We could undoubtedly squeeze even more out of these loops, and in the
long term, a better compiler would be smarter with bounds checks, but in
the short term, this small change is an easy win.
benchmark old ns/op new ns/op delta
BenchmarkFillOver-8 1619470 1323192 -18.29%
BenchmarkCopyOver-8 1129369 1062787 -5.90%
BenchmarkGlyphOver-8 420070 378608 -9.87%
On github.com/golang/freetype/truetype's BenchmarkDrawString:
benchmark old ns/op new ns/op delta
BenchmarkDrawString-8 9561435 8807019 -7.89%
Change-Id: Ib1c6271ac18bced85e0fb5ebf250dd57d7747e75
Reviewed-on: https://go-review.googlesource.com/14093
Reviewed-by: Rob Pike <r@golang.org>
Before, calling the RGBA method of YCbCr color would return red values
in the range [0x0080, 0xff80]. After, the range is [0x0000, 0xffff] and
is consistent with what Gray colors' RGBA method returns. In particular,
pure black, pure white and every Gray color in between are now exactly
representable as a YCbCr color.
This fixes a regression from Go 1.4 (where YCbCr{0x00, 0x80, 0x80} was
no longer equivalent to pure black), introduced by golang.org/cl/8073 in
the Go 1.5 development cycle. In Go 1.4, the +0x80 rounding was not
noticable when Cb == 0x80 && Cr == 0x80, because the YCbCr to RGBA
conversion truncated to 8 bits before multiplying by 0x101, so the
output range was [0x0000, 0xffff].
The TestYCbCrRoundtrip fuzzy-match tolerance grows from 1 to 2 because
the YCbCr to RGB conversion now maps to an ever-so-slightly larger
range, along with the usual imprecision of accumulating rounding errors.
Also s/int/int32/ in ycbcr.go. The conversion shouldn't overflow either
way, as int is always at least 32 bits, but it does make it clearer that
the computation doesn't depend on sizeof(int).
Fixes#11691
Change-Id: I538ca0adf7e040fa96c5bc8b3aef4454535126b9
Reviewed-on: https://go-review.googlesource.com/12220
Reviewed-by: Rob Pike <r@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
The second (fallback) draw is a no-op, but it's a non-trivial amount of work.
Fixes#11550.
benchmark old ns/op new ns/op delta
BenchmarkPaletted-4 16301219 7309568 -55.16%
Change-Id: Ic88c537b2b0c710cf517888f3dd15cb702dd142f
Reviewed-on: https://go-review.googlesource.com/11858
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The imageutil.DrawYCbCr function lives in an internal package because it
is needed by both the image/draw and image/jpeg packages, but it doesn't
seem right for one of those two to depend on the other.
It could eventually go into the image package, but that would require
committing to an API for the rest of Go 1.x.
Change-Id: I7b12555c970d86409365e99eef9360702aaffa30
Reviewed-on: https://go-review.googlesource.com/7925
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Grayscale PNG and JPEG images are not uncommon. We should have a fast path.
Also add a benchmark for the recently added CMYK fast path.
benchmark old ns/op new ns/op delta
BenchmarkGray 13960348 324152 -97.68%
Change-Id: I72b5838c8c3d1f2d0a4536a848e020e80b10c0f7
Reviewed-on: https://go-review.googlesource.com/6237
Reviewed-by: Rob Pike <r@golang.org>
This just adds test cases. Optimizing CMYK draws will be a follow-up
change.
Change-Id: Ic0d6343d420cd021e21f88623ad7182e93017da9
Reviewed-on: https://go-review.googlesource.com/4941
Reviewed-by: Rob Pike <r@golang.org>
https://go-review.googlesource.com/#/c/1876/ introduced a new
TestClipWithNilMP test, along with a code change that fixed a panic,
but the existing TestClip test already contained almost enough machinery
to cover that bug.
There is a small code change in this CL, but it is a no-op: (*x).y is
equivalent to x.y for a pointer-typed x, but the latter is cleaner.
Change-Id: I79cf6952a4999bc4b91f0a8ec500acb108106e56
Reviewed-on: https://go-review.googlesource.com/2304
Reviewed-by: Dave Cheney <dave@cheney.net>
