cursor: Move pointer barrier code over to XI

In order to send events to specific windows associated with the barrier,
we need to move the code that handles barriers to somewhere where it's
easier to construct and send events. Rather than duplicating XSync with
its XSyncSelectAlarm, re-use the existing XI infrastructure.

For now, just move a bunch of code over, rename some things, and initialize
the new structures, but still consider it a separate codebase. Pointer barrier
requests are still handled by XFixes, so this is a weird intermediate state.
It's unknown whether we'll add explicit requests to pointer barriers inside
XI.

Signed-off-by: Jasper St. Pierre <jstpierre@mecheye.net>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

2 files changed, 5 insertions, 444 deletions

diff --git a/xfixes/cursor.c b/xfixes/cursor.c
index ffee4d6ab..568e717fa 100644
--- a/xfixes/cursor.c
+++ b/xfixes/cursor.c
@@ -56,12 +56,11 @@
 #include "windowstr.h"
 #include "xace.h"
 #include "list.h"
-#include "exglobals.h"
+#include "xibarriers.h"
 
 static RESTYPE CursorClientType;
 static RESTYPE CursorHideCountType;
 static RESTYPE CursorWindowType;
-RESTYPE PointerBarrierType;
 static CursorPtr CursorCurrent[MAXDEVICES];
 
 static DevPrivateKeyRec CursorScreenPrivateKeyRec;
@@ -113,16 +112,6 @@ typedef struct _CursorHideCountRec {
     XID resource;
 } CursorHideCountRec;
 
-typedef struct PointerBarrierClient *PointerBarrierClientPtr;
-
-struct PointerBarrierClient {
-    ScreenPtr screen;
-    struct PointerBarrier barrier;
-    struct xorg_list entry;
-    int num_devices;
-    int *device_ids; /* num_devices */
-};
-
 /*
  * Wrap DisplayCursor to catch cursor change events
  */
@@ -130,9 +119,7 @@ struct PointerBarrierClient {
 typedef struct _CursorScreen {
     DisplayCursorProcPtr DisplayCursor;
     CloseScreenProcPtr CloseScreen;
-    ConstrainCursorHarderProcPtr ConstrainCursorHarder;
     CursorHideCountPtr pCursorHideCounts;
-    struct xorg_list barriers;
 } CursorScreenRec, *CursorScreenPtr;
 
 #define GetCursorScreen(s) ((CursorScreenPtr)dixLookupPrivate(&(s)->devPrivates, CursorScreenPrivateKey))
@@ -199,11 +186,9 @@ CursorCloseScreen(ScreenPtr pScreen)
     Bool ret;
     _X_UNUSED CloseScreenProcPtr close_proc;
     _X_UNUSED DisplayCursorProcPtr display_proc;
-    _X_UNUSED ConstrainCursorHarderProcPtr constrain_proc;
 
     Unwrap(cs, pScreen, CloseScreen, close_proc);
     Unwrap(cs, pScreen, DisplayCursor, display_proc);
-    Unwrap(cs, pScreen, ConstrainCursorHarder, constrain_proc);
     deleteCursorHideCountsForScreen(pScreen);
     ret = (*pScreen->CloseScreen) (pScreen);
     free(cs);
@@ -1013,384 +998,15 @@ CursorFreeWindow(pointer data, XID id)
     return 1;
 }
 
