Styling, export and integration

Watermark for the free tier

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The free tier is the whole library

Without a key, PlotScope draws everything it draws with one: every chart kind, every scene item, at every size. The difference is a small mark in the corner of the canvas, reading "PlotScope free tier". Nothing is switched off, nothing is slowed down and nothing stops after a number of days.

That is deliberate. A library that will not draw until it is paid for cannot be tried, and trying it is how a developer decides.

What takes the mark away, and what brings it back

A key that holds takes it away, from the next frame. Press the keys above: the second removes the mark from this plot, and the third, which is the same key with one character changed, leaves it on.

The mark comes back whenever the answer stops being active: a dated demo key runs out, or the page is served from a host the key does not name. It is drawn by the plot, so it is in an exported image as well as on the screen.

A page that wants to know which state it is in asks, and can say so in its own words:

export function describe(licence: LicenceStatus): string {
  switch (licence.status) {
    case "active":
      return licence.expires === 0
        ? `licensed to ${licence.licensee}`
        : `licensed to ${licence.licensee} until ${day(licence.expires)}`;
    case "free":
      return "no key: the free tier, with the mark on";
    case "expired":
      return `expired on ${day(licence.expires)}: the mark is back on`;
    case "wrongPlatform":
      return `this key is for another platform, not ${licence.platform}: the mark is on`;
    case "wrongHost":
      return `this key is not for ${licence.host}: the mark is on`;
    case "invalid":
      return `not a key that holds (${licence.problem}): the mark is on`;
  }
}