雨滴效果

分手后的思念是犯贱 2022-08-05 13:18 180阅读 0赞

一、效果图：（这是我做的一个创意app里面的一个画面，这个界面我也在修改中）

![SouthEast][]

二、我是从OpenGL中学到的算法，然后应用在Android中。可以参看我的博客“[雨滴波纹核心代码][Link 1]”！

三、java代码：

1、定义类：

package com.gzdxid.utils;
    
    import android.opengl.GLES20;
    
    public class DrawRainRipple {
    
    	int mProgram;
    	int muMVPMatrixHandle;
    	int maPositionHandle;
    	
    	public DrawRainRipple(int mProgram) {
    		// TODO Auto-generated constructor stub
    		this.mProgram=mProgram;
    		muMVPMatrixHandle=GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
    		maPositionHandle=GLES20.glGetAttribLocation(mProgram, "aPosition");
    	}
    	
    	public void drawSelf(float[] vertices,int vCount){
    		GLES20.glUseProgram(mProgram);
    		GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);
    		GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 3*4, UtilBufferTransfer.getFloatBuffer(vertices));
    		GLES20.glEnableVertexAttribArray(maPositionHandle);
    		GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vCount);
    	}
    	
    }

2、顶点着色器：

uniform mat4 uMVPMatrix;
    attribute vec3 aPosition;
    
    void main(){
       gl_Position=uMVPMatrix*vec4(aPosition,1);
    }

3、片源着色器：

precision mediump float;
    
    void main(){
       gl_FragColor=vec4(1.0,1.0,1.0,0.2);
    }

4、应用：

private DrawRainRipple rainRipple;
    	private final int MAPX = 128;
    	private final int MAPY = 128;
    	private float[][][] wavemap = new float[2][MAPX][MAPY];
    	private int cmap = 0, nmap = 1;
    	private float damp = 500.0f;
    	private Random random = new Random();
    	private int vCount = (MAPX - 1) * (MAPY - 1) * 3 * 2;
    	private float[] vertices = new float[vCount * 3];<pre name="code" class="java">        rainRipple = new DrawRainRipple(ShaderManager.getRainRippleProgram());
    		for (int i = 0; i < MAPY; i++)
    			for (int j = 0; j < MAPX; j++)
    				for (int k = 0; k < 2; k++)
    					wavemap[k][i][j] = 0;

if (random.nextInt() % 2 == 0) {
    				wavemap[nmap][random.nextInt(MAPY - 2) + 1][random.nextInt(MAPX - 2) + 1] = 30.0f;
    				wavemap[cmap][random.nextInt(MAPY - 2) + 1][random.nextInt(MAPX - 2) + 1] = 30.0f;
    			}
    
    			float temp;
    			for (int i = 1; i < MAPY - 1; i++)
    				for (int j = 1; j < MAPX - 1; j++) {
    					temp = ((wavemap[cmap][i - 1][j] + wavemap[cmap][i + 1][j] + wavemap[cmap][i][j - 1] + wavemap[cmap][i][j + 1] + wavemap[cmap][i - 1][j + 1] + wavemap[cmap][i + 1][j + 1] + wavemap[cmap][i - 1][j - 1] + wavemap[cmap][i + 1][j - 1]) / 4) - wavemap[nmap][i][j];
    					temp = temp - (temp / damp);
    					if (temp < 0.01)
    						temp = 0;
    					wavemap[nmap][i][j] = temp;
    				}
    			int c = 0;
    			for (int i = 0; i < MAPY - 1; i++) {
    				for (int j = 0; j < MAPX - 1; j++) {
    					vertices[c++] = j * 2.0f;
    					vertices[c++] = wavemap[cmap][i][j];
    					vertices[c++] = i * 2.0f;
    					vertices[c++] = (j + 1) * 2.0f;
    					vertices[c++] = wavemap[cmap][i + 1][j + 1];
    					vertices[c++] = (i + 1) * 2.0f;
    					vertices[c++] = j * 2.0f;
    					vertices[c++] = wavemap[cmap][i + 1][j];
    					vertices[c++] = (i + 1) * 2.0f;
    
    					vertices[c++] = j * 2.0f;
    					vertices[c++] = wavemap[cmap][i][j];
    					vertices[c++] = i * 2.0f;
    					vertices[c++] = (j + 1) * 2.0f;
    					vertices[c++] = wavemap[cmap][i][j + 1];
    					vertices[c++] = i * 2.0f;
    					vertices[c++] = (j + 1) * 2.0f;
    					vertices[c++] = wavemap[cmap][i + 1][j + 1];
    					vertices[c++] = (i + 1) * 2.0f;
    
    				}
    			}
    
    			GLES20.glEnable(GLES20.GL_BLEND);
    			GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE);
    			MatrixState.pushMatrix();
    			MatrixState.translate(-0.8f, 1.8f, 2);
    			MatrixState.scale(0.006f, 0.008f, 0.009f);
    			MatrixState.rotate(180, 1, 0, 0);
    			rainRipple.drawSelf(vertices, vCount);
    			MatrixState.popMatrix();
    			GLES20.glDisable(GLES20.GL_BLEND);
    
    			int tempInt = cmap;
    			cmap = nmap;
    			nmap = tempInt;

[SouthEast]: /images/20220805/df17fa8371324b92ad4eca96faf7afbc.png
[Link 1]: http://blog.csdn.net/sh15285118586/article/details/44923635