使用 ImGUI 时 GLUT 不绘制形状

Question

我使用的是 Windows 10、Visual Studio 2022。 后端：imgui_impl_glut.cpp 和 imgui_impl_opengl3.cpp

现在，我只是想让 freeGLUT 和 ImGUI 正常协同工作。问题是，当我使用 ImGUI 创建窗口时，它不显示 GLUT 绘制的形状。没有 ImGUI，它可以完美地绘制球体。

我尝试在 ImGui 渲染周期之后调用球体的渲染程序，但这没有起作用。这是我的代码：

#include <iostream>
#include <GLEW/glew.h>
#include <GL/freeglut.h>
#pragma comment(lib, "glew32.lib")


#include "imgui/imgui.h"
#include "imgui/imgui_impl_glut.h"
#include "imgui/imgui_impl_opengl3.h"

#ifdef _MSC_VER
#pragma warning (disable: 4505) // unreferenced local function has been removed
#endif

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

   
void Window(int w, int h) {
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-5.0, 5.0, -5.0, 5.0, 5.0, 200.0);
    glMatrixMode(GL_MODELVIEW);
}



void my_display_code()
{


    // Sample code taken from the ImGUI example files
    {
        static float f = 0.0f;
        static int counter = 0;

        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.

        ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
        ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
        ImGui::Checkbox("Another Window", &show_another_window);

        ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
        ImGui::ColorEdit3("clear colour", (float*)&clear_color); // Edit 3 floats representing a color

        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
            counter++;
        ImGui::SameLine();
        ImGui::Text("counter = %d", counter);

        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
        ImGui::End();
    }

    // Other sample window
    if (show_another_window)
    {
        ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
        ImGui::Text("Hello from another window!");
        if (ImGui::Button("Close Me"))
            show_another_window = false;
        ImGui::End();
    }
}




//Function where the rendering occurs
void Draw(void) {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();


    my_display_code();

    //Rendering
    ImGui::Render();
    ImGuiIO& io = ImGui::GetIO();

    glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);

    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());


    gluLookAt(5.0f, 35.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f);

    OrbitPath();

    GLUquadric* quadric;
    quadric = gluNewQuadric();

    //Drwaing the Sun
    glPushMatrix();
    glRotatef(0.0, 0.0, 1.0, 0.0);
    glTranslatef(0.0, 0.0f, 0.0);
    glPushMatrix();
    glRotatef(0, 1.0, 0.0, 0.0);
    glRotatef(10, 0.0, 1.0, 0.0);
    glColor3f(1.0f, 1.0f, 1.0f);
    gluQuadricTexture(quadric, 1);
    gluSphere(quadric, 5, 10.0, 10.0);
    glPopMatrix();
    glPopMatrix();

    glutPostRedisplay();
    glutSwapBuffers();
}


//Main function
int main(int argc, char** argv) {
    glutInit(&argc, argv);

    glutInitContextVersion(4, 2);
    glutInitContextProfile(GLUT_COMPATIBILITY_PROFILE);

    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH);
    glutInitWindowSize(700, 700);
    glutInitWindowPosition(500, 0);
    glutCreateWindow("Example");
    glutDisplayFunc(Draw);
    glutReshapeFunc(Window);

/**/
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;

    ImGui::StyleColorsDark();



    ImGui_ImplGLUT_Init();
    ImGui_ImplGLUT_InstallFuncs();
    ImGui_ImplOpenGL3_Init();
/**/

    glewExperimental = GL_TRUE;
    glewInit();

    glClearColor(0.0, 0.0, 0.0, 0.0);
    glEnable(GL_DEPTH_TEST);
    glutMainLoop();

    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGLUT_Shutdown();
    ImGui::DestroyContext();
}

使用 ImGUI 1.87。

Answer 1

您正在混合和匹配（或者更确切地说，不匹配）imgui 正在使用的现代模块化管道（注意 OpenGL3 标头）和过时的固定管道过剩（以及您自己）正在使用。

只是不要使用过剩，而是使用现代管道。