Eclipse CDT + MinGW + GLEW, Type undefined reference to `LoadShaders(char const*, char const*)'

Question

Already get one error only for LoadShaders.

#include <stdio.h>
#include <stdlib.h>

#define GLEW_STATIC
#include <GL/glew.h>

#include <glfw3.h>
GLFWwindow* window;

#include <glm/glm.hpp>
using namespace glm;

#include <common/shader.hpp>

int main( void )
{
    // Initialise GLFW
    if( !glfwInit() )
    {
        fprintf( stderr, "Failed to initialize GLFW\n" );
        return -1;
    }

    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    // Open a window and create its OpenGL context
    window = glfwCreateWindow( 1024, 768, "Tutorial 02 - Red triangle", NULL, NULL);
    if( window == NULL ){
        fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" );
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    // Initialize GLEW
    glewExperimental = true; // Needed for core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        return -1;
    }

    // Ensure we can capture the escape key being pressed below
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);

    // Dark blue background
    glClearColor(0.0f, 0.0f, 0.4f, 0.0f);

    GLuint VertexArrayID;
    glGenVertexArrays(1, &VertexArrayID);
    glBindVertexArray(VertexArrayID);

    // Create and compile our GLSL program from the shaders
    GLuint programID = LoadShaders( "SimpleVertexShader.vertexshader", "SimpleFragmentShader.fragmentshader" );


    static const GLfloat g_vertex_buffer_data[] = {
        -1.0f, -1.0f, 0.0f,
         1.0f, -1.0f, 0.0f,
         0.0f,  1.0f, 0.0f,
    };

    GLuint vertexbuffer;
    glGenBuffers(1, &vertexbuffer);
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);

    do{

        // Clear the screen
        glClear( GL_COLOR_BUFFER_BIT );

        // Use our shader
        glUseProgram(programID);

        // 1rst attribute buffer : vertices
        glEnableVertexAttribArray(0);
        glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
        glVertexAttribPointer(
            0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
            3,                  // size
            GL_FLOAT,           // type
            GL_FALSE,           // normalized?
            0,                  // stride
            (void*)0            // array buffer offset
        );

        // Draw the triangle !
        glDrawArrays(GL_TRIANGLES, 0, 3); // 3 indices starting at 0 -> 1 triangle

        glDisableVertexAttribArray(0);

        // Swap buffers
        glfwSwapBuffers(window);
        glfwPollEvents();

    } // Check if the ESC key was pressed or the window was closed
    while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
           glfwWindowShouldClose(window) == 0 );

    // Cleanup VBO
    glDeleteBuffers(1, &vertexbuffer);
    glDeleteVertexArrays(1, &VertexArrayID);
    glDeleteProgram(programID);

    // Close OpenGL window and terminate GLFW
    glfwTerminate();

    return 0;
}

I get error:

Description Resource Path Location Type undefined reference to `LoadShaders(char const*, char const*)' Opengl33.cpp /Opengl33/src line 63 C/C++ Problem

Library order load:

glew32s 
gdi32 
opengl32 
glfw3dll

Compiler string in console:

g++ -o Opengl33.exe "src\\Opengl33.o" -lglew32s -lgdi32 -lopengl32 -lglfw3dll 

(-DGLEW_STATIC don't help me)

I tried to google this problem, but doesn't find solution.

Answer 1

When implementing methods/classes in different files, one has to compile each of them to object files and then link them together. Here, you are only linking Opengl33.o, although LoadShader is defined in shader.o. Try to change the linker line to:

g++ -o Opengl33.exe "src\\Opengl33.o" "common\\shader.o" -lglew32s -lgdi32 -lopengl32 -lglfw3dll 

Although, I'm wondering why this is necessary, since you're using eclipse.