Render themes: PNG scaling, fix #595

vtm-android/src/org/oscim/android/canvas/AndroidBitmap.java

@@ -1,7 +1,7 @@
 /*
  * Copyright 2013 Hannes Janetzek
  * Copyright 2016 Longri
- * Copyright 2016 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -23,6 +23,8 @@ import android.graphics.BitmapFactory;
 import android.opengl.GLES20;
 import android.opengl.GLUtils;
 
+import org.oscim.backend.CanvasAdapter;
+import org.oscim.utils.GraphicUtils;
 import org.oscim.utils.IOUtils;
 
 import java.io.ByteArrayOutputStream;
@@ -31,7 +33,7 @@ import java.io.InputStream;
 import static android.graphics.Bitmap.Config.ARGB_8888;
 
 public class AndroidBitmap implements org.oscim.backend.canvas.Bitmap {
-    final Bitmap mBitmap;
+    Bitmap mBitmap;
 
     public AndroidBitmap(InputStream inputStream) {
         Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
@@ -43,6 +45,12 @@ public class AndroidBitmap implements org.oscim.backend.canvas.Bitmap {
         mBitmap = bitmap;
     }
 
+    public AndroidBitmap(InputStream inputStream, int width, int height, int percent) {
+        this(inputStream);
+        float[] newSize = GraphicUtils.imageSize(getWidth(), getHeight(), CanvasAdapter.getScale(), width, height, percent);
+        scaleTo((int) newSize[0], (int) newSize[1]);
+    }
+
     @Override
     public boolean isValid() {
         return mBitmap != null;
@@ -117,4 +125,17 @@ public class AndroidBitmap implements org.oscim.backend.canvas.Bitmap {
             IOUtils.closeQuietly(outputStream);
         }
     }
+
+    @Override
+    public void scaleTo(int width, int height) {
+        if (getWidth() != width || getHeight() != height) {
+            // The effect of the filter argument to createScaledBitmap is not well documented in the
+            // official android docs, but according to
+            // http://stackoverflow.com/questions/2895065/what-does-the-filter-parameter-to-createscaledbitmap-do
+            // passing true results in smoother edges, less pixelation.
+            // If smoother corners improve the readability of map labels is perhaps debatable.
+            android.graphics.Bitmap scaledBitmap = android.graphics.Bitmap.createScaledBitmap(mBitmap, width, height, true);
+            mBitmap = scaledBitmap;
+        }
+    }
 }

vtm-android/src/org/oscim/android/canvas/AndroidGraphics.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2010, 2011, 2012 mapsforge.org
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2017 Longri
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
@@ -58,6 +58,11 @@ public final class AndroidGraphics extends CanvasAdapter {
         return new AndroidBitmap(inputStream);
     }
 
+    @Override
+    public Bitmap decodeBitmapImpl(InputStream inputStream, int width, int height, int percent) {
+        return new AndroidBitmap(inputStream, width, height, percent);
+    }
+
     @Override
     public Bitmap decodeSvgBitmapImpl(InputStream inputStream, int width, int height, int percent) throws IOException {
         return new AndroidSvgBitmap(inputStream, width, height, percent);

vtm-android/src/org/oscim/android/canvas/AndroidSvgBitmap.java

@@ -1,7 +1,7 @@
 /*
  * Copyright 2010, 2011, 2012 mapsforge.org
  * Copyright 2013-2014 Ludwig M Brinckmann
- * Copyright 2014-2017 devemux86
+ * Copyright 2014-2018 devemux86
  *
  * This program is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -24,6 +24,7 @@ import android.graphics.RectF;
 import com.caverock.androidsvg.SVG;
 
 import org.oscim.backend.CanvasAdapter;
+import org.oscim.utils.GraphicUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -41,34 +42,12 @@ public class AndroidSvgBitmap extends AndroidBitmap {
 
             double scale = scaleFactor / Math.sqrt((picture.getHeight() * picture.getWidth()) / defaultSize);
 
-            float bitmapWidth = (float) (picture.getWidth() * scale);
-            float bitmapHeight = (float) (picture.getHeight() * scale);
+            float[] bmpSize = GraphicUtils.imageSize(picture.getWidth(), picture.getHeight(), (float) scale, width, height, percent);
 
-            float aspectRatio = (1f * picture.getWidth()) / picture.getHeight();
-
-            if (width != 0 && height != 0) {
-                // both width and height set, override any other setting
-                bitmapWidth = width;
-                bitmapHeight = height;
-            } else if (width == 0 && height != 0) {
-                // only width set, calculate from aspect ratio
-                bitmapWidth = height * aspectRatio;
-                bitmapHeight = height;
-            } else if (width != 0 && height == 0) {
-                // only height set, calculate from aspect ratio
-                bitmapHeight = width / aspectRatio;
-                bitmapWidth = width;
-            }
-
-            if (percent != 100) {
-                bitmapWidth *= percent / 100f;
-                bitmapHeight *= percent / 100f;
-            }
-
-            android.graphics.Bitmap bitmap = android.graphics.Bitmap.createBitmap((int) Math.ceil(bitmapWidth),
-                    (int) Math.ceil(bitmapHeight), Bitmap.Config.ARGB_8888);
+            android.graphics.Bitmap bitmap = android.graphics.Bitmap.createBitmap((int) Math.ceil(bmpSize[0]),
+                    (int) Math.ceil(bmpSize[1]), Bitmap.Config.ARGB_8888);
             Canvas canvas = new Canvas(bitmap);
-            canvas.drawPicture(picture, new RectF(0, 0, bitmapWidth, bitmapHeight));
+            canvas.drawPicture(picture, new RectF(0, 0, bmpSize[0], bmpSize[1]));
 
             return bitmap;
         } catch (Exception e) {