Commit Graph

2 Commits

Author SHA1 Message Date
Nigel Tao
306b829431 draw: alias the standard library's image/draw's exported types.
This relies on type aliases, a language feature new in Go 1.9.

The package documentation, in draw.go, explicitly gives the intent of
this package:

    This package is a superset of and a drop-in replacement for the
    image/draw package in the standard library.

Drop-in replacement means that I can replace all of my "image/draw"
imports with "golang.org/x/image/draw", to access additional features in
this package, and no further changes are required. That's mostly true,
but not completely true unless we use type aliases.

Without type aliases, users might need to import both "image/draw" and
"golang.org/x/image/draw" in order to convert from two conceptually
equivalent but different (from the compiler's point of view) types, such
as from one draw.Op type to another draw.Op type, to satisfy some other
interface or function signature.

Change-Id: Ice6d000d49b019c2d8761739a904232e9cd01cae
Reviewed-on: https://go-review.googlesource.com/36730
Run-TryBot: Nigel Tao <nigeltao@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2017-02-15 00:37:23 +00:00
Nigel Tao
96b77d5c7a draw: new package, a superset of the standard library's image/draw
package, including the ability to scale an image.

Design discussion:
https://groups.google.com/forum/#!topic/golang-dev/B7-OrWdheic

Previous code review (when Go used hg instead of git):
https://codereview.appspot.com/101670045

New benchmarks:
BenchmarkScaleLargeDownNN	     300	   5935174 ns/op
BenchmarkScaleLargeDownAB	     100	  14482372 ns/op
BenchmarkScaleLargeDownBL	       1	1383805986 ns/op
BenchmarkScaleLargeDownCR	       1	2724631789 ns/op
BenchmarkScaleDownNN     	    1000	   1850500 ns/op
BenchmarkScaleDownAB     	     300	   4413499 ns/op
BenchmarkScaleDownBL     	      50	  30498748 ns/op
BenchmarkScaleDownCR     	      20	  58349653 ns/op
BenchmarkScaleUpNN       	      20	  92306475 ns/op
BenchmarkScaleUpAB       	       5	 220103753 ns/op
BenchmarkScaleUpBL       	      10	 122635195 ns/op
BenchmarkScaleUpCR       	      10	 183275927 ns/op

Change-Id: I69d397e68897bae024c7b330a9375fa3e7688591
Reviewed-on: https://go-review.googlesource.com/4210
Reviewed-by: Rob Pike <r@golang.org>
2015-02-17 23:20:02 +00:00