1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/*
* Copyright (c) 2019, 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.
*
* Thanks to Michele Hiki Falcone for the original image that ispired
* the image, part of his game, Plaguemon.
*
* Thanks to the Shhh computer art collective for the help in tuning the
* output to have a better artistic effect.
*/
#include "server.h"
#include "lolwut.h"
/* Render the canvas using the four gray levels of the standard color
* terminal: they match very well to the grayscale display of the gameboy. */
static sds renderCanvas(lwCanvas *canvas) {
sds text = sdsempty();
for (int y = 0; y < canvas->height; y++) {
for (int x = 0; x < canvas->width; x++) {
int color = lwGetPixel(canvas,x,y);
char *ce; /* Color escape sequence. */
/* Note that we set both the foreground and background color.
* This way we are able to get a more consistent result among
* different terminals implementations. */
switch(color) {
case 0: ce = "0;30;40m"; break; /* Black */
case 1: ce = "0;90;100m"; break; /* Gray 1 */
case 2: ce = "0;37;47m"; break; /* Gray 2 */
case 3: ce = "0;97;107m"; break; /* White */
}
text = sdscatprintf(text,"\033[%s \033[0m",ce);
}
if (y != canvas->height-1) text = sdscatlen(text,"\n",1);
}
return text;
}
/* Draw a skyscraper on the canvas, according to the parameters in the
* 'skyscraper' structure. Window colors are random and are always one
* of the two grays. */
struct skyscraper {
int xoff; /* X offset. */
int width; /* Pixels width. */
int height; /* Pixels height. */
int windows; /* Draw windows if true. */
int color; /* Color of the skyscraper. */
};
void generateSkyscraper(lwCanvas *canvas, struct skyscraper *si) {
int starty = canvas->height-1;
int endy = starty - si->height + 1;
for (int y = starty; y >= endy; y--) {
for (int x = si->xoff; x < si->xoff+si->width; x++) {
/* The roof is four pixels less wide. */
if (y == endy && (x <= si->xoff+1 || x >= si->xoff+si->width-2))
continue;
int color = si->color;
/* Alter the color if this is a place where we want to
* draw a window. We check that we are in the inner part of the
* skyscraper, so that windows are far from the borders. */
if (si->windows &&
x > si->xoff+1 &&
x < si->xoff+si->width-2 &&
y > endy+1 &&
y < starty-1)
{
/* Calculate the x,y position relative to the start of
* the window area. */
int relx = x - (si->xoff+1);
int rely = y - (endy+1);
/* Note that we want the windows to be two pixels wide
* but just one pixel tall, because terminal "pixels"
* (characters) are not square. */
if (relx/2 % 2 && rely % 2) {
do {
color = 1 + rand() % 2;
} while (color == si->color);
/* Except we want adjacent pixels creating the same
* window to be the same color. */
if (relx % 2) color = lwGetPixel(canvas,x-1,y);
}
}
lwDrawPixel(canvas,x,y,color);
}
}
}
/* Generate a skyline inspired by the parallax backgrounds of 8 bit games. */
void generateSkyline(lwCanvas *canvas) {
struct skyscraper si;
/* First draw the background skyscraper without windows, using the
* two different grays. We use two passes to make sure that the lighter
* ones are always in the background. */
for (int color = 2; color >= 1; color--) {
si.color = color;
for (int offset = -10; offset < canvas->width;) {
offset += rand() % 8;
si.xoff = offset;
si.width = 10 + rand()%9;
if (color == 2)
si.height = canvas->height/2 + rand()%canvas->height/2;
else
si.height = canvas->height/2 + rand()%canvas->height/3;
si.windows = 0;
generateSkyscraper(canvas, &si);
if (color == 2)
offset += si.width/2;
else
offset += si.width+1;
}
}
/* Now draw the foreground skyscraper with the windows. */
si.color = 0;
for (int offset = -10; offset < canvas->width;) {
offset += rand() % 8;
si.xoff = offset;
si.width = 5 + rand()%14;
if (si.width % 4) si.width += (si.width % 3);
si.height = canvas->height/3 + rand()%canvas->height/2;
si.windows = 1;
generateSkyscraper(canvas, &si);
offset += si.width+5;
}
}
/* The LOLWUT 6 command:
*
* LOLWUT [columns] [rows]
*
* By default the command uses 80 columns, 40 squares per row
* per column.
*/
void lolwut6Command(client *c) {
long cols = 80;
long rows = 20;
/* 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],&rows,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 resulution. */
if (cols < 1) cols = 1;
if (cols > 1000) cols = 1000;
if (rows < 1) rows = 1;
if (rows > 1000) rows = 1000;
/* Generate the city skyline and reply. */
lwCanvas *canvas = lwCreateCanvas(cols,rows,3);
generateSkyline(canvas);
sds rendered = renderCanvas(canvas);
rendered = sdscat(rendered,
"\nDedicated to the 8 bit game developers of past and present.\n"
"Original 8 bit image from Plaguemon by hikikomori. Redis ver. ");
rendered = sdscat(rendered,REDIS_VERSION);
rendered = sdscatlen(rendered,"\n",1);
addReplyVerbatim(c,rendered,sdslen(rendered),"txt");
sdsfree(rendered);
lwFreeCanvas(canvas);
}
|
