransform()
{
if (!this.parented || !(this.parent instanceof Object2D))
{
this.globalPosition = this.position;
this.globalRotationDegrees = this.rotationDegrees;
this.globalScale = this.scale;
}
else
{
this.globalPosition.x = this.parent.globalPosition.x + this.position.x;
this.globalPosition.y = this.parent.globalPosition.y + this.position.y;
this.globalRotationDegrees = this.parent.globalRotationDegrees + this.rotationDegrees;
this.globalScale.x = this.parent.globalScale.x * this.scale.x;
this.globalScale.y = this.parent.globalScale.y * this.scale.y;
}
}
/**
* Updates this Object2D's global transform and recursively calls the _update(delta)
* callback for this GameObject and all of it's children.
*
* @param {number} delta number of ellapsed seconds since the last frame.
*
* @override
*/
update(delta)
{
this.udpateGlobalTransform();
this.updateChildren(delta);
}
/**
* Apply this Object2D's transform to the secondary buffer.
*
* ! This method only exists to modularize the code, and should not be used by the user.
*
* @param {p5.Graphics} db secondary buffer to draw to.
*/
applyTransform(db)
{
db.translate(this.position.x, this.position.y);
db.rotate(this.rotationDegrees / 180 * PI);
db.scale(this.scale.x, this.scale.y);
}
/**
* Applies this Object2D's transform before calling this GameObject's _draw() callback
* and recursively calls the same callback on all of it's children. This results in the
* appearence of relative position.
*
* @param {number} delta number of seconds ellapsed since the last frame.
* @param {p5.Graphics} db secondary buffer to draw to.
*
* @override
*/
draw(delta, db)
{
if (!this.visible) return;
db.push();
this.applyTransform(db);
this.drawChildren(delta, db);
db.pop()
}
}