ImGui 与高兴的 openGL 加载程序抛出分段错误（核心转储）

Question

我是 ImGui 库的新手，最近我一直在尝试其中包含的示例。一切都像魅力一样，直到我更改了（我想使用的加载器）gl3w的包含（和功能）。glad当我在两个加载器之间交换时，我在文件内遇到了分段错误异常imgui_impl_glfw_gl3.cpp。我发现一篇文章表明，这可能是由于某些函数无法“绑定”并产生空指针而发生的。

我发现错误在 第216行的代码中line 216：imgui_impl_glfw_gl3.cpp

glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);

我还将包含文件从 更改imgui_impl_glfw_gl3.cpp为gl3w，glad但没有结果。

这是我正在执行的主要函数（这是使用glad的imgui的基本opengl3示例）：

#include "gui/imgui.h"
#include "gui/imgui_impl_glfw_gl3.h"
#include <stdio.h>
#include <glad/glad.h>    // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you.
#include <GLFW/glfw3.h>

static void error_callback(int error, const char* description)
{
    fprintf(stderr, "Error %d: %s\n", error, description);
}

int main(int, char**)
{
    // Setup window
    glfwSetErrorCallback(error_callback);
    if (!glfwInit())
        return 1;
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    GLFWwindow* window = glfwCreateWindow(1280, 720, "ImGui OpenGL3 example", NULL, NULL);
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1); // Enable vsync
    glfwInit();

    // Setup ImGui binding
    ImGui_ImplGlfwGL3_Init(window, true);

    // Setup style
    //ImGui::StyleColorsDark();
    ImGui::StyleColorsClassic();

    bool show_demo_window = true;
    bool show_another_window = false;
    bool algo = true;
    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

    // Main loop
    while (!glfwWindowShouldClose(window))
    {

        glfwPollEvents();
        ImGui_ImplGlfwGL3_NewFrame();

        // 1. Show a simple window.
        // Tip: if we don't call ImGui::Begin()/ImGui::End() the widgets automatically appears in a window called "Debug".
        {
            static float f = 0.0f;
            static int counter = 0;
            ImGui::Text("Hello, world!");                           // Display some text (you can use a format string too)
            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f    
            ImGui::ColorEdit3("COLORINES", (float*)&clear_color); // Edit 3 floats representing a color

            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our windows open/close state
            ImGui::Checkbox("Booleanooooo", &algo);
            ImGui::Checkbox("Another Window", &show_another_window);

            if (ImGui::Button("Button"))                            // Buttons return true when clicked (NB: most widgets return true when edited/activated)
                counter++;
            ImGui::SameLine();
            ImGui::Text("counter = %d", counter);
            ImGui::Text("pues se ve que hay texto: %d", algo);
            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
        }

        {
            ImGui::Begin("VENTANA WAPA");
            ImGui::Text("POS SA QUEDAO BUENA VENTANA");

            static float yee = 0.0f;
            ImGui::SliderFloat("lel", &yee,1.0f,0.5f);

            ImGui::End();
        }

        // 2. Show another simple window. In most cases you will use an explicit Begin/End pair to name your windows.
        if (show_another_window)
        {
            ImGui::Begin("Another Window", &show_another_window);
            ImGui::Text("Hello from another window!");
            if (ImGui::Button("Close Me"))
                show_another_window = false;
            ImGui::End();
        }

        // 3. Show the ImGui demo window. Most of the sample code is in ImGui::ShowDemoWindow(). Read its code to learn more about Dear ImGui!
        if (show_demo_window)
        {
            ImGui::SetNextWindowPos(ImVec2(650, 20), ImGuiCond_FirstUseEver); // Normally user code doesn't need/want to call this because positions are saved in .ini file anyway. Here we just want to make the demo initial state a bit more friendly!
            ImGui::ShowDemoWindow(&show_demo_window);
        }

        // Rendering
        int display_w, display_h;
        glfwGetFramebufferSize(window, &display_w, &display_h);
        glViewport(0, 0, display_w, display_h);
        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
        glClear(GL_COLOR_BUFFER_BIT);
        ImGui::Render();
        glfwSwapBuffers(window);
    }

    // Cleanup
    //ImGui_ImplGlfwGL3_Shutdown();
    glfwTerminate();

    return 0;
}

我不知道为什么会发生这种情况，而且我对 openGL 和 ImGui 还很陌生，所以有什么想法吗？:(

Answer 1

GLAD 和 gl3w 都是扩展加载器库。它们通常需要在使用前在当前 GL 上下文中进行初始化。

原始代码称为gl3wInit(). 你的缺少任何类型的 GLAD init。

确保在调用任何 OpenGL 函数gladLoadGLLoader((GLADloadproc) glfwGetProcAddress)之后和之前初始化 GLAD ( ) 。glfwMakeContextCurrent()

否则，所有很高兴声明的 OpenGL 函数指针将保持为 NULL。对于进程来说，尝试调用 NULL 函数指针通常不太顺利。