许多未声明的标识符与使用 GLFW 的 OpenGL 相关

Question

我正在尝试在Visual c ++ 2008（Windows 7）中使用GLFW设置一个OpenGL项目。我已将 GLFW 包含和库目录添加到项目的包含和库路径中，并将以下内容放在其他依赖项中：

GLFW.lib glu32.lib opengl32.lib

这就是我需要做的一切，不是吗？但是当我尝试编译任何 OpenGl 程序时（除了一个非常简单的程序，它只使用 glClear 清除屏幕），我得到了一堆未声明的标识符和未找到的标识符错误。知道为什么会发生这种情况吗？以下是完整的错误列表：

1>Compiling...
1>main.cpp
1>c:glfw-2.7.3opengl ikasimain.cpp(9) : error C2146: syntax error : missing ';' before identifier 'VBO'
1>c:glfw-2.7.3opengl ikasimain.cpp(9) : error C2377: 'GLuint' : redefinition; typedef cannot be overloaded with any other symbol
1>        c:program filesmicrosoft sdkswindowsv6.0aincludeglgl.h(52) : see declaration of 'GLuint'
1>c:glfw-2.7.3opengl ikasimain.cpp(9) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:glfw-2.7.3opengl ikasimain.cpp(43) : error C3861: 'glEnableVertexAttribArray': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(45) : error C2065: 'GL_ARRAY_BUFFER' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(45) : error C3861: 'glBindBuffer': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(47) : error C3861: 'glVertexAttribPointer': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(55) : error C3861: 'glDisableVertexAttribArray': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(78) : error C3861: 'glGenBuffers': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(80) : error C2065: 'GL_ARRAY_BUFFER' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(80) : error C3861: 'glBindBuffer': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(82) : error C2065: 'GL_ARRAY_BUFFER' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(82) : error C2065: 'GL_STATIC_DRAW' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(82) : error C3861: 'glBufferData': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(87) : error C2146: syntax error : missing ')' before identifier 'ShaderProgram'
1>c:glfw-2.7.3opengl ikasimain.cpp(87) : error C2182: 'AddShader' : illegal use of type 'void'
1>c:glfw-2.7.3opengl ikasimain.cpp(87) : error C2440: 'initializing' : cannot convert from 'Vector3f' to 'int'
1>        No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>c:glfw-2.7.3opengl ikasimain.cpp(87) : error C2059: syntax error : ')'
1>c:glfw-2.7.3opengl ikasimain.cpp(89) : error C2143: syntax error : missing ';' before '{'
1>c:glfw-2.7.3opengl ikasimain.cpp(89) : error C2447: '{' : missing function header (old-style formal list?)
1>c:glfw-2.7.3opengl ikasimain.cpp(144) : error C2146: syntax error : missing ';' before identifier 'ShaderProgram'
1>c:glfw-2.7.3opengl ikasimain.cpp(144) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(144) : error C3861: 'glCreateProgram': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(148) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(158) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(158) : error C2065: 'GL_VERTEX_SHADER' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(160) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(160) : error C2065: 'GL_FRAGMENT_SHADER' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2065: 'GLchar' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2146: syntax error : missing ';' before identifier 'ErrorLog'
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2059: syntax error : '{'
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2143: syntax error : missing ';' before '{'
1>c:glfw-2.7.3opengl ikasimain.cpp(166) : error C2143: syntax error : missing ';' before '}'
1>c:glfw-2.7.3opengl ikasimain.cpp(170) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(170) : error C3861: 'glLinkProgram': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(172) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(172) : error C2065: 'GL_LINK_STATUS' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(172) : error C3861: 'glGetProgramiv': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(176) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(176) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(176) : error C2070: ''unknown-type'': illegal sizeof operand
1>c:glfw-2.7.3opengl ikasimain.cpp(176) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(176) : error C3861: 'glGetProgramInfoLog': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(178) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(186) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(186) : error C3861: 'glValidateProgram': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(188) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(188) : error C2065: 'GL_VALIDATE_STATUS' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(188) : error C3861: 'glGetProgramiv': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(192) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(192) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(192) : error C2070: ''unknown-type'': illegal sizeof operand
1>c:glfw-2.7.3opengl ikasimain.cpp(192) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(192) : error C3861: 'glGetProgramInfoLog': identifier not found
1>c:glfw-2.7.3opengl ikasimain.cpp(194) : error C2065: 'ErrorLog' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(202) : error C2065: 'ShaderProgram' : undeclared identifier
1>c:glfw-2.7.3opengl ikasimain.cpp(202) : error C3861: 'glUseProgram': identifier not found

