SDL2/src/video/x11/SDL_x11mouse.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"

#if SDL_VIDEO_DRIVER_X11

#include <X11/cursorfont.h>
#include "SDL_x11video.h"
#include "SDL_x11mouse.h"
#include "SDL_x11xinput2.h"
#include "../../events/SDL_mouse_c.h"

/* FIXME: Find a better place to put this... */
static Cursor x11_empty_cursor = None;

static Display *GetDisplay(void)
{
    return SDL_GetVideoDevice()->driverdata->display;
}

static Cursor X11_CreateEmptyCursor()
{
    if (x11_empty_cursor == None) {
        Display *display = GetDisplay();
        char data[1];
        XColor color;
        Pixmap pixmap;

        SDL_zeroa(data);
        color.red = color.green = color.blue = 0;
        pixmap = X11_XCreateBitmapFromData(display, DefaultRootWindow(display),
                                           data, 1, 1);
        if (pixmap) {
            x11_empty_cursor = X11_XCreatePixmapCursor(display, pixmap, pixmap,
                                                       &color, &color, 0, 0);
            X11_XFreePixmap(display, pixmap);
        }
    }
    return x11_empty_cursor;
}

static void X11_DestroyEmptyCursor(void)
{
    if (x11_empty_cursor != None) {
        X11_XFreeCursor(GetDisplay(), x11_empty_cursor);
        x11_empty_cursor = None;
    }
}

static SDL_Cursor *X11_CreateDefaultCursor()
{
    SDL_Cursor *cursor;

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        /* None is used to indicate the default cursor */
        cursor->driverdata = (void *)(uintptr_t)None;
    } else {
        SDL_OutOfMemory();
    }

    return cursor;
}

#if SDL_VIDEO_DRIVER_X11_XCURSOR
static Cursor X11_CreateXCursorCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
    Display *display = GetDisplay();
    Cursor cursor = None;
    XcursorImage *image;

    image = X11_XcursorImageCreate(surface->w, surface->h);
    if (image == NULL) {
        SDL_OutOfMemory();
        return None;
    }
    image->xhot = hot_x;
    image->yhot = hot_y;
    image->delay = 0;

    SDL_assert(surface->format->format == SDL_PIXELFORMAT_ARGB8888);
    SDL_assert(surface->pitch == surface->w * 4);
    SDL_memcpy(image->pixels, surface->pixels, (size_t)surface->h * surface->pitch);

    cursor = X11_XcursorImageLoadCursor(display, image);

    X11_XcursorImageDestroy(image);

    return cursor;
}
#endif /* SDL_VIDEO_DRIVER_X11_XCURSOR */

static Cursor X11_CreatePixmapCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
    Display *display = GetDisplay();
    XColor fg, bg;
    Cursor cursor = None;
    Uint32 *ptr;
    Uint8 *data_bits, *mask_bits;
    Pixmap data_pixmap, mask_pixmap;
    int x, y;
    unsigned int rfg, gfg, bfg, rbg, gbg, bbg, fgBits, bgBits;
    size_t width_bytes = ((surface->w + 7) & ~((size_t)7)) / 8;

    data_bits = SDL_calloc(1, surface->h * width_bytes);
    if (data_bits == NULL) {
        SDL_OutOfMemory();
        return None;
    }

    mask_bits = SDL_calloc(1, surface->h * width_bytes);
    if (mask_bits == NULL) {
        SDL_free(data_bits);
        SDL_OutOfMemory();
        return None;
    }

    /* Code below assumes ARGB pixel format */
    SDL_assert(surface->format->format == SDL_PIXELFORMAT_ARGB8888);

    rfg = gfg = bfg = rbg = gbg = bbg = fgBits = bgBits = 0;
    for (y = 0; y < surface->h; ++y) {
        ptr = (Uint32 *)((Uint8 *)surface->pixels + y * surface->pitch);
        for (x = 0; x < surface->w; ++x) {
            int alpha = (*ptr >> 24) & 0xff;
            int red = (*ptr >> 16) & 0xff;
            int green = (*ptr >> 8) & 0xff;
            int blue = (*ptr >> 0) & 0xff;
            if (alpha > 25) {
                mask_bits[y * width_bytes + x / 8] |= (0x01 << (x % 8));

