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author | Nigel Tao <nigeltao@golang.org> | 2010-05-24 19:32:42 -0700 |
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committer | Nigel Tao <nigeltao@golang.org> | 2010-05-24 19:32:42 -0700 |
commit | 0c662f60a5ef82a92b7bea26788a14f74b12fb52 (patch) | |
tree | 85b56fc8ffca98cf03a46e25f6f54b2b79094c9a | |
parent | 6a060200ccf2f3bb9cc5cf1df84ab1da1f5c3f31 (diff) | |
download | go-0c662f60a5ef82a92b7bea26788a14f74b12fb52.tar.gz go-0c662f60a5ef82a92b7bea26788a14f74b12fb52.zip |
Optimize exp/draw/x11 flusher inner loop.
On my laptop, time to prepare and write 800x600 pixels over the
socket falls from 125-ish ms to 80-ish ms.
Thanks to Roger Peppe for the suggestion.
R=r
CC=golang-dev
https://golang.org/cl/1228044
-rw-r--r-- | src/pkg/exp/draw/x11/conn.go | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/pkg/exp/draw/x11/conn.go b/src/pkg/exp/draw/x11/conn.go index f1a3dca1c6..3579a24c38 100644 --- a/src/pkg/exp/draw/x11/conn.go +++ b/src/pkg/exp/draw/x11/conn.go @@ -91,18 +91,18 @@ func (c *conn) flusher() { close(c.flush) return } + p := c.img.Pixel[y] for x := 0; x < w; { nx := w - x if nx > len(c.flushBuf1)/4 { nx = len(c.flushBuf1) / 4 } - for i := 0; i < nx; i++ { - r, g, b, _ := c.img.At(x, y).RGBA() - c.flushBuf1[4*i+0] = uint8(b >> 24) - c.flushBuf1[4*i+1] = uint8(g >> 24) - c.flushBuf1[4*i+2] = uint8(r >> 24) - x++ + for i, rgba := range p[x : x+nx] { + c.flushBuf1[4*i+0] = rgba.B + c.flushBuf1[4*i+1] = rgba.G + c.flushBuf1[4*i+2] = rgba.R } + x += nx _, err := c.w.Write(c.flushBuf1[0 : 4*nx]) if err != nil { close(c.flush) |