AWTK 嵌入式Linux优秀的平台完成多点触控缩放旋转以及触点丢点挑战应对
前言
最近涉及海图的功能交互，多点触摸又开始找麻烦。
在PC/Web平台awtk是通过底层的sdl2库来实现多点触摸，但是在嵌入式Linux平台，可能是考虑到性能原因，awtk并没有采用sdl库来做事件处理，而是自己实现一个awtk-linux-fb来做适配，多点触摸的相关逻辑必须自己适配。
去年11月的时候，匆忙赶工，自己适配了一份tslib的代码，思路是循环线程内读取触点数据后，直接调用awtk自带的一个multi_gesture.inc文件去计算距离和旋转角度，在应用层注册EVT_MULTI_GESTURE事件。
static ret_t tslib_dispatch_one_event(run_info_t* info) {
#
ifdef MT_TOUCH_ENABLE
int ret = -1
;
if (info->ts != NULL
) {
ret = ts_read_mt(info->ts, info->samp_mt, info->max_slots, info->read_samples)
;
}
uint8_t event_number = 0
, down_number = 0
;
...
int max_slots = info->max_slots;
// note: down, up only trigger once(ET), move will be keep trigger(LT)
for (
int i = 0
; i < max_slots; i++
) {
// printf(YELLOW "sample %d - %ld.%06ld -" RESET " (slot %d) %6d %6d %6d\n",
// 0,
// info->samp_mt[0][i].tv.tv_sec,
// info->samp_mt[0][i].tv.tv_usec,
// info->samp_mt[0][i].slot,
// info->samp_mt[0][i].x,
// info->samp_mt[0][i].y,
// info->samp_mt[0][i].pressure);
if (!(info->samp_mt[0][i].valid & TSLIB_MT_VALID)
){
//for boards that no clear pressure when slot is invaild, need to do it manually
if(!s_points[i].type == EVT_MULTI_TOUCH_DOWN){
info->samp_mt[0][i].pressure = 0
;
}
continue
;
}
event_number++
;
}
for (
int i = 0
; i < CT_MAX_TOUCH; i++
){
s_points[i].touch_id = 0
;
s_points[i].finger_id = i;
if(info->samp_mt[0][i].pressure >
0
) {
down_number++
;
s_points[i].type = (s_points[i].x == info->samp_mt[0][i].x && s_points[i].y == info->samp_mt[0][i].y) ? EVT_MULTI_TOUCH_DOWN : EVT_MULTI_TOUCH_MOVE;
s_points[i].x = info->samp_mt[0][i].x;
s_points[i].y = info->samp_mt[0][i].y;
}
else{
s_points[i].type = EVT_MULTI_TOUCH_UP;
s_points[i].x = 0
;
s_points[i].y = 0
;
}
}
if(event_number == 1 &&
(info->last_down_number == 0 || info->last_down_number == 1
)
){
//单点触摸
...
tslib_dispatch(info)
;
}
else{
//多点触摸
main_loop_t *loop = (main_loop_t*
)info->dispatch_ctx;
//multi_gesture.inc提供的函数
multi_gesture_post_event_from_points(loop, touch_points, down_number, s_points)
;
}
...后面实测multi_gesture.inc完全不堪用，机器上双指缩放判定经常失准，双指拉大，会出现一会放大一会缩小的情况，multi_gesture.inc的业务代码我没有细看，但我估计逻辑肯定是有问题的，至少在现在的机器上无法使用。
适配层设计
只能寻找新的触摸方案了，这时候老板指出来我对触摸屏的理解有误，我一开始的想法是手指一触摸屏幕，立刻会在应用层生成一份即时的完整的触点数组数据对象，通过这个对象来获取各触点坐标，状态（按下，移动，弹起），按下手指的数量。后面才知道，触摸屏是逐个去解析按下的各个手指的数据然后处理的，并不是一次就能全部读取到，也就是说，我想像的这种数据对象的组装只能到应用层去做而不是适配层去做，之前的思路相当于把解析和业务逻辑都在适配层做，结果业务一复杂就变得不敷使用了。
照着这种思路，应该是适配层只需要把所有手指的数据一个个上报上去，业务层实现实际逻辑，这样适配层的代码逻辑会更加简单，那么AWTK有没有代表单个手指的数据？
查阅AWTK代码, 发现有一个touch_event正好符合要求，很幸运也很讽刺，awtk官方在去年12月4日的更新里面已经支持在awtk-linux-fb对touch_event事件上报，还在awtk-web整了一个多点触摸的演示demo，里面的finger_status_t已经把我设想的数据对象的功能给完成了，我累死累活自己适配了一版触摸，结果人家一个月后自己就整好了一个更好的方案，我还一直没有注意到，惭愧。。。
不过项目紧急，有现成的轮子直接拿来用总是好事，重改适配层，这次只需要把ts_read_mt读到的事件封装成touch_event事件直接丢给队列即可：
#
define CT_MAX_TOUCH 10
static multi_touch_point_event_t s_points[CT_MAX_TOUCH]
;
ret_t my_main_loop_post_touch_event(main_loop_t* l, event_type_t event_type, touch_event_t* event) {
