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/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.badlogic.gdx.math;
public class Polyline implements Shape2D {
private float[] localVertices;
private float[] worldVertices;
private float x, y;
private float originX, originY;
private float rotation;
private float scaleX = 1, scaleY = 1;
private float length;
private float scaledLength;
private boolean calculateScaledLength = true;
private boolean calculateLength = true;
private boolean dirty = true;
private Rectangle bounds;
public Polyline () {
this.localVertices = new float[0];
}
public Polyline (float[] vertices) {
if (vertices.length < 4) throw new IllegalArgumentException("polylines must contain at least 2 points.");
this.localVertices = vertices;
}
/** Returns vertices without scaling or rotation and without being offset by the polyline position. */
public float[] getVertices () {
return localVertices;
}
/** Returns vertices scaled, rotated, and offset by the polygon position. */
public float[] getTransformedVertices () {
if (!dirty) return worldVertices;
dirty = false;
final float[] localVertices = this.localVertices;
if (worldVertices == null || worldVertices.length < localVertices.length) worldVertices = new float[localVertices.length];
final float[] worldVertices = this.worldVertices;
final float positionX = x;
final float positionY = y;
final float originX = this.originX;
final float originY = this.originY;
final float scaleX = this.scaleX;
final float scaleY = this.scaleY;
final boolean scale = scaleX != 1 || scaleY != 1;
final float rotation = this.rotation;
final float cos = MathUtils.cosDeg(rotation);
final float sin = MathUtils.sinDeg(rotation);
for (int i = 0, n = localVertices.length; i < n; i += 2) {
float x = localVertices[i] - originX;
float y = localVertices[i + 1] - originY;
// scale if needed
if (scale) {
x *= scaleX;
y *= scaleY;
}
// rotate if needed
if (rotation != 0) {
float oldX = x;
x = cos * x - sin * y;
y = sin * oldX + cos * y;
}
worldVertices[i] = positionX + x + originX;
worldVertices[i + 1] = positionY + y + originY;
}
return worldVertices;
}
/** Returns the euclidean length of the polyline without scaling */
public float getLength () {
if (!calculateLength) return length;
calculateLength = false;
length = 0;
for (int i = 0, n = localVertices.length - 2; i < n; i += 2) {
float x = localVertices[i + 2] - localVertices[i];
float y = localVertices[i + 1] - localVertices[i + 3];
length += (float)Math.sqrt(x * x + y * y);
}
return length;
}
/** Returns the euclidean length of the polyline */
public float getScaledLength () {
if (!calculateScaledLength) return scaledLength;
calculateScaledLength = false;
scaledLength = 0;
for (int i = 0, n = localVertices.length - 2; i < n; i += 2) {
float x = localVertices[i + 2] * scaleX - localVertices[i] * scaleX;
float y = localVertices[i + 1] * scaleY - localVertices[i + 3] * scaleY;
scaledLength += (float)Math.sqrt(x * x + y * y);
}
return scaledLength;
}
public float getX () {
return x;
}
public float getY () {
return y;
}
public float getOriginX () {
return originX;
}
public float getOriginY () {
return originY;
}
public float getRotation () {
return rotation;
}
public float getScaleX () {
return scaleX;
}
public float getScaleY () {
return scaleY;
}
public void setOrigin (float originX, float originY) {
this.originX = originX;
this.originY = originY;
dirty = true;
}
public void setPosition (float x, float y) {
this.x = x;
this.y = y;
dirty = true;
}
public void setVertices (float[] vertices) {
if (vertices.length < 4) throw new IllegalArgumentException("polylines must contain at least 2 points.");
this.localVertices = vertices;
dirty = true;
}
public void setRotation (float degrees) {
this.rotation = degrees;
dirty = true;
}
public void rotate (float degrees) {
rotation += degrees;
dirty = true;
}
public void setScale (float scaleX, float scaleY) {
this.scaleX = scaleX;
this.scaleY = scaleY;
dirty = true;
calculateScaledLength = true;
}
public void scale (float amount) {
this.scaleX += amount;
this.scaleY += amount;
dirty = true;
calculateScaledLength = true;
}
public void calculateLength () {
calculateLength = true;
}
public void calculateScaledLength () {
calculateScaledLength = true;
}
public void dirty () {
dirty = true;
}
public void translate (float x, float y) {
this.x += x;
this.y += y;
dirty = true;
}
/** Returns an axis-aligned bounding box of this polyline.
*
* Note the returned Rectangle is cached in this polyline, and will be reused if this Polyline is changed.
*
* @return this polyline's bounding box {@link Rectangle} */
public Rectangle getBoundingRectangle () {
float[] vertices = getTransformedVertices();
float minX = vertices[0];
float minY = vertices[1];
float maxX = vertices[0];
float maxY = vertices[1];
final int numFloats = vertices.length;
for (int i = 2; i < numFloats; i += 2) {
minX = minX > vertices[i] ? vertices[i] : minX;
minY = minY > vertices[i + 1] ? vertices[i + 1] : minY;
maxX = maxX < vertices[i] ? vertices[i] : maxX;
maxY = maxY < vertices[i + 1] ? vertices[i + 1] : maxY;
}
if (bounds == null) bounds = new Rectangle();
bounds.x = minX;
bounds.y = minY;
bounds.width = maxX - minX;
bounds.height = maxY - minY;
return bounds;
}
@Override
public boolean contains (Vector2 point) {
return false;
}
@Override
public boolean contains (float x, float y) {
return false;
}
}