1 /**
2 * @file lv_utils.c
3 *
4 */
5
6 /*********************
7 * INCLUDES
8 *********************/
9 #include <stdbool.h>
10
11 #include "lv_utils.h"
12 #include "lv_math.h"
13 #include "lv_printf.h"
14 #include "lv_txt.h"
15
16 /*********************
17 * DEFINES
18 *********************/
19
20 /**********************
21 * TYPEDEFS
22 **********************/
23
24 /**********************
25 * STATIC PROTOTYPES
26 **********************/
27
28 /**********************
29 * STATIC VARIABLES
30 **********************/
31
32 /**********************
33 * MACROS
34 **********************/
35
36 /**********************
37 * GLOBAL FUNCTIONS
38 **********************/
39
40 /**
41 * Convert a number to string
42 * @param num a number
43 * @param buf pointer to a `char` buffer. The result will be stored here (max 10 elements)
44 * @return same as `buf` (just for convenience)
45 */
_lv_utils_num_to_str(int32_t num,char * buf)46 char * _lv_utils_num_to_str(int32_t num, char * buf)
47 {
48 if(num == 0) {
49 buf[0] = '0';
50 buf[1] = '\0';
51 return buf;
52 }
53 int8_t digitCount = 0;
54 int8_t i = 0;
55 if(num < 0) {
56 buf[digitCount++] = '-';
57 num = LV_MATH_ABS(num);
58 ++i;
59 }
60 while(num) {
61 char digit = num % 10;
62 buf[digitCount++] = digit + 48;
63 num /= 10;
64 }
65 buf[digitCount] = '\0';
66 digitCount--;
67 while(digitCount > i) {
68 char temp = buf[i];
69 buf[i] = buf[digitCount];
70 buf[digitCount] = temp;
71 digitCount--;
72 i++;
73 }
74 return buf;
75 }
76
77 /** Searches base[0] to base[n - 1] for an item that matches *key.
78 *
79 * @note The function cmp must return negative if its first
80 * argument (the search key) is less that its second (a table entry),
81 * zero if equal, and positive if greater.
82 *
83 * @note Items in the array must be in ascending order.
84 *
85 * @param key Pointer to item being searched for
86 * @param base Pointer to first element to search
87 * @param n Number of elements
88 * @param size Size of each element
89 * @param cmp Pointer to comparison function (see #lv_font_codeCompare as a comparison function
90 * example)
91 *
92 * @return a pointer to a matching item, or NULL if none exists.
93 */
_lv_utils_bsearch(const void * key,const void * base,uint32_t n,uint32_t size,int32_t (* cmp)(const void * pRef,const void * pElement))94 void * _lv_utils_bsearch(const void * key, const void * base, uint32_t n, uint32_t size,
95 int32_t (*cmp)(const void * pRef, const void * pElement))
96 {
97 const char * middle;
98 int32_t c;
99
100 for(middle = base; n != 0;) {
101 middle += (n / 2) * size;
102 if((c = (*cmp)(key, middle)) > 0) {
103 n = (n / 2) - ((n & 1) == 0);
104 base = (middle += size);
105 }
106 else if(c < 0) {
107 n /= 2;
108 middle = base;
109 }
110 else {
111 return (char *)middle;
112 }
113 }
114 return NULL;
115 }
116
117 /**********************
118 * STATIC FUNCTIONS
119 **********************/
120
