From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753100Ab2HLVkr (ORCPT ); Sun, 12 Aug 2012 17:40:47 -0400 Received: from smtprelay-b21.telenor.se ([195.54.99.212]:57847 "EHLO smtprelay-b21.telenor.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752655Ab2HLVjs (ORCPT ); Sun, 12 Aug 2012 17:39:48 -0400 X-SENDER-IP: [85.230.170.20] X-LISTENER: [smtp.bredband.net] X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ap1OAHUhKFBV5qoUPGdsb2JhbABEhRiFI68/GQEBAQE3NIIhAQUnLxMBDxAISTkKFAYBEogRtjoUkS8DmzaNBg X-IronPort-AV: E=Sophos;i="4.77,756,1336341600"; d="scan'208";a="168687036" From: "Henrik Rydberg" To: Dmitry Torokhov , Jiri Kosina Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Henrik Rydberg Subject: [PATCH 10/19] Input: MT - Add in-kernel tracking Date: Sun, 12 Aug 2012 23:42:28 +0200 Message-Id: <1344807757-2217-11-git-send-email-rydberg@euromail.se> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: <1344807757-2217-1-git-send-email-rydberg@euromail.se> References: <1344807757-2217-1-git-send-email-rydberg@euromail.se> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the INPUT_MT_TRACK flag set, the function input_mt_assign_slots() can be used to match a new set of contacts against the currently used slots. The algorithm used is based on Lagrange relaxation, and performs very well in practice; slower than mtdev for a few corner cases, but faster in most commonly occuring cases. Signed-off-by: Henrik Rydberg --- drivers/input/input-mt.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++- include/linux/input/mt.h | 21 +++++++ 2 files changed, 163 insertions(+), 2 deletions(-) diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 21b105e..36c93d7 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -46,7 +46,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL); if (!mt) - return -ENOMEM; + goto err_mem; mt->num_slots = num_slots; mt->flags = flags; @@ -74,6 +74,12 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, } if (flags & INPUT_MT_DIRECT) __set_bit(INPUT_PROP_DIRECT, dev->propbit); + if (flags & INPUT_MT_TRACK) { + unsigned int n2 = num_slots * num_slots; + mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); + if (!mt->red) + goto err_mem; + } /* Mark slots as 'unused' */ for (i = 0; i < num_slots; i++) @@ -81,6 +87,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, dev->mt = mt; return 0; +err_mem: + kfree(mt); + return -ENOMEM; } EXPORT_SYMBOL(input_mt_init_slots); @@ -93,7 +102,10 @@ EXPORT_SYMBOL(input_mt_init_slots); */ void input_mt_destroy_slots(struct input_dev *dev) { - kfree(dev->mt); + if (dev->mt) { + kfree(dev->mt->red); + kfree(dev->mt); + } dev->mt = NULL; } EXPORT_SYMBOL(input_mt_destroy_slots); @@ -247,3 +259,131 @@ void input_mt_sync_frame(struct input_dev *dev) mt->frame++; } EXPORT_SYMBOL(input_mt_sync_frame); + +static int adjust_dual(int *begin, int step, int *end, int eq) +{ + int f, *p, s, c; + + if (begin == end) + return 0; + + f = *begin; + p = begin + step; + s = p == end ? f + 1 : *p; + + for (; p != end; p += step) + if (*p < f) + s = f, f = *p; + else if (*p < s) + s = *p; + + c = (f + s + 1) / 2; + if (c == 0 || (c > 0 && !eq)) + return 0; + if (s < 0) + c *= 2; + + for (p = begin; p != end; p += step) + *p -= c; + + return (c < s && s <= 0) || (f >= 0 && f < c); +} + +static void find_reduced_matrix(int *w, int nr, int nc, int nrc) +{ + int i, k, sum; + + for (k = 0; k < nrc; k++) { + for (i = 0; i < nr; i++) + adjust_dual(w + i, nr, w + i + nrc, nr <= nc); + sum = 0; + for (i = 0; i < nrc; i += nr) + sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr); + if (!sum) + break; + } +} + +static int input_mt_set_matrix(struct input_mt *mt, + const struct input_mt_pos *pos, int num_pos) +{ + const struct input_mt_pos *p; + struct