Function resolveBlipOpacity

apps/sim/lib/pptx-renderer/renderer/image-renderer.ts:190–209

* Resolve overall image opacity from OOXML blip alpha modifiers. * * Supported today: * - alphaModFix amt="N" * - alphaMod val="N" * - alphaOff val="N"

(blip: SafeXmlNode)

 * - alphaOff val="N"
 */
function resolveBlipOpacity(blip: SafeXmlNode): number {
  let alpha = 1

  const alphaModFix = blip.child('alphaModFix')
  if (alphaModFix.exists()) {
    alpha *= (alphaModFix.numAttr('amt') ?? 100000) / 100000
  }

  const alphaMod = blip.child('alphaMod')
  if (alphaMod.exists()) {
    alpha *= (alphaMod.numAttr('val') ?? 100000) / 100000
  }

  const alphaOff = blip.child('alphaOff')
  if (alphaOff.exists()) {
    alpha += (alphaOff.numAttr('val') ?? 0) / 100000
  }

  return Math.max(0, Math.min(1, alpha))
}

/**
 * Render a video element inside the wrapper.