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path: root/src/pkg/exp/draw/draw.go
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Diffstat (limited to 'src/pkg/exp/draw/draw.go')
-rw-r--r--src/pkg/exp/draw/draw.go96
1 files changed, 48 insertions, 48 deletions
diff --git a/src/pkg/exp/draw/draw.go b/src/pkg/exp/draw/draw.go
index d01cdcc16..59adf1f6a 100644
--- a/src/pkg/exp/draw/draw.go
+++ b/src/pkg/exp/draw/draw.go
@@ -14,8 +14,8 @@ import "image"
// A draw.Image is an image.Image with a Set method to change a single pixel.
type Image interface {
- image.Image;
- Set(x, y int, c image.Color);
+ image.Image
+ Set(x, y int, c image.Color)
}
// Draw aligns r.Min in dst with pt in src and mask
@@ -27,7 +27,7 @@ type Image interface {
func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
// Plenty of room for optimizations here.
- dx, dy := src.Width(), src.Height();
+ dx, dy := src.Width(), src.Height()
if mask != nil {
if dx > mask.Width() {
dx = mask.Width()
@@ -36,8 +36,8 @@ func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
dy = mask.Width()
}
}
- dx -= pt.X;
- dy -= pt.Y;
+ dx -= pt.X
+ dy -= pt.Y
if r.Dx() > dx {
r.Max.X = r.Min.X + dx
}
@@ -45,57 +45,57 @@ func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
r.Max.Y = r.Min.Y + dy
}
- x0, x1, dx := r.Min.X, r.Max.X, 1;
- y0, y1, dy := r.Min.Y, r.Max.Y, 1;
+ x0, x1, dx := r.Min.X, r.Max.X, 1
+ y0, y1, dy := r.Min.Y, r.Max.Y, 1
if image.Image(dst) == src && r.Overlaps(r.Add(pt.Sub(r.Min))) {
// Rectangles overlap: process backward?
if pt.Y < r.Min.Y || pt.Y == r.Min.Y && pt.X < r.Min.X {
- x0, x1, dx = x1-1, x0-1, -1;
- y0, y1, dy = y1-1, y0-1, -1;
+ x0, x1, dx = x1-1, x0-1, -1
+ y0, y1, dy = y1-1, y0-1, -1
}
}
- var out *image.RGBA64Color;
+ var out *image.RGBA64Color
for y := y0; y != y1; y += dy {
for x := x0; x != x1; x += dx {
- sx := pt.X + x - r.Min.X;
- sy := pt.Y + y - r.Min.Y;
+ sx := pt.X + x - r.Min.X
+ sy := pt.Y + y - r.Min.Y
if mask == nil {
- dst.Set(x, y, src.At(sx, sy));
- continue;
+ dst.Set(x, y, src.At(sx, sy))
+ continue
}
- _, _, _, ma := mask.At(sx, sy).RGBA();
+ _, _, _, ma := mask.At(sx, sy).RGBA()
switch ma {
case 0:
continue
case 0xFFFFFFFF:
dst.Set(x, y, src.At(sx, sy))
default:
- dr, dg, db, da := dst.At(x, y).RGBA();
- dr >>= 16;
- dg >>= 16;
- db >>= 16;
- da >>= 16;
- sr, sg, sb, sa := src.At(sx, sy).RGBA();
- sr >>= 16;
- sg >>= 16;
- sb >>= 16;
- sa >>= 16;
- ma >>= 16;
- const M = 1<<16 - 1;
- a := sa * ma / M;
- dr = (dr*(M-a) + sr*ma) / M;
- dg = (dg*(M-a) + sg*ma) / M;
- db = (db*(M-a) + sb*ma) / M;
- da = (da*(M-a) + sa*ma) / M;
+ dr, dg, db, da := dst.At(x, y).RGBA()
+ dr >>= 16
+ dg >>= 16
+ db >>= 16
+ da >>= 16
+ sr, sg, sb, sa := src.At(sx, sy).RGBA()
+ sr >>= 16
+ sg >>= 16
+ sb >>= 16
+ sa >>= 16
+ ma >>= 16
+ const M = 1<<16 - 1
+ a := sa * ma / M
+ dr = (dr*(M-a) + sr*ma) / M
+ dg = (dg*(M-a) + sg*ma) / M
+ db = (db*(M-a) + sb*ma) / M
+ da = (da*(M-a) + sa*ma) / M
if out == nil {
out = new(image.RGBA64Color)
}
- out.R = uint16(dr);
- out.G = uint16(dg);
- out.B = uint16(db);
- out.A = uint16(da);
- dst.Set(x, y, out);
+ out.R = uint16(dr)
+ out.G = uint16(dg)
+ out.B = uint16(db)
+ out.A = uint16(da)
+ dst.Set(x, y, out)
}
}
}
@@ -106,20 +106,20 @@ func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
// operation ``src over dst.'' If w is positive, the border extends w pixels inside r.