                if ((red + green + blue) > 0x40) {
                    fgBits++;
                    rfg += red;
                    gfg += green;
                    bfg += blue;
                    data_bits[y * width_bytes + x / 8] |= (0x01 << (x % 8));
                } else {
                    bgBits++;
                    rbg += red;
                    gbg += green;
                    bbg += blue;
                }
            }
            ++ptr;
        }
    }

    if (fgBits) {
        fg.red = rfg * 257 / fgBits;
        fg.green = gfg * 257 / fgBits;
        fg.blue = bfg * 257 / fgBits;
    } else {
        fg.red = fg.green = fg.blue = 0;
    }

    if (bgBits) {
        bg.red = rbg * 257 / bgBits;
        bg.green = gbg * 257 / bgBits;
        bg.blue = bbg * 257 / bgBits;
    } else {
        bg.red = bg.green = bg.blue = 0;
    }

    data_pixmap = X11_XCreateBitmapFromData(display, DefaultRootWindow(display),
                                            (char *)data_bits,
                                            surface->w, surface->h);
    mask_pixmap = X11_XCreateBitmapFromData(display, DefaultRootWindow(display),
                                            (char *)mask_bits,
                                            surface->w, surface->h);
    cursor = X11_XCreatePixmapCursor(display, data_pixmap, mask_pixmap,
                                     &fg, &bg, hot_x, hot_y);
    X11_XFreePixmap(display, data_pixmap);
    X11_XFreePixmap(display, mask_pixmap);
    SDL_free(data_bits);
    SDL_free(mask_bits);

    return cursor;
}

static SDL_Cursor *X11_CreateCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
    SDL_Cursor *cursor;

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        Cursor x11_cursor = None;

#if SDL_VIDEO_DRIVER_X11_XCURSOR
        if (SDL_X11_HAVE_XCURSOR) {
            x11_cursor = X11_CreateXCursorCursor(surface, hot_x, hot_y);
        }
#endif
        if (x11_cursor == None) {
            x11_cursor = X11_CreatePixmapCursor(surface, hot_x, hot_y);
        }
        cursor->driverdata = (void *)(uintptr_t)x11_cursor;
    } else {
        SDL_OutOfMemory();
    }

    return cursor;
}

static SDL_Cursor *X11_CreateSystemCursor(SDL_SystemCursor id)
{
    SDL_Cursor *cursor;
    unsigned int shape;

    switch (id) {
    default:
        SDL_assert(0);
        return NULL;
    /* X Font Cursors reference: */
    /*   http://tronche.com/gui/x/xlib/appendix/b/ */
    case SDL_SYSTEM_CURSOR_ARROW:
        shape = XC_left_ptr;
        break;
    case SDL_SYSTEM_CURSOR_IBEAM:
        shape = XC_xterm;
        break;
    case SDL_SYSTEM_CURSOR_WAIT:
        shape = XC_watch;
        break;
    case SDL_SYSTEM_CURSOR_CROSSHAIR:
        shape = XC_tcross;
        break;
    case SDL_SYSTEM_CURSOR_WAITARROW:
        shape = XC_watch;
        break;
    case SDL_SYSTEM_CURSOR_SIZENWSE:
        shape = XC_top_left_corner;
        break;
    case SDL_SYSTEM_CURSOR_SIZENESW:
        shape = XC_top_right_corner;
        break;
    case SDL_SYSTEM_CURSOR_SIZEWE:
        shape = XC_sb_h_double_arrow;
        break;
    case SDL_SYSTEM_CURSOR_SIZENS:
        shape = XC_sb_v_double_arrow;
        break;
    case SDL_SYSTEM_CURSOR_SIZEALL:
        shape = XC_fleur;
        break;
    case SDL_SYSTEM_CURSOR_NO:
        shape = XC_pirate;
        break;
    case SDL_SYSTEM_CURSOR_HAND:
        shape = XC_hand2;
        break;
    }

