imgui_impl_sdl.cpp (18704B)
1 // dear imgui: Platform Backend for SDL2 2 // This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..) 3 // (Info: SDL2 is a cross-platform general purpose library for handling windows, inputs, graphics context creation, etc.) 4 // (Requires: SDL 2.0. Prefer SDL 2.0.4+ for full feature support.) 5 6 // Implemented features: 7 // [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. 8 // [X] Platform: Clipboard support. 9 // [X] Platform: Keyboard arrays indexed using SDL_SCANCODE_* codes, e.g. ImGui::IsKeyPressed(SDL_SCANCODE_SPACE). 10 // [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'. 11 // Missing features: 12 // [ ] Platform: SDL2 handling of IME under Windows appears to be broken and it explicitly disable the regular Windows IME. You can restore Windows IME by compiling SDL with SDL_DISABLE_WINDOWS_IME. 13 14 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 15 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp. 16 // Read online: https://github.com/ocornut/imgui/tree/master/docs 17 18 // CHANGELOG 19 // (minor and older changes stripped away, please see git history for details) 20 // 2021-03-22: Rework global mouse pos availability check listing supported platforms explicitly, effectively fixing mouse access on Raspberry Pi. (#2837, #3950) 21 // 2020-05-25: Misc: Report a zero display-size when window is minimized, to be consistent with other backends. 22 // 2020-02-20: Inputs: Fixed mapping for ImGuiKey_KeyPadEnter (using SDL_SCANCODE_KP_ENTER instead of SDL_SCANCODE_RETURN2). 23 // 2019-12-17: Inputs: On Wayland, use SDL_GetMouseState (because there is no global mouse state). 24 // 2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor. 25 // 2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter. 26 // 2019-04-23: Inputs: Added support for SDL_GameController (if ImGuiConfigFlags_NavEnableGamepad is set by user application). 27 // 2019-03-12: Misc: Preserve DisplayFramebufferScale when main window is minimized. 28 // 2018-12-21: Inputs: Workaround for Android/iOS which don't seem to handle focus related calls. 29 // 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window. 30 // 2018-11-14: Changed the signature of ImGui_ImplSDL2_ProcessEvent() to take a 'const SDL_Event*'. 31 // 2018-08-01: Inputs: Workaround for Emscripten which doesn't seem to handle focus related calls. 32 // 2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor. 33 // 2018-06-08: Misc: Extracted imgui_impl_sdl.cpp/.h away from the old combined SDL2+OpenGL/Vulkan examples. 34 // 2018-06-08: Misc: ImGui_ImplSDL2_InitForOpenGL() now takes a SDL_GLContext parameter. 35 // 2018-05-09: Misc: Fixed clipboard paste memory leak (we didn't call SDL_FreeMemory on the data returned by SDL_GetClipboardText). 36 // 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors flag + honor ImGuiConfigFlags_NoMouseCursorChange flag. 37 // 2018-02-16: Inputs: Added support for mouse cursors, honoring ImGui::GetMouseCursor() value. 38 // 2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves. 39 // 2018-02-06: Inputs: Added mapping for ImGuiKey_Space. 40 // 2018-02-05: Misc: Using SDL_GetPerformanceCounter() instead of SDL_GetTicks() to be able to handle very high framerate (1000+ FPS). 41 // 2018-02-05: Inputs: Keyboard mapping is using scancodes everywhere instead of a confusing mixture of keycodes and scancodes. 42 // 2018-01-20: Inputs: Added Horizontal Mouse Wheel support. 