MipMapGenerator: add generator that uses raster

The one that uses AWT will be deprecated soon

jme3-core/src/main/java/com/jme3/util/MipMapGenerator.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2009-2012 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.util;
+
+import com.jme3.math.ColorRGBA;
+import com.jme3.math.FastMath;
+import com.jme3.texture.Image;
+import com.jme3.texture.Image.Format;
+import com.jme3.texture.image.ImageRaster;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+
+public class MipMapGenerator {
+
+    private MipMapGenerator() {
+    }
+    
+    public static Image scaleImage(Image inputImage, int outputWidth, int outputHeight) {
+        int size = outputWidth * outputHeight * inputImage.getFormat().getBitsPerPixel() / 8;
+        ByteBuffer buffer = BufferUtils.createByteBuffer(size);
+        Image outputImage = new Image(inputImage.getFormat(), 
+                                      outputWidth, 
+                                      outputHeight, 
+                                      buffer, 
+                                      inputImage.getColorSpace());
+        
+        // Perform scaling in linear colorspace for higher quality.
+        // However it requires a lot of pow() calls.. 
+        ImageRaster input = ImageRaster.create(inputImage, 0, 0, true);
+        ImageRaster output = ImageRaster.create(outputImage, 0, 0, true);
+        
+        float xRatio = ((float)(input.getWidth()  - 1)) / output.getWidth();
+        float yRatio = ((float)(input.getHeight() - 1)) / output.getHeight();
+        
+        ColorRGBA outputColor = new ColorRGBA();
+        ColorRGBA bottomLeft = new ColorRGBA();
+        ColorRGBA bottomRight = new ColorRGBA();
+        ColorRGBA topLeft = new ColorRGBA();
+        ColorRGBA topRight = new ColorRGBA();
+        
+        for (int y = 0; y < outputHeight; y++) {
+            for (int x = 0; x < outputWidth; x++) {
+                float x2f = x * xRatio;
+                float y2f = y * yRatio;
+                
+                int x2 = (int)x2f;
+                int y2 = (int)y2f;
+                
+                float xDiff = x2f - x2;
+                float yDiff = y2f - y2;
+                
+                input.getPixel(x2,     y2,     bottomLeft);
+                input.getPixel(x2 + 1, y2,     bottomRight);
+                input.getPixel(x2,     y2 + 1, topLeft);
+                input.getPixel(x2 + 1, y2 + 1, topRight);
+                
+                bottomLeft.multLocal(  (1f - xDiff) * (1f - yDiff) );
+                bottomRight.multLocal( (xDiff)      * (1f - yDiff) );
+                topLeft.multLocal(     (1f - xDiff) * (yDiff) );
+                topRight.multLocal(    (xDiff)      * (yDiff) );
+                
+                outputColor.set(bottomLeft).addLocal(bottomRight)
+                           .addLocal(topLeft).addLocal(topRight);
+                
+                output.setPixel(x, y, outputColor);
+            }
+        }
+        return outputImage;
+    }
+    
+    public static Image resizeToPowerOf2(Image original){
+        int potWidth = FastMath.nearestPowerOfTwo(original.getWidth());
+        int potHeight = FastMath.nearestPowerOfTwo(original.getHeight());
+        int potSize = Math.max(potWidth, potHeight);
+        return scaleImage(original, potSize, potSize);
+    }
+    
+    public static void generateMipMaps(Image image){
+        int width = image.getWidth();
+        int height = image.getHeight();
+
+        Image current = image;
+        ArrayList<ByteBuffer> output = new ArrayList<ByteBuffer>();
+        int totalSize = 0;
+        
+        while (height >= 1 || width >= 1){
+            output.add(current.getData(0));
+            totalSize += current.getData(0).capacity();
+
+            if (height == 1 || width == 1) {
+                break;
+            }
+
+            height /= 2;
+            width  /= 2;
+
+            current = scaleImage(current, width, height);
+        }
+
+        ByteBuffer combinedData = BufferUtils.createByteBuffer(totalSize);
+        int[] mipSizes = new int[output.size()];
+        for (int i = 0; i < output.size(); i++){
+            ByteBuffer data = output.get(i);
+            data.clear();
+            combinedData.put(data);
+            mipSizes[i] = data.capacity();
+        }
+        combinedData.flip();
+
+        // insert mip data into image
+        image.setData(0, combinedData);
+        image.setMipMapSizes(mipSizes);
+    }
+}