// ImGui Platform Binding for: FreeGLUT // This needs to be used along with a Renderer (e.g. OpenGL2) // Issues: // [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this. // If you use this binding you'll need to call 4 functions: ImGui_ImplXXXX_Init(), ImGui_ImplXXXX_NewFrame(), ImGui::Render() and ImGui_ImplXXXX_Shutdown(). // If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp. // https://github.com/ocornut/imgui // CHANGELOG // (minor and older changes stripped away, please see git history for details) // 2018-03-22: Added FreeGLUT Platform binding. #include "imgui.h" #include "imgui_impl_freeglut.h" #include <GL/freeglut.h> #ifdef _MSC_VER #pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff) #endif static int g_Time = 0; // Current time, in milliseconds bool ImGui_ImplFreeGLUT_Init() { ImGuiIO& io = ImGui::GetIO(); g_Time = 0; // Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above. io.KeyMap[ImGuiKey_Tab] = '\t'; // == 9 == CTRL+I io.KeyMap[ImGuiKey_LeftArrow] = 256 + GLUT_KEY_LEFT; io.KeyMap[ImGuiKey_RightArrow] = 256 + GLUT_KEY_RIGHT; io.KeyMap[ImGuiKey_UpArrow] = 256 + GLUT_KEY_UP; io.KeyMap[ImGuiKey_DownArrow] = 256 + GLUT_KEY_DOWN; io.KeyMap[ImGuiKey_PageUp] = 256 + GLUT_KEY_PAGE_UP; io.KeyMap[ImGuiKey_PageDown] = 256 + GLUT_KEY_PAGE_DOWN; io.KeyMap[ImGuiKey_Home] = 256 + GLUT_KEY_HOME; io.KeyMap[ImGuiKey_End] = 256 + GLUT_KEY_END; io.KeyMap[ImGuiKey_Insert] = 256 + GLUT_KEY_INSERT; io.KeyMap[ImGuiKey_Delete] = 127; io.KeyMap[ImGuiKey_Backspace] = 8; // == CTRL+H io.KeyMap[ImGuiKey_Space] = ' '; io.KeyMap[ImGuiKey_Enter] = 13; // == CTRL+M io.KeyMap[ImGuiKey_Escape] = 27; io.KeyMap[ImGuiKey_A] = 'A'; io.KeyMap[ImGuiKey_C] = 'C'; io.KeyMap[ImGuiKey_V] = 'V'; io.KeyMap[ImGuiKey_X] = 'X'; io.KeyMap[ImGuiKey_Y] = 'Y'; io.KeyMap[ImGuiKey_Z] = 'Z'; return true; } void ImGui_ImplFreeGLUT_InstallFuncs() { glutReshapeFunc(ImGui_ImplFreeGLUT_ReshapeFunc); glutMotionFunc(ImGui_ImplFreeGLUT_MotionFunc); glutPassiveMotionFunc(ImGui_ImplFreeGLUT_MotionFunc); glutMouseFunc(ImGui_ImplFreeGLUT_MouseFunc); glutMouseWheelFunc(ImGui_ImplFreeGLUT_MouseWheelFunc); glutKeyboardFunc(ImGui_ImplFreeGLUT_KeyboardFunc); glutKeyboardUpFunc(ImGui_ImplFreeGLUT_KeyboardUpFunc); glutSpecialFunc(ImGui_ImplFreeGLUT_SpecialFunc); glutSpecialUpFunc(ImGui_ImplFreeGLUT_SpecialUpFunc); } void ImGui_ImplFreeGLUT_Shutdown() { } void ImGui_ImplFreeGLUT_NewFrame() { // Setup time step ImGuiIO& io = ImGui::GetIO(); int current_time = glutGet(GLUT_ELAPSED_TIME); io.DeltaTime = (current_time - g_Time) / 1000.0f; g_Time = current_time; // Start the frame ImGui::NewFrame(); } static void ImGui_ImplFreeGLUT_UpdateKeyboardMods() { ImGuiIO& io = ImGui::GetIO(); int mods = glutGetModifiers(); io.KeyCtrl = (mods & GLUT_ACTIVE_CTRL) != 0; io.KeyShift = (mods & GLUT_ACTIVE_SHIFT) != 0; io.KeyAlt = (mods & GLUT_ACTIVE_ALT) != 0; } void