Examples: SDL: Gamepad support minor amend. Fixes ImGuiBackendFlags_HasGamepad not being set. Enable in Emscripten demo. Tweaks. (#2509, #2484).

docs/CHANGELOG.txt

@@ -70,6 +70,7 @@ Other Changes:
 - Examples: Vulkan: Added missing support for 32-bit indices (#define ImDrawIdx unsigned int).
 - Examples: Vulkan: Avoid passing negative coordinates to vkCmdSetScissor, which debug validation layers do not like.
 - Examples: Vulkan: Added ImGui_ImplVulkan_SetMinImageCount() to change min image count at runtime. (#2071) [@nathanvoglsam]
+- Examples: SDL: Added support for SDL_GameController gamepads (enable with ImGuiConfigFlags_NavEnableGamepad). (#2509) [@DJLink]
 - Examples: DirectX9: Fixed erroneous assert in ImGui_ImplDX9_InvalidateDeviceObjects(). (#2454)
 - Examples: DirectX10/11/12, Allegro, Marmalade: Render functions early out when display size is zero (minimized). (#2496)
 - Examples: GLUT: Fixed existing FreeGLUT example to work with regular GLUT. (#2465) [@andrewwillmott]
@@ -217,7 +218,7 @@ Other Changes:
 - Examples: Win32: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created
   in a different thread or parent. (#1951, #2087, #2156, #2232) [many people]
 - Examples: SDL: Using the SDL_WINDOW_ALLOW_HIGHDPI flag. (#2306, #1676) [@rasky]
-- Examples: Win32: Added support for XInput games (if ImGuiConfigFlags_NavEnableGamepad is enabled).
+- Examples: Win32: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is enabled).
 - Examples: Win32: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages. (#2264)
 - Examples: DirectX9: Explicitly disable fog (D3DRS_FOGENABLE) before drawing in case user state has it set. (#2288, #2230)
 - Examples: OpenGL2: Added #define GL_SILENCE_DEPRECATION to cope with newer XCode warnings.

examples/example_emscripten/main.cpp

@@ -25,7 +25,7 @@ void main_loop(void*);
 int main(int, char**)
 {
     // Setup SDL
-    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0)
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return -1;
@@ -62,6 +62,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 
     // For an Emscripten build we are disabling file-system access, so let's not attempt to do a fopen() of the imgui.ini file.
     // You may manually call LoadIniSettingsFromMemory() to load settings from your own storage.

examples/example_sdl_opengl2/main.cpp

@@ -16,7 +16,7 @@
 int main(int, char**)
 {
     // Setup SDL
-    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER|SDL_INIT_GAMECONTROLLER) != 0)
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return -1;
@@ -38,6 +38,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_sdl_opengl3/main.cpp

@@ -25,7 +25,7 @@
 int main(int, char**)
 {
     // Setup SDL
-    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER|SDL_INIT_GAMECONTROLLER) != 0)
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return -1;
@@ -78,6 +78,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_sdl_vulkan/main.cpp

@@ -319,7 +319,7 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
 int main(int, char**)
 {
     // Setup SDL
-    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER|SDL_INIT_GAMECONTROLLER) != 0)
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return 1;
@@ -356,6 +356,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/imgui_impl_glfw.cpp

@@ -325,6 +325,6 @@ void ImGui_ImplGlfw_NewFrame()
     ImGui_ImplGlfw_UpdateMousePosAndButtons();
     ImGui_ImplGlfw_UpdateMouseCursor();
 
-    // Gamepad navigation mapping
+    // Update game controllers (if enabled and available)
     ImGui_ImplGlfw_UpdateGamepads();
 }

examples/imgui_impl_sdl.cpp

@@ -7,9 +7,9 @@
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Keyboard arrays indexed using SDL_SCANCODE_* codes, e.g. ImGui::IsKeyPressed(SDL_SCANCODE_SPACE).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 // Missing features:
 //  [ ] 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.
-//  [ ] Platform: Gamepad support (need to use SDL_GameController API to fill the io.NavInputs[] value when ImGuiConfigFlags_NavEnableGamepad is set).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
@@ -17,6 +17,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2019-04-23: Inputs: Added support for SDL_GameController (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
 //  2019-03-12: Misc: Preserve DisplayFramebufferScale when main window is minimized.
 //  2018-12-21: Inputs: Workaround for Android/iOS which don't seem to handle focus related calls.
 //  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
@@ -273,16 +274,18 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
         return;
 
