// dear imgui: Platform Backend for GLUT/FreeGLUT
// This needs to be used along with a Renderer (e.g. OpenGL2)
// !!! GLUT/FreeGLUT IS OBSOLETE PREHISTORIC SOFTWARE. Using GLUT is not recommended unless you really miss the 90's. !!!
// !!! If someone or something is teaching you GLUT today, you are being abused. Please show some resistance. !!!
// !!! Nowadays, prefer using GLFW or SDL instead!
// Implemented features:
// [X] Platform: Partial keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLUT values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
// Issues:
// [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I
// [ ] Platform: Missing horizontal mouse wheel support.
// [ ] Platform: Missing mouse cursor shape/visibility support.
// [ ] Platform: Missing clipboard support (not supported by Glut).
// [ ] Platform: Missing gamepad support.
// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
// Learn about Dear ImGui:
// - FAQ https://dearimgui.com/faq
// - Getting Started https://dearimgui.com/getting-started
// - Documentation https://dearimgui.com/docs (same as your local docs/ folder).
// - Introduction, links and more at the top of imgui.cpp
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2023-04-17: BREAKING: Removed call to ImGui::NewFrame() from ImGui_ImplGLUT_NewFrame(). Needs to be called from the main application loop, like with every other backends.
// 2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
// 2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
// 2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
// 2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
// 2019-04-03: Misc: Renamed imgui_impl_freeglut.cpp/.h to imgui_impl_glut.cpp/.h.
// 2019-03-25: Misc: Made io.DeltaTime always above zero.
// 2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
// 2018-03-22: Added GLUT Platform binding.
#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_glut.h"
#define GL_SILENCE_DEPRECATION
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/freeglut.h>
#endif
#ifdef _MSC_VER
#pragma warning (disable: 4505) // unreferenced local function has been removed (stb stuff)
#endif
static int g_Time = 0; // Current time, in milliseconds
// Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
static ImGuiKey ImGui_ImplGLUT_KeyToImGuiKey(int key)
{
switch (key)
{
case '\t': return ImGuiKey_Tab;
case 256 + GLUT_KEY_LEFT: return ImGuiKey_LeftArrow;
case 256 + GLUT_KEY_RIGHT: return ImGuiKey_RightArrow;
case 256 + GLUT_KEY_UP: return ImGuiKey_UpArrow;
case 256 + GLUT_KEY_DOWN: return ImGuiKey_DownArrow;
case 256 + GLUT_KEY_PAGE_UP: return ImGuiKey_PageUp;
case 256 + GLUT_KEY_PAGE_DOWN: return ImGuiKey_PageDown;
case 256 + GLUT_KEY_HOME: return ImGuiKey_Home;
case 256 + GLUT_KEY_END: return ImGuiKey_End;
case 256 + GLUT_KEY_INSERT: return ImGuiKey_Insert;
case 127: return ImGuiKey_Delete;
case 8: return ImGuiKey_Backspace;
case ' ': return ImGuiKey_Space;
case 13: return ImGuiKey_Enter;
case 27: return ImGuiKey_Escape;
case 39: return ImGuiKey_Apostrophe;
case 44: return ImGuiKey_Comma;
case 45: return ImGuiKey_Minus;
case 46: return ImGuiKey_Period;
case 47: return ImGuiKey_Slash;
case 59: return ImGuiKey_Semicolon;
case 61: return ImGuiKey_Equal;
case 91: return ImGuiKey_LeftBracket;
case 92: return ImGuiKey_Backslash;
case 93: return ImGuiKey_RightBracket;
case 96: return ImGuiKey_GraveAccent;
//case 0: return ImGuiKey_CapsLock;
//case 0: return ImGuiKey_ScrollLock;
