device-2016-07-22-112911.png
Demo 介紹
Android 的Samples上有一個例子， 里面包含了圖片中的正方形和三角形的繪制， 但是不包含紋理操作。
這個Demo中加了紋理貼圖， 以及紋理的變換（PS： 這里加了一個紋理模糊效果）。
Texture 代碼
package com.gank.demo.opengl.glsurfaceview;
import android.content.Context;
import android.opengl.GLES20;
import android.util.Log;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
/**
* Created by GankLi on 2016/7/18.
*/
public class Texture {
private final static int COORDS_POS_VERTEX = 3; // 頂點坐標寬度 (x,y,z)
private final static int COORDS_TEX_VERTEX = 2; // 紋理坐標寬度 (x,y)
private static final float[] Full_SquareCoords = new float[]{ //全屏顯示紋理 -- 從(-1, 1)逆時針繪制
-1f, 1f, 0.0f, // Position 0 // (-1, 1) (1, 1)
-1f, -1f, 0.0f, // Position 1 // (-1,-1) (1,-1)
1f, -1f, 0.0f, // Position 2
1f, 1f, 0.0f, // Position 3
};
private static final float[] Texture_SquareCoords = new float[]{ // 紋理坐標 - 從(0, 1)逆時針繪制
0, 0f, // TexCoord 0 // (0, 1) (1, 1)
1.0f, 0f, // TexCoord 1 // (0, 0) (1, 0)
1.0f, 1, // TexCoord 2
0, 1, // TexCoord 3
};
private static final short[] DrawOrder = new short[]{0, 1, 2, 2, 3, 0}; //Opengl 只支持三角形， 所以正方形的紋理是繪制兩次三角形
private static final FloatBuffer VertexBuffer = GLHelper.floatArrayToBuffer(Full_SquareCoords); // Java 層數據轉換成底層數據格式
private static final FloatBuffer TextureBuffer = GLHelper.floatArrayToBuffer(Texture_SquareCoords); // Java 層數據轉換成底層數據格式
private static final ShortBuffer DrawListBuffer = GLHelper.shotArrayToBuffer(DrawOrder); // Java 層數據轉換成底層數據格式
private Context mContext;
private final int mProgram;
private int attrPosition;
private int attrTexCoords;
private int uniformProjection;
private int uniformTexture;
private int uniformSampler;
private int uniformAryWeight;
private int uniformAryVerticalOffset;
private int mTextureId;
private static final float SUM = 137;// (12 + 16 +12 ... 16 + 12)
private static final float Blur = 90f; //(模糊因子)
private static final float AryWeight[] = {12/ SUM,16/ SUM,12/ SUM,16/ SUM,25/ SUM,16/ SUM,12/ SUM,16/ SUM,12/ SUM}; // 網上找的一組數據
private static final float VerticalOffset[] = {-1/Blur,-1/Blur, 0,-1/Blur, 1/Blur,-1/Blur // 網上找的一組數據
-1/Blur, 0, 0, 0, 1/Blur, 0
-1/Blur, 1/Blur, 0, 1/Blur, 1/Blur, 1/Blur};
private static final FloatBuffer AryWeightBuffer = GLHelper.floatArrayToBuffer(AryWeight);
private static final FloatBuffer VerticalOffsetBuffer = GLHelper.floatArrayToBuffer(VerticalOffset);
public Texture(Context context) {
mContext = context;
GLES20.glEnable(GLES20.GL_TEXTURE_2D);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
mProgram = GLHelper.initProgram(GLScript.Texture.VertexShaderCode, GLScript.Texture.FragmentShaderCode);
attrPosition = GLES20.glGetAttribLocation(mProgram, "position");
attrTexCoords = GLES20.glGetAttribLocation(mProgram, "texCoords");
uniformProjection = GLES20.glGetUniformLocation(mProgram, "projection");
uniformTexture = GLES20.glGetUniformLocation(mProgram, "texture");
uniformSampler = GLES20.glGetUniformLocation(mProgram, "sampler");
uniformAryWeight = GLES20.glGetUniformLocation(mProgram, "g_aryWeight");
uniformAryVerticalOffset = GLES20.glGetUniformLocation(mProgram, "g_aryVerticalOffset");
mTextureId = GLHelper.loadTexture(mContext, "test.jpg");
}
/**
* 繪制流程
* 1： 設置 GLSL 的輸出參數 -- glUniformMatrix4fv
* 2： 設置頂點和紋理的坐標 -- glVertexAttribPointer
* 3： 最后繪制 -- glDrawElements
* @param projectionMatrix
* @param textureMatrix
*/
public void draw(float[] projectionMatrix, float[] textureMatrix) {
GLES20.glUseProgram(mProgram);
GLES20.glEnableVertexAttribArray(attrPosition);
