ResolutionFileResolver.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.assets.loaders.resolvers;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.assets.loaders.FileHandleResolver;
import com.badlogic.gdx.files.FileHandle;

public class ResolutionFileResolver implements FileHandleResolver {
	public static class Resolution {
		public final int portraitWidth;
		public final int portraitHeight;
		public final String suffix;

		public Resolution(int portraitWidth, int portraitHeight, String suffix) {
			this.portraitWidth = portraitWidth;
			this.portraitHeight = portraitHeight;
			this.suffix = suffix;
		}
	}

	protected final FileHandleResolver baseResolver;
	protected final Resolution[] descriptors;

	public ResolutionFileResolver(FileHandleResolver baseResolver, Resolution... descriptors) {
		this.baseResolver = baseResolver;
		this.descriptors = descriptors;
	}

	@Override
	public FileHandle resolve(String fileName) {
		Resolution bestDesc = choose(descriptors);
		FileHandle originalHandle = new FileHandle(fileName);
		FileHandle handle = baseResolver.resolve(resolve(originalHandle, bestDesc.suffix));
		if (!handle.exists())
			handle = baseResolver.resolve(fileName);
		return handle;
	}

	protected String resolve(FileHandle originalHandle, String suffix) {
		return originalHandle.parent() + "/" + suffix + "/" + originalHandle.name();
	}

	static public Resolution choose(Resolution... descriptors) {
		if (descriptors == null)
			throw new IllegalArgumentException("descriptors cannot be null.");
		int w = Gdx.graphics.getWidth(), h = Gdx.graphics.getHeight();

		// Prefer the shortest side.
		Resolution best = descriptors[0];
		if (w < h) {
			for (int i = 0, n = descriptors.length; i < n; i++) {
				Resolution other = descriptors[i];
				if (w >= other.portraitWidth && other.portraitWidth >= best.portraitWidth && h >= other.portraitHeight
						&& other.portraitHeight >= best.portraitHeight)
					best = descriptors[i];
			}
		} else {
			for (int i = 0, n = descriptors.length; i < n; i++) {
				Resolution other = descriptors[i];
				if (w >= other.portraitHeight && other.portraitHeight >= best.portraitHeight
						&& h >= other.portraitWidth && other.portraitWidth >= best.portraitWidth)
					best = descriptors[i];
			}
		}
		return best;
	}
}