private void aabbCompute() {
float minX = Integer.MAX_VALUE,
minY = Integer.MAX_VALUE,
maxX = Integer.MIN_VALUE,
maxY = Integer.MIN_VALUE;
for (final FloatArray polygon : polygons) {
float[] vertices = polygon.elements();
for (int vertexIndex = 0, vertexCount = polygon.size();
vertexIndex < vertexCount;
vertexIndex += 2) {
final float x = vertices[vertexIndex];
final float y = vertices[vertexIndex + 1];
minX = Math.min(minX, x);
minY = Math.min(minY, y);
maxX = Math.max(maxX, x);
maxY = Math.max(maxY, y);
}
}
this.minX = minX;
this.minY = minY;
this.maxX = maxX;
this.maxY = maxY;
}
/** Returns true if the polygon contains the line segment. */
public boolean intersectsSegment(
@Nonnull final FloatArray polygon,
final float x1,
final float y1,
final float x2,
final float y2) {
final float[] vertices = polygon.elements();
final int vertexCount = polygon.size();
float width12 = x1 - x2, height12 = y1 - y2;
float det1 = x1 * y2 - y1 * x2;
float x3 = vertices[vertexCount - 2], y3 = vertices[vertexCount - 1];
for (int vertexIndex = 0; vertexIndex < vertexCount; vertexIndex += 2) {
float x4 = vertices[vertexIndex], y4 = vertices[vertexIndex + 1];
float det2 = x3 * y4 - y3 * x4;
float width34 = x3 - x4, height34 = y3 - y4;
float det3 = width12 * height34 - height12 * width34;
float x = (det1 * width34 - width12 * det2) / det3;
if (((x >= x3 && x <= x4) || (x >= x4 && x <= x3))
&& ((x >= x1 && x <= x2) || (x >= x2 && x <= x1))) {
float y = (det1 * height34 - height12 * det2) / det3;
if (((y >= y3 && y <= y4) || (y >= y4 && y <= y3))
&& ((y >= y1 && y <= y2) || (y >= y2 && y <= y1))) return true;
}
x3 = x4;
y3 = y4;
}
return false;
}
public void update(Skeleton skeleton, boolean updateAabb) {
final Array<BoundingBoxAttachment> boundingBoxes = this.boundingBoxes;
final Array<FloatArray> polygons = this.polygons;
final Array<Slot> slots = skeleton.slots;
boundingBoxes.clear();
polygonPool.retAll(polygons);
polygons.clear();
for (final Slot slot : slots) {
final Attachment attachment = slot.attachment;
if (attachment instanceof BoundingBoxAttachment) {
final BoundingBoxAttachment boundingBox = (BoundingBoxAttachment) attachment;
boundingBoxes.push(boundingBox);
final FloatArray polygon = polygonPool.get();
polygons.push(polygon);
final int vertexCount = boundingBox.vertices().length;
polygon.size(vertexCount);
boundingBox.computeWorldVertices(slot.bone, polygon.elements());
}
}
if (updateAabb) {
aabbCompute();
}
}
/** Returns true if the polygon contains the point. */
public boolean containsPoint(@Nonnull final FloatArray polygon, final float x, final float y) {
final float[] vertices = polygon.elements();
final int vertexCount = polygon.size();
int prevIndex = vertexCount - 2;
boolean inside = false;
for (int vertexIndex = 0; vertexIndex < vertexCount; vertexIndex += 2) {
final float vertexY = vertices[vertexIndex + 1];
final float prevY = vertices[prevIndex + 1];
if ((vertexY < y && prevY >= y) || (prevY < y && vertexY >= y)) {
final float vertexX = vertices[vertexIndex];
if (vertexX + (y - vertexY) / (prevY - vertexY) * (vertices[prevIndex] - vertexX) < x) {
inside = !inside;
}
}
prevIndex = vertexIndex;
}
return inside;
}