code review 4515045: image/gif: implement transparency.

image/gif: implement transparency.

At least, as I understand it. The spec is unclear about what happens
with a local color map.

[r, 2011-05-08 16:49:27]

Hello nigeltao (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[nigeltao, 2011-05-08 23:10:11]

lgtm.

maybe make transparentIndex an argument to func setTransparency instead of a
field of struct decoder.

(sent from xoom, can't double-click without zooming so no inline comments.)

[r2, 2011-05-09 00:16:47]

On May 8, 2011, at 4:10 PM, nigeltao@golang.org wrote:

> lgtm.
> 
> maybe make transparentIndex an argument to func setTransparency instead
> of a field of struct decoder.

it needs to be a field anyway because it's set in graphic control but used later
in image decoding.

-rob

[r2, 2011-05-09 00:25:06]

i mean, if you use it for the local color map too, about which i am unsure.

-rob

[r, 2011-05-09 00:26:20]

*** Submitted as http://code.google.com/p/go/source/detail?r=d454f1d43ab0 ***

image/gif: implement transparency.

At least, as I understand it. The spec is unclear about what happens
with a local color map.

R=nigeltao, r2
CC=golang-dev
http://codereview.appspot.com/4515045

[peterGo, 2011-05-09 11:34:33]

Rob,

linux, 386 and amd64, hg id d454f1d43ab0 tip.
$ ./all.bash

test image
TEST FAIL image
make[1]: Entering directory `/home/peter/go/src/pkg/image'
gotest -test.short -test.timeout=120
rm -f _test/image.a
8g  -o _gotest_.8 color.go format.go geom.go image.go names.go  
rm -f _test/image.a
gopack grc _test/image.a _gotest_.8 
--- FAIL: image_test.TestDecode (0.13 seconds)
	testdata/video-001.gif: at (117, 43), want {1 0 0 255} got {0 0 0 0}
FAIL
gotest: "./8.out -test.short=true -test.timeout=120" failed: exit status 1
make[1]: *** [testshort] Error 2
make[1]: Leaving directory `/home/peter/go/src/pkg/image'
make: *** [image.testshort] Error 1

Peter

On 2011/05/09 00:26:20, r wrote:
> *** Submitted as http://code.google.com/p/go/source/detail?r=d454f1d43ab0 ***
> 
> image/gif: implement transparency.