在openGL的顶点着色器中设置属性

如何解决在openGL的顶点着色器中设置属性

我最近一直在学习 OpenGL，但对着色器和 VBO 有点困惑。基本上，我对顶点着色器如何知道 VBO 中的颜色和位置数据感到困惑。据我所知，glBindAttribLocation(program,attribute,variable); 是在着色器中设置属性的原因，但是当我注释掉该代码时，三角形的颜色仍然可以很好地呈现。

这是我的代码：

public static void main(String[] args) {
    String vertexSource = "#version 400 core\n"
            + "in vec3 position;\n"
            + "in vec3 colour;\n"
            + "out vec3 vertexColour;\n"
            + "uniform mat4 model;\n"
            + "uniform mat4 view;\n"
            + "uniform mat4 projection;\n"
            + "void main() {\n"
            + "vertexColour = colour;\n"
            + "mat4 mvp = projection * view * model;\n"
            + "gl_Position = vec4(position,1.0);\n"
            + "}\n";
    
    String fragmentSource = "#version 400 core\n"
            + "in vec3 vertexColour;\n"
            + "out vec4 colours;\n"
            + "void main()\n"
            + "{\n"
            + "    colours = vec4(vertexColour,1);\n"
            + "}";
    
    glfwSetErrorCallback(errorCallBack);
    
    if (!glfwInit()) {
        throw new IllegalStateException("Unable to initialize GLFW");
    }
        
    glfwDefaultwindowHints();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MInor,3);
    glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT,GLFW_TRUE);
    
    glfwWindowHint(GLFW_VISIBLE,GL_TRUE);
    glfwWindowHint(GLFW_RESIZABLE,GL_FALSE);
    
    long window = glfwCreateWindow(640,480,"my window!",0);

    glfwSetKeyCallback(window,keyCallback);
    if (window == 0) {
        glfwTerminate();
        throw new RuntimeException("Failed to create the GLFW window");
    }
    
    glfwMakeContextCurrent(window);
    GL.createCapabilities();
    
    float[] vertexPoints = {
        0f,0.5f,0f,-0.5f,0f
    };
    float[] colours = {
            0.1f,0.3f,0.7f,0.9f,0.4f,0.1f
        };
    
    ArrayList<Integer> vaos = new ArrayList<Integer>();
    ArrayList<Integer> vbos = new ArrayList<Integer>();
    
    int vaoID = glGenVertexArrays();
    vaos.add(vaoID);
    glBindVertexArray(vaoID);
    
    
    FloatBuffer vertices = BufferUtils.createFloatBuffer(vertexPoints.length);
    vertices.put(vertexPoints);
    vertices.flip();
   
    int vboID = GL33.glGenBuffers();
    vbos.add(vboID);
    glBindBuffer(GL_ARRAY_BUFFER,vboID);
    glBufferData(GL_ARRAY_BUFFER,vertices,GL_STATIC_DRAW);
    
    //add it to the vao at position 0,size 3,with data types of float,normalised = false,glVertexAttribPointer(0,3,GL_FLOAT,false,0);
    //unbind currently bound vbo
    glBindBuffer(GL_ARRAY_BUFFER,0);
    
    //and one for the colour data
    vboID = glGenBuffers();
    glBindBuffer(GL_ARRAY_BUFFER,colours,GL_STATIC_DRAW);
    glVertexAttribPointer(1,0);
    glBindBuffer(GL_ARRAY_BUFFER,0);
    
    //finished with vao Now unbind it
    glBindVertexArray(0);

    //vao and vbo stuff is Now finished with
    //Now for the shader stuff
    
    int vertexShaderID = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShaderID,vertexSource);
    glCompileShader(vertexShaderID);
    
    if (!checkForSuccess(vertexShaderID)) {
        
        glfwTerminate();
        throw new IllegalStateException("vertex shader Failed: " + glGetShaderInfoLog(vertexShaderID));
    }
    
    int fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShaderID,fragmentSource);
    glCompileShader(fragmentShaderID);
    
    if (!checkForSuccess(vertexShaderID)) {
        glGetShaderInfoLog(vertexShaderID);
        glfwTerminate();
        throw new IllegalStateException("fragment shader Failed");
    }
    
    //shader program
    int shaderProgramID = glCreateProgram();
    glAttachShader(shaderProgramID,vertexShaderID);
    glAttachShader(shaderProgramID,fragmentShaderID);
    glLinkProgram(shaderProgramID);
    //error test
    int status = glGetProgrami(shaderProgramID,GL_LINK_STATUS);
    if (status != GL_TRUE) {
        glfwTerminate();
        throw new RuntimeException(glGetProgramInfoLog(shaderProgramID));
    }
    
    gluseProgram(shaderProgramID);

    
    //setting position attribute in the shader:
    int positionAttribute = glGetAttribLocation(shaderProgramID,"position");
    glEnabLevertexAttribArray(positionAttribute);
    glBindAttribLocation(shaderProgramID,positionAttribute,"position");
    
    //setting colour attribute in the shader:
    int colourAttribute = glGetAttribLocation(shaderProgramID,"colour");
    glEnabLevertexAttribArray(colourAttribute);
    glBindAttribLocation(shaderProgramID,colourAttribute,"colour");
    
    
    glClearColor(0.5f,1f);
    
    //this will create a wire frame view
    //glpolygonMode(GL_FRONT_AND_BACK,GL_LINE);
    
    glfwShowWindow(window); //optional
    
    while (!glfwWindowShouldClose(window)) {
        double time = glfwGetTime();
        glfwPollEvents();
        glClear(GL_COLOR_BUFFER_BIT);
        
        glBindVertexArray(vaoID);
        
        //enables the position attribute in the vertex shader
        glEnabLevertexAttribArray(0);
        //enables the colour attribute in the vertex shader
        glEnabLevertexAttribArray(1);
        
        glDrawArrays(GL_TRIANGLES,vertexPoints.length);
        //disables the position and colour attribute in the vertex shader
        gldisabLevertexAttribArray(0);
        gldisabLevertexAttribArray(1);
        
        glfwSwapBuffers(window);
    }
    
    //clear vaos and vbos
    for (int vao : vaos) {
        glDeleteVertexArrays(vao);
    }
    for (int vbo : vbos) {
        glDeleteBuffers(vbo);
    }
    //delete shaders
    glDetachShader(shaderProgramID,vertexShaderID);
    glDetachShader(shaderProgramID,fragmentShaderID);
    glDeleteShader(vertexShaderID);
    glDeleteShader(fragmentShaderID);
    glDeleteProgram(shaderProgramID);
    
    Callbacks.glfwFreeCallbacks(window);
    
    glfwDestroyWindow(window);
    glfwTerminate();
   
}

我在 github 上提供了我的完整代码文件（250 行）：https://github.com/OneEgg42/opengl

有人会这么好心向我解释这是如何工作的吗？

提前致谢！

解决方法

VBO 和着色器之间的关系不是由 glBindAttribLocation 建立的。