event_queue_req_t r;
touch_event_t evt;
main_loop_simple_t* loop = (main_loop_simple_t*
)l;
memset(&r, 0x00
,
sizeof(r)
)
;
memset(&evt, 0x00
,
sizeof(multi_gesture_event_t
)
)
;
return_value_if_fail(loop != NULL
, RET_BAD_PARAMS)
;
memcpy(&evt, event,
sizeof(touch_event_t
)
)
;
evt.e.type = event_type;
evt.e.time = time_now_ms(
)
;
evt.e.size =
sizeof(touch_event_t
)
;
r.touch_event = evt;
return main_loop_queue_event(l, &r)
;
}
static ret_t tslib_dispatch_one_event(run_info_t* info) {
....
// note: down, up only trigger once(ET), move will be keep trigger(LT)
for (
int i = 0
; i < max_slots; i++
) {
if (!(info->samp_mt[0][i].valid & TSLIB_MT_VALID)
){
continue
;
}
if(info->samp_mt[0][i].pressure >
0
){
down_number++
;
if(s_points[i].type == 0 || s_points[i].type == EVT_TOUCH_UP){
s_points[i].type = EVT_TOUCH_DOWN;
}
else{
s_points[i].type = EVT_TOUCH_MOVE;
}
}
else{
s_points[i].type = EVT_TOUCH_UP;
}
s_points[i].finger_id = info->samp_mt[0][i].slot;
s_points[i].x = info->samp_mt[0][i].x;
s_points[i].y = info->samp_mt[0][i].y;
event_number++
;
main_loop_t *loop = (main_loop_t*
)info->dispatch_ctx;
touch_event_t touch_event;
touch_event_init(&touch_event, s_points[i].type, NULL
, 0
, info->samp_mt[0][i].slot, info->samp_mt[0][i].x / (
double
)info->max_x, info->samp_mt[0][i].y / (
double
)info->max_y, info->samp_mt[0][i].pressure)
;
my_main_loop_post_touch_event(loop, s_points[i].type, &touch_event)
;
...触点丢失事件
乐极生悲，接下来的一个坑卡了一周都无法解决, 发现应用程序一旦负担比较高，比如渲染复杂图形或者事件处理极为频繁的时候，touch_up的事件经常会被打断。最后问了微信群，才知道是awtk的活动队列处理不过来导致丢事件，把main_loop_simple.h的MAIN_LOOP_QUEUE_SIZE宏从默认的20调高到100，重新编译awtk-linux-fb和应用程序后，问题解决。
对于之前的那个测试demo, 它管理了一个触点对象数组s_fingers_status，一旦检测到手指按下就会生成一个finger_status_t类型的触点对象并加入到s_fingers_status 中，finger_status_t内部也维护了一个point数组，在手指移动的时候就会将手指移动的即时坐标数据加入到数组中，用于on_paint事件的画线测试，然后在手指弹起时，该触点对象会被从s_fingers_status中移除并销毁，如果touch_up事件不上报的话这个事件就会一直留在s_fingers_status里面，导致无法正常获取正确的按下手指数量，出问题的手指对象也会一直停留在move的状态，无法恢复。
on_touch_up: 3 size=0
on_touch_down : 1 size=1 460 103
on_touch_down : 3 size=2 591 214
on_touch_move: 1 size=2 459 105
on_touch_move: 3 size=2 591 214
on_touch_move: 1 size=2 459 112
on_touch_move: 3 size=2 591 219
on_touch_move: 1 size=2 458 121
on_touch_move: 3 size=2 590 225
on_touch_move: 1 size=2 458 139
on_touch_move: 3 size=2 589 237
on_touch_move: 1 size=2 459 162
on_touch_move: 3 size=2 587 251
on_touch_down : 2 size=3 295 112
on_touch_move: 2 size=3 295 113
on_touch_move: 2 size=3 296 118
on_touch_move: 2 size=3 298 125
on_touch_move: 2 size=3 302 143
on_touch_move: 1 size=3 461 193
on_touch_move: 2 size=3 308 166
on_touch_move: 3 size=3 585 272
on_touch_move: 1 size=3 464 228
on_touch_move: 2 size=3 318 200
on_touch_move: 3 size=3 582 296
on_touch_down : 0 size=4 137 279
on_touch_move: 0 size=4 137 280
on_touch_move: 0 size=4 144 294
