ext-imgui/examples/imgui_impl_win32.cpp

249 lines
10 KiB
C++

// dear imgui: Platform Binding for Windows (standard windows API for 32 and 64 bits applications)
// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
// Implemented features:
// [X] Platform: Clipboard support (for Win32 this is actually part of core imgui)
// [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
// [X] Platform: Keyboard arrays indexed using VK_* Virtual Key Codes, e.g. ImGui::IsKeyPressed(VK_SPACE).
// Missing features:
// [ ] Platform: Gamepad support (best leaving it to user application to fill io.NavInputs[] with gamepad inputs from their source of choice).
#include "imgui.h"
#include "imgui_impl_win32.h"
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <tchar.h>
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
// 2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
// 2018-06-08: Misc: Extracted imgui_impl_win32.cpp/.h away from the old combined DX9/DX10/DX11/DX12 examples.
// 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
// 2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
// 2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
// 2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
// 2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
// 2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
// 2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
// 2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
// 2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
// 2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
// 2016-11-12: Inputs: Only call Win32 ::SetCursor(NULL) when io.MouseDrawCursor is set.
// Win32 Data
static HWND g_hWnd = 0;
static INT64 g_Time = 0;
static INT64 g_TicksPerSecond = 0;
static ImGuiMouseCursor g_LastMouseCursor = ImGuiMouseCursor_COUNT;
// Functions
bool ImGui_ImplWin32_Init(void* hwnd)
{
if (!::QueryPerformanceFrequency((LARGE_INTEGER *)&g_TicksPerSecond))
return false;
if (!::QueryPerformanceCounter((LARGE_INTEGER *)&g_Time))
return false;
// Setup back-end capabilities flags
g_hWnd = (HWND)hwnd;
ImGuiIO& io = ImGui::GetIO();
io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors; // We can honor GetMouseCursor() values (optional)
io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos; // We can honor io.WantSetMousePos requests (optional, rarely used)
io.ImeWindowHandle = hwnd;
// Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array that we will update during the application lifetime.
io.KeyMap[ImGuiKey_Tab] = VK_TAB;
io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT;
io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT;
io.KeyMap[ImGuiKey_UpArrow] = VK_UP;
io.KeyMap[ImGuiKey_DownArrow] = VK_DOWN;
io.KeyMap[ImGuiKey_PageUp] = VK_PRIOR;
io.KeyMap[ImGuiKey_PageDown] = VK_NEXT;
io.KeyMap[ImGuiKey_Home] = VK_HOME;
io.KeyMap[ImGuiKey_End] = VK_END;
io.KeyMap[ImGuiKey_Insert] = VK_INSERT;
io.KeyMap[ImGuiKey_Delete] = VK_DELETE;
io.KeyMap[ImGuiKey_Backspace] = VK_BACK;
io.KeyMap[ImGuiKey_Space] = VK_SPACE;
io.KeyMap[ImGuiKey_Enter] = VK_RETURN;
io.KeyMap[ImGuiKey_Escape] = VK_ESCAPE;
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_ImplWin32_Shutdown()
{
g_hWnd = (HWND)0;
}
static bool ImGui_ImplWin32_UpdateMouseCursor()
{
ImGuiIO& io = ImGui::GetIO();
if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
return false;
ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
{
// Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
::SetCursor(NULL);
}
else
{
// Show OS mouse cursor
LPTSTR win32_cursor = IDC_ARROW;
switch (imgui_cursor)
{
case ImGuiMouseCursor_Arrow: win32_cursor = IDC_ARROW; break;
case ImGuiMouseCursor_TextInput: win32_cursor = IDC_IBEAM; break;
case ImGuiMouseCursor_ResizeAll: win32_cursor = IDC_SIZEALL; break;
case ImGuiMouseCursor_ResizeEW: win32_cursor = IDC_SIZEWE; break;
case ImGuiMouseCursor_ResizeNS: win32_cursor = IDC_SIZENS; break;
