INSA/be-graphes
3
0
Fork 0
Code Issues 4 Releases Wiki Activity

Use a better projection for BasicDrawing.

Browse Source
This commit is contained in:
Holt59 2018-03-11 15:50:54 +01:00
parent 0030ab7aef
commit f3964f1958
3 changed files with 198 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
src/main/org/insa/graph/GraphStatistics.java
View File

@ -51,6 +51,36 @@ public class GraphStatistics {
return topLeft;
}
/**
* Create a new bounding box by extending the current one according to the given
* value for each side.
*
* @param left Extra size to add to the left of the box.
* @param top Extra size to add to the top of the box.
* @param right Extra size to add to the right of the box.
* @param bottom Extra size to add to the bottom of the box.
*
* @return New bounding box corresponding to an extension of the current one.
*/
public BoundingBox extend(float left, float top, float right, float bottom) {
return new BoundingBox(
new Point(this.topLeft.getLongitude() - left, this.topLeft.getLatitude() + top),
new Point(this.bottomRight.getLongitude() + right,
this.bottomRight.getLatitude() - bottom));
}
/**
* Create a new bounding box by extending the current one according by the given
* value on each side.
*
* @param size Extra size to add to each side of this box.
*
* @return New bounding box corresponding to an extension of the current one.
*/
public BoundingBox extend(float size) {
return this.extend(size, size, size, size);
}
}
// Bounding box for this graph.

144
src/main/org/insa/graphics/drawing/MercatorProjection.java Normal file
View File

@ -0,0 +1,144 @@
package org.insa.graphics.drawing;
import java.awt.Dimension;
import org.insa.graph.GraphStatistics.BoundingBox;
public class MercatorProjection {
public static final double MAX_LATITUDE = 82;
public static final double MIN_LATITUDE = -MAX_LATITUDE;
// From Wikipedia... for the above max/min latitude.
private static final double IMAGE_WIDTH = 2058, IMAGE_HEIGHT = 1746;
private static final double MAX_LATITUDE_PROJ = projectY(MAX_LATITUDE);
private static final double MIN_LATITUDE_PROJ = projectY(MIN_LATITUDE);
// Bounding box
private final float minLatitude, minLongitude, maxLatitude, maxLongitude;
// Projection of min and max latitude.
private final double minLatitudeProj, maxLatitudeProj;
// Dimension of the image
private final double width, height;
/**
* Create a new MercatorProjection corresponding to the given BoundingBox and
* maxSize.
*
* @param boundingBox Box for this projection.
* @param maxSize Maximum size of any side (width / height) of the image to
* which this projection should draw.
*/
public MercatorProjection(BoundingBox boundingBox, int maxSize) {
// Find minimum/maximum longitude and latitude.
this.minLongitude = boundingBox.getTopLeftPoint().getLongitude();
this.maxLongitude = boundingBox.getBottomRightPoint().getLongitude();
this.minLatitude = boundingBox.getBottomRightPoint().getLatitude();
this.maxLatitude = boundingBox.getTopLeftPoint().getLatitude();
// Compute projection
this.minLatitudeProj = projectY(this.minLatitude);
this.maxLatitudeProj = projectY(this.maxLatitude);
Dimension imageDimension = computeImageSize(maxSize);
this.width = imageDimension.getWidth();
this.height = imageDimension.getHeight();
}
/**
* @return Image width for this projection to work properly.
*/
public double getImageWidth() {
return this.width;
}
/**
* @return Image weight for this projection to work properly.
*/
public double getImageHeight() {
return this.height;
}
/**
* Compute the projection (without scaling) of the given latitude.
*
* @param latitude Latitude to project.
*
* @return Projection of the given latitude (without scaling).
*/
private static double projectY(double latitude) {
double sinLatitude = Math.sin(latitude * Math.PI / 180.0);
return Math.log((1 + sinLatitude) / (1 - sinLatitude)) / 2;
}
/**
* Compute the dimension required for drawing a projection of the given box on
* an image, ensuring that none of the side of image is greater than maxSize.
*
* @param maxSize Maximum side of any side of the image.
*
* @return Dimension corresponding to the preferred size for the image.
*/
protected Dimension computeImageSize(int maxSize) {
double propWidth = (maxLongitude - minLongitude) * IMAGE_WIDTH / 360.0;
double propHeight = (this.maxLatitudeProj - this.minLatitudeProj)
/ (MAX_LATITUDE_PROJ - MIN_LATITUDE_PROJ) * IMAGE_HEIGHT;
return propWidth < propHeight
? new Dimension((int) (maxSize * propWidth / propHeight), maxSize)
: new Dimension(maxSize, (int) (maxSize * propHeight / propWidth));
}
/**
* Project the given latitude on the image.
*
* @param latitude Latitude to project.
*
* @return Projected position of the latitude on the image.
*/
public int latitudeToPixelY(float latitude) {
return (int) ((this.maxLatitudeProj - projectY(latitude))
/ (this.maxLatitudeProj - this.minLatitudeProj) * this.height);
}
/**
* Project the given longitude on the image.
*
* @param longitude Longitude to project.
*
* @return Projected position of the longitude on the image.
*/
public int longitudeToPixelX(float longitude) {
return (int) (width * (longitude - minLongitude) / (maxLongitude - minLongitude));
}
/**
* Retrieve the latitude associated to the given projected point.
*
* @param py Projected y-position for which latitude should be retrieved.
*
* @return The original latitude of the point.
*/
public float pixelYToLatitude(double py) {
float y = (float) (this.maxLatitudeProj
- (py / this.height) * (this.maxLatitudeProj - this.minLatitudeProj));
return (float) (180 * (2 * Math.atan(Math.exp(y)) - Math.PI / 2) / Math.PI);
}
/**
* Retrieve the longitude associated to the given projected point.
*
* @param px Projected x-position for which longitude should be retrieved.
*
* @return The original longitude of the point.
*/
public float pixelXToLongitude(double px) {
return (float) ((px / this.width) * (this.maxLongitude - this.minLongitude)
+ this.minLongitude);
}
}