on_touch_move: 0 size=4 154 312
on_touch_move: 0 size=4 173 348
on_touch_move: 0 size=4 195 394
on_touch_move: 1 size=4 468 268
on_touch_move: 1 size=4 493 388
on_touch_move: 2 size=4 378 391
on_touch_move: 1 size=4 506 420
on_touch_up: 2 size=3
on_touch_move: 1 size=3 518 447
on_touch_move: 1 size=3 525 466
on_touch_move: 1 size=3 525 481
on_touch_up: 1 size=2之前没找到问题根源的时候就隐约觉得问题跟机器的性能有关，因为测试demo在公司的开发板上两指到五指都正常，但是到了自己住处, 用百问网的imx6ull开发板一测试很快就出现丢点问题，后面又在适配层尝试限制touch_move事件的频率，改为30ms上报一次touch_move事件，发现有一定的降低丢点概率的效果（手指一多还是会丢点），但是仍旧未往事件队列本身的处理能力去设想，更没有想到在awtk库里面可以调这个事件队列大小，GUI开发还有很多基础知识需要完善。
最终代码
tslib_thread.c
/**
* File: tslib_thread.c
* Author: AWTK Develop Team
* Brief: thread to handle touch screen events
*
* Copyright (c) 2018 - 2025 Guangzhou ZHIYUAN Electronics Co.,Ltd.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* License file for more details.
*
*/
/**
* History:
* ================================================================
* 2018-09-07 Li XianJing <xianjimli@hotmail.com> created
*
*/
#
include <errno.h>
#
include <fcntl.h>
#
include <unistd.h>
#
include "tslib.h"
#
include "tkc/mem.h"
#
include "tkc/utils.h"
#
include "tkc/thread.h"
#
include "base/keys.h"
#
include "tslib_thread.h"
#
include <linux/input.h>
#
include "multi_gesture.inc"
typedef
struct _run_info_t {
int32_t max_x;
int32_t max_y;
struct tsdev* ts;
void* dispatch_ctx;
char* filename;
input_dispatch_t dispatch;
event_queue_req_t req;
struct ts_sample_mt **samp_mt;
struct input_absinfo slot;
int32_t user_slots;
int32_t max_slots;
int read_samples;
int last_down_number;
} run_info_t
;
#
define RESET "\033[0m"
#
define RED "\033[31m"
#
define GREEN "\033[32m"
#
define BLUE "\033[34m"
#
define YELLOW "\033[33m"
#
define CT_MAX_TOUCH 10
static multi_gesture_touch_points_t* touch_points = NULL
;
static multi_touch_point_event_t s_points[CT_MAX_TOUCH]
;
static ret_t tslib_dispatch(run_info_t* info) {
ret_t ret = RET_FAIL;
char message[MAX_PATH + 1] = {
0
}
;
// tk_snprintf(message, sizeof(message) - 1, "ts[%s]", info->filename);
ret = info->
dispatch(info->dispatch_ctx, &
(info->req)
, message)
;
info->req.event.type = EVT_NONE;
return ret;
}
ret_t my_main_loop_post_touch_event(main_loop_t* l, event_type_t event_type, touch_event_t* event) {
event_queue_req_t r;
touch_event_t evt;
main_loop_simple_t* loop = (main_loop_simple_t*
)l;
memset(&r, 0x00
,
sizeof(r)
)
;
memset(&evt, 0x00
,
sizeof(multi_gesture_event_t
)
)
;
return_value_if_fail(loop != NULL
, RET_BAD_PARAMS)
;
memcpy(&evt, event,
sizeof(touch_event_t
)
)
;
evt.e.type = event_type;
evt.e.time = time_now_ms(
)
;
evt.e.size =
sizeof(touch_event_t
)
;
r.touch_event = evt;
return main_loop_queue_event(l, &r)
;
}
static ret_t tslib_dispatch_one_event(run_info_t* info) {
int ret = -1
;
if (info->ts != NULL
) {
ret = ts_read_mt(info->ts, info->samp_mt, info->max_slots, info->read_samples)