case 256 + 0x006D: return ImGuiKey_NumLock;
//case 0: return ImGuiKey_PrintScreen;
//case 0: return ImGuiKey_Pause;
//case '0': return ImGuiKey_Keypad0;
//case '1': return ImGuiKey_Keypad1;
//case '2': return ImGuiKey_Keypad2;
//case '3': return ImGuiKey_Keypad3;
//case '4': return ImGuiKey_Keypad4;
//case '5': return ImGuiKey_Keypad5;
//case '6': return ImGuiKey_Keypad6;
//case '7': return ImGuiKey_Keypad7;
//case '8': return ImGuiKey_Keypad8;
//case '9': return ImGuiKey_Keypad9;
//case 46: return ImGuiKey_KeypadDecimal;
//case 47: return ImGuiKey_KeypadDivide;
case 42: return ImGuiKey_KeypadMultiply;
//case 45: return ImGuiKey_KeypadSubtract;
case 43: return ImGuiKey_KeypadAdd;
//case 13: return ImGuiKey_KeypadEnter;
//case 0: return ImGuiKey_KeypadEqual;
case 256 + 0x0072: return ImGuiKey_LeftCtrl;
case 256 + 0x0070: return ImGuiKey_LeftShift;
case 256 + 0x0074: return ImGuiKey_LeftAlt;
//case 0: return ImGuiKey_LeftSuper;
case 256 + 0x0073: return ImGuiKey_RightCtrl;
case 256 + 0x0071: return ImGuiKey_RightShift;
case 256 + 0x0075: return ImGuiKey_RightAlt;
//case 0: return ImGuiKey_RightSuper;
//case 0: return ImGuiKey_Menu;
case '0': return ImGuiKey_0;
case '1': return ImGuiKey_1;
case '2': return ImGuiKey_2;
case '3': return ImGuiKey_3;
case '4': return ImGuiKey_4;
case '5': return ImGuiKey_5;
case '6': return ImGuiKey_6;
case '7': return ImGuiKey_7;
case '8': return ImGuiKey_8;
case '9': return ImGuiKey_9;
case 'A': case 'a': return ImGuiKey_A;
case 'B': case 'b': return ImGuiKey_B;
case 'C': case 'c': return ImGuiKey_C;
case 'D': case 'd': return ImGuiKey_D;
case 'E': case 'e': return ImGuiKey_E;
case 'F': case 'f': return ImGuiKey_F;
case 'G': case 'g': return ImGuiKey_G;
case 'H': case 'h': return ImGuiKey_H;
case 'I': case 'i': return ImGuiKey_I;
case 'J': case 'j': return ImGuiKey_J;
case 'K': case 'k': return ImGuiKey_K;
case 'L': case 'l': return ImGuiKey_L;
case 'M': case 'm': return ImGuiKey_M;
case 'N': case 'n': return ImGuiKey_N;
case 'O': case 'o': return ImGuiKey_O;
case 'P': case 'p': return ImGuiKey_P;
case 'Q': case 'q': return ImGuiKey_Q;
case 'R': case 'r': return ImGuiKey_R;
case 'S': case 's': return ImGuiKey_S;
case 'T': case 't': return ImGuiKey_T;
case 'U': case 'u': return ImGuiKey_U;
case 'V': case 'v': return ImGuiKey_V;
case 'W': case 'w': return ImGuiKey_W;
case 'X': case 'x': return ImGuiKey_X;
case 'Y': case 'y': return ImGuiKey_Y;
case 'Z': case 'z': return ImGuiKey_Z;
case 256 + GLUT_KEY_F1: return ImGuiKey_F1;
case 256 + GLUT_KEY_F2: return ImGuiKey_F2;
case 256 + GLUT_KEY_F3: return ImGuiKey_F3;
case 256 + GLUT_KEY_F4: return ImGuiKey_F4;
case 256 + GLUT_KEY_F5: return ImGuiKey_F5;
case 256 + GLUT_KEY_F6: return ImGuiKey_F6;
case 256 + GLUT_KEY_F7: return ImGuiKey_F7;
case 256 + GLUT_KEY_F8: return ImGuiKey_F8;
case 256 + GLUT_KEY_F9: return ImGuiKey_F9;
case 256 + GLUT_KEY_F10: return ImGuiKey_F10;
case 256 + GLUT_KEY_F11: return ImGuiKey_F11;
case 256 + GLUT_KEY_F12: return ImGuiKey_F12;
default: return ImGuiKey_None;
}
}
bool ImGui_ImplGLUT_Init()
{
ImGuiIO& io = ImGui::GetIO();
IMGUI_CHECKVERSION();
#ifdef FREEGLUT
io.BackendPlatformName = "imgui_impl_glut (freeglut)";
#else
io.BackendPlatformName = "imgui_impl_glut";
#endif
g_Time = 0;
return true;
}
void ImGui_ImplGLUT_InstallFuncs()
{
glutReshapeFunc(ImGui_ImplGLUT_ReshapeFunc);
glutMotionFunc(ImGui_ImplGLUT_MotionFunc);
glutPassiveMotionFunc(ImGui_ImplGLUT_MotionFunc);
glutMouseFunc(ImGui_ImplGLUT_MouseFunc);
#ifdef __FREEGLUT_EXT_H__
