1 // dear imgui: Platform Binding for FreeGLUT
2 // This needs to be used along with a Renderer (e.g. OpenGL2)
3
4 // Issues:
5 // [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I
6 // [ ] Platform: Missing gamepad support.
7
8 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
9 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
10 // https://github.com/ocornut/imgui
11
12 // CHANGELOG
13 // (minor and older changes stripped away, please see git history for details)
14 // 2018-03-22: Added FreeGLUT Platform binding.
15
16 #include "imgui.h"
17 #include "imgui_impl_freeglut.h"
18 #include <GL/freeglut.h>
19
20 #ifdef _MSC_VER
21 #pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff)
22 #endif
23
24 static int g_Time = 0; // Current time, in milliseconds
25
ImGui_ImplFreeGLUT_Init()26 bool ImGui_ImplFreeGLUT_Init()
27 {
28 ImGuiIO& io = ImGui::GetIO();
29 g_Time = 0;
30
31 // Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
32 io.KeyMap[ImGuiKey_Tab] = '\t'; // == 9 == CTRL+I
33 io.KeyMap[ImGuiKey_LeftArrow] = 256 + GLUT_KEY_LEFT;
34 io.KeyMap[ImGuiKey_RightArrow] = 256 + GLUT_KEY_RIGHT;
35 io.KeyMap[ImGuiKey_UpArrow] = 256 + GLUT_KEY_UP;
36 io.KeyMap[ImGuiKey_DownArrow] = 256 + GLUT_KEY_DOWN;
37 io.KeyMap[ImGuiKey_PageUp] = 256 + GLUT_KEY_PAGE_UP;
38 io.KeyMap[ImGuiKey_PageDown] = 256 + GLUT_KEY_PAGE_DOWN;
39 io.KeyMap[ImGuiKey_Home] = 256 + GLUT_KEY_HOME;
40 io.KeyMap[ImGuiKey_End] = 256 + GLUT_KEY_END;
41 io.KeyMap[ImGuiKey_Insert] = 256 + GLUT_KEY_INSERT;
42 io.KeyMap[ImGuiKey_Delete] = 127;
43 io.KeyMap[ImGuiKey_Backspace] = 8; // == CTRL+H
44 io.KeyMap[ImGuiKey_Space] = ' ';
45 io.KeyMap[ImGuiKey_Enter] = 13; // == CTRL+M
46 io.KeyMap[ImGuiKey_Escape] = 27;
47 io.KeyMap[ImGuiKey_A] = 'A';
48 io.KeyMap[ImGuiKey_C] = 'C';
49 io.KeyMap[ImGuiKey_V] = 'V';
50 io.KeyMap[ImGuiKey_X] = 'X';
51 io.KeyMap[ImGuiKey_Y] = 'Y';
52 io.KeyMap[ImGuiKey_Z] = 'Z';
53
54 return true;
55 }
56
ImGui_ImplFreeGLUT_InstallFuncs()57 void ImGui_ImplFreeGLUT_InstallFuncs()
58 {
59 glutReshapeFunc(ImGui_ImplFreeGLUT_ReshapeFunc);
60 glutMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
61 glutPassiveMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
62 glutMouseFunc(ImGui_ImplFreeGLUT_MouseFunc);
63 glutMouseWheelFunc(ImGui_ImplFreeGLUT_MouseWheelFunc);
64 glutKeyboardFunc(ImGui_ImplFreeGLUT_KeyboardFunc);
65 glutKeyboardUpFunc(ImGui_ImplFreeGLUT_KeyboardUpFunc);
66 glutSpecialFunc(ImGui_ImplFreeGLUT_SpecialFunc);
67 glutSpecialUpFunc(ImGui_ImplFreeGLUT_SpecialUpFunc);
68 }
69
ImGui_ImplFreeGLUT_Shutdown()70 void ImGui_ImplFreeGLUT_Shutdown()
71 {
72 }
73
ImGui_ImplFreeGLUT_NewFrame()74 void ImGui_ImplFreeGLUT_NewFrame()
75 {
76 // Setup time step
77 ImGuiIO& io = ImGui::GetIO();
78 int current_time = glutGet(GLUT_ELAPSED_TIME);
79 io.DeltaTime = (current_time - g_Time) / 1000.0f;
80 g_Time = current_time;
81
82 // Start the frame
83 ImGui::NewFrame();
84 }
85
ImGui_ImplFreeGLUT_UpdateKeyboardMods()86 static void ImGui_ImplFreeGLUT_UpdateKeyboardMods()
87 {
88 ImGuiIO& io = ImGui::GetIO();
89 int mods = glutGetModifiers();
90 io.KeyCtrl = (mods & GLUT_ACTIVE_CTRL) != 0;
91 io.KeyShift = (mods & GLUT_ACTIVE_SHIFT) != 0;
92 io.KeyAlt = (mods & GLUT_ACTIVE_ALT) != 0;
93 }
94
ImGui_ImplFreeGLUT_KeyboardFunc(unsigned char c,int x,int y)95 void ImGui_ImplFreeGLUT_KeyboardFunc(unsigned char c, int x, int y)
96 {
97 // Send character to imgui
98 //printf("char_down_func %d '%c'\n", c, c);
99 ImGuiIO& io = ImGui::GetIO();
100 if (c >= 32)
101 io.AddInputCharacter((unsigned short)c);
102
103 // Store letters in KeysDown[] array as both uppercase and lowercase + Handle GLUT translating CTRL+A..CTRL+Z as 1..26.
