/**
* Compute the lat/lon position of the view center
*
* @param dc the current DrawContext
* @param view the current View
* @return the ground position of the view center or null
*/
protected Position computeGroundPosition(DrawContext dc, View view) {
if (view == null) return null;
Position groundPos =
view.computePositionFromScreenPoint(
view.getViewport().getWidth() / 2, view.getViewport().getHeight() / 2);
if (groundPos == null) return null;
double elevation =
dc.getGlobe().getElevation(groundPos.getLatitude(), groundPos.getLongitude());
return new Position(
groundPos.getLatitude(),
groundPos.getLongitude(),
elevation * dc.getVerticalExaggeration());
}
/**
* Compute the view range footprint on the globe.
*
* @param dc the current <code>DrawContext</code>
* @param steps the number of steps.
* @return an array list of <code>LatLon</code> forming a closed shape.
*/
protected ArrayList<LatLon> computeViewFootPrint(DrawContext dc, int steps) {
ArrayList<LatLon> positions = new ArrayList<LatLon>();
Position eyePos = dc.getView().getEyePosition();
Angle distance =
Angle.fromRadians(
Math.asin(
dc.getView().getFarClipDistance()
/ (dc.getGlobe().getRadius() + eyePos.getElevation())));
if (distance.degrees > 10) {
double headStep = 360d / steps;
Angle heading = Angle.ZERO;
for (int i = 0; i <= steps; i++) {
LatLon p = LatLon.greatCircleEndPosition(eyePos, heading, distance);
positions.add(p);
heading = heading.addDegrees(headStep);
}
return positions;
} else return null;
}
protected void drawIcon(DrawContext dc) {
if (this.getIconFilePath() == null) return;
GL gl = dc.getGL();
OGLStackHandler ogsh = new OGLStackHandler();
try {
// Initialize texture if necessary
Texture iconTexture = dc.getTextureCache().getTexture(this.getIconFilePath());
if (iconTexture == null) {
this.initializeTexture(dc);
iconTexture = dc.getTextureCache().getTexture(this.getIconFilePath());
if (iconTexture == null) {
String msg = Logging.getMessage("generic.ImageReadFailed");
Logging.logger().finer(msg);
return;
}
}
gl.glDisable(GL.GL_DEPTH_TEST);
double width = this.getScaledIconWidth();
double height = this.getScaledIconHeight();
// Load a parallel projection with xy dimensions (viewportWidth, viewportHeight)
// into the GL projection matrix.
java.awt.Rectangle viewport = dc.getView().getViewport();
ogsh.pushProjectionIdentity(gl);
double maxwh = width > height ? width : height;
gl.glOrtho(0d, viewport.width, 0d, viewport.height, -0.6 * maxwh, 0.6 * maxwh);
// Translate and scale
ogsh.pushModelviewIdentity(gl);
double scale = this.computeScale(viewport);
Vec4 locationSW = this.computeLocation(viewport, scale);
gl.glTranslated(locationSW.x(), locationSW.y(), locationSW.z());
// Scale to 0..1 space
gl.glScaled(scale, scale, 1);
gl.glScaled(width, height, 1d);
if (!dc.isPickingMode()) {
gl.glEnable(GL.GL_BLEND);
gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
// Draw background color behind the map
gl.glColor4ub(
(byte) this.backColor.getRed(),
(byte) this.backColor.getGreen(),
(byte) this.backColor.getBlue(),
(byte) (this.backColor.getAlpha() * this.getOpacity()));
dc.drawUnitQuad();
// Draw world map icon
gl.glColor4d(1d, 1d, 1d, this.getOpacity());
gl.glEnable(GL.GL_TEXTURE_2D);
iconTexture.bind();
TextureCoords texCoords = iconTexture.getImageTexCoords();
dc.drawUnitQuad(texCoords);
gl.glBindTexture(GL.GL_TEXTURE_2D, 0);
gl.glDisable(GL.GL_TEXTURE_2D);
// Draw crosshair for current location
gl.glLoadIdentity();
gl.glTranslated(locationSW.x(), locationSW.y(), locationSW.z());
// Scale to width x height space
gl.glScaled(scale, scale, 1);
// Set color
float[] colorRGB = this.color.getRGBColorComponents(null);
gl.glColor4d(colorRGB[0], colorRGB[1], colorRGB[2], this.getOpacity());
// Draw crosshair
Position groundPos = this.computeGroundPosition(dc, dc.getView());
if (groundPos != null) {
int x = (int) (width * (groundPos.getLongitude().degrees + 180) / 360);
int y = (int) (height * (groundPos.getLatitude().degrees + 90) / 180);
int w = 10; // cross branch length
// Draw
gl.glBegin(GL.GL_LINE_STRIP);
gl.glVertex3d(x - w, y, 0);
gl.glVertex3d(x + w + 1, y, 0);
gl.glEnd();
gl.glBegin(GL.GL_LINE_STRIP);
gl.glVertex3d(x, y - w, 0);
gl.glVertex3d(x, y + w + 1, 0);
gl.glEnd();
}
// Draw view footprint in map icon space
if (this.showFootprint) {
this.footPrintPositions = this.computeViewFootPrint(dc, 32);
if (this.footPrintPositions != null) {
gl.glBegin(GL.GL_LINE_STRIP);
LatLon p1 = this.footPrintPositions.get(0);
for (LatLon p2 : this.footPrintPositions) {
int x = (int) (width * (p2.getLongitude().degrees + 180) / 360);
int y = (int) (height * (p2.getLatitude().degrees + 90) / 180);
// Draw
if (LatLon.locationsCrossDateline(p1, p2)) {
int y1 = (int) (height * (p1.getLatitude().degrees + 90) / 180);
gl.glVertex3d(x < width / 2 ? width : 0, (y1 + y) / 2, 0);
gl.glEnd();
gl.glBegin(GL.GL_LINE_STRIP);
gl.glVertex3d(x < width / 2 ? 0 : width, (y1 + y) / 2, 0);
}
gl.glVertex3d(x, y, 0);
p1 = p2;
}
gl.glEnd();
}
}
// Draw 1px border around and inside the map
gl.glBegin(GL.GL_LINE_STRIP);
gl.glVertex3d(0, 0, 0);
gl.glVertex3d(width, 0, 0);
gl.glVertex3d(width, height - 1, 0);
gl.glVertex3d(0, height - 1, 0);
gl.glVertex3d(0, 0, 0);
gl.glEnd();
} else {
// Picking
this.pickSupport.clearPickList();
this.pickSupport.beginPicking(dc);
// Where in the world are we picking ?
Position pickPosition =
computePickPosition(
dc, locationSW, new Dimension((int) (width * scale), (int) (height * scale)));
Color color = dc.getUniquePickColor();
int colorCode = color.getRGB();
this.pickSupport.addPickableObject(colorCode, this, pickPosition, false);
gl.glColor3ub((byte) color.getRed(), (byte) color.getGreen(), (byte) color.getBlue());
dc.drawUnitQuad();
this.pickSupport.endPicking(dc);
this.pickSupport.resolvePick(dc, dc.getPickPoint(), this);
}
} finally {
dc.restoreDefaultDepthTesting();
dc.restoreDefaultCurrentColor();
if (dc.isPickingMode()) dc.restoreDefaultBlending();
ogsh.pop(gl);
}
}
