/**
* Compute the bounding screen extent of a rotated rectangle.
*
* @param rect Rectangle to rotate.
* @param x X coordinate of the rotation point.
* @param y Y coordinate of the rotation point.
* @param rotation Rotation angle.
* @return The smallest rectangle that completely contains {@code rect} when rotated by the
* specified angle.
*/
protected Rectangle computeRotatedScreenExtent(Rectangle rect, int x, int y, Angle rotation) {
Rectangle r = new Rectangle(rect);
// Translate the rectangle to the rotation point.
r.translate(-x, -y);
// Compute corner points
Vec4[] corners = {
new Vec4(r.getMaxX(), r.getMaxY()),
new Vec4(r.getMaxX(), r.getMinY()),
new Vec4(r.getMinX(), r.getMaxY()),
new Vec4(r.getMinX(), r.getMinY())
};
// Rotate the rectangle
Matrix rotationMatrix = Matrix.fromRotationZ(rotation);
for (int i = 0; i < corners.length; i++) {
corners[i] = corners[i].transformBy3(rotationMatrix);
}
// Find the bounding rectangle of rotated points.
int minX = Integer.MAX_VALUE;
int minY = Integer.MAX_VALUE;
int maxX = -Integer.MAX_VALUE;
int maxY = -Integer.MAX_VALUE;
for (Vec4 v : corners) {
if (v.x > maxX) maxX = (int) v.x;
if (v.x < minX) minX = (int) v.x;
if (v.y > maxY) maxY = (int) v.y;
if (v.y < minY) minY = (int) v.y;
}
// Set bounds and translate the rectangle back to where it started.
r.setBounds(minX, minY, maxX - minX, maxY - minY);
r.translate(x, y);
return r;
}
/**
* Indicates the transform matrix applied to this document.
*
* @return Transform matrix.
*/
protected Matrix getMatrix() {
// If the matrix has already been computed then just return the cached value.
if (this.matrix != null) return this.matrix;
Matrix m = Matrix.IDENTITY;
if (this.heading != null)
m = m.multiply(Matrix.fromRotationZ(Angle.POS360.subtract(this.heading)));
if (this.pitch != null) m = m.multiply(Matrix.fromRotationX(this.pitch));
if (this.roll != null) m = m.multiply(Matrix.fromRotationY(this.roll));
// Apply scaling factor to convert file units to meters.
double scale = this.getScale();
m = m.multiply(Matrix.fromScale(scale));
if (this.modelScale != null) m = m.multiply(Matrix.fromScale(this.modelScale));
this.matrix = m;
return m;
}
/**
* Compute the label's screen position from its geographic position.
*
* @param dc Current draw context.
*/
protected void computeGeometry(DrawContext dc) {
// Project the label position onto the viewport
Position pos = this.getPosition();
if (pos == null) return;
this.placePoint = dc.computeTerrainPoint(pos.getLatitude(), pos.getLongitude(), 0);
this.screenPlacePoint = dc.getView().project(this.placePoint);
this.eyeDistance = this.placePoint.distanceTo3(dc.getView().getEyePoint());
boolean orientationReversed = false;
if (this.orientationPosition != null) {
// Project the orientation point onto the screen
Vec4 orientationPlacePoint =
dc.computeTerrainPoint(
this.orientationPosition.getLatitude(), this.orientationPosition.getLongitude(), 0);
Vec4 orientationScreenPoint = dc.getView().project(orientationPlacePoint);
this.rotation = this.computeRotation(this.screenPlacePoint, orientationScreenPoint);
// The orientation is reversed if the orientation point falls to the right of the screen
// point. Text is
// never drawn upside down, so when the orientation is reversed the text flips vertically to
// keep the text
// right side up.
orientationReversed = (orientationScreenPoint.x <= this.screenPlacePoint.x);
}
this.computeBoundsIfNeeded(dc);
Offset offset = this.getOffset();
Point2D offsetPoint =
offset.computeOffset(this.bounds.getWidth(), this.bounds.getHeight(), null, null);
// If a rotation is applied to the text, then rotate the offset as well. An offset in the x
// direction
// will move the text along the orientation line, and a offset in the y direction will move the
// text
// perpendicular to the orientation line.
if (this.rotation != null) {
double dy = offsetPoint.getY();
// If the orientation is reversed we need to adjust the vertical offset to compensate for the
// flipped
// text. For example, if the offset normally aligns the top of the text with the place point
// then without
// this adjustment the bottom of the text would align with the place point when the
// orientation is
// reversed.
if (orientationReversed) {
dy = -(dy + this.bounds.getHeight());
}
Vec4 pOffset = new Vec4(offsetPoint.getX(), dy);
Matrix rot = Matrix.fromRotationZ(this.rotation.multiply(-1));
pOffset = pOffset.transformBy3(rot);
offsetPoint = new Point((int) pOffset.getX(), (int) pOffset.getY());
}
int x = (int) (this.screenPlacePoint.x + offsetPoint.getX());
int y = (int) (this.screenPlacePoint.y - offsetPoint.getY());
this.screenPoint = new Point(x, y);
this.screenExtent = this.computeTextExtent(x, y, this.rotation);
}