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https://github.com/lvgl/lvgl.git
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98 lines
2.1 KiB
C
98 lines
2.1 KiB
C
/**
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* @file lv_math.c
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*
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*/
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/*********************
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* INCLUDES
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*********************/
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#include "lv_math.h"
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#include <stdbool.h>
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/*********************
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* DEFINES
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*********************/
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/**********************
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* TYPEDEFS
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**********************/
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/**********************
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* STATIC PROTOTYPES
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**********************/
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/**********************
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* STATIC VARIABLES
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**********************/
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/**********************
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* MACROS
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**********************/
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/**********************
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* GLOBAL FUNCTIONS
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**********************/
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/**
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* Convert a number to string
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* @param num a number
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* @param buf pointer to a `char` buffer. The result will be stored here (max 10 elements)
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* @return same as `buf` (just for convenience)
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*/
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char * lv_math_num_to_str(int32_t num, char * buf)
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{
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char * buf_ori = buf;
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if(num == 0) {
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buf[0] = '0';
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buf[1] = '\0';
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return buf;
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} else if(num < 0) {
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(*buf) = '-';
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buf++;
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num = LV_MATH_ABS(num);
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}
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uint32_t output = 0;
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int8_t i;
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for(i = 31; i >= 0; i--) {
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if((output & 0xF) >= 5)
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output += 3;
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if(((output & 0xF0) >> 4) >= 5)
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output += (3 << 4);
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if(((output & 0xF00) >> 8) >= 5)
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output += (3 << 8);
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if(((output & 0xF000) >> 12) >= 5)
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output += (3 << 12);
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if(((output & 0xF0000) >> 16) >= 5)
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output += (3 << 16);
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if(((output & 0xF00000) >> 20) >= 5)
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output += (3 << 20);
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if(((output & 0xF000000) >> 24) >= 5)
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output += (3 << 24);
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if(((output & 0xF0000000) >> 28) >= 5)
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output += (3 << 28);
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output = (output << 1) | ((num >> i) & 1);
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}
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uint8_t digit;
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bool leading_zero_ready = false;
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for(i = 28; i >= 0; i -= 4) {
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digit = ((output >> i) & 0xF) + '0';
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if(digit == '0' && leading_zero_ready == false) continue;
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leading_zero_ready = true;
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(*buf) = digit;
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buf++;
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}
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(*buf) = '\0';
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return buf_ori;
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}
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/**********************
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* STATIC FUNCTIONS
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**********************/
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