package ij.plugin;
import ij.*;
import ij.process.*;
import ij.gui.*;
import ij.measure.*;
import ij.util.Tools;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

/** Implements the Image/Stacks/Reslice command. Known shortcomings: 
    for FREELINE or POLYLINE ROI, spatial calibration is ignored: 
    the image is sampled at constant _pixel_ increments (distance 1), so 
    (if y/x aspect ratio != 1 in source image) one dimension in the output is not
    homogeneous (i.e. pixelWidth not the same everywhere).
*/
public class Slicer implements PlugIn, TextListener, ItemListener {

    private static final String[] starts = {"Top", "Left", "Bottom", "Right"};
    private static String startAtS = starts[0];
    private static boolean rotateS;
    private static boolean flipS;
    private static int sliceCountS = 1;
    
    private String startAt = starts[0];
    private boolean rotate;
    private boolean flip;
    private int sliceCount = 1;
    private boolean nointerpolate = Prefs.avoidResliceInterpolation;
    private double inputZSpacing = 1.0;
    private double outputZSpacing = 1.0;
    private int outputSlices = 1;
    private boolean noRoi;
    private boolean rgb, notFloat;
    private Vector fields, checkboxes;
    private Label message;
    private ImagePlus imp;
    private double gx1, gy1, gx2, gy2, gLength;
    private Color lineColor = new Color(1f, 1f, 0f, 0.4f);

    // Variables used by getIrregularProfile and doIrregularSetup
    private int n;
    private double[] x;
    private double[] y;
    private int xbase;
    private int ybase;
    private double length;
    private double[] segmentLengths;
    private double[] dx;
    private double[] dy;

    public void run(String arg) {
        imp = WindowManager.getCurrentImage();
        if (imp==null) {
            IJ.noImage();
            return;
        }
        int stackSize = imp.getStackSize();
        Roi roi = imp.getRoi();
        int roiType = roi!=null?roi.getType():0;
        // stack required except for ROI = none or RECT
        if (stackSize<2 && roi!=null && roiType!=Roi.RECTANGLE) {
            IJ.error("Reslice...", "Stack required");
            return;
        }
        // permissible ROI types: none,RECT,*LINE
        if (roi!=null && roiType!=Roi.RECTANGLE && roiType!=Roi.LINE && roiType!=Roi.POLYLINE && roiType!=Roi.FREELINE) {
            IJ.error("Reslice...", "Line or rectangular selection required");
            return;
        }
        if (!showDialog(imp))
            return;
        long startTime = System.currentTimeMillis();
        ImagePlus imp2 = null;
        rgb = imp.getType()==ImagePlus.COLOR_RGB;
        notFloat = !rgb && imp.getType()!=ImagePlus.GRAY32;
        if (imp.isHyperStack())
            imp2 = resliceHyperstack(imp);
        else
            imp2 = reslice(imp);
        if (imp2==null)
            return;
        ImageProcessor ip = imp.getProcessor();
        double min = ip.getMin();
        double max = ip.getMax();
        if (!rgb) imp2.getProcessor().setMinAndMax(min, max);
        imp2.show();
        if (noRoi)
            imp.deleteRoi();
        else
            imp.draw();
        IJ.showStatus(IJ.d2s(((System.currentTimeMillis()-startTime)/1000.0),2)+" seconds");
    }

