// dear imgui: Platform Binding for FreeGLUT
// This needs to be used along with a Renderer (e.g. OpenGL2)
// Issues:
// [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I
// [ ] Platform: Missing gamepad support.
// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
// https://github.com/ocornut/imgui
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2018-03-22: Added FreeGLUT Platform binding.
#include "imgui.h"
#include "imgui_impl_freeglut.h"
#include <GL/freeglut.h>
#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
bool ImGui_ImplFreeGLUT_Init()
{
ImGuiIO& io = ImGui::GetIO();
g_Time = 0;
// Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
io.KeyMap[ImGuiKey_Tab] = '\t'; // == 9 == CTRL+I
io.KeyMap[ImGuiKey_LeftArrow] = 256 + GLUT_KEY_LEFT;
io.KeyMap[ImGuiKey_RightArrow] = 256 + GLUT_KEY_RIGHT;
io.KeyMap[ImGuiKey_UpArrow] = 256 + GLUT_KEY_UP;
io.KeyMap[ImGuiKey_DownArrow] = 256 + GLUT_KEY_DOWN;
io.KeyMap[ImGuiKey_PageUp] = 256 + GLUT_KEY_PAGE_UP;
io.KeyMap[ImGuiKey_PageDown] = 256 + GLUT_KEY_PAGE_DOWN;
io.KeyMap[ImGuiKey_Home] = 256 + GLUT_KEY_HOME;
io.KeyMap[ImGuiKey_End] = 256 + GLUT_KEY_END;
io.KeyMap[ImGuiKey_Insert] = 256 + GLUT_KEY_INSERT;
io.KeyMap[ImGuiKey_Delete] = 127;
io.KeyMap[ImGuiKey_Backspace] = 8; // == CTRL+H
io.KeyMap[ImGuiKey_Space] = ' ';
io.KeyMap[ImGuiKey_Enter] = 13; // == CTRL+M
io.KeyMap[ImGuiKey_Escape] = 27;
io.KeyMap[ImGuiKey_A] = 'A';
io.KeyMap[ImGuiKey_C] = 'C';
io.KeyMap[ImGuiKey_V] = 'V';
io.KeyMap[ImGuiKey_X] = 'X';
io.KeyMap[ImGuiKey_Y] = 'Y';
io.KeyMap[ImGuiKey_Z] = 'Z';
return true;
}
void ImGui_ImplFreeGLUT_InstallFuncs()
{
glutReshapeFunc(ImGui_ImplFreeGLUT_ReshapeFunc);
glutMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
glutPassiveMotionFunc(ImGui_ImplFreeGLUT_MotionFunc);
glutMouseFunc(ImGui_ImplFreeGLUT_MouseFunc);
glutMouseWheelFunc(ImGui_ImplFreeGLUT_MouseWheelFunc);
glutKeyboardFunc(ImGui_ImplFreeGLUT_KeyboardFunc);
glutKeyboardUpFunc(ImGui_ImplFreeGLUT_KeyboardUpFunc);
glutSpecialFunc(ImGui_ImplFreeGLUT_SpecialFunc);
glutSpecialUpFunc(ImGui_ImplFreeGLUT_SpecialUpFunc);
}
void ImGui_ImplFreeGLUT_Shutdown()
{
}
void ImGui_ImplFreeGLUT_NewFrame()
{
// Setup time step
ImGuiIO& io = ImGui::GetIO();
int current_time = glutGet(GLUT_ELAPSED_TIME);
io.DeltaTime = (current_time - g_Time) / 1000.0f;
g_Time = current_time;
// Start the frame
ImGui::NewFrame();
}
static void ImGui_ImplFreeGLUT_UpdateKeyboardMods()
{
ImGuiIO& io = ImGui::GetIO();
int mods = glutGetModifiers();
io.KeyCtrl = (mods & GLUT_ACTIVE_CTRL) != 0;
io.KeyShift = (mods & GLUT_ACTIVE_SHIFT) != 0;
io.KeyAlt = (mods & GLUT_ACTIVE_ALT) != 0;
}
void ImGui_ImplFreeGLUT_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 short)c);
// Store letters in KeysDown[] array as both uppercase and lowercase + Handle GLUT translating CTRL+A..CTRL+Z as 1..26.
// 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.
if (c >= 1 && c <= 26)
io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = true;
else if (c >= 'a' && c <= 'z')
io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = true;
else if (c >= 'A' && c <= 'Z')
io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = true;
else
io.KeysDown[c] = true;
ImGui_ImplFreeGLUT_UpdateKeyboardMods();
(void)x; (void)y; // Unused
}
void ImGui_ImplFreeGLUT_KeyboardUpFunc(unsigned char c, int x, int y)
{
//printf("char_up_func %d '%c'\n", c, c);
ImGuiIO& io = ImGui::GetIO();
if (c >= 1 && c <= 26)
io.KeysDown[c] = io.KeysDown[c - 1 + 'a'] = io.KeysDown[c - 1 + 'A'] = false;
else if (c >= 'a' && c <= 'z')
io.KeysDown[c] = io.KeysDown[c - 'a' + 'A'] = false;
else if (c >= 'A' && c <= 'Z')
io.KeysDown[c] = io.KeysDown[c - 'A' + 'a'] = false;
else
io.KeysDown[c] = false;
ImGui_ImplFreeGLUT_UpdateKeyboardMods();
(void)x; (void)y; // Unused
}
void ImGui_ImplFreeGLUT_SpecialFunc(int key, int x, int y)
{
//printf("key_down_func %d\n", key);
ImGuiIO& io = ImGui::GetIO();
if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
io.KeysDown[key + 256] = true;
ImGui_ImplFreeGLUT_UpdateKeyboardMods();
(void)x; (void)y; // Unused
}
void ImGui_ImplFreeGLUT_SpecialUpFunc(int key, int x, int y)
{
//printf("key_up_func %d\n", key);
ImGuiIO& io = ImGui::GetIO();
if (key + 256 < IM_ARRAYSIZE(io.KeysDown))
io.KeysDown[key + 256] = false;
ImGui_ImplFreeGLUT_UpdateKeyboardMods();
(void)x; (void)y; // Unused
}
void ImGui_ImplFreeGLUT_MouseFunc(int glut_button, int state, int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.MousePos = ImVec2((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)
io.MouseDown[button] = true;
if (button != -1 && state == GLUT_UP)
io.MouseDown[button] = false;
}
void ImGui_ImplFreeGLUT_MouseWheelFunc(int button, int dir, int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.MousePos = ImVec2((float)x, (float)y);
if (dir > 0)
io.MouseWheel += 1.0;
else if (dir < 0)
io.MouseWheel -= 1.0;
(void)button; // Unused
}
void ImGui_ImplFreeGLUT_ReshapeFunc(int w, int h)
{
ImGuiIO& io = ImGui::GetIO();
io.DisplaySize = ImVec2((float)w, (float)h);
}
void ImGui_ImplFreeGLUT_MotionFunc(int x, int y)
{
ImGuiIO& io = ImGui::GetIO();
io.MousePos = ImVec2((float)x, (float)y);
}