43 // 2018-01-19: Inputs: When available (SDL 2.0.4+) using SDL_CaptureMouse() to retrieve coordinates outside of client area when dragging. Otherwise (SDL 2.0.3 and before) testing for SDL_WINDOW_INPUT_FOCUS instead of SDL_WINDOW_MOUSE_FOCUS. 44 // 2018-01-18: Inputs: Added mapping for ImGuiKey_Insert. 45 // 2017-08-25: Inputs: MousePos set to -FLT_MAX,-FLT_MAX when mouse is unavailable/missing (instead of -1,-1). 46 // 2016-10-15: Misc: Added a void* user_data parameter to Clipboard function handlers. 47 48 #include "imgui.h" 49 #include "imgui_impl_sdl.h" 50 51 // SDL 52 #include <SDL.h> 53 #include <SDL_syswm.h> 54 #if defined(__APPLE__) 55 #include "TargetConditionals.h" 56 #endif 57 58 #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE SDL_VERSION_ATLEAST(2,0,4) 59 #define SDL_HAS_VULKAN SDL_VERSION_ATLEAST(2,0,6) 60 61 // Data 62 static SDL_Window* g_Window = NULL; 63 static Uint64 g_Time = 0; 64 static bool g_MousePressed[3] = { false, false, false }; 65 static SDL_Cursor* g_MouseCursors[ImGuiMouseCursor_COUNT] = {}; 66 static char* g_ClipboardTextData = NULL; 67 static bool g_MouseCanUseGlobalState = true; 68 69 static const char* ImGui_ImplSDL2_GetClipboardText(void*) 70 { 71 if (g_ClipboardTextData) 72 SDL_free(g_ClipboardTextData); 73 g_ClipboardTextData = SDL_GetClipboardText(); 74 return g_ClipboardTextData; 75 } 76 77 static void ImGui_ImplSDL2_SetClipboardText(void*, const char* text) 78 { 79 SDL_SetClipboardText(text); 80 } 81 82 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs. 83 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application. 84 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application. 85 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags. 86 // If you have multiple SDL events and some of them are not meant to be used by dear imgui, you may need to filter events based on their windowID field. 87 bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event) 88 { 89 ImGuiIO& io = ImGui::GetIO(); 90 switch (event->type) 91 { 92 case SDL_MOUSEWHEEL: 93 { 94 if (event->wheel.x > 0) io.MouseWheelH += 1; 95 if (event->wheel.x < 0) io.MouseWheelH -= 1; 96 if (event->wheel.y > 0) io.MouseWheel += 1; 97 if (event->wheel.y < 0) io.MouseWheel -= 1; 98 return true; 99 } 100 case SDL_MOUSEBUTTONDOWN: 101 { 102 if (event->button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true; 103 if (event->button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true; 104 if (event->button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true; 105 return true; 106 } 107 case SDL_TEXTINPUT: 108 { 109 io.AddInputCharactersUTF8(event->text.text); 110 return true; 111 } 112 case SDL_KEYDOWN: 113 case SDL_KEYUP: 114 { 115 int key = event->key.keysym.scancode; 116 IM_ASSERT(key >= 0 && key < IM_ARRAYSIZE(io.KeysDown)); 117 io.KeysDown[key] = (event->type == SDL_KEYDOWN); 118 io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0); 119 io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0); 120 io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0); 121 #ifdef _WIN32 122 io.KeySuper = false; 123 #else 124 io.KeySuper = ((SDL_GetModState() & KMOD_GUI) != 0); 125 #endif 126 return true; 127 } 128 } 129 return false; 130 } 131 132 static bool ImGui_ImplSDL2_Init(SDL_Window* window) 133 { 134 g_Window = window; 135 136 // Setup backend capabilities flags 137 ImGuiIO& io = ImGui::GetIO(); 138 io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors; // We can honor GetMouseCursor() values (optional) 139 io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos; // We can honor io.WantSetMousePos requests (optional, rarely used) 140 io.BackendPlatformName = "imgui_impl_sdl"; 141 142 // Keyboard mapping. Dear ImGui will use those indices to peek into the io.KeysDown[] array. 