case ImGuiMouseCursor_ResizeNESW: win32_cursor = IDC_SIZENESW; break;
case ImGuiMouseCursor_ResizeNWSE: win32_cursor = IDC_SIZENWSE; break;
case ImGuiMouseCursor_Hand: win32_cursor = IDC_HAND; break;
}
::SetCursor(::LoadCursor(NULL, win32_cursor));
}
return true;
}
static void ImGui_ImplWin32_UpdateMousePos()
{
ImGuiIO& io = ImGui::GetIO();
// Set OS mouse position if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
if (io.WantSetMousePos)
{
POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
::ClientToScreen(g_hWnd, &pos);
::SetCursorPos(pos.x, pos.y);
}
// Set mouse position
io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
POINT pos;
if (::GetActiveWindow() == g_hWnd && ::GetCursorPos(&pos))
if (::ScreenToClient(g_hWnd, &pos))
io.MousePos = ImVec2((float)pos.x, (float)pos.y);
}
void ImGui_ImplWin32_NewFrame()
{
ImGuiIO& io = ImGui::GetIO();
// Setup display size (every frame to accommodate for window resizing)
RECT rect;
::GetClientRect(g_hWnd, &rect);
io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
// Setup time step
INT64 current_time;
::QueryPerformanceCounter((LARGE_INTEGER *)&current_time);
io.DeltaTime = (float)(current_time - g_Time) / g_TicksPerSecond;
g_Time = current_time;
// Read keyboard modifiers inputs
io.KeyCtrl = (::GetKeyState(VK_CONTROL) & 0x8000) != 0;
io.KeyShift = (::GetKeyState(VK_SHIFT) & 0x8000) != 0;
io.KeyAlt = (::GetKeyState(VK_MENU) & 0x8000) != 0;
io.KeySuper = false;
// io.KeysDown[], io.MousePos, io.MouseDown[], io.MouseWheel: filled by the WndProc handler below.
// Update OS mouse position
ImGui_ImplWin32_UpdateMousePos();
// Update OS mouse cursor with the cursor requested by imgui
ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
if (g_LastMouseCursor != mouse_cursor)
{
g_LastMouseCursor = mouse_cursor;
ImGui_ImplWin32_UpdateMouseCursor();
}
}
// Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
#ifndef WM_MOUSEHWHEEL
#define WM_MOUSEHWHEEL 0x020E
#endif
// Process Win32 mouse/keyboard inputs.
// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
// PS: In this Win32 handler, we use the capture API (GetCapture/SetCapture/ReleaseCapture) to be able to read mouse coordinations when dragging mouse outside of our window bounds.
// PS: We treat DBLCLK messages as regular mouse down messages, so this code will work on windows classes that have the CS_DBLCLKS flag set. Our own example app code doesn't set this flag.
IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui::GetCurrentContext() == NULL)
return 0;
ImGuiIO& io = ImGui::GetIO();
switch (msg)
{
case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
{
int button = 0;
if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) button = 0;
if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) button = 1;
if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) button = 2;
if (!ImGui::IsAnyMouseDown() && ::GetCapture() == NULL)
::SetCapture(hwnd);
io.MouseDown[button] = true;
return 0;
}
case WM_LBUTTONUP:
case WM_RBUTTONUP:
case WM_MBUTTONUP:
{
int button = 0;
if (msg == WM_LBUTTONUP) button = 0;
if (msg == WM_RBUTTONUP) button = 1;
if (msg == WM_MBUTTONUP) button = 2;
io.MouseDown[button] = false;
if (!ImGui::IsAnyMouseDown() && ::GetCapture() == hwnd)
::ReleaseCapture();
return 0;
}
case WM_MOUSEWHEEL:
io.MouseWheel += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
return 0;
case WM_MOUSEHWHEEL:
io.MouseWheelH += (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA;
return 0;
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
if (wParam < 256)
io.KeysDown[wParam] = 1;
return 0;
case WM_KEYUP:
case WM_SYSKEYUP:
if (wParam < 256)
io.KeysDown[wParam] = 0;
return 0;
case WM_CHAR:
// You can also use ToAscii()+GetKeyboardState() to retrieve characters.
if (wParam > 0 && wParam < 0x10000)
io.AddInputCharacter((unsigned short)wParam);
return 0;
case WM_SETCURSOR:
if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
return 1;
return 0;
}
return 0;
}