Static Color bug via Qt particles

Jay_emissary

Hey all, I'm trying to work with Qt's particle system and either stumbled upon a bug or failed to grasp the concept of changing a particle's color.

 
                ParticleSystem{
                  id: explosionSystem
                  anchors.fill: parent
                }

                Emitter{
                  id: explosionEmitter
                  system: explosionSystem
                  anchors.bottom: parent.bottom
                  anchors.horizontalCenter: parent.horizontalCenter
                  lifeSpan: 500
                  emitRate: 0
                  size: parent.height * .1
                  velocity: CumulativeDirection{
                    AngleDirection{
                      angleVariation:  360
                      magnitude: 400
                      magnitudeVariation: 50
                    }
                  }



                  ImageParticle {
                    id: explosionImg
                    system: explosionSystem
                    source: "xxx.png" 
                    alpha: 0.2
                    color: "transparent"
                    colorVariation: 0

                  }
                }

Here I have a system, which I use to make the particles burst in all directions at the press of a button. They can change color depending on which button I press:

      function onButtonPressed(type){

           if (type === 1){
               explosionImg.colorVariation = 0
             explosionImg.color = "red"   
   } 
            else if (type === 2){
           explosionImg.colorVariation = 0
              explosionImg.color = "blue"              
 }
            console.log( explosionImg.color)
            explosionEmitter.burst(12)

}

Here's the issue: on the first burst the particles explode using their default color (white), despite the color being logged as changed when I call console.log. Any burst after uses the assigned color.

This gave me hours of headache last night as I was trying different methods to get the color to change on every burst. At some point I just assumed Qt couldn't load particle colors fast enough for the color to show on time, but alas, after hours of banging my head against the wall, I realized this was the issue. Does anyone know the cause or a possible fix? I've looked all over but can't even find anyone who has replicated the issue.

Jonas Karlsson

Could you put your complete code in one qml file so we can more easily test your exact setup?