updated by GinforJM

kumo-core/src/main/java/com/kennycason/kumo/bg/PixelBoundaryBackground.java

@@ -1,8 +1,9 @@
 package com.kennycason.kumo.bg;
 
+import com.kennycason.kumo.collide.Collidable;
 import com.kennycason.kumo.collide.RectanglePixelCollidable;
 import com.kennycason.kumo.image.CollisionRaster;
-
+import sun.font.FontDesignMetrics;
 import javax.imageio.ImageIO;
 import java.awt.*;
 import java.awt.image.BufferedImage;
@@ -16,7 +17,7 @@
  * @author kenny
  * @version 2014.06.30
  */
-public class PixelBoundaryBackground implements Background {
+public class PixelBoundryBackground implements Background {
 
     private final CollisionRaster collisionRaster;
 
@@ -28,9 +29,53 @@ public class PixelBoundaryBackground implements Background {
      * @param imageInputStream InputStream containing an image file
      * @throws IOException when fails to open file stream
      */
-    public PixelBoundaryBackground(final InputStream imageInputStream) throws IOException {
+
+    public PixelBoundryBackground(final InputStream imageInputStream) throws IOException {
         final BufferedImage bufferedImage = ImageIO.read(imageInputStream);
-        this.collisionRaster = new CollisionRaster(bufferedImage);
+        /**
+         *  preprocess the image if the image is not
+         */
+        //CS304 Issue link: https://github.com/kennycason/kumo/issues/81
+        BufferedImage b = preprocess(bufferedImage,5);
+        // changed
+        this.collisionRaster = new CollisionRaster(b);
+    }
+
+    /**
+     *
+     * @param srcImage srcImage will be preprocessed , the method will set the background to be transparent
+     * @param alpha  alpha is a transparency
+     * @return we will return a bufferedimage object which has been preprocessed
+     */
+    //CS304 Issue link: https://github.com/kennycason/kumo/issues/81
+    private BufferedImage preprocess(BufferedImage srcImage,int alpha) {
+        int imgHeight = srcImage.getHeight();//取得图片的长和宽
+        int imgWidth = srcImage.getWidth();
+        int c = srcImage.getRGB(3, 3);
+        //防止越位
+        if (alpha < 0) {
+            alpha = 0;
+        } else if (alpha > 10) {
+            alpha = 10;
+        }
+        BufferedImage bi = new BufferedImage(imgWidth, imgHeight, BufferedImage.TYPE_4BYTE_ABGR);//Create a new type that supports transparent BufferedImage
+        for(int i = 0; i < imgWidth; ++i)//Copy the contents of the original image to the new image, and set the background to transparent
+        {
+            for(int j = 0; j < imgHeight; ++j)
+            {
+                //Set the background to transparent
+                if(srcImage.getRGB(i, j) == c){
+                    bi.setRGB(i, j, c & 0x00ffffff);
+                }
+                //Set transparency
+                else{
+                    int rgb = bi.getRGB(i, j);
+                    rgb = ((alpha * 255 / 10) << 24) | (rgb & 0x00ffffff);
+                    bi.setRGB(i, j, rgb);
+                }
+            }
+        }
+        return bi;
     }
 
     /**
@@ -39,7 +84,7 @@ public PixelBoundaryBackground(final InputStream imageInputStream) throws IOExce
      * @param file a File pointing to an image
      * @throws IOException when fails to open file stream
      */
-    public PixelBoundaryBackground(final File file) throws IOException {
+    public PixelBoundryBackground(final File file) throws IOException {
         this(new FileInputStream(file));
     }
 
@@ -49,22 +94,67 @@ public PixelBoundaryBackground(final File file) throws IOException {
      * @param filepath path to an image file
      * @throws IOException when fails to open file stream
      */
-    public PixelBoundaryBackground(final String filepath) throws IOException {
+    public PixelBoundryBackground(final String filepath) throws IOException {
         this(new File(filepath));
     }
-
+
+    /**
+     *Creates a PixelBoundaryBackground using an image-path
+     *
+     * @param example a string which you want to use to be a background
+     * @param size the size of each character in the string
+     */
+    //CS304 Issue link: https://github.com/kennycason/kumo/issues/70
+    public PixelBoundryBackground(String example , int size){
+        Font font = new Font("微软雅黑", Font.BOLD, size);
+        FontDesignMetrics metrics = FontDesignMetrics.getMetrics(font);
+        int width = getWordWidth(font, example);
+        int height = metrics.getHeight();
+        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
+        Graphics2D graphics = bufferedImage.createGraphics();
+        graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+        graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
+        //Set the back to white
+        graphics.setColor(Color.WHITE);
+        graphics.fillRect(0, 0, bufferedImage.getWidth(), bufferedImage.getHeight());
+        graphics.setFont(font);
+        graphics.setColor(Color.BLACK);
+        graphics.drawString(example, 0, metrics.getAscent());//图片上写文字
+        graphics.dispose();
+        BufferedImage b = preprocess(bufferedImage,5);
+        // changed
+        this.collisionRaster = new CollisionRaster(b);
+      //  this.collisionRaster = new CollisionRaster(bufferedImage);
+      //  write(bufferedImage, "D:\\Gin_app\\IDEA\\kumocore\\test.jpg");
+    }
+
+    /**
+     *
+     * @param font the font of each character
+     * @param content the content of the input string
+     * @return return a width of a word
+     */
+    //CS304 Issue link: https://github.com/kennycason/kumo/issues/70
+    private static int getWordWidth(Font font, String content) {
+        FontDesignMetrics metrics = FontDesignMetrics.getMetrics(font);
+        int width = 0;
+        for (int i = 0; i < content.length(); i++) {
+            width += metrics.charWidth(content.charAt(i));
+        }
+        return width;
+    }
     @Override
-    public void mask(final RectanglePixelCollidable background) {
-        final Dimension dimensionOfShape = collisionRaster.getDimension();
-        final Dimension dimensionOfBackground = background.getDimension();
+    public void mask(RectanglePixelCollidable background) {
+        Dimension dimensionOfShape = collisionRaster.getDimension();
+        Dimension dimensionOfBackground = background.getDimension();
 
-        final int minY = Math.max(position.y, 0);
-        final int minX = Math.max(position.x, 0);
+        int minY = Math.max(position.y, 0);
+        int minX = Math.max(position.x, 0);
 
-        final int maxY = dimensionOfShape.height - position.y - 1;
-        final int maxX = dimensionOfShape.width - position.x - 1;
+        int maxY = dimensionOfShape.height - position.y - 1;
+        int maxX = dimensionOfShape.width - position.x - 1;
 
-        final CollisionRaster rasterOfBackground = background.getCollisionRaster();
+        CollisionRaster rasterOfBackground = background.getCollisionRaster();
 
         for (int y = 0; y < dimensionOfBackground.height; y++) {
             if (y < minY || y > maxY) {
@@ -74,6 +164,7 @@ public void mask(final RectanglePixelCollidable background) {
             } else {
                 for (int x = 0; x < dimensionOfBackground.width; x++) {
                     if (x < minX || x > maxX || collisionRaster.isTransparent(x, y)) {
+
                         rasterOfBackground.setPixelIsNotTransparent(position.x + x, position.y + y);
                     }
                 }