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
|
/*
* Copyright (c) 2018, 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.
*/
#include "server.h"
#include "lolwut.h"
#include <math.h>
void lolwut5Command(client *c);
void lolwut6Command(client *c);
/* The default target for LOLWUT if no matching version was found.
* This is what unstable versions of Redis will display. */
void lolwutUnstableCommand(client *c) {
sds rendered = sdsnew("Redis ver. ");
rendered = sdscat(rendered,REDIS_VERSION);
rendered = sdscatlen(rendered,"\n",1);
addReplyVerbatim(c,rendered,sdslen(rendered),"txt");
sdsfree(rendered);
}
/* LOLWUT [VERSION <version>] [... version specific arguments ...] */
void lolwutCommand(client *c) {
char *v = REDIS_VERSION;
char verstr[64];
if (c->argc >= 3 && !strcasecmp(c->argv[1]->ptr,"version")) {
long ver;
if (getLongFromObjectOrReply(c,c->argv[2],&ver,NULL) != C_OK) return;
snprintf(verstr,sizeof(verstr),"%u.0.0",(unsigned int)ver);
v = verstr;
/* Adjust argv/argc to filter the "VERSION ..." option, since the
* specific LOLWUT version implementations don't know about it
* and expect their arguments. */
c->argv += 2;
c->argc -= 2;
}
if ((v[0] == '5' && v[1] == '.' && v[2] != '9') ||
(v[0] == '4' && v[1] == '.' && v[2] == '9'))
lolwut5Command(c);
else if ((v[0] == '6' && v[1] == '.' && v[2] != '9') ||
(v[0] == '5' && v[1] == '.' && v[2] == '9'))
lolwut6Command(c);
else
lolwutUnstableCommand(c);
/* Fix back argc/argv in case of VERSION argument. */
if (v == verstr) {
c->argv -= 2;
c->argc += 2;
}
}
/* ========================== LOLWUT Canvase ===============================
* Many LOWUT versions will likely print some computer art to the screen.
* This is the case with LOLWUT 5 and LOLWUT 6, so here there is a generic
* canvas implementation that can be reused. */
/* Allocate and return a new canvas of the specified size. */
lwCanvas *lwCreateCanvas(int width, int height, int bgcolor) {
lwCanvas *canvas = zmalloc(sizeof(*canvas));
canvas->width = width;
canvas->height = height;
canvas->pixels = zmalloc(width*height);
memset(canvas->pixels,bgcolor,width*height);
return canvas;
}
/* Free the canvas created by lwCreateCanvas(). */
void lwFreeCanvas(lwCanvas *canvas) {
zfree(canvas->pixels);
zfree(canvas);
}
/* Set a pixel to the specified color. Color is 0 or 1, where zero means no
* dot will be displyed, and 1 means dot will be displayed.
* Coordinates are arranged so that left-top corner is 0,0. You can write
* out of the size of the canvas without issues. */
void lwDrawPixel(lwCanvas *canvas, int x, int y, int color) {
if (x < 0 || x >= canvas->width ||
y < 0 || y >= canvas->height) return;
canvas->pixels[x+y*canvas->width] = color;
}
/* Return the value of the specified pixel on the canvas. */
int lwGetPixel(lwCanvas *canvas, int x, int y) {
if (x < 0 || x >= canvas->width ||
y < 0 || y >= canvas->height) return 0;
return canvas->pixels[x+y*canvas->width];
}
/* Draw a line from x1,y1 to x2,y2 using the Bresenham algorithm. */
void lwDrawLine(lwCanvas *canvas, int x1, int y1, int x2, int y2, int color) {
int dx = abs(x2-x1);
int dy = abs(y2-y1);
int sx = (x1 < x2) ? 1 : -1;
int sy = (y1 < y2) ? 1 : -1;
int err = dx-dy, e2;
while(1) {
lwDrawPixel(canvas,x1,y1,color);
if (x1 == x2 && y1 == y2) break;
e2 = err*2;
if (e2 > -dy) {
err -= dy;
x1 += sx;
}
if (e2 < dx) {
err += dx;
y1 += sy;
}
}
}
/* Draw a square centered at the specified x,y coordinates, with the specified
* rotation angle and size. In order to write a rotated square, we use the
* trivial fact that the parametric equation:
*
* x = sin(k)
* y = cos(k)
*
* Describes a circle for values going from 0 to 2*PI. So basically if we start
* at 45 degrees, that is k = PI/4, with the first point, and then we find
* the other three points incrementing K by PI/2 (90 degrees), we'll have the
* points of the square. In order to rotate the square, we just start with
* k = PI/4 + rotation_angle, and we are done.
*
* Of course the vanilla equations above will describe the square inside a
* circle of radius 1, so in order to draw larger squares we'll have to
* multiply the obtained coordinates, and then translate them. However this
* is much simpler than implementing the abstract concept of 2D shape and then
* performing the rotation/translation transformation, so for LOLWUT it's
* a good approach. */
void lwDrawSquare(lwCanvas *canvas, int x, int y, float size, float angle, int color) {
int px[4], py[4];
/* Adjust the desired size according to the fact that the square inscribed
* into a circle of radius 1 has the side of length SQRT(2). This way
* size becomes a simple multiplication factor we can use with our
* coordinates to magnify them. */
size /= 1.4142135623;
size = round(size);
/* Compute the four points. */
float k = M_PI/4 + angle;
for (int j = 0; j < 4; j++) {
px[j] = round(sin(k) * size + x);
py[j] = round(cos(k) * size + y);
k += M_PI/2;
}
/* Draw the square. */
for (int j = 0; j < 4; j++)
lwDrawLine(canvas,px[j],py[j],px[(j+1)%4],py[(j+1)%4],color);
}
|
