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Issue#550: double buffer pattern (#1024)

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* Basic implementation

* implement double buffer

* add unit test

* add unit test

* Add Readme

* Change local value declaration to var

* Remove unused fields
This commit is contained in:
Azureyjt
2019-10-20 23:55:36 +08:00
committed by Ilkka Seppälä
parent 82f9a6c232
commit 2217fbc5ff
11 changed files with 623 additions and 0 deletions
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double-buffer/src/main/java/com/iluwatar/doublebuffer/App.java Normal file
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/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
* <p>
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* <p>
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* <p>
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.doublebuffer;
import org.apache.commons.lang3.tuple.MutablePair;
import org.apache.commons.lang3.tuple.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
/**
* Double buffering is a term used to describe a device that has two buffers.
* The usage of multiple buffers increases the overall throughput of a device
* and helps prevents bottlenecks. This example shows using double buffer pattern
* on graphics. It is used to show one image or frame while a separate frame
* is being buffered to be shown next. This method makes animations and games
* look more realistic than the same done in a single buffer mode.
*/
public class App {
private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
/**
* Program main entry point.
* @param args runtime arguments
*/
public static void main(String[] args) {
var scene = new Scene();
List<Pair<Integer, Integer>> drawPixels = new ArrayList<>();
Pair<Integer, Integer> pixel1 = new MutablePair<>(1, 1);
Pair<Integer, Integer> pixel2 = new MutablePair<>(5, 6);
Pair<Integer, Integer> pixel3 = new MutablePair<>(3, 2);
drawPixels.add(pixel1);
drawPixels.add(pixel2);
drawPixels.add(pixel3);
scene.draw(drawPixels);
var buffer1 = scene.getBuffer();
printBlackPixelCoordinate(buffer1);
drawPixels.clear();
Pair<Integer, Integer> pixel4 = new MutablePair<>(3, 7);
Pair<Integer, Integer> pixel5 = new MutablePair<>(6, 1);
drawPixels.add(pixel4);
drawPixels.add(pixel5);
scene.draw(drawPixels);
Buffer buffer2 = scene.getBuffer();
printBlackPixelCoordinate(buffer2);
}
private static void printBlackPixelCoordinate(Buffer buffer) {
var log = "Black Pixels: ";
Pixel[] pixels = buffer.getPixels();
for (var i = 0; i < pixels.length; ++i) {
if (pixels[i] == Pixel.BLACK) {
var y = i / FrameBuffer.WIDTH;
var x = i % FrameBuffer.WIDTH;
log += " (" + x + ", " + y + ")";
}
}
LOGGER.info(log);
}
}