-static BOOL
-barrier_is_horizontal(const struct PointerBarrier *barrier)
-{
-    return barrier->y1 == barrier->y2;
-}
-
-static BOOL
-barrier_is_vertical(const struct PointerBarrier *barrier)
-{
-    return barrier->x1 == barrier->x2;
-}
-
-/**
- * @return The set of barrier movement directions the movement vector
- * x1/y1 → x2/y2 represents.
- */
-int
-barrier_get_direction(int x1, int y1, int x2, int y2)
-{
-    int direction = 0;
-
-    /* which way are we trying to go */
-    if (x2 > x1)
-        direction |= BarrierPositiveX;
-    if (x2 < x1)
-        direction |= BarrierNegativeX;
-    if (y2 > y1)
-        direction |= BarrierPositiveY;
-    if (y2 < y1)
-        direction |= BarrierNegativeY;
-
-    return direction;
-}
-
-/**
- * Test if the barrier may block movement in the direction defined by
- * x1/y1 → x2/y2. This function only tests whether the directions could be
- * blocked, it does not test if the barrier actually blocks the movement.
- *
- * @return TRUE if the barrier blocks the direction of movement or FALSE
- * otherwise.
- */
-BOOL
-barrier_is_blocking_direction(const struct PointerBarrier * barrier,
-                              int direction)
-{
-    /* Barriers define which way is ok, not which way is blocking */
-    return (barrier->directions & direction) != direction;
-}
-
-/**
- * Test if the movement vector x1/y1 → x2/y2 is intersecting with the
- * barrier. A movement vector with the startpoint or endpoint adjacent to
- * the barrier itself counts as intersecting.
- *
- * @param x1 X start coordinate of movement vector
- * @param y1 Y start coordinate of movement vector
- * @param x2 X end coordinate of movement vector
- * @param y2 Y end coordinate of movement vector
- * @param[out] distance The distance between the start point and the
- * intersection with the barrier (if applicable).
- * @return TRUE if the barrier intersects with the given vector
- */
-BOOL
-barrier_is_blocking(const struct PointerBarrier * barrier,
-                    int x1, int y1, int x2, int y2, double *distance)
-{
-    BOOL rc = FALSE;
-    float ua, ub, ud;
-    int dir = barrier_get_direction(x1, y1, x2, y2);
-
-    /* Algorithm below doesn't handle edge cases well, hence the extra
-     * checks. */
-    if (barrier_is_vertical(barrier)) {
-        /* handle immediate barrier adjacency, moving away */
-        if (dir & BarrierPositiveX && x1 == barrier->x1)
-            return FALSE;
-        if (dir & BarrierNegativeX && x1 == (barrier->x1 - 1))
-            return FALSE;
-        /* startpoint adjacent to barrier, moving towards -> block */
-        if (dir & BarrierPositiveX && x1 == (barrier->x1 - 1) && y1 >= barrier->y1 && y1 <= barrier->y2) {
-            *distance = 0;
-            return TRUE;
-        }
-        if (dir & BarrierNegativeX && x1 == barrier->x1 && y1 >= barrier->y1 && y1 <= barrier->y2) {
-            *distance = 0;
-            return TRUE;
-        }
-    }
-    else {
-        /* handle immediate barrier adjacency, moving away */
-        if (dir & BarrierPositiveY && y1 == barrier->y1)
-            return FALSE;
-        if (dir & BarrierNegativeY && y1 == (barrier->y1 - 1))
-            return FALSE;
-        /* startpoint adjacent to barrier, moving towards -> block */
-        if (dir & BarrierPositiveY && y1 == (barrier->y1 - 1) && x1 >= barrier->x1 && x1 <= barrier->x2) {
-            *distance = 0;
-            return TRUE;
-        }
-        if (dir & BarrierNegativeY && y1 == barrier->y1 && x1 >= barrier->x1 && x1 <= barrier->x2) {
-            *distance = 0;
-            return TRUE;
-        }
-    }
-
-    /* not an edge case, compute distance */
-    ua = 0;
-    ud = (barrier->y2 - barrier->y1) * (x2 - x1) - (barrier->x2 -
-                                                    barrier->x1) * (y2 - y1);
-    if (ud != 0) {
-        ua = ((barrier->x2 - barrier->x1) * (y1 - barrier->y1) -
-              (barrier->y2 - barrier->y1) * (x1 - barrier->x1)) / ud;
-        ub = ((x2 - x1) * (y1 - barrier->y1) -
-              (y2 - y1) * (x1 - barrier->x1)) / ud;
-        if (ua < 0 || ua > 1 || ub < 0 || ub > 1)
-            ua = 0;
-    }
-
-    if (ua > 0 && ua <= 1) {
-        double ix = barrier->x1 + ua * (barrier->x2 - barrier->x1);
-        double iy = barrier->y1 + ua * (barrier->y2 - barrier->y1);
-
-        *distance = sqrt(pow(x1 - ix, 2) + pow(y1 - iy, 2));
-        rc = TRUE;
-    }
-
-    return rc;
-}
-
-static BOOL
-barrier_blocks_device(struct PointerBarrierClient *client,
-                      DeviceIntPtr dev)
-{
-    int i;
-    int master_id;
-
-    /* Clients with no devices are treated as
-     * if they specified XIAllDevices. */
-    if (client->num_devices == 0)
-        return TRUE;
-
-    master_id = GetMaster(dev, POINTER_OR_FLOAT)->id;
-
-    for (i = 0; i < client->num_devices; i++) {
-        int device_id = client->device_ids[i];
-        if (device_id == XIAllDevices ||
-            device_id == XIAllMasterDevices ||
-            device_id == master_id)
-            return TRUE;
-    }
-
-    return FALSE;
-}
-
-/**
- * Find the nearest barrier that is blocking movement from x1/y1 to x2/y2.
- *
- * @param dir Only barriers blocking movement in direction dir are checked
- * @param x1 X start coordinate of movement vector
- * @param y1 Y start coordinate of movement vector
- * @param x2 X end coordinate of movement vector
- * @param y2 Y end coordinate of movement vector
- * @return The barrier nearest to the movement origin that blocks this movement.
- */
-static struct PointerBarrier *
