compasslayer.java

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/*
Copyright (C) 2001, 2006 United States Government
as represented by the Administrator of the
National Aeronautics and Space Administration.
All Rights Reserved.
*/
package gov.nasa.worldwind.layers;

import com.sun.opengl.util.texture.*;
import gov.nasa.worldwind.exception.WWRuntimeException;
import gov.nasa.worldwind.geom.Vec4;
import gov.nasa.worldwind.geom.Angle;
import gov.nasa.worldwind.render.*;
import gov.nasa.worldwind.util.Logging;
import gov.nasa.worldwind.view.*;
import gov.nasa.worldwind.View;
import gov.nasa.worldwind.avlist.AVKey;
import gov.nasa.worldwind.pick.PickSupport;
import gov.nasa.worldwind.pick.PickedObject;

import javax.media.opengl.GL;
import java.awt.*;
import java.io.*;

/**
 * @author tag
 * @version $Id: CompassLayer.java 7113 2008-10-21 23:32:40Z tgaskins $
 */
public class CompassLayer extends AbstractLayer
{
    private String iconFilePath = "images/notched-compass.png"; // TODO: make configurable
    private double compassToViewportScale = 0.2; // TODO: make configurable
    private double iconScale = 0.5;
    private int borderWidth = 20; // TODO: make configurable
    private String position = AVKey.NORTHEAST; // TODO: make configurable
    private String resizeBehavior = AVKey.RESIZE_SHRINK_ONLY;
    private int iconWidth;
    private int iconHeight;
    private Vec4 locationCenter = null;
    private Vec4 locationOffset = null;
    private boolean showTilt = true;
    private PickSupport pickSupport = new PickSupport();

    // Draw it as ordered with an eye distance of 0 so that it shows up in front of most other things.
    private OrderedIcon orderedImage = new OrderedIcon();

    private class OrderedIcon implements OrderedRenderable
    {
        public double getDistanceFromEye()
        {
            return 0;
        }

        public void pick(DrawContext dc, Point pickPoint)
        {
            CompassLayer.this.draw(dc);
        }

        public void render(DrawContext dc)
        {
            CompassLayer.this.draw(dc);
        }
    }

    public CompassLayer()
    {
        this.setOpacity(0.8); // TODO: make configurable
        this.setPickEnabled(false);  // Default to no picking
    }

    public CompassLayer(String iconFilePath)
    {
        this.setIconFilePath(iconFilePath);
        this.setOpacity(0.8); // TODO: make configurable
        this.setPickEnabled(false); // Default to no picking
    }

    /**
     * Returns the layer's current icon file path.
     *
     * @return the icon file path
     */
    public String getIconFilePath()
    {
        return iconFilePath;
    }

    /**
     * Sets the compass icon's image location. The layer first searches for this location in the current Java classpath.
     * If not found then the specified path is assumed to refer to the local file system. found there then the
     *
     * @param iconFilePath the path to the icon's image file
     */
    public void setIconFilePath(String iconFilePath)
    {
        if (iconFilePath == null)
        {
            String message = Logging.getMessage("nullValue.IconFilePath");
            Logging.logger().severe(message);
            throw new IllegalArgumentException(message);
        }
        this.iconFilePath = iconFilePath;
    }

    /**
     * Returns the layer's compass-to-viewport scale factor.
     *
     * @return the compass-to-viewport scale factor
     */
    public double getCompassToViewportScale()
    {
        return compassToViewportScale;
    }

    /**
     * Sets the scale factor applied to the viewport size to determine the displayed size of the compass icon. This
     * scale factor is used only when the layer's resize behavior is AVKey.RESIZE_STRETCH or AVKey.RESIZE_SHRINK_ONLY.
     * The icon's width is adjusted to occupy the proportion of the viewport's width indicated by this factor. The
     * icon's height is adjusted to maintain the compass image's native aspect ratio.
     *
     * @param compassToViewportScale the compass to viewport scale factor
     */
    public void setCompassToViewportScale(double compassToViewportScale)
    {
        this.compassToViewportScale = compassToViewportScale;
    }

    /**
     * Returns the icon scale factor. See {@link #setIconScale(double)} for a description of the scale factor.
     *
     * @return the current icon scale
     */
    public double getIconScale()
    {
        return iconScale;
    }

    /**
     * Sets the scale factor defining the displayed size of the compass icon relative to the icon's width and height in
     * its image file. Values greater than 1 magify the image, values less than one minify it. If the layer's resize
     * behavior is other than AVKey.RESIZE_KEEP_FIXED_SIZE, the icon's displayed sized is further affected by the value
     * specified by {@link #setCompassToViewportScale(double)} and the current viewport size.
     *
     * @param iconScale the icon scale factor
     */
    public void setIconScale(double iconScale)
    {
        this.iconScale = iconScale;
    }

    /**
     * Returns the compass icon's resize behavior.
     *
     * @return the icon's resize behavior
     */
    public String getResizeBehavior()
    {
        return resizeBehavior;
    }

