imgui_impl_glut.cpp (7547B)
1 // dear imgui: Platform Backend for GLUT/FreeGLUT 2 // This needs to be used along with a Renderer (e.g. OpenGL2) 3 4 // !!! GLUT/FreeGLUT IS OBSOLETE PREHISTORIC SOFTWARE. Using GLUT is not recommended unless you really miss the 90's. !!! 5 // !!! If someone or something is teaching you GLUT today, you are being abused. Please show some resistance. !!! 6 // !!! Nowadays, prefer using GLFW or SDL instead! 7 8 // Issues: 9 // [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I 10 // [ ] Platform: Missing mouse cursor shape/visibility support. 11 // [ ] Platform: Missing clipboard support (not supported by Glut). 12 // [ ] Platform: Missing gamepad support. 13 14 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 15 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp. 16 // Read online: https://github.com/ocornut/imgui/tree/master/docs 17 18 // CHANGELOG 19 // (minor and older changes stripped away, please see git history for details) 20 // 2019-04-03: Misc: Renamed imgui_impl_freeglut.cpp/.h to imgui_impl_glut.cpp/.h. 21 // 2019-03-25: Misc: Made io.DeltaTime always above zero. 22 // 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window. 23 // 2018-03-22: Added GLUT Platform binding. 24 25 #include "imgui.h" 26 #include "imgui_impl_glut.h" 27 #ifdef __APPLE__ 28 #include <GLUT/glut.h> 29 #else 30 #include <GL/freeglut.h> 31 #endif 32 33 #ifdef _MSC_VER 34 #pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff) 35 #endif 36 37 static int g_Time = 0; // Current time, in milliseconds 38 39 bool ImGui_ImplGLUT_Init() 40 { 41 ImGuiIO& io = ImGui::GetIO(); 42 43 #ifdef FREEGLUT 44 io.BackendPlatformName = "imgui_impl_glut (freeglut)"; 45 #else 46 io.BackendPlatformName = "imgui_impl_glut"; 47 #endif 48 49 g_Time = 0; 50 51 // Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above. 52 io.KeyMap[ImGuiKey_Tab] = '\t'; // == 9 == CTRL+I 53 io.KeyMap[ImGuiKey_LeftArrow] = 256 + GLUT_KEY_LEFT; 54 io.KeyMap[ImGuiKey_RightArrow] = 256 + GLUT_KEY_RIGHT; 55 io.KeyMap[ImGuiKey_UpArrow] = 256 + GLUT_KEY_UP; 56 io.KeyMap[ImGuiKey_DownArrow] = 256 + GLUT_KEY_DOWN; 57 io.KeyMap[ImGuiKey_PageUp] = 256 + GLUT_KEY_PAGE_UP; 58 io.KeyMap[ImGuiKey_PageDown] = 256 + GLUT_KEY_PAGE_DOWN; 59 io.KeyMap[ImGuiKey_Home] = 256 + GLUT_KEY_HOME; 60 io.KeyMap[ImGuiKey_End] = 256 + GLUT_KEY_END; 61 io.KeyMap[ImGuiKey_Insert] = 256 + GLUT_KEY_INSERT; 62 io.KeyMap[ImGuiKey_Delete] = 127; 63 io.KeyMap[ImGuiKey_Backspace] = 8; // == CTRL+H 64 io.KeyMap[ImGuiKey_Space] = ' '; 65 io.KeyMap[ImGuiKey_Enter] = 13; // == CTRL+M 66 io.KeyMap[ImGuiKey_Escape] = 27; 67 io.KeyMap[ImGuiKey_KeyPadEnter] = 13; // == CTRL+M 68 io.KeyMap[ImGuiKey_A] = 'A'; 69 io.KeyMap[ImGuiKey_C] = 'C'; 70 io.KeyMap[ImGuiKey_V] = 'V'; 71 io.KeyMap[ImGuiKey_X] = 'X'; 72 io.KeyMap[ImGuiKey_Y] = 'Y'; 73 io.KeyMap[ImGuiKey_Z] = 'Z'; 74 75 return true; 76 } 77 78 void ImGui_ImplGLUT_InstallFuncs() 79 { 80 glutReshapeFunc(ImGui_ImplGLUT_ReshapeFunc); 81 glutMotionFunc(ImGui_ImplGLUT_MotionFunc); 82 glutPassiveMotionFunc(ImGui_ImplGLUT_MotionFunc); 83 glutMouseFunc(ImGui_ImplGLUT_MouseFunc); 84 #ifdef __FREEGLUT_EXT_H__ 85 glutMouseWheelFunc(ImGui_ImplGLUT_MouseWheelFunc); 86 #endif 87 glutKeyboardFunc(ImGui_ImplGLUT_KeyboardFunc); 88 glutKeyboardUpFunc(ImGui_ImplGLUT_KeyboardUpFunc); 89 glutSpecialFunc(ImGui_ImplGLUT_SpecialFunc); 90 glutSpecialUpFunc(ImGui_ImplGLUT_SpecialUpFunc); 91 } 92 93 void ImGui_ImplGLUT_Shutdown() 94 { 95 } 96 97 void ImGui_ImplGLUT_NewFrame() 98 { 99 // Setup time step 100 ImGuiIO& io = ImGui::GetIO(); 101 int current_time = glutGet(GLUT_ELAPSED_TIME); 102 int delta_time_ms = (current_time - g_Time); 103 if (delta_time_ms <= 0) 104 delta_time_ms = 1; 105 io.DeltaTime = delta_time_ms / 1000.0f; 106 g_Time = current_time; 107 108 // Start the frame 109 ImGui::NewFrame(); 110 } 111 112 static void ImGui_ImplGLUT_UpdateKeyboardMods() 113 { 114 ImGuiIO& io = ImGui::GetIO(); 115 int mods = glutGetModifiers(); 116 io.KeyCtrl = (mods & GLUT_ACTIVE_CTRL) != 0; 117 io.KeyShift = (mods & GLUT_ACTIVE_SHIFT) != 0; 118 io.KeyAlt = (mods & GLUT_ACTIVE_ALT) != 0; 119 } 120 121 void ImGui_ImplGLUT_KeyboardFunc(unsigned char c, int x, int y) 122 { 123 // Send character to imgui 124 //printf("char_down_func %d '%c'\n", c, c); 125 ImGuiIO& io = ImGui::GetIO(); 126 if (c >= 32) 127 io.AddInputCharacter((unsigned int)c); 128 129 // Store letters in KeysDown[] array as both uppercase and lowercase + Handle GLUT translating CTRL+A..CTRL+Z as 1..26. 130 // 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. 131 if (c >= 1 && c <= 26) 132 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = true; 133 else if (c >= 'a' && c <= 'z') 134 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = true; 135 else if (c >= 'A' && c <= 'Z') 136 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = true; 137 else 138 io.KeysDown[c] = true; 139 ImGui_ImplGLUT_UpdateKeyboardMods(); 140 (void)x; (void)y; // Unused 141 } 142 143 void ImGui_ImplGLUT_KeyboardUpFunc(unsigned char c, int x, int y) 144 { 145 //printf("char_up_func %d '%c'\n", c, c); 146 ImGuiIO& io = ImGui::GetIO(); 147 if (c >= 1 && c <= 26) 148 io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = false; 149 else if (c >= 'a' && c <= 'z') 150 io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = false; 151 else if (c >= 'A' && c <= 'Z') 152 io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = false; 153 else 154 io.KeysDown[c] = false; 155 ImGui_ImplGLUT_UpdateKeyboardMods(); 156 (void)x; (void)y; // Unused 157 } 158 159 void ImGui_ImplGLUT_SpecialFunc(int key, int x, int y) 160 { 161 //printf("key_down_func %d\n", key); 162 ImGuiIO& io = ImGui::GetIO(); 163 if (key + 256 < IM_ARRAYSIZE(io.KeysDown)) 164 io.KeysDown[key + 256] = true; 165 ImGui_ImplGLUT_UpdateKeyboardMods(); 166 (void)x; (void)y; // Unused 167 } 168 169 void ImGui_ImplGLUT_SpecialUpFunc(int key, int x, int y) 170 { 171 //printf("key_up_func %d\n", key); 172 ImGuiIO& io = ImGui::GetIO(); 173 if (key + 256 < IM_ARRAYSIZE(io.KeysDown)) 174 io.KeysDown[key + 256] = false; 175 ImGui_ImplGLUT_UpdateKeyboardMods(); 176 (void)x; (void)y; // Unused 177 } 178 179 void ImGui_ImplGLUT_MouseFunc(int glut_button, int state, int x, int y) 180 { 181 ImGuiIO& io = ImGui::GetIO(); 182 io.MousePos = ImVec2((float)x, (float)y); 183 int button = -1; 184 if (glut_button == GLUT_LEFT_BUTTON) button = 0; 185 if (glut_button == GLUT_RIGHT_BUTTON) button = 1; 186 if (glut_button == GLUT_MIDDLE_BUTTON) button = 2; 187 if (button != -1 && state == GLUT_DOWN) 188 io.MouseDown[button] = true; 189 if (button != -1 && state == GLUT_UP) 190 io.MouseDown[button] = false; 191 } 192 193 #ifdef __FREEGLUT_EXT_H__ 194 void ImGui_ImplGLUT_MouseWheelFunc(int button, int dir, int x, int y) 195 { 196 ImGuiIO& io = ImGui::GetIO(); 197 io.MousePos = ImVec2((float)x, (float)y); 198 if (dir > 0) 199 io.MouseWheel += 1.0; 200 else if (dir < 0) 201 io.MouseWheel -= 1.0; 202 (void)button; // Unused 203 } 204 #endif 205 206 void ImGui_ImplGLUT_ReshapeFunc(int w, int h) 207 { 208 ImGuiIO& io = ImGui::GetIO(); 209 io.DisplaySize = ImVec2((float)w, (float)h); 210 } 211 212 void ImGui_ImplGLUT_MotionFunc(int x, int y) 213 { 214 ImGuiIO& io = ImGui::GetIO(); 215 io.MousePos = ImVec2((float)x, (float)y); 216 }