// ImGui GLFW binding with OpenGL // https://github.com/ocornut/imgui #include <imgui.h> #include "imgui_impl_glfw.h" // GLFW #include <GLFW/glfw3.h> #ifdef _MSC_VER #undef APIENTRY #define GLFW_EXPOSE_NATIVE_WIN32 #define GLFW_EXPOSE_NATIVE_WGL #include <GLFW/glfw3native.h> #endif // Data static GLFWwindow* g_Window = NULL; static double g_Time = 0.0f; static bool g_MousePressed[3] = { false, false, false }; static float g_MouseWheel = 0.0f; static GLuint g_FontTexture = 0; // This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure) // If text or lines are blurry when integrating ImGui in your engine: // - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f) static void ImGui_ImplGlfw_RenderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count) { if (cmd_lists_count == 0) return; // We are using the OpenGL fixed pipeline to make the example code simpler to read! // A probable faster way to render would be to collate all vertices from all cmd_lists into a single vertex buffer. // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers. glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); glEnable(GL_SCISSOR_TEST); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnableClientState(GL_COLOR_ARRAY); glEnable(GL_TEXTURE_2D); // Setup orthographic projection matrix const float width = ImGui::GetIO().DisplaySize.x; const float height = ImGui::GetIO().DisplaySize.y; glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); glOrtho(0.0f, width, height, 0.0f, -1.0f, +1.0f); glMatrixMode(GL_MODELVIEW); glPushMatrix(); glLoadIdentity(); // Render command lists #define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT)) for (int n = 0; n < cmd_lists_count; n++) { const ImDrawList* cmd_list = cmd_lists[n]; const unsigned char* vtx_buffer = (const unsigned char*)&cmd_list->vtx_buffer.front(); glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, pos))); glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, uv))); glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, col))); int vtx_offset = 0; for (size_t cmd_i = 0; cmd_i < cmd_list->commands.size(); cmd_i++) { const ImDrawCmd* pcmd = &cmd_list->commands[cmd_i]; if (pcmd->user_callback) { pcmd->user_callback(cmd_list, pcmd); } else { glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->texture_id); glScissor((int)pcmd->clip_rect.x, (int)(height - pcmd->clip_rect.w), (int)(pcmd->clip_rect.z - pcmd->clip_rect.x), (int)(pcmd->clip_rect.w - pcmd->clip_rect.y)); glDrawArrays(GL_TRIANGLES, vtx_offset, pcmd->vtx_count); } vtx_offset += pcmd->vtx_count; } } #undef OFFSETOF // Restore modified state glDisableClientState(GL_COLOR_ARRAY); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_VERTEX_ARRAY); glMatrixMode(GL_MODELVIEW); glPopMatrix(); glMatrixMode(GL_PROJECTION); glPopMatrix(); glPopAttrib(); } static const char* ImGui_ImplGlfw_GetClipboardText() { return glfwGetClipboardString(g_Window); } static void ImGui_ImplGlfw_SetClipboardText(const char* text) { glfwSetClipboardString(g_Window, text); } void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow*, int button, int action, int /*mods*/) { if (action == GLFW_PRESS && button >= 0 && button < 3) g_MousePressed[button] = true; } void ImGui_ImplGlfw_ScrollCallback(GLFWwindow*, double /*xoffset*/, double yoffset) { g_MouseWheel += (float)yoffset; // Use fractional mouse wheel, 1.0 unit 5 lines. } void ImGui_ImplGlFw_KeyCallback(GLFWwindow*, int key, int, int action, int mods) { ImGuiIO& io = ImGui::GetIO(); if (action == GLFW_PRESS) io.KeysDown[key] = true; if (action == GLFW_RELEASE) io.KeysDown[key] = false; io.KeyCtrl = (mods & GLFW_MOD_CONTROL) != 0; io.KeyShift = (mods & GLFW_MOD_SHIFT) != 0; io.KeyAlt = (mods & GLFW_MOD_ALT) != 0; } void ImGui_ImplGlfw_CharCallback(GLFWwindow*, unsigned int c) { ImGuiIO& io = ImGui::GetIO(); if (c > 0 && c < 0x10000) io.AddInputCharacter((unsigned short)c); } bool ImGui_ImplGlfw_CreateDeviceObjects() { ImGuiIO& io = ImGui::GetIO(); // Build texture unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height); // Create texture glGenTextures(1, &g_FontTexture); glBindTexture(GL_TEXTURE_2D, g_FontTexture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, pixels); // Store our identifier io.Fonts->TexID = (void *)(intptr_t)g_FontTexture; return true; } void ImGui_ImplGlfw_InvalidateDeviceObjects() { if (g_FontTexture) { glDeleteTextures(1, &g_FontTexture); ImGui::GetIO().Fonts->TexID = 0; g_FontTexture = 0; } } bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks) { g_Window = window; ImGuiIO& io = ImGui::GetIO(); io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array. io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT; io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT; io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP; io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN; io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME; io.KeyMap[ImGuiKey_End] = GLFW_KEY_END; io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE; io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE; io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER; io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE; io.KeyMap[ImGuiKey_A] = GLFW_KEY_A; io.KeyMap[ImGuiKey_C] = GLFW_KEY_C; io.KeyMap[ImGuiKey_V] = GLFW_KEY_V; io.KeyMap[ImGuiKey_X] = GLFW_KEY_X; io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y; io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z; io.RenderDrawListsFn = ImGui_ImplGlfw_RenderDrawLists; io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText; io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText; #ifdef _MSC_VER io.ImeWindowHandle = glfwGetWin32Window(g_Window); #endif if (install_callbacks) { glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback); glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback); glfwSetKeyCallback(window, ImGui_ImplGlFw_KeyCallback); glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback); } return true; } void ImGui_ImplGlfw_Shutdown() { ImGui_ImplGlfw_InvalidateDeviceObjects(); ImGui::Shutdown(); } void ImGui_ImplGlfw_NewFrame() { if (!g_FontTexture) ImGui_ImplGlfw_CreateDeviceObjects(); ImGuiIO& io = ImGui::GetIO(); // Setup display size (every frame to accommodate for window resizing) int w, h; int display_w, display_h; glfwGetWindowSize(g_Window, &w, &h); glfwGetFramebufferSize(g_Window, &display_w, &display_h); io.DisplaySize = ImVec2((float)display_w, (float)display_h); // Setup time step double current_time = glfwGetTime(); io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f); g_Time = current_time; // Setup inputs // (we already got mouse wheel, keyboard keys & characters from glfw callbacks polled in glfwPollEvents()) if (glfwGetWindowAttrib(g_Window, GLFW_FOCUSED)) { double mouse_x, mouse_y; glfwGetCursorPos(g_Window, &mouse_x, &mouse_y); mouse_x *= (float)display_w / w; // Convert mouse coordinates to pixels mouse_y *= (float)display_h / h; io.MousePos = ImVec2((float)mouse_x, (float)mouse_y); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.) } else { io.MousePos = ImVec2(-1,-1); } for (int i = 0; i < 3; i++) { io.MouseDown[i] = g_MousePressed[i] || glfwGetMouseButton(g_Window, i) != 0; // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame. g_MousePressed[i] = false; } io.MouseWheel = g_MouseWheel; g_MouseWheel = 0.0f; // Start the frame ImGui::NewFrame(); }