143 io.KeyMap[ImGuiKey_Tab] = SDL_SCANCODE_TAB; 144 io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT; 145 io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT; 146 io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP; 147 io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN; 148 io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP; 149 io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN; 150 io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME; 151 io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END; 152 io.KeyMap[ImGuiKey_Insert] = SDL_SCANCODE_INSERT; 153 io.KeyMap[ImGuiKey_Delete] = SDL_SCANCODE_DELETE; 154 io.KeyMap[ImGuiKey_Backspace] = SDL_SCANCODE_BACKSPACE; 155 io.KeyMap[ImGuiKey_Space] = SDL_SCANCODE_SPACE; 156 io.KeyMap[ImGuiKey_Enter] = SDL_SCANCODE_RETURN; 157 io.KeyMap[ImGuiKey_Escape] = SDL_SCANCODE_ESCAPE; 158 io.KeyMap[ImGuiKey_KeyPadEnter] = SDL_SCANCODE_KP_ENTER; 159 io.KeyMap[ImGuiKey_A] = SDL_SCANCODE_A; 160 io.KeyMap[ImGuiKey_C] = SDL_SCANCODE_C; 161 io.KeyMap[ImGuiKey_V] = SDL_SCANCODE_V; 162 io.KeyMap[ImGuiKey_X] = SDL_SCANCODE_X; 163 io.KeyMap[ImGuiKey_Y] = SDL_SCANCODE_Y; 164 io.KeyMap[ImGuiKey_Z] = SDL_SCANCODE_Z; 165 166 io.SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText; 167 io.GetClipboardTextFn = ImGui_ImplSDL2_GetClipboardText; 168 io.ClipboardUserData = NULL; 169 170 // Load mouse cursors 171 g_MouseCursors[ImGuiMouseCursor_Arrow] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_ARROW); 172 g_MouseCursors[ImGuiMouseCursor_TextInput] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_IBEAM); 173 g_MouseCursors[ImGuiMouseCursor_ResizeAll] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZEALL); 174 g_MouseCursors[ImGuiMouseCursor_ResizeNS] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENS); 175 g_MouseCursors[ImGuiMouseCursor_ResizeEW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZEWE); 176 g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENESW); 177 g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENWSE); 178 g_MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_HAND); 179 g_MouseCursors[ImGuiMouseCursor_NotAllowed] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NO); 180 181 // Check and store if we are on a SDL backend that supports global mouse position 182 // ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list) 183 const char* sdl_backend = SDL_GetCurrentVideoDriver(); 184 const char* global_mouse_whitelist[] = { "windows", "cocoa", "x11", "DIVE", "VMAN" }; 185 g_MouseCanUseGlobalState = false; 186 for (int n = 0; n < IM_ARRAYSIZE(global_mouse_whitelist); n++) 187 if (strncmp(sdl_backend, global_mouse_whitelist[n], strlen(global_mouse_whitelist[n])) == 0) 188 g_MouseCanUseGlobalState = true; 189 190 #ifdef _WIN32 191 SDL_SysWMinfo wmInfo; 192 SDL_VERSION(&wmInfo.version); 193 SDL_GetWindowWMInfo(window, &wmInfo); 194 io.ImeWindowHandle = wmInfo.info.win.window; 195 #else 196 (void)window; 197 #endif 198 199 return true; 200 } 201 202 bool ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context) 203 { 204 (void)sdl_gl_context; // Viewport branch will need this. 205 return ImGui_ImplSDL2_Init(window); 206 } 207 208 bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window) 209 { 210 #if !SDL_HAS_VULKAN 211 IM_ASSERT(0 && "Unsupported"); 212 #endif 213 return ImGui_ImplSDL2_Init(window); 214 } 215 216 bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window) 