CenterScaleMapBoundsTest.java

package org.mapfish.print.attribute.map;

import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.referencing.CRS;
import org.geotools.referencing.crs.DefaultGeographicCRS;
import org.junit.Test;
import org.opengis.referencing.crs.CoordinateReferenceSystem;

import java.awt.Rectangle;

import static org.junit.Assert.assertEquals;

/**
 * Test bounds implementation.
 */
public class CenterScaleMapBoundsTest {
    static final double OPENLAYERS_2_DPI = 72;
    public static final CoordinateReferenceSystem SPHERICAL_MERCATOR;
    public static final CoordinateReferenceSystem CH1903;
    public static final CoordinateReferenceSystem LAMBERT;

    static {
        try {
            SPHERICAL_MERCATOR = CRS.decode("EPSG:3857");
            CH1903 = CRS.decode("EPSG:21781");
            LAMBERT = CRS.decode("EPSG:2154");
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }
    }

    @Test
    public void testToReferencedEnvelopeCH1903Projection() throws Exception {
        final double startScaleDenominator = 18984.396150703426;
        final CenterScaleMapBounds bounds = new CenterScaleMapBounds(CH1903, 659596.5, 185610.5, startScaleDenominator);
        final Rectangle paintArea = new Rectangle(521, 330);
        final ReferencedEnvelope envelope = bounds.toReferencedEnvelope(paintArea);

        // It would be nice to nail this down in the future to the exact value but the method I used for measurement was openlayers and
        // I don't know what the DPI it was using and I don't know how accurate its calculation is either.
        assertEquals(657851, envelope.getMinX(), 1);
        assertEquals(661341, envelope.getMaxX(), 1);
        assertEquals(184505, envelope.getMinY(), 1);
        assertEquals(186715, envelope.getMaxY(), 1);
        assertEquals(CH1903, envelope.getCoordinateReferenceSystem());
    }

    @Test
    public void testToReferencedEnvelopeLambertProjection() throws Exception {
        final double startScaleDenominator = 17983.582534790035;
        final CenterScaleMapBounds bounds = new CenterScaleMapBounds(LAMBERT, 445000, 6355000, startScaleDenominator);
        final Rectangle paintArea = new Rectangle(418, 512);
        final ReferencedEnvelope envelope = bounds.toReferencedEnvelope(paintArea);

        // It would be nice to nail this down in the future to the exact value but the method I used for measurement was openlayers and
        // I don't know what the DPI it was using and I don't know how accurate its calculation is either.
        assertEquals(443674, envelope.getMinX(), 1);
        assertEquals(446325, envelope.getMaxX(), 1);
        assertEquals(6353375, envelope.getMinY(), 1);
        assertEquals(6356624, envelope.getMaxY(), 1);
        assertEquals(LAMBERT, envelope.getCoordinateReferenceSystem());
    }

    @Test
    public void testToReferencedEnvelopeLatLong() throws Exception {
        final double startScaleDenominator = 56304.83087498591;
        final CenterScaleMapBounds bounds = new CenterScaleMapBounds(DefaultGeographicCRS.WGS84, 8.2335427805083, 46.801424340241,
                startScaleDenominator);
        final Rectangle paintArea = new Rectangle(521, 330);
        final ReferencedEnvelope envelope = bounds.toReferencedEnvelope(paintArea);

        // It would be nice to nail this down in the future to the exact value but the method I used for measurement was openlayers and
        // I don't know what the DPI it was using and I don't know how accurate its calculation is either.
        final double delta = 0.000001;
        assertEquals(8.1657602, envelope.getMinX(), delta);
        assertEquals(8.3013252, envelope.getMaxX(), delta);
        assertEquals(46.771942, envelope.getMinY(), delta);
        assertEquals(46.830906, envelope.getMaxY(), delta);
        assertEquals(DefaultGeographicCRS.WGS84, envelope.getCoordinateReferenceSystem());
    }

    @Test
    public void testZoomOut() throws Exception {
        final double Denominator = 2500.0;
        final CenterScaleMapBounds bounds = new CenterScaleMapBounds(DefaultGeographicCRS.WGS84, 0.0, 0.0, Denominator);
        final Rectangle paintArea = new Rectangle(400, 200);
        final ReferencedEnvelope envelope = bounds.toReferencedEnvelope(paintArea);

        CenterScaleMapBounds newBounds = bounds.zoomOut(1);
        ReferencedEnvelope newEnvelope = newBounds.toReferencedEnvelope(paintArea);

        final double delta = 0.000001;
        assertEquals(envelope.getMinX(), newEnvelope.getMinX(), delta);
        assertEquals(envelope.getMaxX(), newEnvelope.getMaxX(), delta);
        assertEquals(envelope.getMinY(), newEnvelope.getMinY(), delta);
        assertEquals(envelope.getMaxY(), newEnvelope.getMaxY(), delta);

        newBounds = bounds.zoomOut(2);
        newEnvelope = newBounds.toReferencedEnvelope(paintArea);

        assertEquals(envelope.getMinX() * 2, newEnvelope.getMinX(), delta);
        assertEquals(envelope.getMaxX() * 2, newEnvelope.getMaxX(), delta);
        assertEquals(envelope.getMinY() * 2, newEnvelope.getMinY(), delta);
        assertEquals(envelope.getMaxY() * 2, newEnvelope.getMaxY(), delta);
    }
}