    public ImagePlus reslice(ImagePlus imp) {
         ImagePlus imp2;
         Roi roi = imp.getRoi();
         int roiType = roi!=null?roi.getType():0;
         Calibration origCal = imp.getCalibration();
         boolean globalCalibration = false;
         if (nointerpolate) {// temporarily clear spatial calibration
                globalCalibration = imp.getGlobalCalibration()!=null;
                imp.setGlobalCalibration(null);
                Calibration tmpCal = origCal.copy();
                tmpCal.pixelWidth = 1.0;
                tmpCal.pixelHeight = 1.0;
                tmpCal.pixelDepth = 1.0;
                imp.setCalibration(tmpCal);
                inputZSpacing = 1.0;
                if (roiType!=Roi.LINE)
                    outputZSpacing = 1.0;
         }
        double zSpacing = inputZSpacing/imp.getCalibration().pixelWidth;
         if (roi==null || roiType==Roi.RECTANGLE || roiType==Roi.LINE) {
                imp2 = resliceRectOrLine(imp);
         } else {// we assert roiType==Roi.POLYLINE || roiType==Roi.FREELINE
                String status = imp.getStack().isVirtual()?"":null;
                IJ.showStatus("Reslice...");
                ImageProcessor ip2 = getSlice(imp, 0.0, 0.0, 0.0, 0.0, status);
                imp2 = new ImagePlus("Reslice of "+imp.getShortTitle(), ip2);
         }
         if (nointerpolate) { // restore calibration
                if (globalCalibration)
                    imp.setGlobalCalibration(origCal);
                imp.setCalibration(origCal);
         }
         // create Calibration for new stack
         // start from previous cal and swap appropriate fields
         boolean horizontal = false;
         boolean vertical = false;
        if (roi==null || roiType==Roi.RECTANGLE) {
            if (startAt.equals(starts[0]) || startAt.equals(starts[2]))
                horizontal = true;
            else
                vertical = true;
        } 
        if (roi!=null && roiType==Roi.LINE) {
            Line l = (Line)roi;
            horizontal  = (l.y2-l.y1)==0;
            vertical = (l.x2-l.x1)==0;
        }
        if (imp2==null) return null;
        imp2.setCalibration(imp.getCalibration());
        Calibration cal = imp2.getCalibration();
        if (horizontal) {
            cal.pixelWidth = origCal.pixelWidth;
            cal.pixelHeight = origCal.pixelDepth/zSpacing;
            cal.pixelDepth = origCal.pixelHeight*outputZSpacing;
        } else if (vertical) {
            cal.pixelWidth = origCal.pixelHeight;
            cal.pixelHeight = origCal.pixelDepth/zSpacing;
            //cal.pixelWidth = origCal.pixelDepth/zSpacing;
            //cal.pixelHeight = origCal.pixelHeight;
            cal.pixelDepth = origCal.pixelWidth*outputZSpacing;;
        } else { // oblique line, polyLine or freeline
                if (origCal.pixelHeight==origCal.pixelWidth) {
                    cal.pixelWidth = origCal.pixelWidth;
                    cal.pixelHeight=origCal.pixelDepth/zSpacing;
                    cal.pixelDepth = origCal.pixelWidth*outputZSpacing;
                } else {
                    cal.pixelWidth = cal.pixelHeight=cal.pixelDepth=1.0;
                    cal.setUnit("pixel");
                }
         }
         double tmp;
         if (rotate) {// if rotated flip X and Y
                tmp = cal.pixelWidth;
                cal.pixelWidth = cal.pixelHeight;
                cal.pixelHeight = tmp;
         }
         return imp2;
    }

    ImagePlus resliceHyperstack(ImagePlus imp) {
        int channels = imp.getNChannels();
        int slices = imp.getNSlices();
        int frames = imp.getNFrames();
        if (slices==1)
            return resliceTimeLapseHyperstack(imp);
        int c1 = imp.getChannel();
        int z1 = imp.getSlice();
        int t1 = imp.getFrame();
        int width = imp.getWidth();
        int height = imp.getHeight();
        ImagePlus imp2 = null;
        ImageStack stack2 = null;
        Roi roi = imp.getRoi();
        for (int t=1; t<=frames; t++) {
            for (int c=1; c<=channels; c++) {
                ImageStack tmp1Stack = new ImageStack(width, height);
                for (int z=1; z<=slices; z++) {
                    imp.setPositionWithoutUpdate(c, z, t);
                    tmp1Stack.addSlice(null, imp.getProcessor());
                }
                ImagePlus tmp1 = new ImagePlus("tmp", tmp1Stack);
                tmp1.setCalibration(imp.getCalibration());
                tmp1.setRoi(roi);
                ImagePlus tmp2 = reslice(tmp1);
                int slices2 = tmp2.getStackSize();
                if (imp2==null) {
                    imp2 = tmp2.createHyperStack("Reslice of "+imp.getTitle(), channels, slices2, frames, tmp2.getBitDepth());
                    stack2 = imp2.getStack();
                }
                ImageStack tmp2Stack = tmp2.getStack();
                for (int z=1; z<=slices2; z++) {
                    imp.setPositionWithoutUpdate(c, z, t);
                    int n2 = imp2.getStackIndex(c, z, t);
                    stack2.setPixels(tmp2Stack.getPixels(z), n2);
                }
            }
        }
        imp.setPosition(c1, z1, t1);
        if (channels>1 && imp.isComposite()) {
            imp2 = new CompositeImage(imp2, ((CompositeImage)imp).getMode());
            ((CompositeImage)imp2).copyLuts(imp);
        }
        return imp2;
    }