78
src/main/org/insa/graphics/drawing/components/BasicDrawing.java
View File

@ -31,6 +31,7 @@ import org.insa.graphics.drawing.BasicGraphPalette;
import org.insa.graphics.drawing.Drawing;
import org.insa.graphics.drawing.DrawingClickListener;
import org.insa.graphics.drawing.GraphPalette;
import org.insa.graphics.drawing.MercatorProjection;
import org.insa.graphics.drawing.overlays.MarkerOverlay;
import org.insa.graphics.drawing.overlays.MarkerUtils;
import org.insa.graphics.drawing.overlays.Overlay;
@ -146,8 +147,8 @@ public class BasicDrawing extends JPanel implements Drawing {
@Override
public void drawImpl(Graphics2D graphics) {
int px = BasicDrawing.this.projx(getPoint().getLongitude());
int py = BasicDrawing.this.projy(getPoint().getLatitude());
int px = projection.longitudeToPixelX(getPoint().getLongitude());
int py = projection.latitudeToPixelY(getPoint().getLatitude());
graphics.drawImage(this.image, px - MARKER_WIDTH / 2, py - MARKER_HEIGHT, MARKER_WIDTH,
MARKER_HEIGHT, BasicDrawing.this);
@ -193,10 +194,10 @@ public class BasicDrawing extends JPanel implements Drawing {
while (itPoint.hasNext()) {
Point curr = itPoint.next();
int x1 = BasicDrawing.this.projx(prev.getLongitude());
int x2 = BasicDrawing.this.projx(curr.getLongitude());
int y1 = BasicDrawing.this.projy(prev.getLatitude());
int y2 = BasicDrawing.this.projy(curr.getLatitude());
int x1 = projection.longitudeToPixelX(prev.getLongitude());
int x2 = projection.longitudeToPixelX(curr.getLongitude());
int y1 = projection.latitudeToPixelY(prev.getLatitude());
int y2 = projection.latitudeToPixelY(curr.getLatitude());
graphics.drawLine(x1, y1, x2, y2);
@ -253,8 +254,8 @@ public class BasicDrawing extends JPanel implements Drawing {
@Override
public void addPoint(Point point) {
int x = BasicDrawing.this.projx(point.getLongitude()) - this.width / 2;
int y = BasicDrawing.this.projy(point.getLatitude()) - this.width / 2;
int x = projection.longitudeToPixelX(point.getLongitude()) - this.width / 2;
int y = projection.latitudeToPixelY(point.getLatitude()) - this.width / 2;
this.graphics.fillOval(x, y, this.width, this.width);
BasicDrawing.this.repaint();
}
@ -294,7 +295,7 @@ public class BasicDrawing extends JPanel implements Drawing {
// Maximum width for the drawing (in pixels).
private static final int MAXIMUM_DRAWING_WIDTH = 2000;
private double long1, long2, lat1, lat2;
private MercatorProjection projection;
// Width and height of the image
private int width, height;
@ -429,22 +430,6 @@ public class BasicDrawing extends JPanel implements Drawing {
return this.zoomAndPanListener;
}
/**
* @param lon
* @return
*/
private int projx(double lon) {
return (int) (width * (lon - this.long1) / (this.long2 - this.long1));
}
/**
* @param lat
* @return
*/
private int projy(double lat) {
