IMGUI重绘按钮文本按钮

bool ImGui::ImageLabelButtonEx(ImGuiID id, ImTextureID texture_id, const ImVec2& image_size, const char* label, const ImVec2& label_size, const ImVec2& uv0, const ImVec2& uv1, const ImVec2& padding, const ImVec4& bg_col, const ImVec4& tint_col, ImGuiButtonFlags flags)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;
    const ImVec2 label_text_size = CalcTextSize(label, NULL, true);
    ImVec2 label_real_size = CalcItemSize(label_size, label_text_size.x + padding.x * 2.0f, label_text_size.y + padding.y * 2.0f);
    const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(image_size.x + label_real_size.x, (image_size.y > label_real_size.y) ? image_size.y : label_real_size.y) + padding * 2.0f);
    ItemSize(bb);
    if (!ItemAdd(bb, id))
        return false;
    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held);
    // Render
    const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    RenderNavHighlight(bb, id);
    RenderFrame(bb.Min, bb.Max, col, true, ImClamp((float)ImMin(padding.x, padding.y), 0.0f, g.Style.FrameRounding));
    if (bg_col.w > 0.0f)
        window->DrawList->AddRectFilled(bb.Min + padding, bb.Max - padding, GetColorU32(bg_col));
    window->DrawList->AddImage(texture_id, bb.Min + padding, bb.Min + image_size + padding, uv0, uv1, GetColorU32(tint_col));
    RenderTextClipped(bb.Min + ImVec2(image_size.x, 0) + padding, bb.Max - padding, label, NULL, &label_text_size, g.Style.ButtonTextAlign, &bb);
    return pressed;
}
bool ImGui::ImageLabelButton(ImTextureID user_texture_id, const ImVec2& image_size, const char* label, const ImVec2& label_size, const ImVec2& uv0, const ImVec2& uv1, int frame_padding, const ImVec4& bg_col, const ImVec4& tint_col)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    if (window->SkipItems)
        return false;
    // Default to using texture ID as ID. User can still push string/integer prefixes.
    PushID((void*)(intptr_t)user_texture_id);
    const ImGuiID id = window->GetID("#imagelabel");
    PopID();
    const ImVec2 padding = (frame_padding >= 0) ? ImVec2((float)frame_padding, (float)frame_padding) : g.Style.FramePadding;
    return ImageLabelButtonEx(id, user_texture_id, image_size, label, label_size, uv0, uv1, padding, bg_col, tint_col, ImGuiButtonFlags_None);
}

