Android 纹理定距离移动

效果图：右边的文字栏上下移动，没有文字会自动停止移动。这和之前我写的纹理移动不同，之前的是循环移动，这次是定位移动。

顶点着色器：

uniform mat4 uMVPMatrix;attribute vec3 aPosition;attribute vec2 aTexCoor;varying vec2 vTextureCoord;void main(){   gl_Position=uMVPMatrix*vec4(aPosition,1);   vTextureCoord=aTexCoor;}

片元着色器：

precision mediump float;varying vec2 vTextureCoord;uniform sampler2D sTexture;uniform float uSpan;void main(){   vec2 st_Result=vec2(0,0);   st_Result.x=vTextureCoord.x;   st_Result.y=vTextureCoord.y+uSpan;   gl_FragColor=texture2D(sTexture,st_Result);}

java代码：（这里是核心）

package com.hl.paints;import java.nio.ByteBuffer;import java.nio.ByteOrder;import java.nio.FloatBuffer;import com.hl.utils.MatrixState;import android.opengl.GLES20;public class DrawRectMoveStop {int mProgram;int muMVPMatrixHandle;int maPositionHandle;int maTexCoorHandle;int muSpanHandle;FloatBuffer mVertexBuffer;FloatBuffer mTexCoorBuffer;int vCount=0;public DrawRectMoveStop(float width,float height,float s,float t,int mProgram) {// TODO Auto-generated constructor stubinitVertex(width,height,s,t);initShader(mProgram);}private void initVertex(float width, float height,<span style="color:#ff0000;">float s,float t</span>) {// 纹理的传入，目的是在最开始是不是将整个图片放进矩形框中，而是一部分// TODO Auto-generated method stubvCount = 6;float w = width / 2;float h = height / 2;float vertices[] = new float[] { -w,  h, 0,-w, -h, 0, w, -h, 0, w, -h, 0, w,  h, 0,-w,  h, 0,};ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);vbb.order(ByteOrder.nativeOrder());mVertexBuffer = vbb.asFloatBuffer();mVertexBuffer.put(vertices);mVertexBuffer.position(0);float texCoor[] = new float[] { 0, 0, 0, t, s, t, s, t, s, 0, 0, 0 };ByteBuffer cbb = ByteBuffer.allocateDirect(texCoor.length * 4);cbb.order(ByteOrder.nativeOrder());mTexCoorBuffer = cbb.asFloatBuffer();mTexCoorBuffer.put(texCoor);mTexCoorBuffer.position(0);}private void initShader(int mProgram) {// TODO Auto-generated method stubthis.mProgram = mProgram;muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");maTexCoorHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoor");muSpanHandle=GLES20.glGetUniformLocation(mProgram, "uSpan");}public void drawSelf(int texId,float currStart){GLES20.glUseProgram(mProgram);GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 3*4, mVertexBuffer);GLES20.glVertexAttribPointer(maTexCoorHandle, 2, GLES20.GL_FLOAT, false, 2*4, mTexCoorBuffer);GLES20.glEnableVertexAttribArray(maPositionHandle);GLES20.glEnableVertexAttribArray(maTexCoorHandle);GLES20.glUniform1f(muSpanHandle, currStart);GLES20.glActiveTexture(GLES20.GL_TEXTURE0);GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texId);GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vCount);}}

使用代码：

        private DrawRectMoveStop benRightText;        BUTTON_BEN_RIGHT3_WIDTH = 2.0f * ratio * 0.23f;BUTTON_BEN_RIGHT3_HEIGHT = 1.4f;BUTTON_BEN_RIGHT3_XOFFSET = ratio - 2.0f * ratio * 0.23f / 2;BUTTON_BEN_RIGHT3_YOFFSET = 1.0f - 0.15f - 0.37f - 0.02f - 0.7f;benRightText = new DrawRectMoveStop(BUTTON_BEN_RIGHT3_WIDTH, BUTTON_BEN_RIGHT3_HEIGHT,<span style="color:#ff0000;"> 1.0f, 0.7f</span>, ShaderManager.getMoveTextureShaderProgram());

       //1.0f and 0.7f 是根据纹理图片和宽度计算的。效果图中的右边文字部分，是图片形式的。

        <pre name="code" class="java">        MatrixState.pushMatrix();MatrixState.translate(BUTTON_BEN_RIGHT3_XOFFSET, BUTTON_BEN_RIGHT3_YOFFSET, 0);benRightText.drawSelf(rText[condition], textYOffset);MatrixState.popMatrix();

private float textYOffset = 0;

        <span style="color:#ff0000;">if (UtilConfigArea.isInArea(x, y, AREA_BEN_RIGHT3)) {//onTouchEvent ACTION_MOVE:textYOffset -= dy * TOUCH_SCALE_FACTOR * 0.002f;if (textYOffset > 0.3f) {textYOffset = 0.3f;}if (textYOffset < 0.0f) {textYOffset = 0.0f;}}</span>

            注：本文里面用到一些方法，在我的其它博文中有提到，若用到，请查相关博文。