return (int) (height * (1 - (lat - this.lat1) / (this.lat2 - this.lat1)));
}
/**
* Return the longitude and latitude corresponding to the given position of the
* MouseEvent.
@ -465,13 +450,8 @@ public class BasicDrawing extends JPanel implements Drawing {
.inverseTransform(event.getPoint(), null);
// Inverse the "projection" on x/y to get longitude and latitude.
double lon = ptDst.getX();
double lat = ptDst.getY();
lon = (lon / this.width) * (this.long2 - this.long1) + this.long1;
lat = (1 - lat / this.height) * (this.lat2 - this.lat1) + this.lat1;
// Return a new point.
return new Point((float) lon, (float) lat);
return new Point(projection.pixelXToLongitude(ptDst.getX()),
projection.pixelYToLatitude(ptDst.getY()));
}
/*
@ -546,10 +526,10 @@ public class BasicDrawing extends JPanel implements Drawing {
while (it1.hasNext()) {
Point curr = it1.next();
int x1 = this.projx(prev.getLongitude());
int x2 = this.projx(curr.getLongitude());
int y1 = this.projy(prev.getLatitude());
int y2 = this.projy(curr.getLatitude());
int x1 = projection.longitudeToPixelX(prev.getLongitude());
int x2 = projection.longitudeToPixelX(curr.getLongitude());
int y1 = projection.latitudeToPixelY(prev.getLatitude());
int y2 = projection.latitudeToPixelY(curr.getLatitude());
graphGraphics.drawLine(x1, y1, x2, y2);
prev = curr;
@ -573,30 +553,20 @@ public class BasicDrawing extends JPanel implements Drawing {
BoundingBox box = graph.getGraphInformation().getBoundingBox();
// Find minimum/maximum longitude and latitude.
double minLon = box.getTopLeftPoint().getLongitude(),
float minLon = box.getTopLeftPoint().getLongitude(),
maxLon = box.getBottomRightPoint().getLongitude(),
minLat = box.getBottomRightPoint().getLatitude(),
maxLat = box.getTopLeftPoint().getLatitude();
// Add a little delta to avoid drawing on the edge...
double diffLon = maxLon - minLon, diffLat = maxLat - minLat;
double deltaLon = 0.01 * diffLon, deltaLat = 0.01 * diffLat;
float diffLon = maxLon - minLon, diffLat = maxLat - minLat;
float deltaLon = 0.01f * diffLon, deltaLat = 0.01f * diffLat;
this.long1 = minLon - deltaLon;
this.long2 = maxLon + deltaLon;
this.lat1 = minLat - deltaLat;
this.lat2 = maxLat + deltaLat;
// Compute width/height for the image
if (diffLat < diffLon) {
this.width = MAXIMUM_DRAWING_WIDTH;
this.height = (int) (this.width * diffLat / diffLon);
}
else {
this.height = MAXIMUM_DRAWING_WIDTH;
this.width = (int) (this.height * diffLon / diffLat);
}
// Create the projection and retrieve width and height for the box.
projection = new MercatorProjection(box.extend(deltaLon, deltaLat, deltaLon, deltaLat),
MAXIMUM_DRAWING_WIDTH);
this.width = (int) projection.getImageWidth();
this.height = (int) projection.getImageHeight();
// Create the image
BufferedImage img = new BufferedImage(this.width, this.height,