    ImagePlus resliceTimeLapseHyperstack(ImagePlus imp) {
        int channels = imp.getNChannels();
        int frames = imp.getNFrames();
        int c1 = imp.getChannel();
        int t1 = imp.getFrame();
        int width = imp.getWidth();
        int height = imp.getHeight();
        ImagePlus imp2 = null;
        ImageStack stack2 = null;
        Roi roi = imp.getRoi();
        int z = 1;
        for (int c=1; c<=channels; c++) {
            ImageStack tmp1Stack = new ImageStack(width, height);
            for (int t=1; t<=frames; t++) {
                imp.setPositionWithoutUpdate(c, z, t);
                tmp1Stack.addSlice(null, imp.getProcessor());
            }
            ImagePlus tmp1 = new ImagePlus("tmp", tmp1Stack);
            tmp1.setCalibration(imp.getCalibration());
            tmp1.setRoi(roi);
            ImagePlus tmp2 = reslice(tmp1);
            int frames2 = tmp2.getStackSize();
            if (imp2==null) {
                imp2 = tmp2.createHyperStack("Reslice of "+imp.getTitle(), channels, 1, frames2, tmp2.getBitDepth());
                stack2 = imp2.getStack();
            }
            ImageStack tmp2Stack = tmp2.getStack();
            for (int t=1; t<=frames2; t++) {
                imp.setPositionWithoutUpdate(c, z, t);
                int n2 = imp2.getStackIndex(c, z, t);
                stack2.setPixels(tmp2Stack.getPixels(z), n2);
            }
        }
        imp.setPosition(c1, 1, t1);
        if (channels>1 && imp.isComposite()) {
            imp2 = new CompositeImage(imp2, ((CompositeImage)imp).getMode());
            ((CompositeImage)imp2).copyLuts(imp);
        }
        return imp2;
    }

    boolean showDialog(ImagePlus imp) {
        Calibration cal = imp.getCalibration();
        if (cal.pixelDepth<0.0)
            cal.pixelDepth = -cal.pixelDepth;
        String units = cal.getUnits();
        if (cal.pixelWidth==0.0)
            cal.pixelWidth = 1.0;
        inputZSpacing = cal.pixelDepth;
        double outputSpacing = cal.pixelDepth;
        Roi roi = imp.getRoi();
        boolean line = roi!=null && roi.getType()==Roi.LINE;
        if (line) saveLineInfo(roi);
        String macroOptions = Macro.getOptions();
        boolean macroRunning = macroOptions!=null;
        if (macroRunning) {
            if (macroOptions.indexOf("input=")!=-1)
                macroOptions = macroOptions.replaceAll("slice=", "slice_count=");
            macroOptions = macroOptions.replaceAll("slice=", "output=");
            Macro.setOptions(macroOptions);
            nointerpolate = false;
        } else {
            startAt = startAtS;
            rotate = rotateS;
            flip = flipS;
            sliceCount = sliceCountS;
        }
        GenericDialog gd = new GenericDialog("Reslice");
        gd.addNumericField("Output spacing ("+units+"):", outputSpacing, 3);
        if (line) {
            if (!IJ.isMacro()) outputSlices=sliceCount;
            gd.addNumericField("Slice_count:", outputSlices, 0);
        } else
            gd.addChoice("Start at:", starts, startAt);
        gd.addCheckbox("Flip vertically", flip);
        gd.addCheckbox("Rotate 90 degrees", rotate);
        gd.addCheckbox("Avoid interpolation", nointerpolate);
        gd.setInsets(0, 32, 0);
        gd.addMessage("(use 1 pixel spacing)");
        gd.setInsets(15, 0, 0);
        gd.addMessage("Voxel size: "+d2s(cal.pixelWidth)+"x"+d2s(cal.pixelHeight)
            +"x"+d2s(cal.pixelDepth)+" "+cal.getUnit());
        gd.setInsets(5, 0, 0);
        gd.addMessage("Output size: "+getSize(cal.pixelDepth,outputSpacing,outputSlices)+"              ");
        fields = gd.getNumericFields();
        if (!macroRunning) {
            for (int i=0; i<fields.size(); i++)
                ((TextField)fields.elementAt(i)).addTextListener(this);
        }
        checkboxes = gd.getCheckboxes();
        if (!macroRunning)
            ((Checkbox)checkboxes.elementAt(2)).addItemListener(this);
        message = (Label)gd.getMessage();
        gd.addHelp(IJ.URL+"/docs/menus/image.html#reslice");
        gd.showDialog();
        if (gd.wasCanceled())
            return false;
        outputZSpacing = gd.getNextNumber()/cal.pixelWidth;
        if (line) {
            outputSlices = (int)gd.getNextNumber();
            if (!IJ.isMacro()) sliceCount=outputSlices;
            imp.setRoi(roi);
        } else
            startAt = gd.getNextChoice();
        flip = gd.getNextBoolean();
        rotate = gd.getNextBoolean();
        nointerpolate = gd.getNextBoolean();
        if (!macroRunning) {
            Prefs.avoidResliceInterpolation = nointerpolate;
            startAtS = startAt;
            rotateS = rotate;
            flipS = flip;
            sliceCountS = sliceCount;
        }
        return true;
    }
    
