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
|
#include <particle.hpp>
#include <engine.hpp>
#include <render.hpp>
#include <world.hpp>
ParticleSystem::ParticleSystem(unsigned int max)
: maximum(max)
{
parts.reserve(maximum);
}
void ParticleSystem::add(const vec2& pos, const ParticleType& type, const int& timeleft,
const unsigned char& color)
{
if (parts.size() < maximum)
parts.emplace_back(pos, type, timeleft, vec2(color / 8 * 0.25f, color % 8 * 0.125f + 0.0625f));
}
void ParticleSystem::addMultiple(const int& count, const ParticleType& type, std::function<vec2(void)> f,
const int& timeleft, const unsigned char& color)
{
int togo = count;
while (togo-- > 0)
add(f(), type, timeleft, color);
}
void ParticleSystem::render(void)
{
static GLuint particleVBO = 9999;
static const Texture palette ("assets/colorIndex.png");
// six vertices, 3d coord + 2d tex coord = 5
constexpr auto entrySize = (6 * 5) * sizeof(GLfloat);
if (particleVBO == 9999) {
// generate VBO
glGenBuffers(1, &particleVBO);
glBindBuffer(GL_ARRAY_BUFFER, particleVBO);
glBufferData(GL_ARRAY_BUFFER, maximum * entrySize, nullptr, GL_STREAM_DRAW);
}
// clear dead particles
parts.erase(std::remove_if(parts.begin(), parts.end(),
[](const Particle& p) { return p.timeLeft <= 0; }), parts.end());
// copy data into VBO
glBindBuffer(GL_ARRAY_BUFFER, particleVBO);
int offset = 0;
for (const auto& p : parts) {
static const auto& hl = game::HLINE;
GLfloat coords[30] = {
p.location.x, p.location.y, -1, p.color.x, p.color.y,
p.location.x, p.location.y + hl, -1, p.color.x, p.color.y,
p.location.x + hl, p.location.y + hl, -1, p.color.x, p.color.y,
p.location.x + hl, p.location.y + hl, -1, p.color.x, p.color.y,
p.location.x + hl, p.location.y, -1, p.color.x, p.color.y,
p.location.x, p.location.y, -1, p.color.x, p.color.y
};
glBufferSubData(GL_ARRAY_BUFFER, offset, entrySize, coords);
offset += entrySize;
}
// begin actual rendering
Render::worldShader.use();
Render::worldShader.enable();
// set coords
glVertexAttribPointer(Render::worldShader.coord, 3, GL_FLOAT, GL_FALSE,
5 * sizeof(GLfloat), 0);
// set tex coords
glVertexAttribPointer(Render::worldShader.tex, 2, GL_FLOAT, GL_FALSE,
5 * sizeof(GLfloat), reinterpret_cast<void*>(3 * sizeof(GLfloat)));
palette.use();
glDrawArrays(GL_TRIANGLES, 0, parts.size() * 6);
Render::worldShader.disable();
Render::worldShader.unuse();
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void ParticleSystem::update(entityx::EntityManager &en, entityx::EventManager &ev, entityx::TimeDelta dt)
{
(void)en;
(void)ev;
(void)dt; // TODO use for time to die
auto& worldSystem = *game::engine.getSystem<WorldSystem>();
for (auto part = std::begin(parts); part != std::end(parts); part++) {
auto& p = *part;
// update timers
p.timeLeft -= dt;
// update movement
switch (p.type) {
case ParticleType::Drop:
if (p.velocity.y > -.6)
p.velocity.y -= 0.001f;
break;
case ParticleType::Confetti:
if (p.velocity.x > -0.01 && p.velocity.x < 0.01) {
p.velocity.x = randGet() % 12 / 30.0f - 0.2f;
} else {
p.velocity.x += (p.velocity.x > 0) ? -0.002f : 0.002f;
}
p.velocity.y = -0.15f;
p.timeLeft = 1000;
break;
case ParticleType::SmallBlast:
if (p.velocity.x == 0) {
int degree = randGet() % 100;
p.velocity.x = cos(degree) / 4.0f;
p.velocity.y = sin(degree) / 4.0f;
} else {
p.velocity.x += (p.velocity.x > 0) ? -0.001f : 0.001f;
p.velocity.y += (p.velocity.y > 0) ? -0.001f : 0.001f;
if ((p.velocity.x > -0.01 && p.velocity.x < 0.01) &&
(p.velocity.y > -0.01 && p.velocity.y < 0.01)) {
p.timeLeft = 0;
}
}
break;
case ParticleType::SmallPoof:
if (p.velocity.x == 0) {
p.velocity.y = 0.1f;
p.velocity.x = randGet() % 12 / 30.0f - 0.2f;
} else {
p.velocity.x += (p.velocity.x > 0) ? -0.001f : 0.001f;
p.velocity.y -= 0.0015f;
}
break;
}
// really update movement
p.location.x += p.velocity.x * dt;
p.location.y += p.velocity.y * dt;
// world collision
auto height = worldSystem.isAboveGround(p.location);
if (height != 0) {
if (p.type == ParticleType::Drop || p.type == ParticleType::SmallPoof)
p.location.y = height + 5, p.velocity.y = randGet() % 10 / 40.0f;
else
p.timeLeft = 0;
}
}
}
int ParticleSystem::getCount(void) const
{
return parts.size();
}
|
