[Closed] Modifying the Gamma Of A Bitmap

May 13, 2014 6:52 pm

So I’ve written a little test scrip here:

rollout ui_imgtag "imgtag"
(
local bm = openbitmap "E:\\personal\\1.jpg"
local nbm = bitmap 600 600 color:white gamma:2.2
copy bm nbm
imgtag img_tag "imgtag" bitmap:nbm
)
createdialog ui_imgtag width:1000

If I try and run this, I get an error:

– Compile error: control already defined: bm
– In line: copy bm n

I am trying to copy the bitmap in bm into the gamma modified bitmap nbm, but copy doesn’t seem to be working.

Also, if I change these two variable from local, I get a different error. Which is confusing, since they should work whether they’re local or not.

Anyone know what may be going on here?

Neil

5 Replies

spacefrog

May 13, 2014 6:52 pm

placing the bitmap assignment into an “on <rollout> open” handler works

rollout ui_imgtag "imgtag" 
( 
	local bm
	local nbm
	
	on ui_imgtag open do
	(
		bm= openbitmap "E:\\personal\\1.jpg"
		nbm = bitmap 600 600 color:white gamma:2.2 
		
		copy bm nbm 
	
		imgtag img_tag "imgtag" bitmap:nbm 
	)		
) 	
createdialog ui_imgtag width:1000

ArtOfSoulburn

May 13, 2014 6:52 pm

Oh stupid me, of course I’m running code in a rollout. No wonder it was failing. So here’s a revision:

global bm = openbitmap "E:\\personal\\1.jpg"
global nbm = bitmap 600 600 gamma:2.2
copy bm nbm
rollout ui_imgtag "imgtag"
(
imgtag img_tag "imgtag" bitmap:nbm transparent:(color 257 257 257)
)
createdialog ui_imgtag width:1000

However, it still doesn’t do what I need, which is modifies the gamma of the original bitmap. Maxscript helps says:

It is not possible to change the gamma or pixel aspect of a bitmap once created, though you can copy one bitmap into a newly created one that has a different gamma or pixel aspect to achieve this effect.

But changing the gamma value of the second bitmap doesn’t seem to change the pixel values of the loaded bitmap. Any idea what I might be doing wrong?

Neil

wallworm

May 13, 2014 6:52 pm

Here Neil,

rollout ui_imgtag "imgtag" width:600 height:600
(
local bm , nbm
	ImgTag img_tag "imgtag" pos:[12,46] width:136 height:14 bitmap:nbm
	on ui_imgtag open do
	(
			
			local bm = openbitmap "E:\\personal\\1.jpg"
			local nbm = bitmap (bm.width) (bm.height) color:white gamma:2.2
			
			pasteBitmap bm nbm [0,0] [0,0]
			img_tag.bitmap = nbm
			img_tag.height = nbm.height
			img_tag.width = nbm.width
			ui_imgtag.height = nbm.height
			ui_imgtag.width = nbm.width
		
		)
)
createdialog ui_imgtag width:1000