    String d2s(double n) {
        String s;
        if (n==(int)n)
            s = ResultsTable.d2s(n, 0);
        else
            s = ResultsTable.d2s(n, 2);
        if (s.indexOf(".")!=-1 && s.endsWith("0"))
            s = s.substring(0, s.length()-1);
        return s;
    }

    void saveLineInfo(Roi roi) {
         Line line = (Line)roi;
         gx1 = line.x1;
         gy1 = line.y1;
         gx2 = line.x2;
         gy2 = line.y2;
         gLength = line.getRawLength();
    }

    ImagePlus resliceRectOrLine(ImagePlus imp) {
         double x1 = 0.0;
         double y1 = 0.0;
         double x2 = 0.0;
         double y2 = 0.0;
         double xInc = 0.0;
         double yInc = 0.0;
         noRoi = false;

         Roi roi = imp.getRoi();
         if (roi==null) {
                noRoi = true;
                imp.setRoi(0, 0, imp.getWidth(), imp.getHeight());
                roi = imp.getRoi();
         }
         if (roi.getType()==Roi.RECTANGLE) {
                Rectangle r = roi.getBounds();
                if (startAt.equals(starts[0])) { // top
                    x1 = r.x;
                    y1 = r.y;
                    x2 = r.x + r.width;
                    y2 = r.y;
                    xInc = 0.0;
                    yInc = outputZSpacing;
                    outputSlices =  (int)(r.height/outputZSpacing);
                } else if (startAt.equals(starts[1])) { // left
                    x1 = r.x;
                    y1 = r.y;
                    x2 = r.x;
                    y2 = r.y + r.height;
                    xInc = outputZSpacing;
                    yInc = 0.0;
                    outputSlices =  (int)(r.width/outputZSpacing);
                } else if (startAt.equals(starts[2])) { // bottom
                    x1 = r.x;
                    y1 = r.y + r.height-1;
                    x2 = r.x + r.width;
                    y2 = r.y + r.height-1;
                    xInc = 0.0;
                    yInc = -outputZSpacing;
                    outputSlices =  (int)(r.height/outputZSpacing);
                } else if (startAt.equals(starts[3])) { // right
                    x1 = r.x + r.width-1;
                    y1 = r.y;
                    x2 = r.x + r.width-1;
                    y2 = r.y + r.height;
                    xInc = -outputZSpacing;
                    yInc = 0.0;
                    outputSlices =  (int)(r.width/outputZSpacing);
                }
         } else if (roi.getType()==Roi.LINE) {
                Line line = (Line)roi;
                x1 = line.x1;
                y1 = line.y1;
                x2 = line.x2;
                y2 = line.y2;
                double dx = x2 - x1;
                double dy = y2 - y1;
                double nrm = Math.sqrt(dx*dx + dy*dy)/outputZSpacing;
                xInc = -(dy/nrm);
                yInc = (dx/nrm);
         } else
                return null;

