X-Git-Url: https://gitweb.fperrin.net/?a=blobdiff_plain;f=tim%2Fprune%2Fgui%2FImageUtils.java;h=d152ecca5b1c78549d6fcb7ea0f65878984a5436;hb=4d5796d02a15808311c09448d79e6e7d1de9d636;hp=4b46959f55c575d46fe0670851925fd91580cdf6;hpb=5625a1abadb5f2ca5f017fe7dbda1d5141cb637b;p=GpsPrune.git

diff --git a/tim/prune/gui/ImageUtils.java b/tim/prune/gui/ImageUtils.java
index 4b46959..d152ecc 100644
--- a/tim/prune/gui/ImageUtils.java
+++ b/tim/prune/gui/ImageUtils.java
@@ -2,6 +2,7 @@ package tim.prune.gui;
 
 import java.awt.Dimension;
 import java.awt.Graphics;
+import java.awt.Graphics2D;
 import java.awt.Image;
 import java.awt.image.BufferedImage;
 import java.awt.image.ConvolveOp;
@@ -69,18 +70,67 @@ public abstract class ImageUtils
 	 */
 	public static Dimension getThumbnailSize(int inOrigWidth, int inOrigHeight, int inMaxWidth, int inMaxHeight)
 	{
-		if (inMaxWidth <= 0 || inMaxHeight <= 0)
-		{
-			//System.out.println("Can't do it - maxwidth=" + inMaxWidth + ", maxheight=" + inMaxHeight);
-			return new Dimension(0,0);
-		}
+		if (inMaxWidth <= 0 || inMaxHeight <= 0) {return new Dimension(1, 1);}
 		// work out maximum zoom ratio available so that thumbnail isn't too big
 		double xZoom = inMaxWidth * 1.0 / inOrigWidth;
 		double yZoom = inMaxHeight * 1.0 / inOrigHeight;
 		double zoom = (xZoom > yZoom?yZoom:xZoom);
 		// Don't make thumbnail bigger than picture
 		if (zoom > 1.0) {return new Dimension(inOrigWidth, inOrigHeight);}
+
 		// calculate new width and height
-		return new Dimension ((int) (zoom * inOrigWidth), (int) (zoom * inOrigHeight));
+		final int xSize = (int) (zoom * inOrigWidth);
+		final int ySize = (int) (zoom * inOrigHeight);
+		if (xSize <= 0 || ySize <= 0) {return new Dimension(1, 1);}
+		return new Dimension (xSize, ySize);
+	}
+
+
+	/**
+	 * Create a new image by rotating and scaling the given one
+	 * @param inImage input image
+	 * @param inMaxWidth maximum width of output image
+	 * @param inMaxHeight maximum height of output image
+	 * @param inRotationDegrees number of degrees to rotate clockwise (0, 90, 180 or 270)
+	 * @return rotated, scaled image
+	 */
+	public static BufferedImage rotateImage(Image inImage, int inMaxWidth, int inMaxHeight, int inRotationDegrees)
+	{
+		// Create scaled image of suitable size
+		boolean isRotated = (inRotationDegrees % 180 != 0);
+		int origWidth = inImage.getWidth(null);
+		int origHeight = inImage.getHeight(null);
+		int thumbWidth = isRotated?origHeight:origWidth;
+		int thumbHeight = isRotated?origWidth:origHeight;
+		Dimension scaledSize = getThumbnailSize(thumbWidth, thumbHeight, inMaxWidth, inMaxHeight);
+		BufferedImage result = new BufferedImage(scaledSize.width, scaledSize.height, BufferedImage.TYPE_INT_RGB);
+		// Do different things according to rotation angle (a bit messy, sorry!)
+		if (inRotationDegrees == 0)
+		{
+			// Not rotated, so just copy image directly
+			result.getGraphics().drawImage(inImage, 0, 0, scaledSize.width, scaledSize.height, null);
+		}
+		else
+		{
+			// Need to use Graphics2D for rotation, not Graphics
+			Graphics2D g2d = result.createGraphics();
+			switch (inRotationDegrees)
+			{
+				case 90:
+					g2d.rotate(Math.PI / 2, 0.0, 0.0);
+					g2d.drawImage(inImage, 0, -scaledSize.width, scaledSize.height, scaledSize.width, null);
+					break;
+				case 180:
+					g2d.rotate(Math.PI, scaledSize.width/2.0, scaledSize.height/2.0);
+					g2d.drawImage(inImage, 0, 0, scaledSize.width, scaledSize.height, null);
+					break;
+				case 270:
+					g2d.rotate(Math.PI * 3/2, 0.0, 0.0);
+					g2d.drawImage(inImage, -scaledSize.height, 0, scaledSize.height, scaledSize.width, null);
+			}
+			// Clear up memory
+			g2d.dispose();
+		}
+		return result;
 	}
 }