    cursor = SDL_calloc(1, sizeof(*cursor));
    if (cursor) {
        Cursor x11_cursor;

        x11_cursor = X11_XCreateFontCursor(GetDisplay(), shape);

        cursor->driverdata = (void *)(uintptr_t)x11_cursor;
    } else {
        SDL_OutOfMemory();
    }

    return cursor;
}

static void X11_FreeCursor(SDL_Cursor *cursor)
{
    Cursor x11_cursor = (Cursor)cursor->driverdata;

    if (x11_cursor != None) {
        X11_XFreeCursor(GetDisplay(), x11_cursor);
    }
    SDL_free(cursor);
}

static int X11_ShowCursor(SDL_Cursor *cursor)
{
    Cursor x11_cursor = 0;

    if (cursor) {
        x11_cursor = (Cursor)cursor->driverdata;
    } else {
        x11_cursor = X11_CreateEmptyCursor();
    }

    /* FIXME: Is there a better way than this? */
    {
        SDL_VideoDevice *video = SDL_GetVideoDevice();
        Display *display = GetDisplay();
        SDL_Window *window;

        for (window = video->windows; window; window = window->next) {
            SDL_WindowData *data = window->driverdata;
            if (data) {
                if (x11_cursor != None) {
                    X11_XDefineCursor(display, data->xwindow, x11_cursor);
                } else {
                    X11_XUndefineCursor(display, data->xwindow);
                }
            }
        }
        X11_XFlush(display);
    }
    return 0;
}

static void X11_WarpMouseInternal(Window xwindow, float x, float y)
{
    SDL_VideoData *videodata = SDL_GetVideoDevice()->driverdata;
    Display *display = videodata->display;
#if SDL_VIDEO_DRIVER_X11_XINPUT2
    int deviceid = 0;
    /* It seems XIWarpPointer() doesn't work correctly on multi-head setups:
     * https://developer.blender.org/rB165caafb99c6846e53d11c4e966990aaffc06cea
     */
    if (ScreenCount(display) == 1) {
        X11_XIGetClientPointer(display, None, &deviceid);
    }
    if (deviceid != 0) {
        X11_XIWarpPointer(display, deviceid, None, xwindow, 0.0, 0.0, 0, 0, x, y);
    } else
#endif
    {
        X11_XWarpPointer(display, None, xwindow, 0, 0, 0, 0, (int)x, (int)y);
    }
    X11_XSync(display, False);
    videodata->global_mouse_changed = SDL_TRUE;
}

static int X11_WarpMouse(SDL_Window *window, float x, float y)
{
    SDL_WindowData *data = window->driverdata;

#if SDL_VIDEO_DRIVER_X11_XFIXES
    /* If we have no barrier, we need to warp */
    if (data->pointer_barrier_active == SDL_FALSE) {
        X11_WarpMouseInternal(data->xwindow, x, y);
    }
#else
    X11_WarpMouseInternal(data->xwindow, x, y);
#endif
    return 0;
}

static int X11_WarpMouseGlobal(float x, float y)
{
    X11_WarpMouseInternal(DefaultRootWindow(GetDisplay()), x, y);
    return 0;
}

static int X11_SetRelativeMouseMode(SDL_bool enabled)
{
#if SDL_VIDEO_DRIVER_X11_XINPUT2
    if (X11_Xinput2IsInitialized()) {
        return 0;
    }
#endif
    return SDL_Unsupported();
}

static int X11_CaptureMouse(SDL_Window *window)
{
    Display *display = GetDisplay();
    SDL_Window *mouse_focus = SDL_GetMouseFocus();

    if (window) {
        SDL_WindowData *data = window->driverdata;
        const unsigned int mask = ButtonPressMask | ButtonReleaseMask | PointerMotionMask | FocusChangeMask;
        Window confined = (data->mouse_grabbed ? data->xwindow : None);
        const int rc = X11_XGrabPointer(display, data->xwindow, False,
                                        mask, GrabModeAsync, GrabModeAsync,
                                        confined, None, CurrentTime);
        if (rc != GrabSuccess) {
            return SDL_SetError("X server refused mouse capture");
        }
    } else if (mouse_focus) {
        SDL_UpdateWindowGrab(mouse_focus);
    } else {
        X11_XUngrabPointer(display, CurrentTime);
    }