         if (outputSlices==0) {
                IJ.error("Reslicer", "Output Z spacing ("+IJ.d2s(outputZSpacing,0)+" pixels) is too large.\n"
                    +"Is the voxel size in Image>Properties correct?.");
                return null;
         }
         boolean virtualStack = imp.getStack().isVirtual();
         String status = null;
         ImagePlus imp2 = null;
         ImageStack stack2 = null;
         boolean isStack = imp.getStackSize()>1;
         IJ.resetEscape();
         boolean macro = IJ.isMacro();
         for (int i=0; i<outputSlices; i++) {
            if (virtualStack)
                status = outputSlices>1?(i+1)+"/"+outputSlices+", ":"";
            ImageProcessor ip = getSlice(imp, x1, y1, x2, y2, status);
            if (macro)
                IJ.showProgress(i,outputSlices-1);
            else
                drawLine(x1, y1, x2, y2, imp);
            if (stack2==null) {
                stack2 = createOutputStack(imp, ip);
                if (stack2==null || stack2.getSize()<outputSlices) return null; // out of memory
            }
            stack2.setPixels(ip.getPixels(), i+1);
            x1+=xInc; x2+=xInc; y1+=yInc; y2+=yInc;
            if (IJ.escapePressed()) {
                IJ.beep();
                imp.draw();
                IJ.showProgress(1.0);
                return null;
            }
         }
         if (macro) IJ.showProgress(1.0);
         return new ImagePlus("Reslice of "+imp.getShortTitle(), stack2);
    }

    ImageStack createOutputStack(ImagePlus imp, ImageProcessor ip) {
         int bitDepth = imp.getBitDepth();
         int w2=ip.getWidth(), h2=ip.getHeight(), d2=outputSlices;
         int flags = NewImage.FILL_BLACK + NewImage.CHECK_AVAILABLE_MEMORY;
         ImagePlus imp2 = NewImage.createImage("temp", w2, h2, d2, bitDepth, flags);
         if (imp2!=null && imp2.getStackSize()==d2)
                IJ.showStatus("Reslice... (press 'Esc' to abort)");
         if (imp2==null)
                return null;
         else {
                ImageStack stack2 = imp2.getStack();
                stack2.setColorModel(ip.getColorModel());
                return stack2;
         }
    }

    ImageProcessor getSlice(ImagePlus imp, double x1, double y1, double x2, double y2, String status) {
         Roi roi = imp.getRoi();
         int roiType = roi!=null?roi.getType():0;
         ImageStack stack = imp.getStack();
         int stackSize = stack.size();
         ImageProcessor ip,ip2=null;
         float[] line = null;
         boolean ortho = (int)x1==x1&&(int)y1==y1&&x1==x2||y1==y2;
         for (int i=0; i<stackSize; i++) {
                ip = stack.getProcessor(flip?stackSize-i:i+1);
                if (roiType==Roi.POLYLINE || roiType==Roi.FREELINE)
                    line = getIrregularProfile(roi, ip);
                else if (ortho)
                    line = getOrthoLine(ip, (int)x1, (int)y1, (int)x2, (int)y2, line);
                else
                    line = getLine(ip, x1, y1, x2, y2, line);
                if (rotate) {
                    if (i==0) ip2 = ip.createProcessor(stackSize, line.length);
                    putColumn(ip2, i, 0, line, line.length);
                } else {
                    if (i==0) ip2 = ip.createProcessor(line.length, stackSize);
                    putRow(ip2, 0, i, line, line.length);
                }
                if (status!=null) IJ.showStatus("Slicing: "+status +i+"/"+stackSize);
         }
         Calibration cal = imp.getCalibration();
         double zSpacing = inputZSpacing/cal.pixelWidth;
         if (zSpacing!=1.0) {
                ip2.setInterpolate(true);
                if (rotate)
                    ip2 = ip2.resize((int)(stackSize*zSpacing), line.length);
                else
                    ip2 = ip2.resize(line.length, (int)(stackSize*zSpacing));
         }
         return ip2;
    }

    public void putRow(ImageProcessor ip, int x, int y, float[] data, int length) {
         if (rgb) {
                for (int i=0; i<length; i++)
                    ip.putPixel(x++, y, Float.floatToIntBits(data[i]));
         } else {
                for (int i=0; i<length; i++)
                    ip.setf(x++, y, data[i]);
         }
    }

