#9 Screenshot using OpenGl buffer

android/src/main/java/cz/nic/tablexia/android/AndroidLauncher.java

@@ -36,14 +36,18 @@ public class AndroidLauncher extends AndroidApplication {
                 int width = Gdx.graphics.getWidth();
                 int height = Gdx.graphics.getHeight();
                 try {
-                    Bitmap sb = Bitmap.createBitmap(screen, width, height, Bitmap.Config.ARGB_8888);
+                    for (int i = 0; i < screen.length; ++i) {
+                        // The alpha and green channels' positions are preserved while the red and blue are swapped
+                        screen[i] = ((screen[i] & 0xff00ff00)) | ((screen[i] & 0x000000ff) << 16) | ((screen[i] & 0x00ff0000) >> 16);
+                    }
+                    Bitmap sb = Bitmap.createBitmap(screen, width, height, Bitmap.Config.RGB_565);
                     String file_path = Environment.getExternalStorageDirectory().getAbsolutePath();
                     File dir = new File(file_path);
                     dir.mkdirs();
                     File file = new File(dir, "screenshot_tablexia_" + System.currentTimeMillis() + ".png");
 
                     FileOutputStream fOut = new FileOutputStream(file);
-                    sb.compress(Bitmap.CompressFormat.PNG, 85, fOut);
+                    sb.compress(Bitmap.CompressFormat.PNG, 100, fOut);
                     sb.recycle();
                     fOut.flush();
                     fOut.close();

core/src/cz/nic/tablexia/Tablexia.java

@@ -7,6 +7,7 @@ import com.badlogic.gdx.graphics.GL30;
 import net.engio.mbassy.listener.Handler;
 
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.Locale;
 
 import cz.nic.tablexia.bus.ApplicationBus;
@@ -179,24 +180,10 @@ public class Tablexia extends TablexiaApplication {
         int height = Gdx.graphics.getHeight();
         int bt[] = new int[width * height];
 
-            ByteBuffer pbuf = ByteBuffer.allocateDirect(width * height * 4);
-        //pbuf.order(ByteOrder.LITTLE_ENDIAN);
+        ByteBuffer pbuf = ByteBuffer.allocateDirect(width * height * 4);
+        pbuf.order(ByteOrder.nativeOrder());
         Gdx.gl.glReadPixels(0, 0, width, height, GL30.GL_RGBA, GL30.GL_UNSIGNED_BYTE, pbuf);
-
-        for (int i = 0; i < height; i++) {//remember, that OpenGL bitmap is incompatible with Android bitmap
-            //and so, some correction need.
-            for (int j = 0; j < width; j++) {
-                int pr = pbuf.get(4 * i * j + j);
-                int pg = pbuf.get(4 * i * j + j + 1);
-                int pb = pbuf.get(4 * i * j + j + 2);
-                //int pa = pbuf.get(4 * i * j + j + 3);
-                int pa = 1;
-
-                int color = (pa << 24) | (pr << 16) | (pg << 8) | pb;
-                bt[(i * j) + j] = color;
-            }
-        }
-
+        pbuf.asIntBuffer().get(bt);
         if (listener != null) {
             listener.screenshotTaken(bt);
         }