217 { 218 #if !defined(_WIN32) 219 IM_ASSERT(0 && "Unsupported"); 220 #endif 221 return ImGui_ImplSDL2_Init(window); 222 } 223 224 bool ImGui_ImplSDL2_InitForMetal(SDL_Window* window) 225 { 226 return ImGui_ImplSDL2_Init(window); 227 } 228 229 void ImGui_ImplSDL2_Shutdown() 230 { 231 g_Window = NULL; 232 233 // Destroy last known clipboard data 234 if (g_ClipboardTextData) 235 SDL_free(g_ClipboardTextData); 236 g_ClipboardTextData = NULL; 237 238 // Destroy SDL mouse cursors 239 for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++) 240 SDL_FreeCursor(g_MouseCursors[cursor_n]); 241 memset(g_MouseCursors, 0, sizeof(g_MouseCursors)); 242 } 243 244 static void ImGui_ImplSDL2_UpdateMousePosAndButtons() 245 { 246 ImGuiIO& io = ImGui::GetIO(); 247 248 // Set OS mouse position if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user) 249 if (io.WantSetMousePos) 250 SDL_WarpMouseInWindow(g_Window, (int)io.MousePos.x, (int)io.MousePos.y); 251 else 252 io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX); 253 254 int mx, my; 255 Uint32 mouse_buttons = SDL_GetMouseState(&mx, &my); 256 io.MouseDown[0] = g_MousePressed[0] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_LEFT)) != 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. 257 io.MouseDown[1] = g_MousePressed[1] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0; 258 io.MouseDown[2] = g_MousePressed[2] || (mouse_buttons & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0; 259 g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false; 260 261 #if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__) && !(defined(__APPLE__) && TARGET_OS_IOS) 262 SDL_Window* focused_window = SDL_GetKeyboardFocus(); 263 if (g_Window == focused_window) 264 { 265 if (g_MouseCanUseGlobalState) 266 { 267 // SDL_GetMouseState() gives mouse position seemingly based on the last window entered/focused(?) 268 // The creation of a new windows at runtime and SDL_CaptureMouse both seems to severely mess up with that, so we retrieve that position globally. 269 // Won't use this workaround on SDL backends that have no global mouse position, like Wayland or RPI 270 int wx, wy; 271 SDL_GetWindowPosition(focused_window, &wx, &wy); 272 SDL_GetGlobalMouseState(&mx, &my); 273 mx -= wx; 274 my -= wy; 275 } 276 io.MousePos = ImVec2((float)mx, (float)my); 277 } 278 279 // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger the OS window resize cursor. 280 // The function is only supported from SDL 2.0.4 (released Jan 2016) 281 bool any_mouse_button_down = ImGui::IsAnyMouseDown(); 282 SDL_CaptureMouse(any_mouse_button_down ? SDL_TRUE : SDL_FALSE); 283 #else 284 if (SDL_GetWindowFlags(g_Window) & SDL_WINDOW_INPUT_FOCUS) 285 io.MousePos = ImVec2((float)mx, (float)my); 286 #endif 287 } 288 289 static void ImGui_ImplSDL2_UpdateMouseCursor() 290 { 291 ImGuiIO& io = ImGui::GetIO(); 292 if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange) 293 return; 294 295 ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor(); 296 if (io.MouseDrawCursor || imgui_cursor == ImGuiMouseCursor_None) 297 { 298 // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor 299 SDL_ShowCursor(SDL_FALSE); 300 } 301 else 302 { 303 // Show OS mouse cursor 304 SDL_SetCursor(g_MouseCursors[imgui_cursor] ? g_MouseCursors[imgui_cursor] : g_MouseCursors[ImGuiMouseCursor_Arrow]); 305 SDL_ShowCursor(SDL_TRUE); 306 } 307 } 308 309 static void ImGui_ImplSDL2_UpdateGamepads() 310 { 311 ImGuiIO& io = ImGui::GetIO(); 312 memset(io.NavInputs, 0, sizeof(io.NavInputs)); 313 if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0) 314 return; 315 316 // Get gamepad 317 SDL_GameController* game_controller = SDL_GameControllerOpen(0); 318 if (!game_controller) 319 { 320 io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad; 321 return; 322 } 323 324 // Update gamepad inputs 325 #define MAP_BUTTON(NAV_NO, BUTTON_NO) { io.NavInputs[NAV_NO] = (SDL_GameControllerGetButton(game_controller, BUTTON_NO) != 0) ? 