/**
* Called when some fundamental parameters change.
*
* <p>Each projection will decide how to respond to this change. For instance, they may need to
* recalculate "constant" parameters used in the forward() and inverse() calls.
*
* <p>
*/
protected void computeParameters() {
Debug.message("proj", "Gnomonic.computeParameters()");
super.computeParameters();
// maxscale = scale at which a world hemisphere fits in the
// window
maxscale =
(width < height)
? (float) (planetPixelRadius * 2 * hPrime) / (float) width
: (float) (planetPixelRadius * 2 * hPrime) / (float) height;
if (maxscale < minscale) {
maxscale = minscale;
}
if (scale > maxscale) {
scale = maxscale;
}
scaled_radius = planetPixelRadius / scale;
// width of the world in pixels at current scale. We see only
// one hemisphere.
world.x = (int) ((planetPixelRadius * 2 * hPrime) / scale);
// do some precomputation of stuff
cosCtrLat = Math.cos(centerY);
sinCtrLat = Math.sin(centerY);
// compute the offsets
hy = height / 2;
wx = width / 2;
}
protected void init() {
super.init();
// minscale is the minimum scale allowable (before integer
// wrapping can occur)
minscale = (float) Math.ceil((2 * hPrime * planetPixelRadius) / (int) Integer.MAX_VALUE);
if (minscale < 1) minscale = 1;
// calculate cutoff scale for XWindows workaround
XSCALE_THRESHOLD = (int) ((planetPixelRadius * 2 * hPrime) / 64000); // fudge
}