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 // 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
15 // 2018-03-22: Added FreeGLUT Platform binding.
16
17 #include "imgui.h"
18 #include "imgui_impl_freeglut.h"
19 #include <GL/freeglut.h>
20
21 #ifdef _MSC_VER
22 #pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff)
23 #endif
24
25 static int g_Time = 0; // Current time, in milliseconds
26
ImGui_ImplFreeGLUT_Init()27 bool ImGui_ImplFreeGLUT_Init()
28 {
29 ImGuiIO& io = ImGui::GetIO();
30 io.BackendPlatformName ="imgui_impl_freeglut";
31
32 g_Time = 0;
33
34 // Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
35 io.KeyMap[ImGuiKey_Tab] = '\t'; // == 9 == CTRL+I
36 io.KeyMap[ImGuiKey_LeftArrow] = 256 + GLUT_KEY_LEFT;
37 io.KeyMap[ImGuiKey_RightArrow] = 256 + GLUT_KEY_RIGHT;
38 io.KeyMap[ImGuiKey_UpArrow] = 256 + GLUT_KEY_UP;
39 io.KeyMap[ImGuiKey_DownArrow] = 256 + GLUT_KEY_DOWN;
40 io.KeyMap[ImGuiKey_PageUp] = 256 + GLUT_KEY_PAGE_UP;
41 io.KeyMap[ImGuiKey_PageDown] = 256 + GLUT_KEY_PAGE_DOWN;
42 io.KeyMap[ImGuiKey_Home] = 256 + GLUT_KEY_HOME;
43 io.KeyMap[ImGuiKey_End] = 256 + GLUT_KEY_END;
44 io.KeyMap[ImGuiKey_Insert] = 256 + GLUT_KEY_INSERT;
45 io.KeyMap[ImGuiKey_Delete] = 127;
46 io.KeyMap[ImGuiKey_Backspace] = 8; // == CTRL+H
47 io.KeyMap[ImGuiKey_Space] = ' ';
48 io.KeyMap[ImGuiKey_Enter] = 13; // == CTRL+M
49 io.KeyMap[ImGuiKey_Escape] = 27;
50 io.KeyMap[ImGuiKey_A] = 'A';
51 io.KeyMap[ImGuiKey_C] = 'C';
52 io.KeyMap[ImGuiKey_V] = 'V';
53 io.KeyMap[ImGuiKey_X] = 'X';
54 io.KeyMap[ImGuiKey_Y] = 'Y';
55 io.KeyMap[ImGuiKey_Z] = 'Z';
56
57 return true;
58 }
59
ImGui_ImplFreeGLUT_InstallFuncs()60 void ImGui_ImplFreeGLUT_InstallFuncs()
61 {
62 glutReshapeFunc(ImGui_ImplFreeGLUT_ReshapeFunc);
63 glutMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
64 glutPassiveMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
65 glutMouseFunc(ImGui_ImplFreeGLUT_MouseFunc);
66 glutMouseWheelFunc(ImGui_ImplFreeGLUT_MouseWheelFunc);
67 glutKeyboardFunc(ImGui_ImplFreeGLUT_KeyboardFunc);
68 glutKeyboardUpFunc(ImGui_ImplFreeGLUT_KeyboardUpFunc);
69 glutSpecialFunc(ImGui_ImplFreeGLUT_SpecialFunc);
70 glutSpecialUpFunc(ImGui_ImplFreeGLUT_SpecialUpFunc);
71 }
72
ImGui_ImplFreeGLUT_Shutdown()73 void ImGui_ImplFreeGLUT_Shutdown()
74 {
75 }
76
ImGui_ImplFreeGLUT_NewFrame()77 void ImGui_ImplFreeGLUT_NewFrame()
78 {
79 // Setup time step
80 ImGuiIO& io = ImGui::GetIO();
81 int current_time = glutGet(GLUT_ELAPSED_TIME);
82 io.DeltaTime = (current_time - g_Time) / 1000.0f;
83 g_Time = current_time;
84
85 // Start the frame
86 ImGui::NewFrame();
87 }
88
ImGui_ImplFreeGLUT_UpdateKeyboardMods()89 static void ImGui_ImplFreeGLUT_UpdateKeyboardMods()
90 {
91 ImGuiIO& io = ImGui::GetIO();
92 int mods = glutGetModifiers();
93 io.KeyCtrl = (mods & GLUT_ACTIVE_CTRL) != 0;
94 io.KeyShift = (mods & GLUT_ACTIVE_SHIFT) != 0;
95 io.KeyAlt = (mods & GLUT_ACTIVE_ALT) != 0;
96 }
97
ImGui_ImplFreeGLUT_KeyboardFunc(unsigned char c,int x,int y)98 void ImGui_ImplFreeGLUT_KeyboardFunc(unsigned char c, int x, int y)
99 {
100 // Send character to imgui
101 //printf("char_down_func %d '%c'\n", c, c);
102 ImGuiIO& io = ImGui::GetIO();
103 if (c >= 32)
104 io.AddInputCharacter((unsigned short)c);
105
106 // Store letters in KeysDown[] array as both uppercase and lowercase + Handle GLUT translating CTRL+A..CTRL+Z as 1..26.
