part_emitter_relative

This function sets relative mode for a particle emitter. With relative mode enabled, the number of particles created becomes relative to its area.

Usage Notes

• The larger the emitter area set using part_emitter_region, the more particles that will be created.
• The number parameter of the functions part_emitter_stream and part_emitter_burst changes: it becomes the percentage of the emitter area that should be covered with new particles.
• By default, new particle emitters created using part_emitter_create don't have relative mode enabled.

Syntax:

part_emitter_relative(ps, ind, enable);

Returns:

N/A

Example:

Create Event

ps = part_system_create();
pe = part_emitter_create(ps);
part_emitter_region(ps, pe, 20, 120, 20, 120, ps_shape_rectangle, ps_distr_linear);
part_emitter_relative(ps, pe, true);
pt = part_type_create();
part_type_shape(pt, pt_shape_flare);

part_emitter_stream(ps, pe, pt, 2);

Cleanup Event

part_emitter_destroy(pe);
part_system_destroy(ps);
part_type_destroy(pt);

The above code creates a particle system ps and adds a single emitter pe to it. The emitter is set to emit particles in a rectangular region of 100x100 pixels, starting at (20, 20). It is then set to emit particles in relative mode. Next, a particle type is created and configured to draw a flare shape pt_shape_flare. Finally, the emitter is set to stream particles of the created type continuously. Since relative mode was enabled, the number of 2 means that the emitter will create the number of particles needed to cover 2% of the emitter area every step.