[Known Issue] Target Buffer Specification for StackViewport

[sedghi]

CSWIL has been recently equipped with an option to scale the array given the scaling parameters. It also can accept a targetBuffer to store the pixelData in the specified typedArray constructor name (Float32Array, Uint8Array etc).

Here are the problems:

1. Memory inefficiency: Right now we are putting every thing regardless of the bitsAllocation into a Float32Array. The reason is scaling, since we are scaling PT series which will end up with float pixelData.

Potential Solution:
CSWIL should have a mechanism to compute the proper typed Array for the given pixelData, intercept, slop. It would be something like:

function getMinMaxAfterScaling(minValue, maxValue, slope, intercept, scalingParam){
  const minValueAfterScale = minValue * slope + intercept 
  const maxValueAfterScale = maxValue * slope + intercept 

  if (scalingParam){
    minValueAfterScale *= scalingParam
    maxValueAfterScale *= scalingParam
  }
}

Then we need a function to reason about the minValueAfterScale (MVAS) and maxValueAfterScale(MXVAS), something like

function getTypedArrayConstructor(MVAS, MXVAS){

  if (MVAS>0 && MXVAS<255 && isInteger(MVAS)) return Uint8Array
  If (MVAS < 0 && MVAS > -128 && MXVAS < 127 && isInteger(MVAS)) return Int8Array
  If (isFloat) return Float32Array
  ...

Notes:

• Volume Loaders should still specify their targetBuffer since we use SharedArrayBuffer and fill it by pointers.
• IsInteger and IsFloat should be written in a way that 1.0 be a float, and not integer (maybe we need to take into account the floatness of slope and intercept and scalingParams too?)