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 startAt = starts[0];
	private static boolean rotate;
	private static boolean flip;
	private static 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;

	// 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) {
			IJ.error("Reslice...", "Cannot reslice z=1 hyperstacks");
			return null;
		}
		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;
	}

	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();
		if (macroOptions!=null) {
			if (macroOptions.indexOf("input=")!=-1)
				macroOptions = macroOptions.replaceAll("slice=", "slice_count=");
			macroOptions = macroOptions.replaceAll("slice=", "output=");
			Macro.setOptions(macroOptions);
			nointerpolate = false;
		}
		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 (!IJ.macroRunning()) {
			for (int i=0; i<fields.size(); i++)
				((TextField)fields.elementAt(i)).addTextListener(this);
		}
		checkboxes = gd.getCheckboxes();
		if (!IJ.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;
		//inputZSpacing = gd.getNextNumber();
		//if (cal.pixelDepth==0.0) cal.pixelDepth = 1.0;
		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 (!IJ.isMacro())
			Prefs.avoidResliceInterpolation = nointerpolate;
		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();
		 for (int i=0; i<outputSlices; i++)	{
				if (virtualStack)
					status = outputSlices>1?(i+1)+"/"+outputSlices+", ":"";
				ImageProcessor ip = getSlice(imp, x1, y1, x2, y2, status);
				//IJ.log(i+" "+x1+" "+y1+" "+x2+" "+y2+"   "+ip);
				if (isStack) 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(); return null;}
		 }
		 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.getSize();
		 ImageProcessor ip,ip2=null;
		 float[] line = null;
		 boolean ortho = (int)x1==x1&&(int)y1==y1&&x1==x2||y1==y2;
		//boolean vertical = x1==x2 && (roi==null||roiType==Roi.RECTANGLE);
		//if (rotate) vertical = !vertical;
		 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.putPixelValue(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.putPixelValue(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;
				//double d=0;;
				//IJ.write("new segment: "+IJ.d2s(xinc)+" "+IJ.d2s(yinc)+" "+IJ.d2s(len)+" "+IJ.d2s(len2)+" "+IJ.d2s(n2)+" "+IJ.d2s(leftOver));
				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;
		 int rx = x1;
		 int ry = y1;
		 for (int i=0; i<n; i++) {
		 		if (notFloat)
					data[i] = (float)ip.getPixel(rx, ry);
				else if (rgb) {
					int rgbPixel = ((ColorProcessor)ip).getPixel(rx, ry);
					data[i] = Float.intBitsToFloat(rgbPixel&0xffffff);
				} else
					data[i] = (float)ip.getPixelValue(rx, ry);
				rx += xinc;
				ry += 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();
		 g.setColor(new Color(1f, 1f, 0f, 0.4f));
		 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);
	}
}