使用案例

class PictureTexture {
public:
    PictureTexture() {}
    PictureTexture(const std::string& fname) :m_fname(fname) {}
    ~PictureTexture()
    {
        exit();
    }
private:
    bool m_b_init = false;
public:
    std::string m_fname = (u8"");
    GLuint m_texture_id = 0;
    ImVec2 m_texture_size = ImVec2(0, 0);
public:
    bool is_init() {
        return m_b_init;
    }
    void init(int width, int height) {
        if (m_b_init == false)
        {
            glGenTextures(1, &m_texture_id);
            m_b_init = true;
        }
        cv::Mat img = cv::imread(m_fname.c_str(), cv::IMREAD_UNCHANGED);
        if (!img.empty())
        {
            cv::Mat tmp = {};
            switch (img.channels())
            {
            case 3: {
                tmp = cv::Mat::zeros(width, height, CV_8UC3);
                resize(img, tmp, tmp.size());
                cv::cvtColor(tmp, tmp, cv::COLOR_BGR2RGBA);
            }
                  break;
            case 4: {
                tmp = cv::Mat::zeros(width, height, CV_8UC4);
                resize(img, tmp, tmp.size());
                cv::cvtColor(tmp, tmp, cv::COLOR_BGRA2RGBA);
            }
                  break;
            default: break;
            }
            m_texture_size = ImVec2((float)tmp.rows, (float)tmp.cols);
            //将texture_ID设置为2D纹理信息
            glBindTexture(GL_TEXTURE_2D, m_texture_id);
            //纹理放大缩小使用线性插值
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            //纹理水平竖直方向外扩使用重复贴图
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
            //纹理水平竖直方向外扩使用边缘像素贴图(与重复贴图二选一)
            //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
            //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
            glPixelStorei(GL_PACK_ALIGNMENT, 1);
            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
            glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
            //将图像内存用作纹理信息
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tmp.cols, tmp.rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, tmp.data);
            glGenerateMipmap(GL_TEXTURE_2D);
        }
    }
    void init() {
        if (m_b_init == false)
        {
            glGenTextures(1, &m_texture_id);
            m_b_init = true;
        }
        cv::Mat tmp = cv::imread(m_fname.c_str(), cv::IMREAD_UNCHANGED);
        if (!tmp.empty())
        {
            switch (tmp.channels())
            {
            case 3: {
                cv::cvtColor(tmp, tmp, cv::COLOR_BGR2RGBA);
            }
                  break;
            case 4: {
                cv::cvtColor(tmp, tmp, cv::COLOR_BGRA2RGBA);
            }
                  break;
            default: break;
            }
            m_texture_size = ImVec2((float)tmp.cols, (float)tmp.rows);
            //将texture_ID设置为2D纹理信息
            glBindTexture(GL_TEXTURE_2D, m_texture_id);
            //纹理放大缩小使用线性插值
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            //纹理水平竖直方向外扩使用重复贴图
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
            //纹理水平竖直方向外扩使用边缘像素贴图(与重复贴图二选一)
            //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
            //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
            glPixelStorei(GL_PACK_ALIGNMENT, 1);
            glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
            glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
            //将图像内存用作纹理信息
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tmp.cols, tmp.rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, tmp.data);
            glGenerateMipmap(GL_TEXTURE_2D);
        }
    }
    void exit() {
        if (m_b_init == true)
        {
            glBindTexture(GL_TEXTURE_2D, 0);  // unbind texture
            glDeleteTextures(1, &m_texture_id);
            m_b_init = false;
        }
    }
};
typedef enum ImgType {
    IMGTYPE_NUL = 0,
    /////////////////
    IMGTYPE_LOGO,
    /////////////////
    IMGTYPE_ROTATE,
    IMGTYPE_REFOCUS,
    IMGTYPE_EXPOSURE,
    IMGTYPE_RESET,
    /////////////////
    IMGTYPE_COLORSETTING,
    IMGTYPE_POSITION,
    IMGTYPE_TRACKCURSOR,
    IMGTYPE_TARGETCURSOR,
    IMGTYPE_SCREENCONTROL,
    /////////////////
    IMGTYPE_MAX,
}ImgType;
std::unordered_map<ImgType, PictureTexture> m_imgMap = {
    {IMGTYPE_LOGO, PictureTexture(u8"res/img/logo.png")},
};
void ShowLogo()
{
     auto itLogo = m_imgMap.find(IMGTYPE_LOGO);
     if (itLogo != m_imgMap.end())
     {
         if (!itLogo->second.is_init())
         {
            itLogo->second.init();
         }
         ImGui::Image(GLuint2ImTextureID(itLogo->second.m_texture_id), itLogo->second.m_texture_size);
     }
}
void MainLoop()
{
        // Main loop
        while (!glfwWindowShouldClose(window))
        {
            // Poll and handle events (inputs, window resize, etc.)
            // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
            // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
            // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
            // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
            glfwPollEvents();
            // Start the Dear ImGui frame
            ImGui_ImplOpenGL3_NewFrame();
            ImGui_ImplGlfw_NewFrame();
            ImGui::NewFrame();
            ShowLogo();
            // Rendering
            ImGui::Render();
            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_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
            glfwSwapBuffers(window);
        }
}