;
}
uint8_t event_number = 0
, down_number = 0
;
event_queue_req_t* req = &
(info->req)
;
if (ret == 0
) {
log_warn("%s:%d: get tslib data failed, filename=%s\n"
, __func__
, __LINE__
, info->filename)
;
sleep(1
)
;
return RET_OK;
}
else
if (ret <
0
) {
sleep(2
)
;
if (access(info->filename, R_OK) == 0
) {
if (info->ts != NULL
) {
ts_close(info->ts)
;
}
info->ts = ts_open(info->filename, 0
)
;
return_value_if_fail(info->ts != NULL
, RET_OK)
;
ts_config(info->ts)
;
if (info->ts == NULL
) {
log_debug("%s:%d: open tslib failed, filename=%s\n"
, __func__
, __LINE__
, info->filename)
;
perror("print tslib: "
)
;
}
else {
log_debug("%s:%d: open tslib successful, filename=%s\n"
, __func__
, __LINE__
,
info->filename)
;
}
}
return RET_OK;
}
int max_slots = info->max_slots;
// note: down, up only trigger once(ET), move will be keep trigger(LT)
for (
int i = 0
; i < max_slots; i++
) {
if (!(info->samp_mt[0][i].valid & TSLIB_MT_VALID)
){
continue
;
}
// printf(YELLOW "BSP sample %d - %ld.%06ld -" RESET " (slot %d) %6d %6d %6d\n",
// 0,
// info->samp_mt[0][i].tv.tv_sec,
// info->samp_mt[0][i].tv.tv_usec,
// info->samp_mt[0][i].slot,
// info->samp_mt[0][i].x,
// info->samp_mt[0][i].y,
// info->samp_mt[0][i].pressure);
if(info->samp_mt[0][i].pressure >
0
){
down_number++
;
if(s_points[i].type == 0 || s_points[i].type == EVT_TOUCH_UP){
s_points[i].type = EVT_TOUCH_DOWN;
}
else{
s_points[i].type = EVT_TOUCH_MOVE;
}
}
else{
s_points[i].type = EVT_TOUCH_UP;
}
s_points[i].finger_id = info->samp_mt[0][i].slot;
s_points[i].x = info->samp_mt[0][i].x;
s_points[i].y = info->samp_mt[0][i].y;
event_number++
;
main_loop_t *loop = (main_loop_t*
)info->dispatch_ctx;
touch_event_t touch_event;
touch_event_init(&touch_event, s_points[i].type, NULL
, 0
, info->samp_mt[0][i].slot, info->samp_mt[0][i].x / (
double
)info->max_x, info->samp_mt[0][i].y / (
double
)info->max_y, info->samp_mt[0][i].pressure)
;
my_main_loop_post_touch_event(loop, s_points[i].type, &touch_event)
;
// print debug
// char *msg = "down";
// if(s_points[i].type == EVT_TOUCH_MOVE){
// msg = "move";
// }
// else if(s_points[i].type == EVT_TOUCH_UP){
// msg = "up";
// }
// printf("slot %d %s at (%d %d) press %d\r\n",
// s_points[i].finger_id,
// msg,
// s_points[i].x,
// s_points[i].y,
// info->samp_mt[0][i].pressure);
}
// printf("down number: %d\r\n", down_number);
if(event_number == 1 &&
(info->last_down_number == 0 || info->last_down_number == 1
)
){
struct ts_sample_mt e = info->samp_mt[0][0]
;
req->event.type = EVT_NONE;
req->pointer_event.x = e.x;
req->pointer_event.y = e.y;
// log_debug("%s%d: e.pressure=%d x=%d y=%d ret=%d\n", __func__, __LINE__, e.pressure, e.x, e.y,
// ret);
if (e.pressure >
0
) {
if (req->pointer_event.pressed) {
req->event.type = EVT_POINTER_MOVE;
}
else {
req->event.type = EVT_POINTER_DOWN;
