模糊LibGDX中的屏幕

Question

我试图为我的暂停菜单创建背景效果like this。我目前的想法是暂停，保存，打开它，高斯模糊它，然后渲染到屏幕上，并呈现菜单ontop。唯一的问题是我不知道如何有效地保存屏幕截图。

我试过用batch.setColor(0,0,0,0.7f);在背景上渲染一个褪色的图像ontop，但它没有给我我想要的模糊效果，而只是一个色调，因为我认为它会。

示例/文档非常感谢。

编辑：发现这个代码

package com.me.mygdxgame; 

import java.awt.Point; 
import java.awt.color.ColorSpace; 
import java.awt.image.BufferedImage; 
import java.awt.image.ColorModel; 
import java.awt.image.ComponentColorModel; 
import java.awt.image.DataBuffer; 
import java.awt.image.DataBufferByte; 
import java.awt.image.PixelInterleavedSampleModel; 
import java.awt.image.Raster; 
import java.awt.image.WritableRaster; 
import java.io.File; 
import java.io.IOException; 

import javax.imageio.ImageIO; 

import com.badlogic.gdx.Application.ApplicationType; 
import com.badlogic.gdx.Gdx; 
import com.badlogic.gdx.utils.ScreenUtils; 

public class ScreenShot { 

    private static final int[] RGBA_OFFSETS = { 0, 1, 2, 3 }; 
    private static final int[] RGB_OFFSETS = { 0, 1, 2 }; 

    public static void saveScreenshot(String baseName) throws IOException { 
     File createTempFile = File.createTempFile(baseName, ".png"); 
     saveScreenshot(createTempFile); 
    } 

    public static void saveScreenshot(File file) throws IOException { 
     saveScreenshot(file, false); 
    } 

    public static void saveScreenshot(File file, boolean hasAlpha) throws IOException { 
     if (Gdx.app.getType() == ApplicationType.Android) 
      return; 

     byte[] screenshotPixels = ScreenUtils.getFrameBufferPixels(true); 

     int width = Gdx.graphics.getWidth(); 
     int height = Gdx.graphics.getHeight(); 

     saveScreenshot(file, screenshotPixels, width, height, hasAlpha); 
    } 

    public static void saveScreenshot(File file, byte[] pixels, int width, int height, boolean hasAlpha) throws IOException { 
     DataBufferByte dataBuffer = new DataBufferByte(pixels, pixels.length); 

     PixelInterleavedSampleModel sampleModel = new PixelInterleavedSampleModel(DataBuffer.TYPE_BYTE, width, height, 4, 4 * width, getOffsets(hasAlpha)); 

     WritableRaster raster = Raster.createWritableRaster(sampleModel, dataBuffer, new Point(0, 0)); 

     BufferedImage img = new BufferedImage(getColorModel(hasAlpha), raster, false, null); 

     ImageIO.write(img, "png", file); 
    } 

    private static ColorModel getColorModel(boolean alpha) { 
     if (alpha) 
      return new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), new int[] { 8, 8, 8, 8 }, true, false, ComponentColorModel.TRANSLUCENT, DataBuffer.TYPE_BYTE); 
     return new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), new int[] { 8, 8, 8 }, false, false, ComponentColorModel.OPAQUE, DataBuffer.TYPE_BYTE); 
    } 

    private static int[] getOffsets(boolean alpha) { 
     if (alpha) 
      return RGBA_OFFSETS; 
     return RGB_OFFSETS; 
    } 

} 

，但它给了我这个错误，当我尝试saveScreenshot("output");

Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: java.awt.image.RasterFormatException: Incorrect scanline stride: 3200 
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:111) 
Caused by: java.awt.image.RasterFormatException: Incorrect scanline stride: 3200 

（runnign桌面版本，如果有差别有没有在Android测试。）

错误行： ImageIO.write(img, "png", file);

Answer 1

，我迟到了，但这正是你要寻找的：

https://github.com/mattdesl/lwjgl-basics/wiki/ShaderLesson5

渲染到一个场缓冲器对象使用着色器来创建模糊，然后从帧缓冲器到屏幕上绘制。