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2 new area particle distributions: borderellipse and borderrectangle

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--HG--
branch : particle system new features
This commit is contained in:
lognz
2017-03-10 06:42:52 -06:00
parent 856a4e60ae
commit 09b757f018
2 changed files with 41 additions and 5 deletions
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src/modules/graphics/ParticleSystem.cpp
+38 -4
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@@ -261,6 +261,10 @@ void ParticleSystem::initParticle(Particle *p, float t)
p->position = pos;
min = direction - spread/2.0f;
max = direction + spread/2.0f;
float dir = (float) rng.random(min, max);
float rand_x, rand_y;
switch (areaSpreadDistribution)
{
@@ -278,6 +282,38 @@ void ParticleSystem::initParticle(Particle *p, float t)
p->position.x += areaSpread.getX() * (rand_x * sqrt(1 - 0.5f*pow(rand_y, 2)));
p->position.y += areaSpread.getY() * (rand_y * sqrt(1 - 0.5f*pow(rand_x, 2)));
break;
case DISTRIBUTION_BORDER_ELLIPSE:
rand_x = (float) rng.random(0, LOVE_M_PI * 2);
p->position.x += cosf(rand_x) * areaSpread.getX();
p->position.y += sinf(rand_x) * areaSpread.getY();
dir += rand_x;
break;
case DISTRIBUTION_BORDER_RECTANGLE:
// Unwraps rectangle border onto straight line and pick random point
rand_x = (float) rng.random((areaSpread.getX() + areaSpread.getY()) * -2, (areaSpread.getX() + areaSpread.getY()) * 2);
min = areaSpread.getY() * 2;
if (rand_x < -min)
{
p->position.x += rand_x + min + areaSpread.getX();
p->position.y += -areaSpread.getY();
}
else if (rand_x < 0)
{
p->position.x += -areaSpread.getX();
p->position.y += rand_x + (areaSpread.getY());
}
else if (rand_x < min)
{
p->position.x += areaSpread.getX();
p->position.y += rand_x - (areaSpread.getY());
}
else
{
p->position.x += rand_x - min - areaSpread.getX();
p->position.y += areaSpread.getY();
}
dir += atan2(p->position.y - pos.getY(), p->position.x - pos.getX());
break;
case DISTRIBUTION_NONE:
default:
break;
@@ -289,10 +325,6 @@ void ParticleSystem::initParticle(Particle *p, float t)
max = speedMax;
float speed = (float) rng.random(min, max);
min = direction - spread/2.0f;
max = direction + spread/2.0f;
float dir = (float) rng.random(min, max);
p->velocity = love::Vector(cosf(dir), sinf(dir)) * speed;
p->linearAcceleration.x = (float) rng.random(linearAccelerationMin.x, linearAccelerationMax.x);
@@ -1029,6 +1061,8 @@ StringMap<ParticleSystem::AreaSpreadDistribution, ParticleSystem::DISTRIBUTION_M
{ "uniform", DISTRIBUTION_UNIFORM },
{ "normal", DISTRIBUTION_NORMAL },
{ "ellipse", DISTRIBUTION_ELLIPSE },
{ "borderellipse", DISTRIBUTION_BORDER_ELLIPSE },
{ "borderrectangle", DISTRIBUTION_BORDER_RECTANGLE }
};
StringMap<ParticleSystem::AreaSpreadDistribution, ParticleSystem::DISTRIBUTION_MAX_ENUM> ParticleSystem::distributions(ParticleSystem::distributionsEntries, sizeof(ParticleSystem::distributionsEntries));