Examples: Win32: Added support for XInput games (if ImGuiConfigFlags_NavEnableGamepad is enabled).

docs/CHANGELOG.txt

@@ -36,6 +36,7 @@ HOW TO UPDATE?
 Other Changes:
 - Examples: Win32: Using GetForegroundWindow() instead of GetActiveWindow() to be compatible with windows created 
   in a different thread. (#1951, #2087, #2156, #2232) [many people]
+- Examples: Win32: Added support for XInput games (if ImGuiConfigFlags_NavEnableGamepad is enabled).
 
 
 -----------------------------------------------------------------------

examples/imgui_impl_glfw.cpp

@@ -286,7 +286,7 @@ void ImGui_ImplGlfw_NewFrame()
     ImGui_ImplGlfw_UpdateMousePosAndButtons();
     ImGui_ImplGlfw_UpdateMouseCursor();
 
-    // Gamepad navigation mapping [BETA]
+    // Gamepad navigation mapping
     memset(io.NavInputs, 0, sizeof(io.NavInputs));
     if (io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad)
     {

examples/imgui_impl_win32.cpp

@@ -5,8 +5,7 @@
 //  [X] Platform: Clipboard support (for Win32 this is actually part of core imgui)
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Keyboard arrays indexed using VK_* Virtual Key Codes, e.g. ImGui::IsKeyPressed(VK_SPACE).
-// Missing features:
-//  [ ] Platform: Gamepad support (best leaving it to user application to fill io.NavInputs[] with gamepad inputs from their source of choice).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 
 #include "imgui.h"
 #include "imgui_impl_win32.h"
@@ -14,11 +13,13 @@
 #define WIN32_LEAN_AND_MEAN
 #endif
 #include <windows.h>
+#include <XInput.h>
 #include <tchar.h>
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2019-01-15: Inputs: Using GetForegroundWindow() instead of GetActiveWindow() to be compatible with windows created in a different thread.
+//  2019-01-15: Inputs: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
 //  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
 //  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
 //  2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
@@ -40,6 +41,8 @@ static HWND                 g_hWnd = 0;
 static INT64                g_Time = 0;
 static INT64                g_TicksPerSecond = 0;
 static ImGuiMouseCursor     g_LastMouseCursor = ImGuiMouseCursor_COUNT;
+static bool                 g_HasGamepad = false;
+static bool                 g_WantUpdateHasGamepad = true;
 
 // Functions
 bool    ImGui_ImplWin32_Init(void* hwnd)
@@ -140,6 +143,57 @@ static void ImGui_ImplWin32_UpdateMousePos()
             io.MousePos = ImVec2((float)pos.x, (float)pos.y);
 }
 
