Merge pull request #77 from yangwenmai/improve_adjust_apply

feat: improve adjust apply
anthonynsimon · Feb 4, 2020 · c7da305 · c7da305
2 parents 05cf37d + bb01dfa
commit c7da305
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Showing 2 changed files with 31 additions and 8 deletions.
diff --git a/adjust/apply.go b/adjust/apply.go
@@ -21,17 +21,22 @@ func Apply(img image.Image, fn func(color.RGBA) color.RGBA) *image.RGBA {
 
 				c := color.RGBA{}
 
-				c.R = dst.Pix[dstPos+0]
-				c.G = dst.Pix[dstPos+1]
-				c.B = dst.Pix[dstPos+2]
-				c.A = dst.Pix[dstPos+3]
+				dr := &dst.Pix[dstPos+0]
+				dg := &dst.Pix[dstPos+1]
+				db := &dst.Pix[dstPos+2]
+				da := &dst.Pix[dstPos+3]
+
+				c.R = *dr
+				c.G = *dg
+				c.B = *db
+				c.A = *da
 
 				c = fn(c)
 
-				dst.Pix[dstPos+0] = c.R
-				dst.Pix[dstPos+1] = c.G
-				dst.Pix[dstPos+2] = c.B
-				dst.Pix[dstPos+3] = c.A
+				*dr = c.R
+				*dg = c.G
+				*db = c.B
+				*da = c.A
 			}
 		}
 	})

diff --git a/adjust/apply_test.go b/adjust/apply_test.go
@@ -111,3 +111,21 @@ func TestClampFloat64(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkApply(b *testing.B) {
+	val := &image.RGBA{
+		Rect:   image.Rect(0, 0, 2, 2),
+		Stride: 2 * 4,
+		Pix: []uint8{
+			0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+			0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		},
+	}
+	fn := func(c color.RGBA) color.RGBA {
+		return color.RGBA{c.R - 64, c.G - 64, c.B - 64, c.A - 64}
+	}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Apply(val, fn)
+	}
+}