Add missing actions for Particle Emitter properties

[tristanbob]

Description

Particle emitters are missing actions for some properties.

Solution suggested

New Actions:

• Particle type (Circle/Line/Image)
• Circle radius (pixles)
• Line length (pixels)
• Line thickness (pixels)
• Select an image (image)
• Additive rendering (bool)
• Delete when out of particles (bool)
• Maximum number of particles displayed (number)
• Particle minimum rotation speed (degrees/second)
• Particle maximum rotation speed (degrees/second)

Mismatched:

Gravity actions and properties do not appear to be referring to the same thing. (My preference would be to change both the properties and actions to use the "angle and speed" method which makes it easy for the user to pull/push particles in a direction.)

• Actions
  • Gravity
  • Gravity Angle
• Properties
  • Gravity on particles on X axis
  • Gravity on particles on Y axis

[tristanbob]

FYI - I need these actions so that I can build a "Particle Emitter Builder" that lets you see how the parameters affect the look, in real-time.

Once we have a Particle Emitter Builder, we can create a contest for people to build new emitters!

[Oxey405]

Okay it's seems a little hard to implement for a noob like me but still can try ^^
I think this is it :
GDevelop/Extensions/ParticleSystem/Extension.cpp

[4ian]

@Oxey405 Please use the Discord/forum to discuss or share your comments, GitHub is only for constructed collaboration with clear question/answers. Thanks!

[Oxey405]

Ok... I give up ! I can't understand !

[AlexandreSi]

If you ever want to try again, I can help with some indications

[AlexandreSi]

I ticked the following actions from your list (done with #4419):

• Additive rendering (bool)
• Maximum number of particles displayed (number)
• Particle minimum rotation speed (degrees/second)
• Particle maximum rotation speed (degrees/second)

The actions regarding the particle (type and shape) are not straightforward as we have to decide how it would be done: Is it a single action that can set the particle or should we have 3 different actions?
But they're doable.

The action to set the option to delete when it's out of particles is quite easy to create.

Regarding the setting of the gravity in the object parameters we have to think about how we would handle the transition from the current way (X and Y) to the new way (intensity and angle). Maybe we can add a checkbox to trigger one way or the other