1 // dear imgui: Platform Binding for GLFW
2 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan..)
3 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
4 
5 // Implemented features:
6 //  [X] Platform: Clipboard support.
7 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
8 //  [x] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. FIXME: 3 cursors types are missing from GLFW.
9 //  [X] Platform: Keyboard arrays indexed using GLFW_KEY_* codes, e.g. ImGui::IsKeyPressed(GLFW_KEY_SPACE).
10 
11 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
12 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
13 // https://github.com/ocornut/imgui
14 
15 // CHANGELOG
16 // (minor and older changes stripped away, please see git history for details)
17 //  2018-08-01: Inputs: Workaround for Emscripten which doesn't seem to handle focus related calls.
18 //  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
19 //  2018-06-08: Misc: Extracted imgui_impl_glfw.cpp/.h away from the old combined GLFW+OpenGL/Vulkan examples.
20 //  2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors flag + honor ImGuiConfigFlags_NoMouseCursorChange flag.
21 //  2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value, passed to glfwSetCursor()).
22 //  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
23 //  2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
24 //  2018-01-25: Inputs: Added gamepad support if ImGuiConfigFlags_NavEnableGamepad is set.
25 //  2018-01-25: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
26 //  2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
27 //  2018-01-18: Inputs: Added mapping for ImGuiKey_Insert.
28 //  2017-08-25: Inputs: MousePos set to -FLT_MAX,-FLT_MAX when mouse is unavailable/missing (instead of -1,-1).
29 //  2016-10-15: Misc: Added a void* user_data parameter to Clipboard function handlers.
30 
31 #include "imgui.h"
32 #include "imgui_impl_glfw.h"
33 
34 // GLFW
35 #include <GLFW/glfw3.h>
36 #ifdef _WIN32
37 #undef APIENTRY
38 #define GLFW_EXPOSE_NATIVE_WIN32
39 #include <GLFW/glfw3native.h>   // for glfwGetWin32Window
40 #endif
41 #define GLFW_HAS_WINDOW_TOPMOST     (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3200) // 3.2+ GLFW_FLOATING
42 #define GLFW_HAS_WINDOW_HOVERED     (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ GLFW_HOVERED
43 #define GLFW_HAS_WINDOW_ALPHA       (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ glfwSetWindowOpacity
44 #define GLFW_HAS_PER_MONITOR_DPI    (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ glfwGetMonitorContentScale
45 #define GLFW_HAS_VULKAN             (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3200) // 3.2+ glfwCreateWindowSurface
46 
47 // Data
48 enum GlfwClientApi
49 {
50     GlfwClientApi_Unknown,
51     GlfwClientApi_OpenGL,
52     GlfwClientApi_Vulkan
53 };
54 static GLFWwindow*      g_Window = NULL;
55 static GlfwClientApi    g_ClientApi = GlfwClientApi_Unknown;
56 static double           g_Time = 0.0;
57 static bool             g_MouseJustPressed[5] = { false, false, false, false, false };
58 static GLFWcursor*      g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
59 
ImGui_ImplGlfw_GetClipboardText(void * user_data)60 static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
61 {
62     return glfwGetClipboardString((GLFWwindow*)user_data);
63 }
64 
ImGui_ImplGlfw_SetClipboardText(void * user_data,const char * text)65 static void ImGui_ImplGlfw_SetClipboardText(void* user_data, const char* text)
66 {
67     glfwSetClipboardString((GLFWwindow*)user_data, text);
68 }
69 
ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow *,int button,int action,int)70 void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow*, int button, int action, int /*mods*/)
71 {
72     if (action == GLFW_PRESS && button >= 0 && button < IM_ARRAYSIZE(g_MouseJustPressed))
73         g_MouseJustPressed[button] = true;
74 }
75 