glutMouseWheelFunc(ImGui_ImplGLUT_MouseWheelFunc);
#endif
glutKeyboardFunc(ImGui_ImplGLUT_KeyboardFunc);
glutKeyboardUpFunc(ImGui_ImplGLUT_KeyboardUpFunc);
glutSpecialFunc(ImGui_ImplGLUT_SpecialFunc);
glutSpecialUpFunc(ImGui_ImplGLUT_SpecialUpFunc);
}
void ImGui_ImplGLUT_Shutdown()
{
ImGuiIO& io = ImGui::GetIO();
io.BackendPlatformName = nullptr;
}
void ImGui_ImplGLUT_NewFrame()
{
// Setup time step
ImGuiIO& io = ImGui::GetIO();
int current_time = glutGet(GLUT_ELAPSED_TIME);
int delta_time_ms = (current_time - g_Time);
if (delta_time_ms <= 0)
delta_time_ms = 1;
io.DeltaTime = delta_time_ms / 1000.0f;
g_Time = current_time;
}
static void ImGui_ImplGLUT_UpdateKeyModifiers()
{
ImGuiIO& io = ImGui::GetIO();
int glut_key_mods = glutGetModifiers();
io.AddKeyEvent(ImGuiMod_Ctrl, (glut_key_mods & GLUT_ACTIVE_CTRL) != 0);
io.AddKeyEvent(ImGuiMod_Shift, (glut_key_mods & GLUT_ACTIVE_SHIFT) != 0);
io.AddKeyEvent(ImGuiMod_Alt, (glut_key_mods & GLUT_ACTIVE_ALT) != 0);
}
static void ImGui_ImplGLUT_AddKeyEvent(ImGuiKey key, bool down, int native_keycode)
{
ImGuiIO& io = ImGui::GetIO();
io.AddKeyEvent(key, down);
io.SetKeyEventNativeData(key, native_keycode, -1); // To support legacy indexing (<1.87 user code)
}
void ImGui_ImplGLUT_KeyboardFunc(unsigned char c, int x, int y)
{
// Send character to imgui
//printf("char_down_func %d '%c'\n", c, c);
ImGuiIO& io = ImGui::GetIO();
if (c >= 32)
io.AddInputCharacter((unsigned int)c);
ImGuiKey key = ImGui_ImplGLUT_KeyToImGuiKey(c);
ImGui_ImplGLUT_AddKeyEvent(key, true, c);
ImGui_ImplGLUT_UpdateKeyModifiers();
(void)x; (void)y; // Unused
}
void ImGui_ImplGLUT_KeyboardUpFunc(unsigned char c, int x, int y)
{
//printf("char_up_func %d '%c'\n", c, c);
ImGuiKey key = ImGui_ImplGLUT_KeyToImGuiKey(c);
ImGui_ImplGLUT_AddKeyEvent(key, false, c);
ImGui_ImplGLUT_UpdateKeyModifiers();
(void)x; (void)y; // Unused
}
void ImGui_ImplGLUT_SpecialFunc(int key, int x, int y)
{
//printf("key_down_func %d\n", key);
ImGuiKey imgui_key = ImGui_ImplGLUT_KeyToImGuiKey(key + 256);
ImGui_ImplGLUT_AddKeyEvent(imgui_key, true, key + 256);
ImGui_ImplGLUT_UpdateKeyModifiers();
(void)x; (void)y; // Unused
}
void ImGui_ImplGLUT_SpecialUpFunc(int key, int x, int y)
{
//printf("key_up_func %d\n", key);
ImGuiKey imgui_key = ImGui_ImplGLUT_KeyToImGuiKey(key + 256);
ImGui_ImplGLUT_AddKeyEvent(imgui_key, false, key + 256);
ImGui_ImplGLUT_UpdateKeyModifiers();
(void)x; (void)y; // Unused
}
void ImGui_ImplGLUT_MouseFunc(int glut_button, int state, int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.AddMousePosEvent((float)x, (float)y);
int button = -1;
if (glut_button == GLUT_LEFT_BUTTON) button = 0;
if (glut_button == GLUT_RIGHT_BUTTON) button = 1;
if (glut_button == GLUT_MIDDLE_BUTTON) button = 2;
if (button != -1 && (state == GLUT_DOWN || state == GLUT_UP))
io.AddMouseButtonEvent(button, state == GLUT_DOWN);
}
#ifdef __FREEGLUT_EXT_H__
void ImGui_ImplGLUT_MouseWheelFunc(int button, int dir, int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.AddMousePosEvent((float)x, (float)y);
if (dir != 0)
io.AddMouseWheelEvent(0.0f, dir > 0 ? 1.0f : -1.0f);
(void)button; // Unused
}
#endif
void ImGui_ImplGLUT_ReshapeFunc(int w, int h)
{
ImGuiIO& io = ImGui::GetIO();
io.DisplaySize = ImVec2((float)w, (float)h);
}
void ImGui_ImplGLUT_MotionFunc(int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.AddMousePosEvent((float)x, (float)y);
}
//-----------------------------------------------------------------------------
#endif // #ifndef IMGUI_DISABLE