-barrier_find_nearest(CursorScreenPtr cs, DeviceIntPtr dev,
-                     int dir,
-                     int x1, int y1, int x2, int y2)
-{
-    struct PointerBarrierClient *c;
-    struct PointerBarrier *nearest = NULL;
-    double min_distance = INT_MAX;      /* can't get higher than that in X anyway */
-
-    xorg_list_for_each_entry(c, &cs->barriers, entry) {
-        struct PointerBarrier *b = &c->barrier;
-        double distance;
-
-        if (!barrier_is_blocking_direction(b, dir))
-            continue;
-
-        if (!barrier_blocks_device(c, dev))
-            continue;
-
-        if (barrier_is_blocking(b, x1, y1, x2, y2, &distance)) {
-            if (min_distance > distance) {
-                min_distance = distance;
-                nearest = b;
-            }
-        }
-    }
-
-    return nearest;
-}
-
-/**
- * Clamp to the given barrier given the movement direction specified in dir.
- *
- * @param barrier The barrier to clamp to
- * @param dir The movement direction
- * @param[out] x The clamped x coordinate.
- * @param[out] y The clamped x coordinate.
- */
-void
-barrier_clamp_to_barrier(struct PointerBarrier *barrier, int dir, int *x,
-                         int *y)
-{
-    if (barrier_is_vertical(barrier)) {
-        if ((dir & BarrierNegativeX) & ~barrier->directions)
-            *x = barrier->x1;
-        if ((dir & BarrierPositiveX) & ~barrier->directions)
-            *x = barrier->x1 - 1;
-    }
-    if (barrier_is_horizontal(barrier)) {
-        if ((dir & BarrierNegativeY) & ~barrier->directions)
-            *y = barrier->y1;
-        if ((dir & BarrierPositiveY) & ~barrier->directions)
-            *y = barrier->y1 - 1;
-    }
-}
-
-static void
-CursorConstrainCursorHarder(DeviceIntPtr dev, ScreenPtr screen, int mode,
-                            int *x, int *y)
-{
-    CursorScreenPtr cs = GetCursorScreen(screen);
-
-    if (!xorg_list_is_empty(&cs->barriers) && !IsFloating(dev) &&
-        mode == Relative) {
-        int ox, oy;
-        int dir;
-        int i;
-        struct PointerBarrier *nearest = NULL;
-
-        /* where are we coming from */
-        miPointerGetPosition(dev, &ox, &oy);
-
-        /* How this works:
-         * Given the origin and the movement vector, get the nearest barrier
-         * to the origin that is blocking the movement.
-         * Clamp to that barrier.
-         * Then, check from the clamped intersection to the original
-         * destination, again finding the nearest barrier and clamping.
-         */
-        dir = barrier_get_direction(ox, oy, *x, *y);
-
-#define MAX_BARRIERS 2
-        for (i = 0; i < MAX_BARRIERS; i++) {
-            nearest = barrier_find_nearest(cs, dev, dir, ox, oy, *x, *y);
-            if (!nearest)
-                break;
-
-            barrier_clamp_to_barrier(nearest, dir, x, y);
-
-            if (barrier_is_vertical(nearest)) {
-                dir &= ~(BarrierNegativeX | BarrierPositiveX);
-                ox = *x;
-            }
-            else if (barrier_is_horizontal(nearest)) {
-                dir &= ~(BarrierNegativeY | BarrierPositiveY);
-                oy = *y;
-            }
-        }
-    }
-
-    if (cs->ConstrainCursorHarder) {
-        screen->ConstrainCursorHarder = cs->ConstrainCursorHarder;
-        screen->ConstrainCursorHarder(dev, screen, mode, x, y);
-        screen->ConstrainCursorHarder = CursorConstrainCursorHarder;
-    }
-}
-
-static int
-CreatePointerBarrierClient(ScreenPtr screen, ClientPtr client,
-                           xXFixesCreatePointerBarrierReq * stuff,
-                           PointerBarrierClientPtr *client_out)
-{
-    CursorScreenPtr cs = GetCursorScreen(screen);
-    int err;
-    int size;
-    int i;
-    CARD16 *in_devices;
-    struct PointerBarrierClient *ret;
-
-    size = sizeof(*ret) + sizeof(int) * stuff->num_devices;
-    ret = malloc(size);
-
-    *client_out = NULL;
-
-    if (!ret) {
-        return BadAlloc;
-    }
-
-    ret->screen = screen;
-    ret->num_devices = stuff->num_devices;
-    if (ret->num_devices > 0)
-        ret->device_ids = (int*)&ret[1];
-    else
-        ret->device_ids = NULL;
-
-    in_devices = (CARD16 *) &stuff[1];
-    for (i = 0; i < stuff->num_devices; i++) {
-        int device_id = in_devices[i];
-        DeviceIntPtr device;
-
-        if ((err = dixLookupDevice (&device, device_id,
-                                    client, DixReadAccess))) {
-            client->errorValue = device_id;
-            goto error;
-        }
-
-        if (!IsMaster (device)) {
-            client->errorValue = device_id;
-            err = BadDevice;
-            goto error;
-        }
-
-        ret->device_ids[i] = device_id;
-    }
-
-    ret->barrier.x1 = min(stuff->x1, stuff->x2);
-    ret->barrier.x2 = max(stuff->x1, stuff->x2);
-    ret->barrier.y1 = min(stuff->y1, stuff->y2);
-    ret->barrier.y2 = max(stuff->y1, stuff->y2);
-    ret->barrier.directions = stuff->directions & 0x0f;
-    if (barrier_is_horizontal(&ret->barrier))
-        ret->barrier.directions &= ~(BarrierPositiveX | BarrierNegativeX);
-    if (barrier_is_vertical(&ret->barrier))
-        ret->barrier.directions &= ~(BarrierPositiveY | BarrierNegativeY);
-    xorg_list_add(&ret->entry, &cs->barriers);
-
-    *client_out = ret;
-    return Success;
-
- error:
-    free(ret);
-    return err;
-}
-
 int
 ProcXFixesCreatePointerBarrier(ClientPtr client)
 {
-    int err;
-    WindowPtr pWin;
-    struct PointerBarrierClient *barrier;
-    struct PointerBarrier b;
-
     REQUEST(xXFixesCreatePointerBarrierReq);
 
