+ drawTrackPoint: function(aIndex) {
+ gTrackLayer.running = true;
+ if (!aIndex && aIndex !== 0) {
+ // We can be called this way to make sure we draw an actual line up to where we are right now.
+ if (gTrackLayer.lastDrawnPoint && gTrackLayer.lastDrawnPoint.optimized) {
+ gTrackLayer.context.stroke();
+ gTrackLayer.lastDrawnPoint.optimized = false;
+ }
+ return;
+ }
+ var trackpoint = {"worldpos": gps2xy(gTrack[aIndex].coords.latitude, gTrack[aIndex].coords.longitude)};
+ var isLastPoint = (aIndex + 1 >= gTrack.length || gTrack[aIndex+1].beginSegment);
+ var update_drawnpoint = true;
+ // lastPoint is for optimizing (not actually executing the draw until the last)
+ trackpoint.segmentEnd = (isLastPoint === true);
+ trackpoint.optimized = (isLastPoint === false);
+ trackpoint.mappos = {x: Math.round((trackpoint.worldpos.x - gMap.pos.x) / gMap.zoomFactor + gMap.width / 2),
+ y: Math.round((trackpoint.worldpos.y - gMap.pos.y) / gMap.zoomFactor + gMap.height / 2)};
+ trackpoint.skip_drawing = false;
+ if (gTrackLayer.lastDrawnPoint) {
+ // Lines completely outside the current display should not be drawn.
+ if ((trackpoint.mappos.x < 0 && gTrackLayer.lastDrawnPoint.mappos.x < 0) ||
+ (trackpoint.mappos.x > gMap.width && gTrackLayer.lastDrawnPoint.mappos.x > gMap.width) ||
+ (trackpoint.mappos.y < 0 && gTrackLayer.lastDrawnPoint.mappos.y < 0) ||
+ (trackpoint.mappos.y > gMap.height && gTrackLayer.lastDrawnPoint.mappos.y > gMap.height)) {
+ trackpoint.skip_drawing = true;
+ }
+ }
+ if (!gTrackLayer.lastDrawnPoint || !gTrackLayer.lastDrawnPoint.optimized) {
+ gTrackLayer.context.strokeStyle = gTrackLayer.trackColor;
+ gTrackLayer.context.fillStyle = gTrackLayer.context.strokeStyle;
+ gTrackLayer.context.lineWidth = gTrackLayer.trackWidth;
+ gTrackLayer.context.lineCap = "round";
+ gTrackLayer.context.lineJoin = "round";
+ }
+ // This breaks optimiziation, so make sure to reset optimization.
+ if (trackpoint.skip_drawing || !gTrackLayer.lastDrawnPoint) {
+ trackpoint.optimized = false;
+ // Close path if one was open.
+ if (gTrackLayer.lastDrawnPoint && gTrackLayer.lastDrawnPoint.optimized) {
+ gTrackLayer.context.stroke();
+ }
+ }
+ if (!trackpoint.skip_drawing) {
+ if (gTrackLayer.lastDrawnPoint && gTrackLayer.lastDrawnPoint.skip_drawing && !gTrackLayer.lastDrawnPoint.segmentEnd) {
+ // If the last point was skipped but the current one isn't, draw a segment start
+ // for the off-screen previous one as well as a connection line.
+ gTrackLayer.context.beginPath();
+ gTrackLayer.context.arc(gTrackLayer.lastDrawnPoint.mappos.x, gTrackLayer.lastDrawnPoint.mappos.y,
+ gTrackLayer.context.lineWidth, 0, Math.PI * 2, false);
+ gTrackLayer.context.fill();
+ gTrackLayer.context.lineTo(trackpoint.mappos.x, trackpoint.mappos.y);
+ }
+ else if (!gTrackLayer.lastDrawnPoint || !gTrackLayer.lastDrawnPoint.optimized) {
+ // Start drawing a segment with the current point.
+ gTrackLayer.context.beginPath();
+ gTrackLayer.context.arc(trackpoint.mappos.x, trackpoint.mappos.y,
+ gTrackLayer.context.lineWidth, 0, Math.PI * 2, false);
+ gTrackLayer.context.fill();
+ }
+ else if (!trackpoint.segmentEnd && gTrackLayer.lastDrawnPoint &&
+ (Math.abs(gTrackLayer.lastDrawnPoint.mappos.x - trackpoint.mappos.x) <= 1) &&
+ (Math.abs(gTrackLayer.lastDrawnPoint.mappos.y - trackpoint.mappos.y) <= 1)) {
+ // We would draw the same or almost the same point, don't do any actual drawing.
+ update_drawnpoint = false;
+ }
+ else {
+ // Continue drawing segment, close if needed.
+ gTrackLayer.context.lineTo(trackpoint.mappos.x, trackpoint.mappos.y);
+ if (!trackpoint.optimized)
+ gTrackLayer.context.stroke();
+ }
+ }
+ if (update_drawnpoint) {
+ gTrackLayer.lastDrawnPoint = trackpoint;
+ }
+ },