    X11_XSync(display, False);

    return 0;
}

static Uint32 X11_GetGlobalMouseState(float *x, float *y)
{
    SDL_VideoData *videodata = SDL_GetVideoDevice()->driverdata;
    SDL_DisplayID *displays;
    Display *display = GetDisplay();
    int i;

    /* !!! FIXME: should we XSync() here first? */

#if !SDL_VIDEO_DRIVER_X11_XINPUT2
    videodata->global_mouse_changed = SDL_TRUE;
#endif

    /* check if we have this cached since XInput last saw the mouse move. */
    /* !!! FIXME: can we just calculate this from XInput's events? */
    if (videodata->global_mouse_changed) {
        displays = SDL_GetDisplays(NULL);
        if (displays) {
            for (i = 0; displays[i]; ++i) {
                SDL_DisplayData *data = SDL_GetDisplayDriverData(displays[i]);
                if (data != NULL) {
                    Window root, child;
                    int rootx, rooty, winx, winy;
                    unsigned int mask;
                    if (X11_XQueryPointer(display, RootWindow(display, data->screen), &root, &child, &rootx, &rooty, &winx, &winy, &mask)) {
                        XWindowAttributes root_attrs;
                        Uint32 buttons = 0;
                        buttons |= (mask & Button1Mask) ? SDL_BUTTON_LMASK : 0;
                        buttons |= (mask & Button2Mask) ? SDL_BUTTON_MMASK : 0;
                        buttons |= (mask & Button3Mask) ? SDL_BUTTON_RMASK : 0;
                        /* Use the SDL state for the extended buttons - it's better than nothing */
                        buttons |= (SDL_GetMouseState(NULL, NULL) & (SDL_BUTTON_X1MASK | SDL_BUTTON_X2MASK));
                        /* SDL_DisplayData->x,y point to screen origin, and adding them to mouse coordinates relative to root window doesn't do the right thing
                         * (observed on dual monitor setup with primary display being the rightmost one - mouse was offset to the right).
                         *
                         * Adding root position to root-relative coordinates seems to be a better way to get absolute position. */
                        X11_XGetWindowAttributes(display, root, &root_attrs);
                        videodata->global_mouse_position.x = root_attrs.x + rootx;
                        videodata->global_mouse_position.y = root_attrs.y + rooty;
                        videodata->global_mouse_buttons = buttons;
                        videodata->global_mouse_changed = SDL_FALSE;
                        break;
                    }
                }
            }
            SDL_free(displays);
        }
    }

    SDL_assert(!videodata->global_mouse_changed); /* The pointer wasn't on any X11 screen?! */

    *x = (float)videodata->global_mouse_position.x;
    *y = (float)videodata->global_mouse_position.y;
    return videodata->global_mouse_buttons;
}

void X11_InitMouse(_THIS)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    mouse->CreateCursor = X11_CreateCursor;
    mouse->CreateSystemCursor = X11_CreateSystemCursor;
    mouse->ShowCursor = X11_ShowCursor;
    mouse->FreeCursor = X11_FreeCursor;
    mouse->WarpMouse = X11_WarpMouse;
    mouse->WarpMouseGlobal = X11_WarpMouseGlobal;
    mouse->SetRelativeMouseMode = X11_SetRelativeMouseMode;
    mouse->CaptureMouse = X11_CaptureMouse;
    mouse->GetGlobalMouseState = X11_GetGlobalMouseState;

    SDL_SetDefaultCursor(X11_CreateDefaultCursor());
}

void X11_QuitMouse(_THIS)
{
    SDL_VideoData *data = _this->driverdata;
    SDL_XInput2DeviceInfo *i;
    SDL_XInput2DeviceInfo *next;

    for (i = data->mouse_device_info; i != NULL; i = next) {
        next = i->next;
        SDL_free(i);
    }
    data->mouse_device_info = NULL;

    X11_DestroyEmptyCursor();
}

#endif /* SDL_VIDEO_DRIVER_X11 */