编辑：这是整个程序

#include <stdio.h>
#include <string.h>
#include <GL/glfw.h>
#include "math_3d.h"

GLuint VBO;

static const char* pVS = "                                                    n
#version 150                                                                  n
n
layout (location = 0) in vec3 Position;                                       n
n
void main()                                                                   n
{                                                                             n
gl_Position = vec4(0.5 * Position.x, 0.5 * Position.y, Position.z, 1.0);  n
}";

static const char* pFS = "                                                    n
#version 150                                                                  n
n
out vec4 FragColor;                                                           n
n
void main()                                                                   n
{                                                                             n
FragColor = vec4(1.0, 0.0, 0.0, 1.0);                                     n
}";

static void RenderSceneCB()
{
    glClear(GL_COLOR_BUFFER_BIT);

    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);

    glDrawArrays(GL_TRIANGLES, 0, 3);

    glDisableVertexAttribArray(0);
    glfwSwapBuffers();
}


static void CreateVertexBuffer()
{
    Vector3f Vertices[3];
    Vertices[0] = Vector3f(-1.0f, -1.0f, 0.0f);
    Vertices[1] = Vector3f(1.0f, -1.0f, 0.0f);
    Vertices[2] = Vector3f(0.0f, 1.0f, 0.0f);

    glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
}

static void AddShader(GLuint ShaderProgram, const char* pShaderText, GLenum ShaderType)
{
    GLuint ShaderObj = glCreateShader(ShaderType);

    if (ShaderObj == 0) {
        fprintf(stderr, "Error creating shader type %dn", ShaderType);
        return ;
    }

    const GLchar* p[1];
    p[0] = pShaderText;
    GLint Lengths[1];
    Lengths[0]= strlen(pShaderText);
    glShaderSource(ShaderObj, 1, p, Lengths);
    glCompileShader(ShaderObj);
    GLint success;
    glGetShaderiv(ShaderObj, GL_COMPILE_STATUS, &success);
    if (!success) {
        GLchar InfoLog[1024];
        glGetShaderInfoLog(ShaderObj, 1024, NULL, InfoLog);
        fprintf(stderr, "Error compiling shader type %d: '%s'n", ShaderType, InfoLog);
        return;
    }

    glAttachShader(ShaderProgram, ShaderObj);
}

static void CompileShaders()
{
    GLuint ShaderProgram = glCreateProgram();

    if (ShaderProgram == 0) {
        fprintf(stderr, "Error creating shader programn");
        return;
    }

    AddShader(ShaderProgram, pVS, GL_VERTEX_SHADER);
    AddShader(ShaderProgram, pFS, GL_FRAGMENT_SHADER);

    GLint Success = 0;
    GLchar ErrorLog[1024] = { 0 };

    glLinkProgram(ShaderProgram);
    glGetProgramiv(ShaderProgram, GL_LINK_STATUS, &Success);
if (Success == 0) {
glGetProgramInfoLog(ShaderProgram, sizeof(ErrorLog), NULL, ErrorLog);
fprintf(stderr, "Error linking shader program: '%s'n", ErrorLog);
        return;
}

    glValidateProgram(ShaderProgram);
    glGetProgramiv(ShaderProgram, GL_VALIDATE_STATUS, &Success);
    if (!Success) {
        glGetProgramInfoLog(ShaderProgram, sizeof(ErrorLog), NULL, ErrorLog);
        fprintf(stderr, "Invalid shader program: '%s'n", ErrorLog);
        return;
    }

    glUseProgram(ShaderProgram);
}

int main(int argc, char** argv)
{
    glfwInit();
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
    glfwOpenWindow(600, 600, 0, 0, 0, 0, 0, 0, GLFW_WINDOW);


    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

    CreateVertexBuffer();

    CompileShaders();

   while (1)
   {
       RenderSceneCB();
   }

    return 0;
}

编辑2：这里是math_3d.h标题

#ifndef MATH_3D_H
#define MATH_3D_H

struct Vector3f
{
    float x;
    float y;
    float z;
    Vector3f()
    {
    }
    Vector3f(float _x, float _y, float _z)
    {
        x = _x;
        y = _y;
        z = _z;
    }
};
#endif  

Answer 1

这个问题在OpenGL Wiki的入门页面上有非常清楚的解释。您的问题是您没有加载 OpenGL 函数的机制，这是使用 OpenGL 的必要步骤。强烈建议您使用库来执行此操作。