     REQUEST_FIXED_SIZE(xXFixesCreatePointerBarrierReq, pad_to_int32(stuff->num_devices));
     LEGAL_NEW_RESOURCE(stuff->barrier, client);
 
-    err = dixLookupWindow(&pWin, stuff->window, client, DixReadAccess);
-    if (err != Success) {
-        client->errorValue = stuff->window;
-        return err;
-    }
-
-    b.x1 = stuff->x1;
-    b.x2 = stuff->x2;
-    b.y1 = stuff->y1;
-    b.y2 = stuff->y2;
-
-    if (!barrier_is_horizontal(&b) && !barrier_is_vertical(&b))
-        return BadValue;
-
-    /* no 0-sized barriers */
-    if (barrier_is_horizontal(&b) && barrier_is_vertical(&b))
-        return BadValue;
-
-    if ((err = CreatePointerBarrierClient(pWin->drawable.pScreen,
-                                          client, stuff, &barrier)))
-        return err;
-
-    if (!AddResource(stuff->barrier, PointerBarrierType, &barrier->barrier))
-        return BadAlloc;
-
-    return Success;
+    return XICreatePointerBarrier(client, stuff);
 }
 
 int
@@ -1418,49 +1034,14 @@ SProcXFixesCreatePointerBarrier(ClientPtr client)
     return ProcXFixesVector[stuff->xfixesReqType] (client);
 }
 
