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
|
// Copyright 2013 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
//
// Based on joelgwebber's Box2D benchmarks,
// https://github.com/joelgwebber/bench2d/blob/master/c/Bench2d.cpp
//
// Settings =====================
// Turn this on to include the y-position of the top box in the output.
#define DEBUG 0
int WARMUP;
int FRAMES;
typedef struct {
float mean;
float stddev;
} result_t;
// ==============================
#include <cstdio>
#include <time.h>
#include <math.h>
#ifdef __EMSCRIPTEN__
#include <emscripten.h>
#endif
#if NO_PRINTING
#define printf(fmt, ...) (0)
#endif
#include "Box2D/Box2D.h"
using namespace std;
const int e_count = 40;
result_t measure(clock_t *times) {
float values[FRAMES];
result_t r;
float total = 0;
for (int i = 0; i < FRAMES; ++i) {
values[i] = (float)times[i] / CLOCKS_PER_SEC * 1000;
total += values[i];
}
r.mean = total / FRAMES;
float variance = 0;
for (int i = 0; i < FRAMES; ++i) {
float diff = values[i] - r.mean;
variance += diff * diff;
}
r.stddev = sqrt(variance / FRAMES);
return r;
}
b2World *world;
clock_t *times, minn = CLOCKS_PER_SEC * 1000 * 100, maxx = -1;
b2Body* topBody;
int32 frameCounter = 0;
void iter();
int main(int argc, char **argv) {
int arg = argc > 1 ? argv[1][0] - '0' : 3;
switch(arg) {
case 0: return 0; break;
case 1: WARMUP = 5; FRAMES = 35; break;
case 2: WARMUP = 32; FRAMES = 161; break;
case 3: WARMUP = 64; FRAMES = 333; break;
case 4: WARMUP = 5*64; FRAMES = 7*333; break;
case 5: WARMUP = 10*64; FRAMES = 17*333; break;
default: printf("error: %d\\n", arg); return -1;
}
// do not split out warmup, do not ignore initial stalls
FRAMES += WARMUP;
WARMUP = 0;
times = new clock_t[FRAMES];
// Define the gravity vector.
b2Vec2 gravity(0.0f, -10.0f);
// Construct a world object, which will hold and simulate the rigid bodies.
world = new b2World(gravity);
world->SetAllowSleeping(false);
{
b2BodyDef bd;
b2Body* ground = world->CreateBody(&bd);
b2EdgeShape shape;
shape.Set(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
ground->CreateFixture(&shape, 0.0f);
}
{
float32 a = 0.5f;
b2PolygonShape shape;
shape.SetAsBox(a, a);
b2Vec2 x(-7.0f, 0.75f);
b2Vec2 y;
b2Vec2 deltaX(0.5625f, 1);
b2Vec2 deltaY(1.125f, 0.0f);
for (int32 i = 0; i < e_count; ++i) {
y = x;
for (int32 j = i; j < e_count; ++j) {
b2BodyDef bd;
bd.type = b2_dynamicBody;
bd.position = y;
b2Body* body = world->CreateBody(&bd);
body->CreateFixture(&shape, 5.0f);
topBody = body;
y += deltaY;
}
x += deltaX;
}
}
for (int32 i = 0; i < WARMUP; ++i) {
world->Step(1.0f/60.0f, 3, 3);
}
do {
iter();
} while (frameCounter <= FRAMES);
return 0;
}
void iter() {
if (frameCounter < FRAMES) {
clock_t start = clock();
world->Step(1.0f/60.0f, 3, 3);
clock_t end = clock();
clock_t curr = end - start;
times[frameCounter] = curr;
if (curr < minn) minn = curr;
if (curr > maxx) maxx = curr;
#if DEBUG
printf("%f :: ", topBody->GetPosition().y);
printf("%f\n", (float32)(end - start) / CLOCKS_PER_SEC * 1000);
#endif
frameCounter++;
return;
}
// that's it!
frameCounter++;
result_t result = measure(times);
printf("frame averages: %.3f +- %.3f, range: %.3f to %.3f \n", result.mean, result.stddev, float(minn)/CLOCKS_PER_SEC * 1000, float(maxx)/CLOCKS_PER_SEC * 1000);
}
|
