分析一下以下代码:#define ABS(a) (0 - (a)) > 0 ? (-(a)) : (a) #define DYNAMIC_PRECISION 30 /*动态精度*/ /*一个线性移位寄存器,用于过滤高频噪声*/ typedef struct slid_reg{ axis_info_t new_sample; axis_info_t old_sample; }slid_reg_t; static char slid_update(slid_reg_t *slid, axis_info_t *cur_sample) { char res = 0; if (ABS((cur_sample->x - slid->new_sample.x)) > DYNAMIC_PRECISION) { slid->old_sample.x = slid->new_sample.x; slid->new_sample.x = cur_sample->x; res = 1; } else { slid->old_sample.x = slid->new_sample.x; } if (ABS((cur_sample->y - slid->new_sample.y)) > DYNAMIC_PRECISION) { slid->old_sample.y = slid->new_sample.y; slid->new_sample.y = cur_sample->y; res = 1; } else { slid->old_sample.y = slid->new_sample.y; } if (ABS((cur_sample->z - slid->new_sample.z)) > DYNAMIC_PRECISION) { slid->old_sample.z = slid->new_sample.z; slid->new_sample.z = cur_sample->z; res = 1; } else { slid->old_sample.z = slid->new_sample.z; } return res; }
时间: 2023-06-26 14:05:37 浏览: 366
这段代码定义了一个宏 ABS(a) 和一个结构体 slid_reg_t,以及一个用于更新线性移位寄存器的函数 slid_update。下面对代码进行详细解析:
1. 宏定义
#define ABS(a) (0 - (a)) > 0 ? (-(a)) : (a)
该宏定义了一个对传入的参数取绝对值的操作,如果传入的参数 a 小于 0,则取其相反数作为返回值。
2. 静态常量
#define DYNAMIC_PRECISION 30
该宏定义了一个静态常量 DYNAMIC_PRECISION,其初始值为 30,用于过滤高频噪声。
3. 结构体定义
typedef struct slid_reg{
axis_info_t new_sample;
axis_info_t old_sample;
}slid_reg_t;
该结构体定义了一个线性移位寄存器 slid_reg_t,其中包含两个 axis_info_t 类型的变量 new_sample 和 old_sample,用于存储当前样本和旧样本的信息。
4. 函数定义
static char slid_update(slid_reg_t *slid, axis_info_t *cur_sample) {
char res = 0;
if (ABS((cur_sample->x - slid->new_sample.x)) > DYNAMIC_PRECISION) {
slid->old_sample.x = slid->new_sample.x;
slid->new_sample.x = cur_sample->x;
res = 1;
} else {
slid->old_sample.x = slid->new_sample.x;
}
if (ABS((cur_sample->y - slid->new_sample.y)) > DYNAMIC_PRECISION) {
slid->old_sample.y = slid->new_sample.y;
slid->new_sample.y = cur_sample->y;
res = 1;
} else {
slid->old_sample.y = slid->new_sample.y;
}
if (ABS((cur_sample->z - slid->new_sample.z)) > DYNAMIC_PRECISION) {
slid->old_sample.z = slid->new_sample.z;
slid->new_sample.z = cur_sample->z;
res = 1;
} else {
slid->old_sample.z = slid->new_sample.z;
}
return res;
}
该函数用于更新线性移位寄存器 slid 中的样本信息。首先定义了一个 char 类型的变量 res,并初始化为 0,用于记录是否更新了样本信息。然后分别对 x、y、z 三个轴上的样本信息进行判断,如果当前样本与新样本之间的差值大于 DYNAMIC_PRECISION,则将旧样本更新为新样本,将新样本更新为当前样本,并将 res 设为 1;否则只更新旧样本。最后返回 res。
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