I cann't display a picture with the function "ImGui::Image((void*)(intptr_t)my_opengl_texture, ImVec2(my_image_width, my_image_height))"

[nonlinear1]

 I want display a picture with OpenGL accoriding to the way of imgui.cpp. My program is just add some lines to exampe_glfw_openglfw3. But I failed and display nothing ,just a black windows! Could you someone know why?

here is my environment: My os: ubuntu18.04 Hardware: i7-7700 ram 16G GPU: gtx1070 the following is my program source code: // ImGui - standalone example application for GLFW + OpenGL 3, using programmable pipeline // If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp. // (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)

include

include "imgui.h"

include "imgui_impl_glfw.h"

include "imgui_impl_opengl3.h"

include

define STB_IMAGE_IMPLEMENTATION

include

// About OpenGL function loaders: modern OpenGL doesn't have a standard header file and requires individual function pointers to be loaded manually. // Helper libraries are often used for this purpose! Here we are supporting a few common ones: gl3w, glew, glad. // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.

if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)

include <GL/gl3w.h> // Initialize with gl3wInit()

elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)

include <GL/glew.h> // Initialize with glewInit()

elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)

include <glad/glad.h> // Initialize with gladLoadGL()

else

include IMGUI_IMPL_OPENGL_LOADER_CUSTOM

endif

include <GLFW/glfw3.h> // Include glfw3.h after our OpenGL definitions

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

int main(int, char**) { // Setup window glfwSetErrorCallback(glfw_error_callback); if (!glfwInit()) return 1;

// Decide GL+GLSL versions

if APPLE

// GL 3.2 + GLSL 150
const char* glsl_version = "#version 150";
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // Required on Mac

else

// GL 3.0 + GLSL 130
const char* glsl_version = "#version 130";
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
//glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // 3.0+ only

endif

// Create window with graphics context
GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL3 example", NULL, NULL);
if (window == NULL)
    return 1;
glfwMakeContextCurrent(window);
glfwSwapInterval(1); // Enable vsync

// Initialize OpenGL loader

if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)

bool err = gl3wInit() != 0;

elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)

bool err = glewInit() != GLEW_OK;

elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)

bool err = gladLoadGL() != 0;

endif

if (err)
{
    fprintf(stderr, "Failed to initialize OpenGL loader!\n");
    return 1;
}

// Setup Dear ImGui binding
IMGUI_CHECKVERSION();
ImGui::CreateContext();
ImGuiIO& io = ImGui::GetIO(); (void)io;
//io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
//io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls

ImGui_ImplGlfw_InitForOpenGL(window, true);
ImGui_ImplOpenGL3_Init(glsl_version);

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

// Load Fonts
// - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
// - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
// - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
// - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
// - Read 'misc/fonts/README.txt' for more instructions and details.
// - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
//io.Fonts->AddFontDefault();
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
//IM_ASSERT(font != NULL);

bool show_demo_window = true;
bool show_another_window = false;
ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
//
int my_image_width, my_image_height;
unsigned char* my_image_data = stbi_load("my_image.png", &my_image_width, &my_image_height, NULL, 4);

GLuint my_opengl_texture;
glGenTextures(1, &my_opengl_texture);
glBindTexture(GL_TEXTURE_2D, my_opengl_texture);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, my_image_width, my_image_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, my_image_data);

// 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();

    ImGui::Image((void*)(intptr_t)my_opengl_texture, ImVec2(my_image_width, my_image_height));

    // Rendering
    ImGui::Render();
    int display_w, display_h;
    glfwMakeContextCurrent(window);
    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());

    glfwMakeContextCurrent(window);
    glfwSwapBuffers(window);
}

// Cleanup
ImGui_ImplOpenGL3_Shutdown();
ImGui_ImplGlfw_Shutdown();
ImGui::DestroyContext();

glfwDestroyWindow(window);
glfwTerminate();

return 0;

}

[ocornut]

Hello, try asking on the Discord channel https://discordapp.com/invite/NgJ4SEP

[nonlinear1]

I cann't link the web cite, may be my internet is constrained.

在 2019-09-20 17:23:19，omar notifications@github.com 写道：

Hello, try asking on the Discord channel https://discordapp.com/invite/NgJ4SEP

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[nonlinear1]

Thank you ocornut, I have join the channel

[ocornut]

I have now written a tutorial to cover image file loading for common graphics API: https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples

[redgogh]

hi ocornut, i readed u document, i not found any about vulkan add image content. just have gl and dx, for use vulkan what should to do?

[PathogenDavid]

@AncientPaper The Vulkan backend doesn't support user-specified textures. You can try applying https://github.com/ocornut/imgui/pull/914 to your local copy of the backend to enable support.