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/*
* Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ----------------------------------------------------------------------------
*
* This file implements the LOLWUT command. The command should do something
* fun and interesting, and should be replaced by a new implementation at
* each new version of Redis.
*/
/* This function represents our canvas. Drawing functions will take a pointer
* to a canvas to write to it. Later the canvas can be rendered to a string
* suitable to be printed on the screen, using unicode Braille characters. */
struct lwCanvas {
int width;
int height;
char *pixels;
};
/* Translate a group of 8 pixels (2x8 vertical rectangle) to the corresponding
* braille character. The byte should correspond to the pixels arranged as
* follows, where 0 is the least significant bit, and 7 the most significant
* bit:
*
* 0 3
* 1 4
* 2 5
* 6 7
*
* The corresponding utf8 encoded character is set into the three bytes
* pointed by 'output'.
*/
#include <stdio.h>
void lwEmitPixelsGroup(int byte, char *output) {
int code = 0x2800 + byte;
/* Convert to unicode. This is in the U0800-UFFFF range, so we need to
* emit it like this in three bytes:
* 1110xxxx 10xxxxxx 10xxxxxx. */
output[1] = 0xE0 | (code >> 12); /* 1110-xxxx */
output[2] = 0x80 | ((code >> 6) & 0x3F); /* 10-xxxxxx */
output[3] = 0x80 | (code & 0x3F); /* 10-xxxxxx */
}
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