How to convert cv::mat to ImTextureID in ImGUI

Question

I have a render app. And it's the basis source code

std::vector<Eigen::Vector3f> frame_buffer;

I have rendered in the opencv

    pipeline.refresh();
    pipeline.draw();
    cv::Mat image(700, 700, CV_32FC3, pipeline.raster.frameBuffer().data());
    image.convertTo(image, CV_8UC3, 1.0f);
    cv::cvtColor(image, image, cv::COLOR_RGB2BGRA);
    cv::imshow("image", image);

It's correct.

But I wanna show in ImGUI. I use these code to convert and show in ImGUI.

// UI.h
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <opencv2/opencv.hpp>

// show function
while (!glfwWindowShouldClose(windows)){
    glfwPollEvents();

    // Start the Dear ImGui frame
    ImGui_ImplOpenGL3_NewFrame();
    ImGui_ImplGlfw_NewFrame();
    ImGui::NewFrame();

    // window
    ImGui::Begin("LRenderer");

    pipeline.refresh();
    pipeline.draw();
    cv::Mat image(700, 700, CV_32FC3, pipeline.raster.frameBuffer().data());
    image.convertTo(image, CV_8UC3, 1.0f);
    cv::cvtColor(image, image, cv::COLOR_RGB2BGRA);

    Mat2Texture(image, image_texture);

    ImGui::Image((void*)(intptr_t)image_texture,
                 ImVec2(image.cols, image.rows));
    ImGui::End();
    
    // render
    ImGui::Render();
    int display_w, display_h;
    glfwGetFramebufferSize(windows, &display_w, &display_h);
    glViewport(0, 0, display_w, display_h);
    glClearColor(0, 0, 0, 0);
    glClear(GL_COLOR_BUFFER_BIT);
    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

    const ImGuiIO& io = ImGui::GetIO();
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) {
      GLFWwindow* backup_current_context = glfwGetCurrentContext();
      ImGui::UpdatePlatformWindows();
      ImGui::RenderPlatformWindowsDefault();
      glfwMakeContextCurrent(backup_current_context);
    }

    glfwSwapBuffers(windows);
}

// convert function
void LRenderer::UI::Mat2Texture(const cv::Mat& image, GLuint& imageTexture) {
  if (image.empty()) {
    std::cout << "image is empty! " << std::endl;
    return;
  } else {
    // generate texture using GL commands
    glGenTextures(1, &image_texture);
    glBindTexture(GL_TEXTURE_2D, imageTexture);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_BGRA, image.cols, image.rows, 0, GL_RGBA,
                 GL_UNSIGNED_BYTE, image.data);
  }
}

The glfw version is 3.3, and the glew version is 4.6. All up to date. I had try to use glad which version is 3.3 and 4.6, but it didn't work.

How should I do? Which library version is correct? And how to convert cv::mat to ImTextureID in ImGUI? I had seek for the solution before.

Which library version is correct? And how to convert cv::mat to ImTextureID in ImGUI?

How to convert cv::mat to ImTextureID in ImGUI

0 Answers0