Imported Upstream version 4.8.1

[platform/upstream/gcc48.git] / libgo / go / image / draw / draw.go

diff --git a/libgo/go/image/draw/draw.go b/libgo/go/image/draw/draw.go
index bef325c..56d30dd 100644 (file)
--- a/libgo/go/image/draw/draw.go
+++ b/libgo/go/image/draw/draw.go
@@ -81,8 +81,9 @@ func DrawMask(dst Image, r image.Rectangle, src image.Image, sp image.Point, mas
                                        drawNRGBAOver(dst0, r, src0, sp)
                                        return
                                case *image.YCbCr:
-                                       drawYCbCr(dst0, r, src0, sp)
-                                       return
+                                       if drawYCbCr(dst0, r, src0, sp) {
+                                               return
+                                       }
                                }
                        } else if mask0, ok := mask.(*image.Alpha); ok {
                                switch src0 := src.(type) {
@@ -104,8 +105,9 @@ func DrawMask(dst Image, r image.Rectangle, src image.Image, sp image.Point, mas
                                        drawNRGBASrc(dst0, r, src0, sp)
                                        return
                                case *image.YCbCr:
-                                       drawYCbCr(dst0, r, src0, sp)
-                                       return
+                                       if drawYCbCr(dst0, r, src0, sp) {
+                                               return
+                                       }
                                }
                        }
                }
@@ -345,7 +347,7 @@ func drawNRGBASrc(dst *image.RGBA, r image.Rectangle, src *image.NRGBA, sp image
        }
 }
 
-func drawYCbCr(dst *image.RGBA, r image.Rectangle, src *image.YCbCr, sp image.Point) {
+func drawYCbCr(dst *image.RGBA, r image.Rectangle, src *image.YCbCr, sp image.Point) (ok bool) {
        // An image.YCbCr is always fully opaque, and so if the mask is implicitly nil
        // (i.e. fully opaque) then the op is effectively always Src.
        x0 := (r.Min.X - dst.Rect.Min.X) * 4
@@ -353,6 +355,19 @@ func drawYCbCr(dst *image.RGBA, r image.Rectangle, src *image.YCbCr, sp image.Po
        y0 := r.Min.Y - dst.Rect.Min.Y
        y1 := r.Max.Y - dst.Rect.Min.Y
        switch src.SubsampleRatio {
+       case image.YCbCrSubsampleRatio444:
+               for y, sy := y0, sp.Y; y != y1; y, sy = y+1, sy+1 {
+                       dpix := dst.Pix[y*dst.Stride:]
+                       yi := (sy-src.Rect.Min.Y)*src.YStride + (sp.X - src.Rect.Min.X)
+                       ci := (sy-src.Rect.Min.Y)*src.CStride + (sp.X - src.Rect.Min.X)
+                       for x := x0; x != x1; x, yi, ci = x+4, yi+1, ci+1 {
+                               rr, gg, bb := color.YCbCrToRGB(src.Y[yi], src.Cb[ci], src.Cr[ci])
+                               dpix[x+0] = rr
+                               dpix[x+1] = gg
+                               dpix[x+2] = bb
+                               dpix[x+3] = 255
+                       }
+               }
        case image.YCbCrSubsampleRatio422:
                for y, sy := y0, sp.Y; y != y1; y, sy = y+1, sy+1 {
                        dpix := dst.Pix[y*dst.Stride:]
@@ -381,12 +396,11 @@ func drawYCbCr(dst *image.RGBA, r image.Rectangle, src *image.YCbCr, sp image.Po
                                dpix[x+3] = 255
                        }
                }
-       default:
-               // Default to 4:4:4 subsampling.
+       case image.YCbCrSubsampleRatio440:
                for y, sy := y0, sp.Y; y != y1; y, sy = y+1, sy+1 {
                        dpix := dst.Pix[y*dst.Stride:]
                        yi := (sy-src.Rect.Min.Y)*src.YStride + (sp.X - src.Rect.Min.X)
-                       ci := (sy-src.Rect.Min.Y)*src.CStride + (sp.X - src.Rect.Min.X)
+                       ci := (sy/2-src.Rect.Min.Y/2)*src.CStride + (sp.X - src.Rect.Min.X)
                        for x := x0; x != x1; x, yi, ci = x+4, yi+1, ci+1 {
                                rr, gg, bb := color.YCbCrToRGB(src.Y[yi], src.Cb[ci], src.Cr[ci])
                                dpix[x+0] = rr
@@ -395,7 +409,10 @@ func drawYCbCr(dst *image.RGBA, r image.Rectangle, src *image.YCbCr, sp image.Po
                                dpix[x+3] = 255
                        }
                }
+       default:
+               return false
        }
+       return true
 }
 
 func drawGlyphOver(dst *image.RGBA, r image.Rectangle, src *image.Uniform, mask *image.Alpha, mp image.Point) {