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#include <particle.hpp>
#include <engine.hpp>
#include <error.hpp>
#include <render.hpp>
#include <world.hpp>
#include <mutex>
std::vector<Particle> ParticleSystem::parts;
unsigned int ParticleSystem::maximum;
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;
static const Texture palette ("assets/colorIndex.png");
// six vertices, 3d coord + 2d tex coord = 5
constexpr auto entrySize = (6 * 5) * sizeof(GLfloat);
static std::once_flag init;
std::call_once(init, [&entrySize](GLuint& vbo) {
// generate VBO
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, maximum * entrySize, nullptr, GL_DYNAMIC_DRAW);
}, particleVBO);
if (parts.empty())
return;
// 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);
auto vbobuf = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
UserAssert(vbobuf != nullptr, "Failed to map the particle VBO");
for (unsigned int i = 0, offset = 0; i < parts.size(); i++, offset += entrySize) {
const auto& p = parts[i];
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);
std::memcpy(reinterpret_cast<void*>(reinterpret_cast<unsigned long long>(vbobuf) + offset), coords, entrySize);
}
UserAssert(glUnmapBuffer(GL_ARRAY_BUFFER) == GL_TRUE, "Failed to unmap the particle VBO");
// 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;
for (unsigned int i = 0; i < parts.size(); i++) {
auto& p = parts[i];
auto& vel = p.velocity;
// update timers
if (p.timeLeft > 0)
p.timeLeft -= dt;
else
continue;
// update movement
switch (p.type) {
case ParticleType::Drop:
if (vel.y > -.6)
vel.y -= 0.001f;
break;
case ParticleType::Confetti:
if (vel.x > -0.01 && vel.x < 0.01) {
vel.x = randGet() % 12 / 30.0f - 0.2f;
vel.y = -0.15f;
} else {
vel.x += (vel.x > 0) ? -0.002f : 0.002f;
}
break;
case ParticleType::SmallBlast:
if (vel.x == 0) {
int degree = randGet() % 100;
vel.x = cos(degree) / 4.0f;
vel.y = sin(degree) / 4.0f;
} else {
vel.x += (vel.x > 0) ? -0.001f : 0.001f;
vel.y += (vel.y > 0) ? -0.001f : 0.001f;
if ((vel.x > -0.01 && vel.x < 0.01) &&
(vel.y > -0.01 && vel.y < 0.01)) {
p.timeLeft = 0;
}
}
break;
case ParticleType::SmallPoof:
if (vel.x == 0) {
vel.x = randGet() % 10 / 20.0f - 0.25f;
vel.y = 0.1f;
} else {
vel.x += (vel.x > 0) ? -0.001f : 0.001f;
vel.y -= 0.0015f;
}
break;
case ParticleType::DownSlash:
if (vel.x == 0) {
vel.x = 0.2f * (randGet() % 16 - 8) / 10.0f;
vel.y = -vel.x;
}
break;
}
// really update movement
p.location.x += vel.x * dt;
p.location.y += vel.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)
{
return parts.size();
}
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