ImGui_ImplGlfw_ScrollCallback(GLFWwindow *,double xoffset,double yoffset)76 void ImGui_ImplGlfw_ScrollCallback(GLFWwindow*, double xoffset, double yoffset)
77 {
78     ImGuiIO& io = ImGui::GetIO();
79     io.MouseWheelH += (float)xoffset;
80     io.MouseWheel += (float)yoffset;
81 }
82 
ImGui_ImplGlfw_KeyCallback(GLFWwindow *,int key,int,int action,int mods)83 void ImGui_ImplGlfw_KeyCallback(GLFWwindow*, int key, int, int action, int mods)
84 {
85     ImGuiIO& io = ImGui::GetIO();
86     if (action == GLFW_PRESS)
87         io.KeysDown[key] = true;
88     if (action == GLFW_RELEASE)
89         io.KeysDown[key] = false;
90 
91     (void)mods; // Modifiers are not reliable across systems
92     io.KeyCtrl = io.KeysDown[GLFW_KEY_LEFT_CONTROL] || io.KeysDown[GLFW_KEY_RIGHT_CONTROL];
93     io.KeyShift = io.KeysDown[GLFW_KEY_LEFT_SHIFT] || io.KeysDown[GLFW_KEY_RIGHT_SHIFT];
94     io.KeyAlt = io.KeysDown[GLFW_KEY_LEFT_ALT] || io.KeysDown[GLFW_KEY_RIGHT_ALT];
95     io.KeySuper = io.KeysDown[GLFW_KEY_LEFT_SUPER] || io.KeysDown[GLFW_KEY_RIGHT_SUPER];
96 }
97 
ImGui_ImplGlfw_CharCallback(GLFWwindow *,unsigned int c)98 void ImGui_ImplGlfw_CharCallback(GLFWwindow*, unsigned int c)
99 {
100     ImGuiIO& io = ImGui::GetIO();
101     if (c > 0 && c < 0x10000)
102         io.AddInputCharacter((unsigned short)c);
103 }
104 
ImGui_ImplGlfw_InstallCallbacks(GLFWwindow * window)105 void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
106 {
107     glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
108     glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
109     glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
110     glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
111 }
112 
ImGui_ImplGlfw_Init(GLFWwindow * window,bool install_callbacks,GlfwClientApi client_api)113 static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, GlfwClientApi client_api)
114 {
115     g_Window = window;
116     g_Time = 0.0;
117 
118     // Setup back-end capabilities flags
119     ImGuiIO& io = ImGui::GetIO();
120     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
121     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
122 
123     // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
124     io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB;
125     io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT;
126     io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT;
127     io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP;
128     io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN;
129     io.KeyMap[ImGuiKey_PageUp] = GLFW_KEY_PAGE_UP;
130     io.KeyMap[ImGuiKey_PageDown] = GLFW_KEY_PAGE_DOWN;
131     io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME;
132     io.KeyMap[ImGuiKey_End] = GLFW_KEY_END;
133     io.KeyMap[ImGuiKey_Insert] = GLFW_KEY_INSERT;
134     io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE;
135     io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE;
136     io.KeyMap[ImGuiKey_Space] = GLFW_KEY_SPACE;
137     io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER;
138     io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE;
139     io.KeyMap[ImGuiKey_A] = GLFW_KEY_A;
140     io.KeyMap[ImGuiKey_C] = GLFW_KEY_C;
141     io.KeyMap[ImGuiKey_V] = GLFW_KEY_V;
142     io.KeyMap[ImGuiKey_X] = GLFW_KEY_X;
143     io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y;
144     io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z;
145 
146     io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
147     io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
148     io.ClipboardUserData = g_Window;
149 #if defined(_WIN32)
150     io.ImeWindowHandle = (void*)glfwGetWin32Window(g_Window);
151 #endif
152 
153     g_MouseCursors[ImGuiMouseCursor_Arrow] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
154     g_MouseCursors[ImGuiMouseCursor_TextInput] = glfwCreateStandardCursor(GLFW_IBEAM_CURSOR);
155     g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);   // FIXME: GLFW doesn't have this.
