/**
* Compute the bounds of the text, if necessary.
*
* @param dc the current DrawContext.
*/
protected void computeBoundsIfNeeded(DrawContext dc) {
// Do not compute bounds if they are available. Computing text bounds is expensive, so only do
// this
// calculation if necessary.
if (this.bounds != null) return;
TextRenderer textRenderer =
OGLTextRenderer.getOrCreateTextRenderer(dc.getTextRendererCache(), this.getFont());
int width = 0;
int maxLineHeight = 0;
this.lineBounds = new Rectangle2D[this.lines.length];
for (int i = 0; i < this.lines.length; i++) {
Rectangle2D lineBounds = textRenderer.getBounds(lines[i]);
width = (int) Math.max(lineBounds.getWidth(), width);
double thisLineHeight = Math.abs(lineBounds.getY());
maxLineHeight = (int) Math.max(thisLineHeight, maxLineHeight);
this.lineBounds[i] = lineBounds;
}
this.lineHeight = maxLineHeight;
// Compute final height using maxLineHeight and number of lines
this.bounds =
new Rectangle(
this.lines.length,
maxLineHeight,
width,
this.lines.length * maxLineHeight + this.lines.length * this.lineSpacing);
}
/**
* Compute the amount of rotation to apply to a label in order to keep it oriented toward its
* orientation position.
*
* @param screenPoint Geographic position of the text, projected onto the screen.
* @param orientationScreenPoint Orientation position, projected onto the screen.
* @return The rotation angle to apply when drawing the label.
*/
protected Angle computeRotation(Vec4 screenPoint, Vec4 orientationScreenPoint) {
// Determine delta between the orientation position and the label position
double deltaX = screenPoint.x - orientationScreenPoint.x;
double deltaY = screenPoint.y - orientationScreenPoint.y;
if (deltaX != 0) {
double angle = Math.atan(deltaY / deltaX);
return Angle.fromRadians(angle);
} else {
return Angle.POS90; // Vertical label
}
}