-    // Update gamepad inputs
-#define MAP_BUTTON(NAV_NO, BUTTON_NO)       { io.NavInputs[NAV_NO] = (SDL_GameControllerGetButton(game_controller, BUTTON_NO) == 1) ? 1.0f : 0.0f; }
-#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; }
-   
-    int axes_count = 0, buttons_count = 0;
+    // Get gamepad
     SDL_GameController* game_controller = SDL_GameControllerOpen(0);
-    if(game_controller !=NULL)
+    if (!game_controller)
     {
-        const int thumb_dead_zone = 8000;
+        io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+        return;
+    }
 
+    // Update gamepad inputs
+    #define MAP_BUTTON(NAV_NO, BUTTON_NO)       { io.NavInputs[NAV_NO] = (SDL_GameControllerGetButton(game_controller, BUTTON_NO) != 0) ? 1.0f : 0.0f; }
+    #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; }
+    const int thumb_dead_zone = 8000;           // SDL_gamecontroller.h suggests using this value.
     MAP_BUTTON(ImGuiNavInput_Activate,      SDL_CONTROLLER_BUTTON_A);               // Cross / A
     MAP_BUTTON(ImGuiNavInput_Cancel,        SDL_CONTROLLER_BUTTON_B);               // Circle / B
     MAP_BUTTON(ImGuiNavInput_Menu,          SDL_CONTROLLER_BUTTON_X);               // Square / X
@@ -299,14 +302,10 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     MAP_ANALOG(ImGuiNavInput_LStickRight,   SDL_CONTROLLER_AXIS_LEFTX, +thumb_dead_zone, +32767);
     MAP_ANALOG(ImGuiNavInput_LStickUp,      SDL_CONTROLLER_AXIS_LEFTY, -thumb_dead_zone, -32767);
     MAP_ANALOG(ImGuiNavInput_LStickDown,    SDL_CONTROLLER_AXIS_LEFTY, +thumb_dead_zone, +32767);
-#undef MAP_BUTTON
-#undef MAP_ANALOG
-    }
 
-    if (axes_count > 0 && buttons_count > 0)
     io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
-    else
-        io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+    #undef MAP_BUTTON
+    #undef MAP_ANALOG
 }
 
 void ImGui_ImplSDL2_NewFrame(SDL_Window* window)
@@ -332,6 +331,6 @@ void ImGui_ImplSDL2_NewFrame(SDL_Window* window)
     ImGui_ImplSDL2_UpdateMousePosAndButtons();
     ImGui_ImplSDL2_UpdateMouseCursor();
 
-    // Gamepad navigation mapping
+    // Update game controllers (if enabled and available)
     ImGui_ImplSDL2_UpdateGamepads();
 }

examples/imgui_impl_sdl.h

@@ -6,9 +6,9 @@
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Keyboard arrays indexed using SDL_SCANCODE_* codes, e.g. ImGui::IsKeyPressed(SDL_SCANCODE_SPACE).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 // Missing features:
 //  [ ] 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.
-//  [ ] Platform: Gamepad support (need to use SDL_GameController API to fill the io.NavInputs[] value when ImGuiConfigFlags_NavEnableGamepad is set).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.

examples/imgui_impl_win32.cpp

@@ -230,7 +230,7 @@ void    ImGui_ImplWin32_NewFrame()
         ImGui_ImplWin32_UpdateMouseCursor();
     }
 
-    // Update game controllers (if available)
+    // Update game controllers (if enabled and available)
     ImGui_ImplWin32_UpdateGamepads();
 }