GLES20.glEnableVertexAttribArray(attrTexCoords);
// Set the sampler to texture unit 0
GLES20.glUniform1i(uniformSampler, 0);
GLES20.glUniformMatrix4fv(uniformProjection, 1, false, projectionMatrix, 0);
GLES20.glUniformMatrix4fv(uniformTexture, 1, false, textureMatrix, 0);
GLES20.glUniform1fv(uniformAryWeight,AryWeight.length, AryWeightBuffer);
GLES20.glUniform2fv(uniformAryVerticalOffset,AryWeight.length, VerticalOffsetBuffer);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureId);
// load the position
VertexBuffer.position(0);
GLES20.glVertexAttribPointer(attrPosition,
COORDS_POS_VERTEX, GLES20.GL_FLOAT,
false, Full_SquareCoords.length, VertexBuffer);
// load the texture coordinate
VertexBuffer.position(0);
GLES20.glVertexAttribPointer(attrTexCoords,
COORDS_TEX_VERTEX, GLES20.GL_FLOAT,
false, Texture_SquareCoords.length, TextureBuffer);
GLES20.glDrawElements(GLES20.GL_TRIANGLES, DrawOrder.length, GLES20.GL_UNSIGNED_SHORT,
DrawListBuffer);
// Disable VertexBuffer array
GLES20.glDisableVertexAttribArray(attrPosition);
GLES20.glDisableVertexAttribArray(attrTexCoords);
}
static class Matrix {
public final static float[] Projection = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
public final static float[] Projection_TEST = {0.5f, 0, 0, 0, // 0.5 -- X軸縮放0.5
0, 0.5f, 0, 0, // 0.5 -- 軸縮放0.5
0, 0, 1, 0,
0, 0, 0, 1}; // 0.5 -- 整體放大2倍
public final static float[] Texture_Normal = {-1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1};
public final static float[] Texture_90 = {0, 1, 0, 0, -1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1};
public final static float[] Texture_180 = {1, 0, 0, 0, 0, -1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1};
}
}
GLSL代碼
package com.gank.demo.opengl.glsurfaceview;
/**
* @author Gank
*/
public class GLScript {
public class Texture1 {
public static final String VertexShaderCode =
"attribute vec4 position;" +
"attribute vec2 texCoords;" + //紋理坐標
"varying vec2 outTexCoords;" + //頂點坐標
"void main() {" +
"gl_Position = position;" + //設置內置變量
"outTexCoords = texCoords;" + //設置紋理位置并傳給 FragmentShader
"}";
public static final String FragmentShaderCode =
"precision lowp float;" +
"varying vec2 outTexCoords;" + //接收 VertexShader 的參數
"uniform sampler2D sampler;" + //紋理采樣
"void main() {" +
"gl_FragColor = texture2D(sampler, outTexCoords);" + //根據位置（outTexCoords）獲取紋理上的顏色， 設置像素的顏色
"}";
}
public class Texture {
public static final String VertexShaderCode =
"attribute vec4 texCoords;" + //紋理坐標
"attribute vec4 position;" + //頂點坐標
"uniform mat4 projection;" + //頂點矩陣 做旋轉
"uniform mat4 texture;" + //紋理矩陣 做旋轉
"varying vec2 outTexCoords;" +
"void main() {" +
"gl_Position = projection * position;" +
"outTexCoords = (texture * texCoords).st;" +
"}";
public static final String FragmentShaderCode =
"precision lowp float;" +
"const int g_iWeightNumber = 9;" +
"const float g_fGene = 0.7;" +
"uniform vec2 g_aryVerticalOffset[g_iWeightNumber];" + //采樣的位置便宜
"uniform float g_aryWeight[g_iWeightNumber]; " + //每個點的權重
"uniform sampler2D sampler;" +
"varying vec2 outTexCoords;" +
"void main() {" +
"vec4 vec4Sum = vec4(0.0);" +
"for(int i = 0; i < g_iWeightNumber; ++i)" +
"{" +
"vec4Sum += texture2D(sampler, outTexCoords + g_aryVerticalOffset[i])*g_aryWeight[i]*g_fGene;" + // X軸模糊
"vec4Sum += texture2D(sampler, outTexCoords - g_aryVerticalOffset[i])*g_aryWeight[i]*g_fGene;" + // Y軸模糊
"}" +
"gl_FragColor = vec4Sum;" +
"}";
}
}
//TODO
代碼整理好了傳一份