156     g_MouseCursors[ImGuiMouseCursor_ResizeNS] = glfwCreateStandardCursor(GLFW_VRESIZE_CURSOR);
157     g_MouseCursors[ImGuiMouseCursor_ResizeEW] = glfwCreateStandardCursor(GLFW_HRESIZE_CURSOR);
158     g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);  // FIXME: GLFW doesn't have this.
159     g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);  // FIXME: GLFW doesn't have this.
160     g_MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
161 
162     if (install_callbacks)
163         ImGui_ImplGlfw_InstallCallbacks(window);
164 
165     g_ClientApi = client_api;
166     return true;
167 }
168 
ImGui_ImplGlfw_InitForOpenGL(GLFWwindow * window,bool install_callbacks)169 bool ImGui_ImplGlfw_InitForOpenGL(GLFWwindow* window, bool install_callbacks)
170 {
171     return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_OpenGL);
172 }
173 
ImGui_ImplGlfw_InitForVulkan(GLFWwindow * window,bool install_callbacks)174 bool ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool install_callbacks)
175 {
176     return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_Vulkan);
177 }
178 
ImGui_ImplGlfw_Shutdown()179 void ImGui_ImplGlfw_Shutdown()
180 {
181     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
182     {
183         glfwDestroyCursor(g_MouseCursors[cursor_n]);
184         g_MouseCursors[cursor_n] = NULL;
185     }
186     g_ClientApi = GlfwClientApi_Unknown;
187 }
188 
ImGui_ImplGlfw_UpdateMousePosAndButtons()189 static void ImGui_ImplGlfw_UpdateMousePosAndButtons()
190 {
191     // Update buttons
192     ImGuiIO& io = ImGui::GetIO();
193     for (int i = 0; i < IM_ARRAYSIZE(io.MouseDown); i++)
194     {
195         // 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.
196         io.MouseDown[i] = g_MouseJustPressed[i] || glfwGetMouseButton(g_Window, i) != 0;
197         g_MouseJustPressed[i] = false;
198     }
199 
200     // Update mouse position
201     const ImVec2 mouse_pos_backup = io.MousePos;
202     io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
203 #ifdef __EMSCRIPTEN__
204     const bool focused = true; // Emscripten
205 #else
206     const bool focused = glfwGetWindowAttrib(g_Window, GLFW_FOCUSED) != 0;
207 #endif
208     if (focused)
209     {
210         if (io.WantSetMousePos)
211         {
212             glfwSetCursorPos(g_Window, (double)mouse_pos_backup.x, (double)mouse_pos_backup.y);
213         }
214         else
215         {
216             double mouse_x, mouse_y;
217             glfwGetCursorPos(g_Window, &mouse_x, &mouse_y);
218             io.MousePos = ImVec2((float)mouse_x, (float)mouse_y);
219         }
220     }
221 }
222 
ImGui_ImplGlfw_UpdateMouseCursor()223 static void ImGui_ImplGlfw_UpdateMouseCursor()
224 {
225     ImGuiIO& io = ImGui::GetIO();
226     if ((io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange) || glfwGetInputMode(g_Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
227         return;
228 
229     ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
230     if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
231     {
232         // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
233         glfwSetInputMode(g_Window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
234     }
235     else
236     {
237         // Show OS mouse cursor
238         // FIXME-PLATFORM: Unfocused windows seems to fail changing the mouse cursor with GLFW 3.2, but 3.3 works here.
