/** 
    The available display options to change the particle rendering
*/
export interface DisplayOptions {

    /**
     * Minimum velcity that will applied to a particle
     * default: 0
     * */
    minVelocity?: number;

    /**
     * Maimum velocity that will be applied to a particle
     * default: 10
     * */
    maxVelocity?: number;

    /**
     * Determines how quickly the particle moves based on it's velocity. Higher values mean faster moving.
     * default: 0.005
     * */
    velocityScale?: number;

    /**
     * The number of frames a particle will live for.
     * default: 90
     * */
    particleAge?: number;


    /**
     * The number of particles per 50x50 pixel block.
     * If a number that density is applied across the board. 
     * If a DensityStop[] declare the zoom level and density that would you like to apply in each entry. Start with higher zoom first eg: [{ zoom: 2, density: 10 }, { zoom: 5, density: 8 }, {zoom: 6, density: 7}]
     * default: 10
     * */
    particleDensity?: number | DensityStop[];


    /**
     * The frame rate to use when animating. If the velocityScale parameter is higher then this will need to be increased to keep up with the required frames to draw the particles at a quicker speed. 
     * If it's not a high enough value the animations could appear jumpy.
     * default: 15
     * */
    frameRate?: number;

    /**
     * An array of color values to use. Velocity values will be mapped to this color scale.
     * default: ["rgb(61,160,247)", "rgb(99,164,217)", "rgb(138,168,188)", "rgb(177,173,158)", "rgb(216,177,129)", "rgb(255,182,100)", "rgb(240,145,87)", "rgb(225,109,74)", "rgb(210,72,61)", "rgb(195,36,48)", "rgb(180,0,35)"];
     * */
    colorScale?: string[];

    /**
     * The width of the line for default rendering.
     * default: 1
     * */
    lineWidth?: number;

    /**
     * An amount to reduce particle numbers by on mobile devices
     * default: (Math.pow(window.devicePixelRatio, 1 / 3) || 1.6)
     * */
    particleReduction?: number;

    /** 
     * A function that if exists will be called in the draw method that allows for specific code to be run for the fading out part of the drawing. 
     * */
    customFadeFunction?: CustomFadeFunction; 

    /**
     * A function that if exists will be called to draw the particles. Allows for caller to have complete control over drawing. Will pass the context, particle object and the color style. 
     * */
    customDrawFunction?: CustomDrawFunction;
}