ImGui_ImplFreeGLUT_KeyboardFunc(unsigned char c, int x, int y) { // Send character to imgui //printf("char_down_func %d '%c'\n", c, c); ImGuiIO& io = ImGui::GetIO(); if (c >= 32) io.AddInputCharacter(c); // Store letters in KeysDown[] array as both uppercase and lowercase + Handle GLUT translating CTRL+A..CTRL+Z as 1..26. // This is a hacky mess but GLUT is unable to distinguish e.g. a TAB key from CTRL+I so this is probably the best we can do here. if (c >= 1 && c <= 26) io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = true; else if (c >= 'a' && c <= 'z') io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = true; else if (c >= 'A' && c <= 'Z') io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = true; else io.KeysDown[c] = true; ImGui_ImplFreeGLUT_UpdateKeyboardMods(); (void)x; (void)y; // Unused } void ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c, int x, int y) { //printf("char_up_func %d '%c'\n", c, c); ImGuiIO& io = ImGui::GetIO(); if (c >= 1 && c <= 26) io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = false; else if (c >= 'a' && c <= 'z') io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = false; else if (c >= 'A' && c <= 'Z') io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = false; else io.KeysDown[c] = false; ImGui_ImplFreeGLUT_UpdateKeyboardMods(); (void)x; (void)y; // Unused } void ImGui_ImplFreeGLUT_SpecialFunc(int key, int x, int y) { //printf("key_down_func %d\n", key); ImGuiIO& io = ImGui::GetIO(); if (key + 256 < IM_ARRAYSIZE(io.KeysDown)) io.KeysDown[key + 256] = true; ImGui_ImplFreeGLUT_UpdateKeyboardMods(); (void)x; (void)y; // Unused } void ImGui_ImplFreeGLUT_SpecialUpFunc(int key, int x, int y) { //printf("key_up_func %d\n", key); ImGuiIO& io = ImGui::GetIO(); if (key + 256 < IM_ARRAYSIZE(io.KeysDown)) io.KeysDown[key + 256] = false; ImGui_ImplFreeGLUT_UpdateKeyboardMods(); (void)x; (void)y; // Unused } void ImGui_ImplFreeGLUT_MouseFunc(int glut_button, int state, int x, int y) { ImGuiIO& io = ImGui::GetIO(); io.MousePos = ImVec2((float)x, (float)y); int button = -1; if (glut_button == GLUT_LEFT_BUTTON) button = 0; if (glut_button == GLUT_RIGHT_BUTTON) button = 1; if (glut_button == GLUT_MIDDLE_BUTTON) button = 2; if (button != -1 && state == GLUT_DOWN) io.MouseDown[button] = true; if (button != -1 && state == GLUT_UP) io.MouseDown[button] = false; } void ImGui_ImplFreeGLUT_MouseWheelFunc(int button, int dir, int x, int y) { ImGuiIO& io = ImGui::GetIO(); io.MousePos = ImVec2((float)x, (float)y); if (dir > 0) io.MouseWheel += 1.0; else if (dir < 0) io.MouseWheel -= 1.0; (void)button; // Unused } void ImGui_ImplFreeGLUT_ReshapeFunc(int w, int h) { ImGuiIO& io = ImGui::GetIO(); io.DisplaySize = ImVec2((float)w, (float)h); } void ImGui_ImplFreeGLUT_MotionFunc(int x, int y) { ImGuiIO& io = ImGui::GetIO(); io.MousePos = ImVec2((float)x, (float)y); }