// If w is negative, the border extends w pixels outside r.
func Border(dst Image, r Rectangle, w int, src image.Image, sp Point) {
- i := w;
+ i := w
if i > 0 {
// inside r
- Draw(dst, Rect(r.Min.X, r.Min.Y, r.Max.X, r.Min.Y+i), src, nil, sp); // top
- Draw(dst, Rect(r.Min.X, r.Min.Y+i, r.Min.X+i, r.Max.Y-i), src, nil, sp.Add(Pt(0, i))); // left
- Draw(dst, Rect(r.Max.X-i, r.Min.Y+i, r.Max.X, r.Max.Y-i), src, nil, sp.Add(Pt(r.Dx()-i, i))); // right
- Draw(dst, Rect(r.Min.X, r.Max.Y-i, r.Max.X, r.Max.Y), src, nil, sp.Add(Pt(0, r.Dy()-i))); // bottom
- return;
+ Draw(dst, Rect(r.Min.X, r.Min.Y, r.Max.X, r.Min.Y+i), src, nil, sp) // top
+ Draw(dst, Rect(r.Min.X, r.Min.Y+i, r.Min.X+i, r.Max.Y-i), src, nil, sp.Add(Pt(0, i))) // left
+ Draw(dst, Rect(r.Max.X-i, r.Min.Y+i, r.Max.X, r.Max.Y-i), src, nil, sp.Add(Pt(r.Dx()-i, i))) // right
+ Draw(dst, Rect(r.Min.X, r.Max.Y-i, r.Max.X, r.Max.Y), src, nil, sp.Add(Pt(0, r.Dy()-i))) // bottom
+ return
}
// outside r;
- i = -i;
- Draw(dst, Rect(r.Min.X-i, r.Min.Y-i, r.Max.X+i, r.Min.Y), src, nil, sp.Add(Pt(-i, -i))); // top
- Draw(dst, Rect(r.Min.X-i, r.Min.Y, r.Min.X, r.Max.Y), src, nil, sp.Add(Pt(-i, 0))); // left
- Draw(dst, Rect(r.Max.X, r.Min.Y, r.Max.X+i, r.Max.Y), src, nil, sp.Add(Pt(r.Dx(), 0))); // right
- Draw(dst, Rect(r.Min.X-i, r.Max.Y, r.Max.X+i, r.Max.Y+i), src, nil, sp.Add(Pt(-i, 0))); // bottom
+ i = -i
+ Draw(dst, Rect(r.Min.X-i, r.Min.Y-i, r.Max.X+i, r.Min.Y), src, nil, sp.Add(Pt(-i, -i))) // top
+ Draw(dst, Rect(r.Min.X-i, r.Min.Y, r.Min.X, r.Max.Y), src, nil, sp.Add(Pt(-i, 0))) // left
+ Draw(dst, Rect(r.Max.X, r.Min.Y, r.Max.X+i, r.Max.Y), src, nil, sp.Add(Pt(r.Dx(), 0))) // right
+ Draw(dst, Rect(r.Min.X-i, r.Max.Y, r.Max.X+i, r.Max.Y+i), src, nil, sp.Add(Pt(-i, 0))) // bottom
}