+#ifdef _MSC_VER
+#pragma comment(lib, "xinput")
+#endif
+
+// Gamepad navigation mapping
+void    ImGui_ImplWin32_UpdateGameControllers()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    memset(io.NavInputs, 0, sizeof(io.NavInputs));
+    if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
+        return;
+
+    // Calling XInputGetState() every frame on disconnected gamepads is unfortunately too slow.
+    // Instead we refresh gamepad availability by calling XInputGetCapabilities() _only_ after receiving WM_DEVICECHANGE.
+    if (g_WantUpdateHasGamepad)
+    {
+        XINPUT_CAPABILITIES caps;
+        g_HasGamepad = (XInputGetCapabilities(0, XINPUT_FLAG_GAMEPAD, &caps) == ERROR_SUCCESS);
+        g_WantUpdateHasGamepad = false;
+    }
+
+    XINPUT_STATE xinput_state;
+    io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+    if (g_HasGamepad && XInputGetState(0, &xinput_state) == ERROR_SUCCESS)
+    {
+        const XINPUT_GAMEPAD& gamepad = xinput_state.Gamepad;
+        io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+
+        #define MAP_BUTTON(NAV_NO, BUTTON_ENUM)     { io.NavInputs[NAV_NO] = (gamepad.wButtons & BUTTON_ENUM) ? 1.0f : 0.0f; }
+        #define MAP_ANALOG(NAV_NO, VALUE, V0, V1)   { float vn = (float)(VALUE - 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; }
+        MAP_BUTTON(ImGuiNavInput_Activate,      XINPUT_GAMEPAD_A);              // Cross / A
+        MAP_BUTTON(ImGuiNavInput_Cancel,        XINPUT_GAMEPAD_B);              // Circle / B
+        MAP_BUTTON(ImGuiNavInput_Menu,          XINPUT_GAMEPAD_X);              // Square / X
+        MAP_BUTTON(ImGuiNavInput_Input,         XINPUT_GAMEPAD_Y);              // Triangle / Y
+        MAP_BUTTON(ImGuiNavInput_DpadLeft,      XINPUT_GAMEPAD_DPAD_LEFT);      // D-Pad Left
+        MAP_BUTTON(ImGuiNavInput_DpadRight,     XINPUT_GAMEPAD_DPAD_RIGHT);     // D-Pad Right
+        MAP_BUTTON(ImGuiNavInput_DpadUp,        XINPUT_GAMEPAD_DPAD_UP);        // D-Pad Up
+        MAP_BUTTON(ImGuiNavInput_DpadDown,      XINPUT_GAMEPAD_DPAD_DOWN);      // D-Pad Down
+        MAP_BUTTON(ImGuiNavInput_FocusPrev,     XINPUT_GAMEPAD_LEFT_SHOULDER);  // L1 / LB
+        MAP_BUTTON(ImGuiNavInput_FocusNext,     XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
+        MAP_BUTTON(ImGuiNavInput_TweakSlow,     XINPUT_GAMEPAD_LEFT_SHOULDER);  // L1 / LB
+        MAP_BUTTON(ImGuiNavInput_TweakFast,     XINPUT_GAMEPAD_RIGHT_SHOULDER); // R1 / RB
+        MAP_ANALOG(ImGuiNavInput_LStickLeft,    gamepad.sThumbLX,  -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
+        MAP_ANALOG(ImGuiNavInput_LStickRight,   gamepad.sThumbLX,  +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+        MAP_ANALOG(ImGuiNavInput_LStickUp,      gamepad.sThumbLY,  +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+        MAP_ANALOG(ImGuiNavInput_LStickDown,    gamepad.sThumbLY,  -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32767);
+        #undef MAP_BUTTON
+        #undef MAP_ANALOG
+    }
+}
+
 void    ImGui_ImplWin32_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -173,12 +227,18 @@ void    ImGui_ImplWin32_NewFrame()
         g_LastMouseCursor = mouse_cursor;
         ImGui_ImplWin32_UpdateMouseCursor();
     }
+
+    // Update game controllers (if available)
+    ImGui_ImplWin32_UpdateGameControllers();
 }
 
 // Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
 #ifndef WM_MOUSEHWHEEL
 #define WM_MOUSEHWHEEL 0x020E
 #endif
+#ifndef DBT_DEVNODES_CHANGED
+#define DBT_DEVNODES_CHANGED 0x0007
+#endif
 
 // Process Win32 mouse/keyboard inputs. 
 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
@@ -246,6 +306,10 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
             return 1;
         return 0;
+    case WM_DEVICECHANGE:
+        if ((UINT)wParam == DBT_DEVNODES_CHANGED)
+            g_WantUpdateHasGamepad = true;
+        return 0;
     }
     return 0;
 }

examples/imgui_impl_win32.h

@@ -5,8 +5,7 @@
 //  [X] Platform: Clipboard support (for Win32 this is actually part of core imgui)
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Keyboard arrays indexed using VK_* Virtual Key Codes, e.g. ImGui::IsKeyPressed(VK_SPACE).
-// Missing features:
-//  [ ] Platform: Gamepad support (best leaving it to user application to fill io.NavInputs[] with gamepad inputs from their source of choice).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 
 #pragma once