    public void putColumn(ImageProcessor ip, int x, int y, float[] data, int length) {
         if (rgb) {
                for (int i=0; i<length; i++)
                    ip.putPixel(x, y++, Float.floatToIntBits(data[i]));
         } else {
                for (int i=0; i<length; i++)
                    ip.setf(x, y++, data[i]);
         }
    }

    float[] getIrregularProfile(Roi roi, ImageProcessor ip) {
         if (x==null)
                doIrregularSetup(roi);
         float[] values = new float[(int)length];
         double leftOver = 1.0;
         double distance = 0.0;
         int index;
         double oldx=xbase, oldy=ybase;
         for (int i=0; i<n; i++) {
                double len = segmentLengths[i];
                if (len==0.0)
                    continue;
                double xinc = dx[i]/len;
                double yinc = dy[i]/len;
                double start = 1.0-leftOver;
                double rx = xbase+x[i]+start*xinc;
                double ry = ybase+y[i]+start*yinc;
                double len2 = len - start;
                int n2 = (int)len2;
                for (int j=0; j<=n2; j++) {
                    index = (int)distance+j;
                    if (index<values.length) {
                         if (notFloat)
                                values[index] = (float)ip.getInterpolatedPixel(rx, ry);
                         else if (rgb) {
                                int rgbPixel = ((ColorProcessor)ip).getInterpolatedRGBPixel(rx, ry);
                                values[index] = Float.intBitsToFloat(rgbPixel&0xffffff);
                         } else
                                values[index] = (float)ip.getInterpolatedValue(rx, ry);
                    }
                    rx += xinc;
                    ry += yinc;
                }
                distance += len;
                leftOver = len2 - n2;
         }

         return values;

    }

    void doIrregularSetup(Roi roi) {
         n = ((PolygonRoi)roi).getNCoordinates();
         int[] ix = ((PolygonRoi)roi).getXCoordinates();
         int[] iy = ((PolygonRoi)roi).getYCoordinates();
         x = new double[n];
         y = new double[n];
         for (int i=0; i<n; i++) {
                x[i] = ix[i];
                y[i] = iy[i];
         }
         if (roi.getType()==Roi.FREELINE) {
                // smooth line
                for (int i=1; i<n-1; i++) {
                    x[i] = (x[i-1] + x[i] + x[i+1])/3.0+0.5;
                    y[i] = (y[i-1] + y[i] + y[i+1])/3.0+0.5;
                }
         }
         Rectangle r = roi.getBounds();
         xbase = r.x;
         ybase = r.y;
         length = 0.0;
         double segmentLength;
         double xdelta, ydelta;
         segmentLengths = new double[n];
         dx = new double[n];
         dy = new double[n];
         for (int i=0; i<(n-1); i++) {
                xdelta = x[i+1] - x[i];
                ydelta = y[i+1] - y[i];
                segmentLength = Math.sqrt(xdelta*xdelta+ydelta*ydelta);
                length += segmentLength;
                segmentLengths[i] = segmentLength;
                dx[i] = xdelta;
                dy[i] = ydelta;
         }
    }

    private float[] getLine(ImageProcessor ip, double x1, double y1, double x2, double y2, float[] data) {
         double dx = x2-x1;
         double dy = y2-y1;
         int n = (int)Math.round(Math.sqrt(dx*dx + dy*dy));
         if (data==null)
                data = new float[n];
         double xinc = dx/n;
         double yinc = dy/n;
         double rx = x1;
         double ry = y1;
         for (int i=0; i<n; i++) {
                if (notFloat)
                    data[i] = (float)ip.getInterpolatedPixel(rx, ry);
                else if (rgb) {
                    int rgbPixel = ((ColorProcessor)ip).getInterpolatedRGBPixel(rx, ry);
                    data[i] = Float.intBitsToFloat(rgbPixel&0xffffff);
                } else
                    data[i] = (float)ip.getInterpolatedValue(rx, ry);
                rx += xinc;
                ry += yinc;
         }
         return data;
    }
    
    private float[] getOrthoLine(ImageProcessor ip, int x1, int y1, int x2, int y2, float[] data) {
        int dx = x2-x1;
        int dy = y2-y1;
        int n = Math.max(Math.abs(dx), Math.abs(dy));
        if (data==null)
            data = new float[n];
        int xinc = dx/n;
        int yinc = dy/n;
        for (int i=0; i<n; i++) {
            if (rgb) {
                int rgbPixel = ((ColorProcessor)ip).getPixel(x1, y1);
                data[i] = Float.intBitsToFloat(rgbPixel&0xffffff);
            } else
                data[i] = ip.getf(x1,y1);
            x1 += xinc;
            y1 += yinc;
        }
        return data;
    }

