Question

所以我尝试过关于OpenGL和GLSL的一些教程。我用Java编写它们，使用JOGL2，Original是用C ++编写的。所有代码编译都没有任何问题，Shader设计器中的着色器预览甚至显示正确的效果，但是当我运行我的应用程序时，它只绘制空白的白色三角形。我无法找到我在哪里犯错误。-btw我的显卡是Geforce GT330M，支持OpenGL 3.3，GLSL 3.30。安装了最新的驱动程序，所以我想这不应该是一个问题。

我的加载和创建着色器的代码：

package OpenGL33.Utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import javax.media.opengl.GL3;

public class ShaderUtils {

    public int createProgram(GL3 gl, String vertexSource, String fragmentSource)    throws IOException{

    int v = gl.glCreateShader(GL3.GL_VERTEX_SHADER);
    int f = gl.glCreateShader(GL3.GL_FRAGMENT_SHADER);

    String[] strings;

    /*
     * vertex shader
     */ 
    strings = loadResource(vertexSource);
    gl.glShaderSource(v, strings.length, strings, (int[]) null, 0);
    gl.glCompileShader(v);

    /*
     * fragment shader
     */
    strings = loadResource(fragmentSource);
    gl.glShaderSource(f, strings.length, strings, (int[]) null, 0);
    gl.glCompileShader(f);

    /*
     * Create shader program and attach shaders
     */
    int program = gl.glCreateProgram();
    gl.glAttachShader(program, v);
    gl.glAttachShader(program, f);
    gl.glLinkProgram(program);
    gl.glValidateProgram(program);

    return program;
}

private String[] loadResource(String resource) throws IOException{

    BufferedReader reader;
    ArrayList<String> input = new ArrayList<String>();
    String line;

    reader = new BufferedReader(new InputStreamReader(getClass().getResource(resource).openStream()));
    while ((line = reader.readLine()) != null) {
        input.add(line);
    }

    String[] strings = new String[input.size()];
    input.toArray(strings);
    return strings;
    }    
}

顶点着色器：

#version 330

layout(location = 0) in vec4 position;
void main()
{
    gl_Position = position;
}

片段着色器：

#version 330

out vec4 outputColor;

 void main()
{
    float lerpValue = gl_FragCoord.y / 500.0f;

    outputColor = mix(vec4(1.0f, 1.0f, 1.0f, 1.0f),
        vec4(0.0f, 0.0f, 0.0f, 1.0f), lerpValue);
}

和OpenGlListener类：

package OpenGL33;

import OpenGL33.Utils.ShaderUtils;
import com.jogamp.common.nio.Buffers;
import com.jogamp.opengl.util.gl2.GLUT;
import java.io.IOException;
import java.nio.FloatBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.media.opengl.GL3;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.glu.GLU;

class OpenGlListener implements GLEventListener{

private GLU glu = new GLU();
private GLUT glut = new GLUT();

// vertex buffer
private FloatBuffer vertices;
private int[] verticesBuffer = new int[1];

private int shaderProgram;
private ShaderUtils sUtils;

// triangle coords
public static final float[] vertexPositions = {
    0.0f, 0.5f, 0.0f, 1.0f,
    0.5f, -0.366f, 0.0f, 1.0f,
    -0.5f, -0.366f, 0.0f, 1.0f};

public OpenGlListener(){
    sUtils = new ShaderUtils();
}

public void initializeVertexBuffer(GLAutoDrawable drawable){
    GL3 gl = drawable.getGL().getGL3bc();

    vertices = Buffers.newDirectFloatBuffer(vertexPositions.length);
    vertices.put(vertexPositions);
    vertices.position(0);

    gl.glGenBuffers(1, verticesBuffer, 0);

    gl.glBindBuffer(GL3.GL_ARRAY_BUFFER, verticesBuffer[0]);
    gl.glBufferData(GL3.GL_ARRAY_BUFFER, vertexPositions.length * 4 * Buffers.SIZEOF_FLOAT, vertices, GL3.GL_STATIC_DRAW);
    gl.glBindBuffer(GL3.GL_ARRAY_BUFFER, 0);
}

@Override
public void init(GLAutoDrawable drawable) {
    GL3 gl = drawable.getGL().getGL3();

    // check VBO support
    if(!gl.isExtensionAvailable("GL_ARB_vertex_buffer_object")){
        System.err.println("Error - missing VBO support");
    }  

    // load shaders
    try{
        //tutorial 1 
        shaderProgram = sUtils.createProgram(gl, "/resources/shaders/FragPosition.vert", "/resources/shaders/FragPosition.frag");
        //tutorial 2
        //shaderProgram = sUtils.createProgram(gl, "/resources/shaders/MultiInput.vert", "/resources/shaders/MultiInput.frag");
    }
     catch (IOException ex) {
        Logger.getLogger(OpenGlListener.class.getName()).log(Level.SEVERE, null, ex);
    } 

    initializeVertexBuffer(drawable);
}

@Override
public void dispose(GLAutoDrawable drawable) {
    //To change body of generated methods, choose Tools | Templates.
}

@Override
public void display(GLAutoDrawable drawable) {
    GL3 gl = drawable.getGL().getGL3();

    gl.glClear(GL3.GL_COLOR_BUFFER_BIT);

    gl.glUseProgram(shaderProgram);

    gl.glBindBuffer(GL3.GL_ARRAY_BUFFER, verticesBuffer[0]);

    gl.glEnableVertexAttribArray(0);
    gl.glVertexAttribPointer(0, 4, GL3.GL_FLOAT, false, 0, 0);


    gl.glDrawArrays(GL3.GL_TRIANGLES, 0, 3);

    gl.glDisableVertexAttribArray(0);
    gl.glUseProgram(0);

    drawable.swapBuffers();


}

@Override
public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
     GL3 gl = drawable.getGL().getGL3bc();

     gl.glViewport(0, 0, width, height);
}

}

App在swing窗口中运行，在GLJPanel中绘图。

基本的GLSL着色器不起作用

0 个答案: