[LDCad] Simple LDCad script

[N. W. Perry]

So, I wrote my first script for LDCad, hooray!

It is a simple macro to transpose two colors in a selection. You might use it if you have built a huge checkered floor out of tiles and realized you have the pattern backwards!

I'm sure there are ways to improve it, but I'm actually pleased I was able to work it out in one day.

Here it is:

Code:

genTools=require('genTools')

function runColorSwap()

  local ses=ldc.session()
  local sel=ses:getSelection()
  local cnt=sel:getRefCount()
 
  if not ses:isLinked() then
    ldc.dialog.runMessage('No active model.')
    return
  end

  if cnt==0 then
    ldc.dialog.runMessage('No selection active.')
    return
  elseif cnt<2 then
    ldc.dialog.runMessage('At least two items must be selected.')
    return
  end

  local colors={}
 
  local function has_value (tab, val)
    for k, v in ipairs(tab) do
        if v == val then
            return true
        end
    end

    return false
  end

  for i=1,cnt do
    local ref=sel:getRef(i)
    local col=ref:getColor()
    if not has_value(colors, col) then
      table.insert(colors, col)
    end
  end

  if #colors==2 then
    for i=1,cnt do
      local ref=sel:getRef(i)
      local col=ref:getColor()
      if col==colors[1] then
        ref:setColor(colors[2])
      elseif col==colors[2] then
        ref:setColor(colors[1])
      end
    end
  else ldc.dialog.runMessage('The selection must contain exactly two colors.')
  end
end
--===================

function register()

  local macro=ldc.macro('Color swap')
  macro:setHint('Transposes two colors in a selection.')
  macro:setEvent('run', 'runColorSwap')
end

register()

Suggestions are welcome!

[Roland Melkert]

So, I wrote my first script for LDCad, hooray!

Congratulations, be careful though it can be addictive

Minor potential bug:

Code:

local cnt=sel:getRefCount()

will cause a runtime error when no model is open, easily fixed by moving the line (and the one above it) below the ses:isLinked() test.

[N. W. Perry]

Minor potential bug:

Code:

local cnt=sel:getRefCount()

will cause a runtime error when no model is open, easily fixed by moving the line (and the one above it) below the ses:isLinked() test.

Fixed. Couldn't I also move the local variables col and ref up higher somewhere, so I don't have to repeat them?

My next attempt will be a macro to comment out BUFEXCHG lines. I think I know how to identify the affected ref lines, now to learn how to actually alter them. :-)

[Roland Melkert]

Couldn't I also move the local variables col and ref up higher somewhere, so I don't have to repeat them?

Yes, just write them without the value assignment.

My next attempt will be a macro to comment out BUFEXCHG lines. I think I know how to identify the affected ref lines, now to learn how to actually alter them. :-)

scripts can't actually modify lines on a string level (mostly because of the undo tracking), but you get the same effect by creating a new line and deleting the old one.

For an example of this see the global mlcad.lua script.

[N. W. Perry]

Yes, just write them without the value assignment.

I couldn't get them to work except inside the loops themselves (which meant I had to declare them in both loops). But the cnt variable does, for some reason.

scripts can't actually modify lines on a string level (mostly because of the undo tracking), but you get the same effect by creating a new line and deleting the old one.

For an example of this see the global mlcad.lua script.

Yes, I'll be studying that one tonight. :-)

[Yx Wang]

Is there any auto-save script available?

[Roland Melkert]

Is there any auto-save script available?

It is possible to save the current file with script, but currently there is no way to do this at a set time interval.

[HWQ]

It is possible to save the current file with script, but currently there is no way to do this at a set time interval.

Why can't we add a function to automatically save backups at intervals through scripts?

[Roland Melkert]

Why can't we add a function to automatically save backups at intervals through scripts?

The current scripting environment is not designed for this. 

The one in 2.0 will have a much deeper integration with the internals which should make these kinds of thins naturally available.

Not sure if the 2.0 scripting language will be lua though, I'm also researching embedded JavaScript for this.