req->pointer_event.pressed = TRUE;
}
}
else {
if (req->pointer_event.pressed) {
req->event.type = EVT_POINTER_UP;
}
req->pointer_event.pressed = FALSE;
}
info->last_down_number = down_number;
return tslib_dispatch(info)
;
}
info->last_down_number = down_number;
return 0
;
}
void* tslib_run(
void* ctx) {
run_info_t info = *(run_info_t*
)ctx;
if (info.ts == NULL
) {
log_debug("%s:%d: open tslib failed, filename=%s\n"
, __func__
, __LINE__
, info.filename)
;
}
else {
log_debug("%s:%d: open tslib successful, filename=%s\n"
, __func__
, __LINE__
, info.filename)
;
}
TKMEM_FREE(ctx)
;
while (tslib_dispatch_one_event(&info) == RET_OK) {
}
;
ts_close(info.ts)
;
TKMEM_FREE(info.filename)
;
return NULL
;
}
static run_info_t* info_dup(run_info_t* info) {
run_info_t* new_info = TKMEM_ZALLOC(run_info_t
)
;
*new_info = *info;
return new_info;
}
tk_thread_t* tslib_thread_run(
const
char* filename, input_dispatch_t dispatch,
void* ctx,
int32_t max_x, int32_t max_y) {
run_info_t info;
tk_thread_t* thread = NULL
;
return_value_if_fail(filename != NULL && dispatch != NULL
, NULL
)
;
memset(&info, 0x00
,
sizeof(info)
)
;
info.max_x = max_x;
info.max_y = max_y;
info.dispatch_ctx = ctx;
info.dispatch = dispatch;
info.ts = ts_open(filename, 0
)
;
info.filename = tk_strdup(filename)
;
if (info.ts != NULL
) {
ts_config(info.ts)
;
}
///
struct tsdev *ts = info.ts;
info.read_samples = 1
;
info.max_slots = CT_MAX_TOUCH;
printf("max_x %d max_y %d TOUCH MAX SLOT=%d\r\n"
, info.max_x, info.max_y, info.max_slots)
;
info.samp_mt = malloc(info.read_samples *
sizeof(
struct ts_sample_mt *
)
)
;
if (!info.samp_mt) {
printf("create samp_mt failed\r\n"
)
;
ts_close(ts)
;
return NULL
;
}
for (
int i = 0
; i < info.read_samples; i++
) {
info.samp_mt[i] = calloc(info.max_slots,
sizeof(
struct ts_sample_mt
)
)
;
if (!info.samp_mt[i]
) {
printf("create samp_mt[%d] failed\r\n"
, i)
;
for (i--
; i >= 0
; i--
)
free(info.samp_mt[i]
)
;
free(info.samp_mt)
;
ts_close(ts)
;
return NULL
;
}
}
/* 创建不可识别手指类型的多点触控句柄 */
touch_points = multi_gesture_touch_points_create(15
)
;
memset(s_points, 0x0
,
sizeof(multi_touch_point_event_t
) * CT_MAX_TOUCH)
;
/
thread = tk_thread_create(tslib_run, info_dup(&info)
)
;
if (thread != NULL
) {
tk_thread_start(thread)
;
}
else {
multi_gesture_gesture_touch_points_destroy(touch_points)
;
if (info.samp_mt) {
for (
int i = 0
; i < info.read_samples; i++
) {
free(info.samp_mt[i]
)
;
}
free(info.samp_mt)
;
}
ts_close(info.ts)
;
TKMEM_FREE(info.filename)
;
}
return thread;
}练习demo地址
https://gitee.com/tracker647/awtk-practice/tree/master/MapImageTouchZoomTest
为了记录做业务学到的东西，我额外写了个demo来演示手指缩放和旋转的操作，采用vgcanvas矢量画布来实现旋转和缩放的效果，原本我想直接从网上下载个地图图片然后用vgcanvas_draw_image绘制，来表示地图的旋转和缩放，但是不知道是不是imx6ull本身图形性能太拉，一在on_paint函数调用vgcanvas_draw_image事件整个应用fps就会下降至1，根本无法正常操作图片，最后只好放弃，改成画一个红色矩形来演示效果:
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