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Diffstat (limited to 'examples/redis-unstable/src/lolwut5.c')
| -rw-r--r-- | examples/redis-unstable/src/lolwut5.c | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/examples/redis-unstable/src/lolwut5.c b/examples/redis-unstable/src/lolwut5.c deleted file mode 100644 index 29f0a2f..0000000 --- a/examples/redis-unstable/src/lolwut5.c +++ /dev/null @@ -1,157 +0,0 @@ -/* - * Copyright (c) 2018-Present, Redis Ltd. - * All rights reserved. - * - * Licensed under your choice of (a) the Redis Source Available License 2.0 - * (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the - * GNU Affero General Public License v3 (AGPLv3). - * - * ---------------------------------------------------------------------------- - * - * 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. - */ - -#include "server.h" -#include "lolwut.h" -#include <math.h> - -/* Translate a group of 8 pixels (2x4 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 lwTranslatePixelsGroup(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[0] = 0xE0 | (code >> 12); /* 1110-xxxx */ - output[1] = 0x80 | ((code >> 6) & 0x3F); /* 10-xxxxxx */ - output[2] = 0x80 | (code & 0x3F); /* 10-xxxxxx */ -} - -/* Schotter, the output of LOLWUT of Redis 5, is a computer graphic art piece - * generated by Georg Nees in the 60s. It explores the relationship between - * caos and order. - * - * The function creates the canvas itself, depending on the columns available - * in the output display and the number of squares per row and per column - * requested by the caller. */ -lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_col) { - /* Calculate the canvas size. */ - int canvas_width = console_cols*2; - int padding = canvas_width > 4 ? 2 : 0; - float square_side = (float)(canvas_width-padding*2) / squares_per_row; - int canvas_height = square_side * squares_per_col + padding*2; - lwCanvas *canvas = lwCreateCanvas(canvas_width, canvas_height, 0); - - for (int y = 0; y < squares_per_col; y++) { - for (int x = 0; x < squares_per_row; x++) { - int sx = x * square_side + square_side/2 + padding; - int sy = y * square_side + square_side/2 + padding; - /* Rotate and translate randomly as we go down to lower - * rows. */ - float angle = 0; - if (y > 1) { - float r1 = (float)rand() / (float) RAND_MAX / squares_per_col * y; - float r2 = (float)rand() / (float) RAND_MAX / squares_per_col * y; - float r3 = (float)rand() / (float) RAND_MAX / squares_per_col * y; - if (rand() % 2) r1 = -r1; - if (rand() % 2) r2 = -r2; - if (rand() % 2) r3 = -r3; - angle = r1; - sx += r2*square_side/3; - sy += r3*square_side/3; - } - lwDrawSquare(canvas,sx,sy,square_side,angle,1); - } - } - - return canvas; -} - -/* Converts the canvas to an SDS string representing the UTF8 characters to - * print to the terminal in order to obtain a graphical representation of the - * logical canvas. The actual returned string will require a terminal that is - * width/2 large and height/4 tall in order to hold the whole image without - * overflowing or scrolling, since each Barille character is 2x4. */ -static sds renderCanvas(lwCanvas *canvas) { - sds text = sdsempty(); - for (int y = 0; y < canvas->height; y += 4) { - for (int x = 0; x < canvas->width; x += 2) { - /* We need to emit groups of 8 bits according to a specific - * arrangement. See lwTranslatePixelsGroup() for more info. */ - int byte = 0; - if (lwGetPixel(canvas,x,y)) byte |= (1<<0); - if (lwGetPixel(canvas,x,y+1)) byte |= (1<<1); - if (lwGetPixel(canvas,x,y+2)) byte |= (1<<2); - if (lwGetPixel(canvas,x+1,y)) byte |= (1<<3); - if (lwGetPixel(canvas,x+1,y+1)) byte |= (1<<4); - if (lwGetPixel(canvas,x+1,y+2)) byte |= (1<<5); - if (lwGetPixel(canvas,x,y+3)) byte |= (1<<6); - if (lwGetPixel(canvas,x+1,y+3)) byte |= (1<<7); - char unicode[3]; - lwTranslatePixelsGroup(byte,unicode); - text = sdscatlen(text,unicode,3); - } - if (y != canvas->height-1) text = sdscatlen(text,"\n",1); - } - return text; -} - -/* The LOLWUT command: - * - * LOLWUT [terminal columns] [squares-per-row] [squares-per-col] - * - * By default the command uses 66 columns, 8 squares per row, 12 squares - * per column. - */ -void lolwut5Command(client *c) { - long cols = 66; - long squares_per_row = 8; - long squares_per_col = 12; - - /* Parse the optional arguments if any. */ - if (c->argc > 1 && - getLongFromObjectOrReply(c,c->argv[1],&cols,NULL) != C_OK) - return; - - if (c->argc > 2 && - getLongFromObjectOrReply(c,c->argv[2],&squares_per_row,NULL) != C_OK) - return; - - if (c->argc > 3 && - getLongFromObjectOrReply(c,c->argv[3],&squares_per_col,NULL) != C_OK) - return; - - /* Limits. We want LOLWUT to be always reasonably fast and cheap to execute - * so we have maximum number of columns, rows, and output resolution. */ - if (cols < 1) cols = 1; - if (cols > 1000) cols = 1000; - if (squares_per_row < 1) squares_per_row = 1; - if (squares_per_row > 200) squares_per_row = 200; - if (squares_per_col < 1) squares_per_col = 1; - if (squares_per_col > 200) squares_per_col = 200; - - /* Generate some computer art and reply. */ - lwCanvas *canvas = lwDrawSchotter(cols,squares_per_row,squares_per_col); - sds rendered = renderCanvas(canvas); - rendered = sdscat(rendered, - "\nGeorg Nees - schotter, plotter on paper, 1968. Redis ver. "); - rendered = sdscat(rendered,REDIS_VERSION); - rendered = sdscatlen(rendered,"\n",1); - addReplyVerbatim(c,rendered,sdslen(rendered),"txt"); - sdsfree(rendered); - lwFreeCanvas(canvas); -} |