104 // 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.
105 if (c >= 1 && c <= 26)
106 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = true;
107 else if (c >= 'a' && c <= 'z')
108 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = true;
109 else if (c >= 'A' && c <= 'Z')
110 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = true;
111 else
112 io.KeysDown[c] = true;
113 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
114 (void)x; (void)y; // Unused
115 }
116
ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c,int x,int y)117 void ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c, int x, int y)
118 {
119 //printf("char_up_func %d '%c'\n", c, c);
120 ImGuiIO& io = ImGui::GetIO();
121 if (c >= 1 && c <= 26)
122 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = false;
123 else if (c >= 'a' && c <= 'z')
124 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = false;
125 else if (c >= 'A' && c <= 'Z')
126 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = false;
127 else
128 io.KeysDown[c] = false;
129 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
130 (void)x; (void)y; // Unused
131 }
132
ImGui_ImplFreeGLUT_SpecialFunc(int key,int x,int y)133 void ImGui_ImplFreeGLUT_SpecialFunc(int key, int x, int y)
134 {
135 //printf("key_down_func %d\n", key);
136 ImGuiIO& io = ImGui::GetIO();
137 if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
138 io.KeysDown[key + 256] = true;
139 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
140 (void)x; (void)y; // Unused
141 }
142
ImGui_ImplFreeGLUT_SpecialUpFunc(int key,int x,int y)143 void ImGui_ImplFreeGLUT_SpecialUpFunc(int key, int x, int y)
144 {
145 //printf("key_up_func %d\n", key);
146 ImGuiIO& io = ImGui::GetIO();
147 if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
148 io.KeysDown[key + 256] = false;
149 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
150 (void)x; (void)y; // Unused
151 }
152
ImGui_ImplFreeGLUT_MouseFunc(int glut_button,int state,int x,int y)153 void ImGui_ImplFreeGLUT_MouseFunc(int glut_button, int state, int x, int y)
154 {
155 ImGuiIO& io = ImGui::GetIO();
156 io.MousePos = ImVec2((float)x, (float)y);
157 int button = -1;
158 if (glut_button == GLUT_LEFT_BUTTON) button = 0;
159 if (glut_button == GLUT_RIGHT_BUTTON) button = 1;
160 if (glut_button == GLUT_MIDDLE_BUTTON) button = 2;
161 if (button != -1 && state == GLUT_DOWN)
162 io.MouseDown[button] = true;
163 if (button != -1 && state == GLUT_UP)
164 io.MouseDown[button] = false;
165 }
166
ImGui_ImplFreeGLUT_MouseWheelFunc(int button,int dir,int x,int y)167 void ImGui_ImplFreeGLUT_MouseWheelFunc(int button, int dir, int x, int y)
168 {
169 ImGuiIO& io = ImGui::GetIO();
170 io.MousePos = ImVec2((float)x, (float)y);
171 if (dir > 0)
172 io.MouseWheel += 1.0;
173 else if (dir < 0)
174 io.MouseWheel -= 1.0;
175 (void)button; // Unused
176 }
177
ImGui_ImplFreeGLUT_ReshapeFunc(int w,int h)178 void ImGui_ImplFreeGLUT_ReshapeFunc(int w, int h)
179 {
180 ImGuiIO& io = ImGui::GetIO();
181 io.DisplaySize = ImVec2((float)w, (float)h);
182 }
183
ImGui_ImplFreeGLUT_MotionFunc(int x,int y)184 void ImGui_ImplFreeGLUT_MotionFunc(int x, int y)
185 {
186 ImGuiIO& io = ImGui::GetIO();
187 io.MousePos = ImVec2((float)x, (float)y);
188 }
189