Drawing from camera

[shaunlebron]

current plan to redo #38 with correct transformation

User-facing:

• program must request the most recent camera image from main thread:
  • const camera = await paper.get('camera')
• program can draw image regions from the camera onto the supporter canvas:
  • drawFromCamera(supporterCtx, camera, srcPoints, dstPoints)
• program can use existing points property on each paper to retrieve/draw images over them:
  • drawFromCamera(supporterCtx, camera, otherPaper.points, myPaper.points)

Internal:

• camera image
  • in order to pass an image via postMessage, we may have to render video element to a canvas first
  • render an image from video element at most once per frame if any programs are requesting 'camera', then send the image to each.
• drawFromCamera utility function in paper.js
  • points format should either be an array of four or three points, or {topLeft,topRight,bottomLeft,bottomRight}
  • should project the srcPoints using forwardProjectionMatrixForPoints(config.knobPoints) to convert our canvas coords to camera coords.
  • will need to check the texture mapping code here to see if we need to perform a similar operation for dstPoints

[janpaul123]

Done in #54 (also see #38 and #44).