    void drawLine(double x1, double y1, double x2, double y2, ImagePlus imp) {
         ImageCanvas ic = imp.getCanvas();
         if (ic==null)
            return;
         Graphics g = ic.getGraphics();
         ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_ANTIALIASING,  RenderingHints.VALUE_ANTIALIAS_ON);
         g.setColor(lineColor);
         g.drawLine(ic.screenX((int)(x1+0.5)), ic.screenY((int)(y1+0.5)), ic.screenX((int)(x2+0.5)), ic.screenY((int)(y2+0.5)));
    }

    public void textValueChanged(TextEvent e) {
        updateSize();
    }

    public void itemStateChanged(ItemEvent e) {
        if (IJ.isMacOSX()) IJ.wait(100);
        Checkbox cb = (Checkbox)checkboxes.elementAt(2);
        nointerpolate = cb.getState();
        updateSize();
    }

    void updateSize() {
         //double inSpacing = Tools.parseDouble(((TextField)fields.elementAt(0)).getText(),0.0);
         double outSpacing = Tools.parseDouble(((TextField)fields.elementAt(0)).getText(),0.0);
         int count = 0;
         boolean lineSelection = fields.size()==2;
         if (lineSelection) {
                count = (int)Tools.parseDouble(((TextField)fields.elementAt(1)).getText(), 0.0);
                if (count>0) makePolygon(count, outSpacing);
         }
         String size = getSize(inputZSpacing, outSpacing, count);
         message.setText("Output Size: "+size);
    }

    String getSize(double inSpacing, double outSpacing, int count) {
         int size = getOutputStackSize(inSpacing, outSpacing, count);
         int mem = getAvailableMemory();
         String available = mem!=-1?" ("+mem+"MB free)":"";
         if (message!=null)
                message.setForeground(mem!=-1&&size>mem?Color.red:Color.black);
         if (size>0)
                return size+"MB"+available;
         else
                return "<1MB"+available;
    }

    void makePolygon(int count, double outSpacing) {
        int[] x = new int[4];
        int[] y = new int[4];
        Calibration cal = imp.getCalibration();
        double cx = cal.pixelWidth; //corrects preview for x calibration
        double cy = cal.pixelHeight;    //corrects preview for y calibration
        x[0] = (int)gx1;
        y[0] = (int)gy1;
        x[1] = (int)gx2;
        y[1] = (int)gy2;
        double dx = gx2 - gx1;
        double dy = gy2 - gy1;
        double nrm = Math.sqrt(dx*dx + dy*dy)/outSpacing;
        double xInc = -(dy/(cx*nrm));   //cx scales the x increment
        double yInc = (dx/(cy*nrm));    //cy scales the y increment
        x[2] = x[1] + (int)(xInc*count);
        y[2] = y[1] + (int)(yInc*count);
        x[3] = x[0] + (int)(xInc*count);
        y[3] = y[0] + (int)(yInc*count);
        imp.setRoi(new PolygonRoi(x, y, 4, PolygonRoi.FREEROI));
    }

    int getOutputStackSize(double inSpacing, double outSpacing, int count) {
        Roi roi = imp.getRoi();
        int width = imp.getWidth();
        int height = imp.getHeight();
        if (roi!=null) {
            Rectangle r = roi.getBounds();
            width = r.width;
            width = r.height;
        }
        int type = roi!=null?roi.getType():0;
        int stackSize = imp.getStackSize();
        double size = 0.0;
        if (type==Roi.RECTANGLE) {
            size = width*height*stackSize;
            if (outSpacing>0&&!nointerpolate) size *= inSpacing/outSpacing;
        } else
            size = gLength*count*stackSize;
        int bits = imp.getBitDepth();
        switch (bits) {
            case 16: size*=2; break;
            case 24: case 32: size*=4; break;
        }
        return (int)Math.round(size/1048576.0);
    }

    int getAvailableMemory() {
         long max = IJ.maxMemory();
         if (max==0) return -1;
         long inUse = IJ.currentMemory();
         long available = max - inUse;
         return (int)((available+524288L)/1048576L);
    }
}