    /**
     * Sets the behavior the layer uses to size the compass icon when the viewport size changes, typically when the
     * World Wind window is resized. If the value is AVKey.RESIZE_KEEP_FIXED_SIZE, the icon size is kept to the size
     * specified in its image file scaled by the layer's current icon scale. If the value is AVKey.RESIZE_STRETCH, the
     * icon is resized to have a constant size relative to the current viewport size. If the viewport shrinks the icon
     * size decreases; if it expands then the icon file enlarges. The relative size is determined by the current
     * compass-to-viewport scale and by the icon's image file size scaled by the current icon scale. If the value is
     * AVKey.RESIZE_SHRINK_ONLY (the default), icon sizing behaves as for AVKey.RESIZE_STRETCH but the icon will not
     * grow larger than the size specified in its image file scaled by the current icon scale.
     *
     * @param resizeBehavior the desired resize behavior
     */
    public void setResizeBehavior(String resizeBehavior)
    {
        this.resizeBehavior = resizeBehavior;
    }

    public int getBorderWidth()
    {
        return borderWidth;
    }

    /**
     * Sets the compass icon offset from the viewport border.
     *
     * @param borderWidth the number of pixels to offset the compass icon from the borders indicated by {@link
     *                    #setPosition(String)}.
     */
    public void setBorderWidth(int borderWidth)
    {
        this.borderWidth = borderWidth;
    }

    /**
     * Returns the current relative compass icon position.
     *
     * @return the current compass position
     */
    public String getPosition()
    {
        return position;
    }

    /**
     * Sets the relative viewport location to display the compass icon. Can be one of AVKey.NORTHEAST (the default),
     * AVKey.NORTHWEST, AVKey.SOUTHEAST, or AVKey.SOUTHWEST. These indicate the corner of the viewport to place the
     * icon.
     *
     * @param position the desired compass position
     */
    public void setPosition(String position)
    {
        if (position == null)
        {
            String message = Logging.getMessage("nullValue.CompassPositionIsNull");
            Logging.logger().severe(message);
            throw new IllegalArgumentException(message);
        }
        this.position = position;
    }

    /**
     * Returns the current compass image location.
     *
     * @return the current location center. May be null.
     */
    public Vec4 getLocationCenter()
    {
        return locationCenter;
    }

    /**
     * Specifies the screen location of the compass image, relative to the image's center. May be null. If this value is
     * non-null, it overrides the position specified by #setPosition. The location is specified in pixels. The origin is
     * the window's lower left corner. Positive X values are to the right of the origin, positive Y values are upwards
     * from the origin. The final image location will be affected by the currently specified location offset if a
     * non-null location offset has been specified (see #setLocationOffset).
     *
     * @param locationCenter the location center. May be null.
     * @see #setPosition, #setLocationOffset
     */
    public void setLocationCenter(Vec4 locationCenter)
    {
        this.locationCenter = locationCenter;
    }

    /**
     * Returns the current location offset. See #setLocationOffset for a description of the offset and its values.
     *
     * @return the location offset. Will be null if no offset has been specified.
     */
    public Vec4 getLocationOffset()
    {
        return locationOffset;
    }

    /**
     * Specifies a placement offset from the compass' position on the screen.
     *
     * @param locationOffset the number of pixels to shift the compass image from its specified screen position. A
     *                       positive X value shifts the image to the right. A positive Y value shifts the image up. If
     *                       null, no offset is applied. The default offset is null.
     * @see #setLocationCenter, #setPosition
     */
    public void setLocationOffset(Vec4 locationOffset)
    {
        this.locationOffset = locationOffset;
    }

    protected void doRender(DrawContext dc)
    {
        dc.addOrderedRenderable(this.orderedImage);
    }

    protected void doPick(DrawContext dc, Point pickPoint)
    {
        dc.addOrderedRenderable(this.orderedImage);
    }

    public boolean isShowTilt()
    {
        return showTilt;
    }

    public void setShowTilt(boolean showTilt)
    {
        this.showTilt = showTilt;
    }

    private void draw(DrawContext dc)
    {
        if (this.iconFilePath == null)
            return;

        GL gl = dc.getGL();

        boolean attribsPushed = false;
        boolean modelviewPushed = false;
        boolean projectionPushed = false;

        try
        {
            gl.glPushAttrib(GL.GL_DEPTH_BUFFER_BIT
                | GL.GL_COLOR_BUFFER_BIT
                | GL.GL_ENABLE_BIT
                | GL.GL_TEXTURE_BIT
                | GL.GL_TRANSFORM_BIT
                | GL.GL_VIEWPORT_BIT
                | GL.GL_CURRENT_BIT);
            attribsPushed = true;

            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();
            gl.glMatrixMode(javax.media.opengl.GL.GL_PROJECTION);
            gl.glPushMatrix();
            projectionPushed = true;
            gl.glLoadIdentity();
            double maxwh = width > height ? width : height;
            if (maxwh == 0)
                maxwh = 1;
            gl.glOrtho(0d, viewport.width, 0d, viewport.height, -0.6 * maxwh, 0.6 * maxwh);

            gl.glMatrixMode(GL.GL_MODELVIEW);
            gl.glPushMatrix();
            modelviewPushed = true;
            gl.glLoadIdentity();

            double scale = this.computeScale(viewport);