// Copyright 2002, FreeHEP.
package org.freehep.graphicsio.emf.gdi;

import java.io.IOException;
import com.google.code.appengine.awt.geom.AffineTransform;

import org.freehep.graphicsio.emf.EMFConstants;
import org.freehep.graphicsio.emf.EMFInputStream;
import org.freehep.graphicsio.emf.EMFOutputStream;
import org.freehep.graphicsio.emf.EMFTag;
import org.freehep.graphicsio.emf.EMFRenderer;

/**
 * SetMapMode TAG.
 * 
 * @author Mark Donszelmann
 * @version $Id: SetMapMode.java 10367 2007-01-22 19:26:48Z duns $
 */
public class SetMapMode extends EMFTag implements EMFConstants {

    private int mode;

    public SetMapMode() {
        super(17, 1);
    }

    public SetMapMode(int mode) {
        this();
        this.mode = mode;
    }

    public EMFTag read(int tagID, EMFInputStream emf, int len)
            throws IOException {

        return new SetMapMode(emf.readDWORD());
    }

    public void write(int tagID, EMFOutputStream emf) throws IOException {
        emf.writeDWORD(mode);
    }

    public String toString() {
        return super.toString() + "\n  mode: " + mode;
    }

    /**
     * displays the tag using the renderer
     *
     * @param renderer EMFRenderer storing the drawing session data
     */
    public void render(EMFRenderer renderer) {
        // MM_ANISOTROPIC 	Logical units are mapped to arbitrary
        // units with arbitrarily scaled axes. Use the SetWindowExtEx
        // and SetViewportExtEx functions to specify the units,
        // orientation, and scaling.
        if (mode == EMFConstants.MM_ANISOTROPIC) {
            renderer.setMapModeIsotropic(false);
        }

        // MM_HIENGLISH 	Each logical unit is mapped to 0.001 inch.
        // Positive x is to the right; positive y is up.
        else if (mode == EMFConstants.MM_HIENGLISH) {
            // TODO not sure
            double scale = 0.001 * 25.4;
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(scale, scale));
        }

        // MM_HIMETRIC 	Each logical unit is mapped to 0.01 millimeter.
        // Positive x is to the right; positive y is up.
        else if (mode == EMFConstants.MM_HIMETRIC) {
            // TODO not sure
            double scale = 0.01;
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(scale, scale));
        }

        // MM_ISOTROPIC 	Logical units are mapped to arbitrary units
        // with equally scaled axes; that is, one unit along the x-axis
        // is equal to one unit along the y-axis. Use the SetWindowExtEx
        // and SetViewportExtEx functions to specify the units and the
        // orientation of the axes. Graphics device interface (GDI) makes
        // adjustments as necessary to ensure the x and y units remain
        // the same size (When the window extent is set, the viewport will
        // be adjusted to keep the units isotropic).
        else if (mode == EMFConstants.MM_ISOTROPIC) {
            renderer.setMapModeIsotropic(true);
            renderer.fixViewportSize();
        }

        // MM_LOENGLISH 	Each logical unit is mapped to 0.01 inch.
        // Positive x is to the right; positive y is up.
        else if (mode == EMFConstants.MM_LOENGLISH) {
            // TODO not sure
            double scale = 0.01 * 25.4;
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(scale, scale));
        }

        // MM_LOMETRIC 	Each logical unit is mapped to 0.1 millimeter.
        // Positive x is to the right; positive y is up.
        else if (mode == EMFConstants.MM_LOMETRIC) {
            // TODO not sure
            double scale = 0.1;
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(scale, scale));
        }

        // MM_TEXT 	Each logical unit is mapped to one device pixel. Positive
        // x is to the right; positive y is down.
        else if (mode == EMFConstants.MM_TEXT) {
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(1, -1));
        }

        // MM_TWIPS 	Each logical unit is mapped to one twentieth of a
        // printer's point (1/1440 inch, also called a twip). Positive x
        // is to the right; positive y is up.
        else if (mode == EMFConstants.MM_TWIPS) {
            renderer.setMapModeTransform(
                AffineTransform.getScaleInstance(
                    EMFRenderer.TWIP_SCALE, EMFRenderer.TWIP_SCALE));
        }
    }
}