1.0f : 0.0f; } 326 #define MAP_ANALOG(NAV_NO, AXIS_NO, V0, V1) { float vn = (float)(SDL_GameControllerGetAxis(game_controller, AXIS_NO) - V0) / (float)(V1 - V0); if (vn > 1.0f) vn = 1.0f; if (vn > 0.0f && io.NavInputs[NAV_NO] < vn) io.NavInputs[NAV_NO] = vn; } 327 const int thumb_dead_zone = 8000; // SDL_gamecontroller.h suggests using this value. 328 MAP_BUTTON(ImGuiNavInput_Activate, SDL_CONTROLLER_BUTTON_A); // Cross / A 329 MAP_BUTTON(ImGuiNavInput_Cancel, SDL_CONTROLLER_BUTTON_B); // Circle / B 330 MAP_BUTTON(ImGuiNavInput_Menu, SDL_CONTROLLER_BUTTON_X); // Square / X 331 MAP_BUTTON(ImGuiNavInput_Input, SDL_CONTROLLER_BUTTON_Y); // Triangle / Y 332 MAP_BUTTON(ImGuiNavInput_DpadLeft, SDL_CONTROLLER_BUTTON_DPAD_LEFT); // D-Pad Left 333 MAP_BUTTON(ImGuiNavInput_DpadRight, SDL_CONTROLLER_BUTTON_DPAD_RIGHT); // D-Pad Right 334 MAP_BUTTON(ImGuiNavInput_DpadUp, SDL_CONTROLLER_BUTTON_DPAD_UP); // D-Pad Up 335 MAP_BUTTON(ImGuiNavInput_DpadDown, SDL_CONTROLLER_BUTTON_DPAD_DOWN); // D-Pad Down 336 MAP_BUTTON(ImGuiNavInput_FocusPrev, SDL_CONTROLLER_BUTTON_LEFTSHOULDER); // L1 / LB 337 MAP_BUTTON(ImGuiNavInput_FocusNext, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER); // R1 / RB 338 MAP_BUTTON(ImGuiNavInput_TweakSlow, SDL_CONTROLLER_BUTTON_LEFTSHOULDER); // L1 / LB 339 MAP_BUTTON(ImGuiNavInput_TweakFast, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER); // R1 / RB 340 MAP_ANALOG(ImGuiNavInput_LStickLeft, SDL_CONTROLLER_AXIS_LEFTX, -thumb_dead_zone, -32768); 341 MAP_ANALOG(ImGuiNavInput_LStickRight, SDL_CONTROLLER_AXIS_LEFTX, +thumb_dead_zone, +32767); 342 MAP_ANALOG(ImGuiNavInput_LStickUp, SDL_CONTROLLER_AXIS_LEFTY, -thumb_dead_zone, -32767); 343 MAP_ANALOG(ImGuiNavInput_LStickDown, SDL_CONTROLLER_AXIS_LEFTY, +thumb_dead_zone, +32767); 344 345 io.BackendFlags |= ImGuiBackendFlags_HasGamepad; 346 #undef MAP_BUTTON 347 #undef MAP_ANALOG 348 } 349 350 void ImGui_ImplSDL2_NewFrame(SDL_Window* window) 351 { 352 ImGuiIO& io = ImGui::GetIO(); 353 IM_ASSERT(io.Fonts->IsBuilt() && "Font atlas not built! It is generally built by the renderer backend. Missing call to renderer _NewFrame() function? e.g. ImGui_ImplOpenGL3_NewFrame()."); 354 355 // Setup display size (every frame to accommodate for window resizing) 356 int w, h; 357 int display_w, display_h; 358 SDL_GetWindowSize(window, &w, &h); 359 if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED) 360 w = h = 0; 361 SDL_GL_GetDrawableSize(window, &display_w, &display_h); 362 io.DisplaySize = ImVec2((float)w, (float)h); 363 if (w > 0 && h > 0) 364 io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h); 365 366 // Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution) 367 static Uint64 frequency = SDL_GetPerformanceFrequency(); 368 Uint64 current_time = SDL_GetPerformanceCounter(); 369 io.DeltaTime = g_Time > 0 ? (float)((double)(current_time - g_Time) / frequency) : (float)(1.0f / 60.0f); 370 g_Time = current_time; 371 372 ImGui_ImplSDL2_UpdateMousePosAndButtons(); 373 ImGui_ImplSDL2_UpdateMouseCursor(); 374 375 // Update game controllers (if enabled and available) 376 ImGui_ImplSDL2_UpdateGamepads(); 377 }