107 // 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.
108 if (c >= 1 && c <= 26)
109 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = true;
110 else if (c >= 'a' && c <= 'z')
111 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = true;
112 else if (c >= 'A' && c <= 'Z')
113 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = true;
114 else
115 io.KeysDown[c] = true;
116 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
117 (void)x; (void)y; // Unused
118 }
119
ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c,int x,int y)120 void ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c, int x, int y)
121 {
122 //printf("char_up_func %d '%c'\n", c, c);
123 ImGuiIO& io = ImGui::GetIO();
124 if (c >= 1 && c <= 26)
125 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = false;
126 else if (c >= 'a' && c <= 'z')
127 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = false;
128 else if (c >= 'A' && c <= 'Z')
129 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = false;
130 else
131 io.KeysDown[c] = false;
132 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
133 (void)x; (void)y; // Unused
134 }
135
ImGui_ImplFreeGLUT_SpecialFunc(int key,int x,int y)136 void ImGui_ImplFreeGLUT_SpecialFunc(int key, int x, int y)
137 {
138 //printf("key_down_func %d\n", key);
139 ImGuiIO& io = ImGui::GetIO();
140 if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
141 io.KeysDown[key + 256] = true;
142 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
143 (void)x; (void)y; // Unused
144 }
145
ImGui_ImplFreeGLUT_SpecialUpFunc(int key,int x,int y)146 void ImGui_ImplFreeGLUT_SpecialUpFunc(int key, int x, int y)
147 {
148 //printf("key_up_func %d\n", key);
149 ImGuiIO& io = ImGui::GetIO();
150 if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
151 io.KeysDown[key + 256] = false;
152 ImGui_ImplFreeGLUT_UpdateKeyboardMods();
153 (void)x; (void)y; // Unused
154 }
155
ImGui_ImplFreeGLUT_MouseFunc(int glut_button,int state,int x,int y)156 void ImGui_ImplFreeGLUT_MouseFunc(int glut_button, int state, int x, int y)
157 {
158 ImGuiIO& io = ImGui::GetIO();
159 io.MousePos = ImVec2((float)x, (float)y);
160 int button = -1;
161 if (glut_button == GLUT_LEFT_BUTTON) button = 0;
162 if (glut_button == GLUT_RIGHT_BUTTON) button = 1;
163 if (glut_button == GLUT_MIDDLE_BUTTON) button = 2;
164 if (button != -1 && state == GLUT_DOWN)
165 io.MouseDown[button] = true;
166 if (button != -1 && state == GLUT_UP)
167 io.MouseDown[button] = false;
168 }
169
ImGui_ImplFreeGLUT_MouseWheelFunc(int button,int dir,int x,int y)170 void ImGui_ImplFreeGLUT_MouseWheelFunc(int button, int dir, int x, int y)
171 {
172 ImGuiIO& io = ImGui::GetIO();
173 io.MousePos = ImVec2((float)x, (float)y);
174 if (dir > 0)
175 io.MouseWheel += 1.0;
176 else if (dir < 0)
177 io.MouseWheel -= 1.0;
178 (void)button; // Unused
179 }
180
ImGui_ImplFreeGLUT_ReshapeFunc(int w,int h)181 void ImGui_ImplFreeGLUT_ReshapeFunc(int w, int h)
182 {
183 ImGuiIO& io = ImGui::GetIO();
184 io.DisplaySize = ImVec2((float)w, (float)h);
185 }
186
ImGui_ImplFreeGLUT_MotionFunc(int x,int y)187 void ImGui_ImplFreeGLUT_MotionFunc(int x, int y)
188 {
189 ImGuiIO& io = ImGui::GetIO();
190 io.MousePos = ImVec2((float)x, (float)y);
191 }
192