Pixel-Composer/scripts/BBMOD_TerrainCollisionModule/BBMOD_TerrainCollisionModule.gml
2023-04-23 16:47:33 +02:00

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/// @func BBMOD_TerrainCollisionModule([_terrain])
///
/// @extends BBMOD_ParticleModule
///
/// @desc A particle module that handles collisions with a terrain.
///
/// @param {Struct.BBMOD_Terrain} [_terrain] The terrain to collide with.
/// Defaults to `undefined`.
function BBMOD_TerrainCollisionModule(_terrain=undefined)
: BBMOD_ParticleModule() constructor
{
BBMOD_CLASS_GENERATED_BODY;
/// @var {Struct.BBMOD_Terrain} The terrain to collide with. Default value
/// is `undefined`.
Terrain = _terrain;
static on_update = function (_emitter, _deltaTime) {
var _terrain = Terrain;
if (!_terrain)
{
return;
}
var _particles = _emitter.Particles;
var _particleIndex = 0;
repeat (_emitter.ParticlesAlive)
{
var _positionX = _particles[# BBMOD_EParticle.PositionX, _particleIndex];
var _positionY = _particles[# BBMOD_EParticle.PositionY, _particleIndex];
var _terrainZ = _terrain.get_height(_positionX, _positionY);
if (_terrainZ != undefined)
{
var _positionZ = _particles[# BBMOD_EParticle.PositionZ, _particleIndex];
if (_positionZ < _terrainZ)
{
_particles[# BBMOD_EParticle.PositionZ, _particleIndex] = _terrainZ;
var _normal = _terrain.get_normal(_positionX, _positionY);
var _velocityX = _particles[# BBMOD_EParticle.VelocityX, _particleIndex];
var _velocityY = _particles[# BBMOD_EParticle.VelocityY, _particleIndex];
var _velocityZ = _particles[# BBMOD_EParticle.VelocityZ, _particleIndex];
var _dot2 = (
_velocityX * _normal.X
+ _velocityY * _normal.Y
+ _velocityZ * _normal.Z
) * 2.0;
var _bounce = _particles[# BBMOD_EParticle.Bounce, _particleIndex];
_particles[# BBMOD_EParticle.VelocityX, _particleIndex] =
(_velocityX - (_dot2 * _normal.X)) * _bounce;
_particles[# BBMOD_EParticle.VelocityY, _particleIndex] =
(_velocityY - (_dot2 * _normal.Y)) * _bounce;
_particles[# BBMOD_EParticle.VelocityZ, _particleIndex] =
(_velocityZ - (_dot2 * _normal.Z)) * _bounce;
_particles[# BBMOD_EParticle.HasCollided, _particleIndex] =
true;
}
}
++_particleIndex;
}
};
}