ClickHouse/dbms/src/Common/UnicodeBar.h
2017-05-09 13:03:35 -04:00

64 lines
1.4 KiB
C++

#pragma once
#include <cstring>
#include <cmath>
#include <string>
#include <Core/Types.h>
#define UNICODE_BAR_CHAR_SIZE (strlen("█"))
/** Allows you to draw a unicode-art bar whose width is displayed with a resolution of 1/8 character.
*/
namespace UnicodeBar
{
using DB::Int64;
inline double getWidth(Int64 x, Int64 min, Int64 max, double max_width)
{
if (x <= min)
return 0;
if (x >= max)
return max_width;
return (x - min) * max_width / (max - min);
}
inline size_t getWidthInBytes(double width)
{
return ceil(width - 1.0 / 8) * UNICODE_BAR_CHAR_SIZE;
}
/// In `dst` there must be a space for barWidthInBytes(width) characters and a trailing zero.
inline void render(double width, char * dst)
{
size_t floor_width = floor(width);
for (size_t i = 0; i < floor_width; ++i)
{
memcpy(dst, "", UNICODE_BAR_CHAR_SIZE);
dst += UNICODE_BAR_CHAR_SIZE;
}
size_t remainder = floor((width - floor_width) * 8);
if (remainder)
{
memcpy(dst, &"▏▎▍▌▋▋▊▉"[(remainder - 1) * UNICODE_BAR_CHAR_SIZE], UNICODE_BAR_CHAR_SIZE);
dst += UNICODE_BAR_CHAR_SIZE;
}
*dst = 0;
}
inline std::string render(double width)
{
std::string res(getWidthInBytes(width), '\0');
render(width, &res[0]);
return res;
}
}