public MeshTile[] subdivide(Level nextLevel) {
Angle p0 = this.getSector().getMinLatitude();
Angle p2 = this.getSector().getMaxLatitude();
Angle p1 = Angle.midAngle(p0, p2);
Angle t0 = this.getSector().getMinLongitude();
Angle t2 = this.getSector().getMaxLongitude();
Angle t1 = Angle.midAngle(t0, t2);
int row = this.getRow();
int col = this.getColumn();
MeshCoords[] coords = this.coords.subdivide();
MeshTile[] subTiles = new MeshTile[4];
subTiles[0] =
new MeshTile(
new Sector(p0, p1, t0, t1),
nextLevel,
2 * row,
2 * col,
coords[0]); // Lower left quadrant.
subTiles[1] =
new MeshTile(
new Sector(p0, p1, t1, t2),
nextLevel,
2 * row,
2 * col + 1,
coords[1]); // Lower right quadrant.
subTiles[2] =
new MeshTile(
new Sector(p1, p2, t1, t2),
nextLevel,
2 * row + 1,
2 * col + 1,
coords[2]); // Upper right quadrant
subTiles[3] =
new MeshTile(
new Sector(p1, p2, t0, t1),
nextLevel,
2 * row + 1,
2 * col,
coords[3]); // Upper left quadrant.
return subTiles;
}
protected Angle computeIconRadius(DrawContext dc, double regionPixelSize, Sector drawSector) {
double minCosLat =
Math.min(drawSector.getMinLatitude().cos(), drawSector.getMaxLatitude().cos());
if (minCosLat < 0.001) return Angle.POS180;
Rectangle2D iconDimension = this.computeDrawDimension(regionPixelSize); // Meter
double dLat = iconDimension.getHeight() / dc.getGlobe().getRadius();
double dLon = iconDimension.getWidth() / dc.getGlobe().getRadius() / minCosLat;
return Angle.fromRadians(Math.sqrt(dLat * dLat + dLon * dLon) / 2);
}
private static MeshTile[] createTiles(LevelSet levelSet, int levelNumber, MeshCoords coords) {
Sector sector = levelSet.getSector();
Level level = levelSet.getLevel(levelNumber);
Angle dLat = level.getTileDelta().getLatitude();
Angle dLon = level.getTileDelta().getLongitude();
Angle latOrigin = levelSet.getTileOrigin().getLatitude();
Angle lonOrigin = levelSet.getTileOrigin().getLongitude();
// Determine the row and column offset from the common World Wind global tiling origin.
int firstRow = Tile.computeRow(dLat, sector.getMinLatitude(), latOrigin);
int firstCol = Tile.computeColumn(dLon, sector.getMinLongitude(), lonOrigin);
int lastRow = Tile.computeRow(dLat, sector.getMaxLatitude(), latOrigin);
int lastCol = Tile.computeColumn(dLon, sector.getMaxLongitude(), lonOrigin);
int numLatTiles = lastRow - firstRow + 1;
int numLonTiles = lastCol - firstCol + 1;
AffineTransform sectorTransform = createTransform(sector, coords);
MeshTile[] tiles = new MeshTile[numLatTiles * numLonTiles];
int index = 0;
Angle p1 = Tile.computeRowLatitude(firstRow, dLat, latOrigin);
for (int row = firstRow; row <= lastRow; row++) {
Angle p2 = p1.add(dLat);
Angle t1 = Tile.computeColumnLongitude(firstCol, dLon, lonOrigin);
for (int col = firstCol; col <= lastCol; col++) {
Angle t2 = t1.add(dLon);
Sector tileSector = new Sector(p1, p2, t1, t2);
MeshCoords tileCoords = transformSector(sectorTransform, tileSector);
tiles[index++] = new MeshTile(tileSector, level, row, col, tileCoords);
t1 = t2;
}
p1 = p2;
}
return tiles;
}
private void createTopLevelTiles() {
MercatorSector sector = (MercatorSector) this.levels.getSector();
Level level = levels.getFirstLevel();
Angle dLat = level.getTileDelta().getLatitude();
Angle dLon = level.getTileDelta().getLongitude();
Angle latOrigin = this.levels.getTileOrigin().getLatitude();
Angle lonOrigin = this.levels.getTileOrigin().getLongitude();
// Determine the row and column offset from the common World Wind global tiling origin.
int firstRow = Tile.computeRow(dLat, sector.getMinLatitude(), latOrigin);
int firstCol = Tile.computeColumn(dLon, sector.getMinLongitude(), lonOrigin);
int lastRow = Tile.computeRow(dLat, sector.getMaxLatitude(), latOrigin);
int lastCol = Tile.computeColumn(dLon, sector.getMaxLongitude(), lonOrigin);
int nLatTiles = lastRow - firstRow + 1;
int nLonTiles = lastCol - firstCol + 1;
this.topLevels = new ArrayList<MercatorTextureTile>(nLatTiles * nLonTiles);
// Angle p1 = Tile.computeRowLatitude(firstRow, dLat);
double deltaLat = dLat.degrees / 90;
double d1 = -1.0 + deltaLat * firstRow;
for (int row = firstRow; row <= lastRow; row++) {
// Angle p2;
// p2 = p1.add(dLat);
double d2 = d1 + deltaLat;
Angle t1 = Tile.computeColumnLongitude(firstCol, dLon, lonOrigin);
for (int col = firstCol; col <= lastCol; col++) {
Angle t2;
t2 = t1.add(dLon);
this.topLevels.add(
new MercatorTextureTile(new MercatorSector(d1, d2, t1, t2), level, row, col));
t1 = t2;
}
d1 = d2;
}
}
/**
* 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
}
}
protected Angle computeSafeRadius(DrawContext dc, SurfaceTileDrawContext sdc) {
double regionPixelSize = this.computeDrawPixelSize(dc, sdc);
Angle sectorRadius = this.computeSectorRadius(sdc.getSector());
Angle iconRadius = this.computeIconRadius(dc, regionPixelSize, sdc.getSector());
return sectorRadius.add(iconRadius);
}
protected Angle computeSectorRadius(Sector sector) {
double dLat = sector.getDeltaLatRadians();
double dLon = sector.getDeltaLonRadians();
return Angle.fromRadians(Math.sqrt(dLat * dLat + dLon * dLon) / 2);
}