-static int
-CursorFreeBarrier(void *data, XID id)
-{
-    struct PointerBarrierClient *b = NULL, *barrier;
-    ScreenPtr screen;
-    CursorScreenPtr cs;
-
-    barrier = container_of(data, struct PointerBarrierClient, barrier);
-
-    screen = barrier->screen;
-    cs = GetCursorScreen(screen);
-
-    /* find and unlink from the screen private */
-    xorg_list_for_each_entry(b, &cs->barriers, entry) {
-        if (b == barrier) {
-            xorg_list_del(&b->entry);
-            break;
-        }
-    }
-
-    free(barrier);
-    return Success;
-}
-
 int
 ProcXFixesDestroyPointerBarrier(ClientPtr client)
 {
-    int err;
-    void *barrier;
-
     REQUEST(xXFixesDestroyPointerBarrierReq);
 
     REQUEST_SIZE_MATCH(xXFixesDestroyPointerBarrierReq);
 
-    err = dixLookupResourceByType((void **) &barrier, stuff->barrier,
-                                  PointerBarrierType, client, DixDestroyAccess);
-    if (err != Success) {
-        client->errorValue = stuff->barrier;
-        return err;
-    }
-
-    FreeResource(stuff->barrier, RT_NONE);
-    return Success;
+    return XIDestroyPointerBarrier(client, stuff);
 }
 
 int
@@ -1492,10 +1073,8 @@ XFixesCursorInit(void)
         cs = (CursorScreenPtr) calloc(1, sizeof(CursorScreenRec));
         if (!cs)
             return FALSE;
-        xorg_list_init(&cs->barriers);
         Wrap(cs, pScreen, CloseScreen, CursorCloseScreen);
         Wrap(cs, pScreen, DisplayCursor, CursorDisplayCursor);
-        Wrap(cs, pScreen, ConstrainCursorHarder, CursorConstrainCursorHarder);
         cs->pCursorHideCounts = NULL;
         SetCursorScreen(pScreen, cs);
     }
@@ -1505,9 +1084,6 @@ XFixesCursorInit(void)
                                                 "XFixesCursorHideCount");
     CursorWindowType = CreateNewResourceType(CursorFreeWindow,
                                              "XFixesCursorWindow");
-    PointerBarrierType = CreateNewResourceType(CursorFreeBarrier,
-                                               "XFixesPointerBarrier");
 
-    return CursorClientType && CursorHideCountType && CursorWindowType &&
-        PointerBarrierType;
+    return CursorClientType && CursorHideCountType && CursorWindowType;
 }
diff --git a/xfixes/xfixes.h b/xfixes/xfixes.h
index 19af09f7d..98828710f 100644
--- a/xfixes/xfixes.h
+++ b/xfixes/xfixes.h
@@ -30,7 +30,6 @@
 #include "resource.h"
 
 extern _X_EXPORT RESTYPE RegionResType;
-extern _X_EXPORT RESTYPE PointerBarrierType;
 extern _X_EXPORT int XFixesErrorBase;
 
 #define VERIFY_REGION(pRegion, rid, client, mode)			\
@@ -52,20 +51,6 @@ extern _X_EXPORT int XFixesErrorBase;
 extern _X_EXPORT RegionPtr
  XFixesRegionCopy(RegionPtr pRegion);
 
-struct PointerBarrier {
-    CARD16 x1, x2, y1, y2;
-    CARD32 directions;
-};
-
-extern int
- barrier_get_direction(int, int, int, int);
-extern BOOL
-barrier_is_blocking(const struct PointerBarrier *, int, int, int, int,
-                    double *);
-extern BOOL barrier_is_blocking_direction(const struct PointerBarrier *, int);
-extern void
-
-barrier_clamp_to_barrier(struct PointerBarrier *barrier, int dir, int *x,
-                         int *y);
+#include "xibarriers.h"
 
 #endif                          /* _XFIXES_H_ */