input_mt_slot *s; + int *w = mt->red; + int x, y; + + for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { + if (!input_mt_is_active(s)) + continue; + x = input_mt_get_value(s, ABS_MT_POSITION_X); + y = input_mt_get_value(s, ABS_MT_POSITION_Y); + for (p = pos; p != pos + num_pos; p++) { + int dx = x - p->x, dy = y - p->y; + *w++ = dx * dx + dy * dy; + } + } + + return w - mt->red; +} + +static void input_mt_set_slots(struct input_mt *mt, + int *slots, int num_pos) +{ + struct input_mt_slot *s; + int *w = mt->red, *p; + + for (p = slots; p != slots + num_pos; p++) + *p = -1; + + for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { + if (!input_mt_is_active(s)) + continue; + for (p = slots; p != slots + num_pos; p++) + if (*w++ < 0) + *p = s - mt->slots; + } + + for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { + if (input_mt_is_active(s)) + continue; + for (p = slots; p != slots + num_pos; p++) + if (*p < 0) { + *p = s - mt->slots; + break; + } + } +} + +/** + * input_mt_assign_slots() - perform a best-match assignment + * @dev: input device with allocated MT slots + * @slots: the slot assignment to be filled + * @pos: the position array to match + * @num_pos: number of positions + * + * Performs a best match against the current contacts and returns + * the slot assignment list. New contacts are assigned to unused + * slots. + * + * Returns zero on success, or negative error in case of failure. + */ +int input_mt_assign_slots(struct input_dev *dev, int *slots, + const struct input_mt_pos *pos, int num_pos) +{ + struct input_mt *mt = dev->mt; + int nrc; + + if (!mt || !mt->red) + return -ENXIO; + if (num_pos > mt->num_slots) + return -EINVAL; + if (num_pos < 1) + return 0; + + nrc = input_mt_set_matrix(mt, pos, num_pos); + find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc); + input_mt_set_slots(mt, slots, num_pos); + + return 0; +} +EXPORT_SYMBOL(input_mt_assign_slots); diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h index a11d485..10bb77c 100644 --- a/include/linux/input/mt.h +++ b/include/linux/input/mt.h @@ -18,6 +18,8 @@ #define INPUT_MT_POINTER 0x0001 /* pointer device, e.g. trackpad */ #define INPUT_MT_DIRECT 0x0002 /* direct device, e.g. touchscreen */ #define INPUT_MT_DROP_UNUSED 0x0004 /* drop contacts not seen in frame */ +#define INPUT_MT_TRACK 0x0008 /* use in-kernel tracking */ + /** * struct input_mt_slot - represents the state of an input MT slot * @abs: holds current values of ABS_MT axes for this slot @@ -34,6 +36,7 @@ struct input_mt_slot { * @num_slots: number of MT slots the device uses * @flags: input_mt operation flags * @frame: increases every time input_mt_sync_frame() is called + * @red: reduced cost matrix for in-kernel tracking * @slots: array of slots holding current values of tracked contacts */ struct input_mt { @@ -41,6 +44,7 @@ struct input_mt { int num_slots; unsigned int flags; unsigned int frame; + int *red; struct input_mt_slot slots[]; }; @@ -56,6 +60,11 @@ static inline int input_mt_get_value(const struct input_mt_slot *slot, return slot->abs[code - ABS_MT_FIRST]; } +static inline bool input_mt_is_active(const struct input_mt_slot *slot) +{ + return input_mt_get_value(slot, ABS_MT_TRACKING_ID) >= 0; +} + int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, unsigned int flags); void input_mt_destroy_slots(struct input_dev *dev); @@ -88,4 +97,16 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count); void input_mt_sync_frame(struct input_dev *dev); +/** + * struct input_mt_pos - contact position + * @x: horizontal coordinate + * @y: vertical coordinate + */ +struct input_mt_pos { + s16 x, y; +}; + +int input_mt_assign_slots(struct input_dev *dev, int *slots, + const struct input_mt_pos *pos, int num_pos); + #endif -- 1.7.11.4