239         glfwSetCursor(g_Window, g_MouseCursors[imgui_cursor] ? g_MouseCursors[imgui_cursor] : g_MouseCursors[ImGuiMouseCursor_Arrow]);
240         glfwSetInputMode(g_Window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
241     }
242 }
243 
ImGui_ImplGlfw_NewFrame()244 void ImGui_ImplGlfw_NewFrame()
245 {
246     ImGuiIO& io = ImGui::GetIO();
247     IM_ASSERT(io.Fonts->IsBuilt());     // Font atlas needs to be built, call renderer _NewFrame() function e.g. ImGui_ImplOpenGL3_NewFrame()
248 
249     // Setup display size
250     int w, h;
251     int display_w, display_h;
252     glfwGetWindowSize(g_Window, &w, &h);
253     glfwGetFramebufferSize(g_Window, &display_w, &display_h);
254     io.DisplaySize = ImVec2((float)w, (float)h);
255     io.DisplayFramebufferScale = ImVec2(w > 0 ? ((float)display_w / w) : 0, h > 0 ? ((float)display_h / h) : 0);
256 
257     // Setup time step
258     double current_time = glfwGetTime();
259     io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f);
260     g_Time = current_time;
261 
262     ImGui_ImplGlfw_UpdateMousePosAndButtons();
263     ImGui_ImplGlfw_UpdateMouseCursor();
264 
265     // Gamepad navigation mapping [BETA]
266     memset(io.NavInputs, 0, sizeof(io.NavInputs));
267     if (io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad)
268     {
269         // Update gamepad inputs
270         #define MAP_BUTTON(NAV_NO, BUTTON_NO)       { if (buttons_count > BUTTON_NO && buttons[BUTTON_NO] == GLFW_PRESS) io.NavInputs[NAV_NO] = 1.0f; }
271         #define MAP_ANALOG(NAV_NO, AXIS_NO, V0, V1) { float v = (axes_count > AXIS_NO) ? axes[AXIS_NO] : V0; v = (v - V0) / (V1 - V0); if (v > 1.0f) v = 1.0f; if (io.NavInputs[NAV_NO] < v) io.NavInputs[NAV_NO] = v; }
272         int axes_count = 0, buttons_count = 0;
273         const float* axes = glfwGetJoystickAxes(GLFW_JOYSTICK_1, &axes_count);
274         const unsigned char* buttons = glfwGetJoystickButtons(GLFW_JOYSTICK_1, &buttons_count);
275         MAP_BUTTON(ImGuiNavInput_Activate,   0);     // Cross / A
276         MAP_BUTTON(ImGuiNavInput_Cancel,     1);     // Circle / B
277         MAP_BUTTON(ImGuiNavInput_Menu,       2);     // Square / X
278         MAP_BUTTON(ImGuiNavInput_Input,      3);     // Triangle / Y
279         MAP_BUTTON(ImGuiNavInput_DpadLeft,   13);    // D-Pad Left
280         MAP_BUTTON(ImGuiNavInput_DpadRight,  11);    // D-Pad Right
281         MAP_BUTTON(ImGuiNavInput_DpadUp,     10);    // D-Pad Up
282         MAP_BUTTON(ImGuiNavInput_DpadDown,   12);    // D-Pad Down
283         MAP_BUTTON(ImGuiNavInput_FocusPrev,  4);     // L1 / LB
284         MAP_BUTTON(ImGuiNavInput_FocusNext,  5);     // R1 / RB
285         MAP_BUTTON(ImGuiNavInput_TweakSlow,  4);     // L1 / LB
286         MAP_BUTTON(ImGuiNavInput_TweakFast,  5);     // R1 / RB
287         MAP_ANALOG(ImGuiNavInput_LStickLeft, 0,  -0.3f,  -0.9f);
288         MAP_ANALOG(ImGuiNavInput_LStickRight,0,  +0.3f,  +0.9f);
289         MAP_ANALOG(ImGuiNavInput_LStickUp,   1,  +0.3f,  +0.9f);
290         MAP_ANALOG(ImGuiNavInput_LStickDown, 1,  -0.3f,  -0.9f);
291         #undef MAP_BUTTON
292         #undef MAP_ANALOG
293         if (axes_count > 0 && buttons_count > 0)
294             io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
295         else
296             io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
297     }
298 }
299