def _init_compute_kernels(self):
bgfx.setUniform(
self.size_uniform, as_void_ptr((c_float * 2)(self._width, self._height))
)
bgfx.setBuffer(1, self._velocity_buffer[self.VELOCITY_READ], bgfx.Access.Read)
bgfx.setBuffer(2, self._velocity_buffer[self.VELOCITY_WRITE], bgfx.Access.Write)
bgfx.setBuffer(3, self._pressure_buffer[self.PRESSURE_READ], bgfx.Access.Read)
bgfx.setBuffer(4, self._pressure_buffer[self.PRESSURE_WRITE], bgfx.Access.Write)
bgfx.setBuffer(5, self._divergence_buffer, bgfx.Access.ReadWrite)
bgfx.setBuffer(6, self._vorticity_buffer, bgfx.Access.ReadWrite)
bgfx.setBuffer(7, self._obstacles_buffer, bgfx.Access.ReadWrite)
def _init_compute_kernels(self):
bgfx.setUniform(
self.particle_size_uniform,
as_void_ptr((c_float * 2)(self._particle_size[0],
self._particle_size[1])),
)
bgfx.setUniform(
self.velocity_size_uniform,
as_void_ptr((c_float * 2)(self._velocity_size[0],
self._velocity_size[1])),
)
bgfx.setBuffer(
TemplateConstants.PARTICLES_IN.value,
self._particles_buffer[self.PARTICLES_IN],
bgfx.Access.Write,
)
bgfx.setBuffer(
TemplateConstants.PARTICLES_OUT.value,
self._particles_buffer[self.PARTICLES_OUT],
bgfx.Access.Write,
)
def add_triangle_obstacle(self, p1: tuple, p2: tuple, p3: tuple, static=False):
if self.simulate:
self._init_compute_kernels()
bgfx.setUniform(self.p1_uniform, as_void_ptr((c_float * 2)(p1[0], p1[1])))
bgfx.setUniform(self.p2_uniform, as_void_ptr((c_float * 2)(p2[0], p2[1])))
bgfx.setUniform(self.p3_uniform, as_void_ptr((c_float * 2)(p3[0], p3[1])))
bgfx.setUniform(
self.static_uniform, as_void_ptr((c_float * 1)(1.0 if static else 0.0))
)
bgfx.dispatch(
0,
self._add_triangle_obstacle_kernel,
self._num_groups_x,
self._num_groups_y,
1,
)
def add_particles(self, position: tuple, radius: float, strength: float):
if self.simulate:
self._init_compute_kernels()
bgfx.setUniform(
self.position_uniform,
as_void_ptr((c_float * 2)(position[0], position[1])),
)
bgfx.setUniform(self.value_uniform,
as_void_ptr((c_float * 1)(strength)))
bgfx.setUniform(self.radius_uniform,
as_void_ptr((c_float * 1)(radius)))
bgfx.dispatch(0, self._add_particles_kernel, self._num_groups_x,
self._num_groups_x, 1)
self._flip_buffer()
def add_velocity(self, position: tuple, velocity: tuple, radius: float):
if self.simulate:
self._init_compute_kernels()
bgfx.setUniform(
self.position_uniform,
as_void_ptr((c_float * 2)(position[0], position[1])),
)
bgfx.setUniform(
self.value_uniform, as_void_ptr((c_float * 2)(velocity[0], velocity[1]))
)
bgfx.setUniform(self.radius_uniform, as_void_ptr((c_float * 1)(radius)))
bgfx.dispatch(
0, self._add_velocity_kernel, self._num_groups_x, self._num_groups_y, 1
)
self._flip_velocity_buffer()
def add_circle_obstacle(self, position: tuple, radius: float, static=False):
if self.simulate:
self._init_compute_kernels()
bgfx.setUniform(
self.position_uniform,
as_void_ptr((c_float * 2)(position[0], position[1])),
)
bgfx.setUniform(self.radius_uniform, as_void_ptr((c_float * 1)(radius)))
bgfx.setUniform(
self.static_uniform, as_void_ptr((c_float * 1)(1.0 if static else 0.0))
)
bgfx.dispatch(
0,
self._add_circle_obstacle_kernel,
self._num_groups_x,
self._num_groups_y,
1,
)
def update(self, time_delta: float):
self._init_compute_kernels()
if self.simulate:
bgfx.setUniform(self.dissipation_uniform,
as_void_ptr((c_float * 1)(self.dissipation)))
bgfx.setUniform(self.elapsed_time_uniform,
as_void_ptr((c_float * 1)(time_delta)))
bgfx.setUniform(self.speed_uniform,
as_void_ptr((c_float * 1)(self.speed)))
bgfx.dispatch(
0,
self._advect_particles_kernel,
self._num_groups_x,
self._num_groups_y,
1,
)
self._flip_buffer()
def _update_params(self, time_delta: float):
bgfx.setUniform(
self.elapsed_time_uniform, as_void_ptr((c_float * 1)(time_delta))
)
bgfx.setUniform(self.speed_uniform, as_void_ptr((c_float * 1)(self.speed)))
bgfx.setUniform(
self.dissipation_uniform, as_void_ptr((c_float * 1)(self.dissipation))
)
bgfx.setUniform(
self.vorticity_scale_uniform, as_void_ptr((c_float * 1)(self.vorticity))
)
if self._viscosity > 0.0:
centre_factor = 1.0 / self.viscosity
stencil_factor = 1.0 / (4.0 + centre_factor)
bgfx.setUniform(
self.alpha_uniform, as_void_ptr((c_float * 1)(centre_factor))
)
bgfx.setUniform(
self.rbeta_uniform, as_void_ptr((c_float * 1)(stencil_factor))
)