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Commit 4e2035bd authored by Nigel Tao's avatar Nigel Tao
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In draw.Draw, separate the source-point and mask-point. 

This lets you draw text (i.e. with mask = a font image) with
sources that aren't uniform colors.

R=r, rsc
CC=golang-dev
https://golang.org/cl/193067
parent f2317d3e
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Inline Side-by-side
Showing with 66 additions and 56 deletions
src/pkg/exp/4s/xs.go
View file @ 4e2035bd
......@@ -226,8 +226,8 @@ func collider(pt, pmax draw.Point) bool {
}
func setpiece(p *Piece) {
draw.Draw(bb, bbr, draw.White, nil, draw.ZP)
draw.Draw(bbmask, bbr, draw.Transparent, nil, draw.ZP)
draw.Draw(bb, bbr, draw.White, draw.ZP)
draw.Draw(bbmask, bbr, draw.Transparent, draw.ZP)
br = draw.Rect(0, 0, 0, 0)
br2 = br
piece = p
......@@ -243,13 +243,13 @@ func setpiece(p *Piece) {
r.Max.X = r.Min.X + pcsz
r.Max.Y = r.Min.Y + pcsz
if i == 0 {
draw.Draw(bb, r, draw.Black, nil, draw.ZP)
draw.Draw(bb, r.Inset(1), txpix[piece.tx], nil, draw.ZP)
draw.Draw(bbmask, r, draw.Opaque, nil, draw.ZP)
draw.Draw(bb, r, draw.Black, draw.ZP)
draw.Draw(bb, r.Inset(1), txpix[piece.tx], draw.ZP)
draw.Draw(bbmask, r, draw.Opaque, draw.ZP)
op = r.Min
} else {
draw.Draw(bb, r, bb, nil, op)
draw.Draw(bbmask, r, bbmask, nil, op)
draw.Draw(bb, r, bb, op)
draw.Draw(bbmask, r, bbmask, op)
}
if br.Max.X < r.Max.X {
br.Max.X = r.Max.X
......@@ -263,17 +263,17 @@ func setpiece(p *Piece) {
br2.Max = br.Max.Add(delta)
r = br.Add(bb2r.Min)
r2 := br2.Add(bb2r.Min)
draw.Draw(bb2, r2, draw.White, nil, draw.ZP)
draw.Draw(bb2, r.Add(delta), bb, nil, bbr.Min)
draw.Draw(bb2mask, r2, draw.Transparent, nil, draw.ZP)
draw.Draw(bb2mask, r, draw.Opaque, bbmask, bbr.Min)
draw.Draw(bb2mask, r.Add(delta), draw.Opaque, bbmask, bbr.Min)
draw.Draw(bb2, r2, draw.White, draw.ZP)
draw.Draw(bb2, r.Add(delta), bb, bbr.Min)
draw.Draw(bb2mask, r2, draw.Transparent, draw.ZP)
draw.DrawMask(bb2mask, r, draw.Opaque, bbr.Min, bbmask, draw.ZP, draw.SoverD)
draw.DrawMask(bb2mask, r.Add(delta), draw.Opaque, bbr.Min, bbmask, draw.ZP, draw.SoverD)
}
func drawpiece() {
draw.Draw(screen, br.Add(pos), bb, bbmask, bbr.Min)
draw.DrawMask(screen, br.Add(pos), bb, bbr.Min, bbmask, draw.ZP, draw.SoverD)
if suspended {
draw.Draw(screen, br.Add(pos), draw.White, whitemask, draw.ZP)
draw.DrawMask(screen, br.Add(pos), draw.White, draw.ZP, whitemask, draw.ZP, draw.SoverD)
}
}
......@@ -282,7 +282,7 @@ func undrawpiece() {
if collider(pos, br.Max) {
mask = bbmask
}
draw.Draw(screen, br.Add(pos), draw.White, mask, bbr.Min)
draw.DrawMask(screen, br.Add(pos), draw.White, bbr.Min, mask, bbr.Min, draw.SoverD)
}
func rest() {
......@@ -323,7 +323,7 @@ func canfit(p *Piece) bool {
func score(p int) {
points += p
// snprint(buf, sizeof(buf), "%.6ld", points);
// draw.Draw(screen, draw.Rpt(pscore, pscore.Add(scoresz)), draw.White, nil, draw.ZP);
// draw.Draw(screen, draw.Rpt(pscore, pscore.Add(scoresz)), draw.White, draw.ZP);
// string(screen, pscore, draw.Black, draw.ZP, font, buf);
}
......@@ -332,14 +332,14 @@ func drawsq(b draw.Image, p draw.Point, ptx int) {
r.Min = p
r.Max.X = r.Min.X + pcsz
r.Max.Y = r.Min.Y + pcsz
draw.Draw(b, r, draw.Black, nil, draw.ZP)
draw.Draw(b, r.Inset(1), txpix[ptx], nil, draw.ZP)
draw.Draw(b, r, draw.Black, draw.ZP)
draw.Draw(b, r.Inset(1), txpix[ptx], draw.ZP)
}
func drawboard() {
draw.Border(screen, rboard.Inset(-2), 2, draw.Black, draw.ZP)
draw.Draw(screen, draw.Rect(rboard.Min.X, rboard.Min.Y-2, rboard.Max.X, rboard.Min.Y),
draw.White, nil, draw.ZP)
draw.White, draw.ZP)
for i := 0; i < NY; i++ {
for j := 0; j < NX; j++ {
if board[i][j] != 0 {
......@@ -349,7 +349,7 @@ func drawboard() {
}
score(0)
if suspended {
draw.Draw(screen, screenr, draw.White, whitemask, draw.ZP)
draw.DrawMask(screen, screenr, draw.White, draw.ZP, whitemask, draw.ZP, draw.SoverD)
}
}
......@@ -375,7 +375,7 @@ func movepiece() bool {
if collider(pos, br2.Max) {
mask = bb2mask
}
draw.Draw(screen, br2.Add(pos), bb2, mask, bb2r.Min)
draw.DrawMask(screen, br2.Add(pos), bb2, bb2r.Min, mask, bb2r.Min, draw.SoverD)
pos.Y += DY
display.FlushImage()
return true
......@@ -444,7 +444,7 @@ func horiz() bool {
for j := 0; j < h; j++ {
r.Min.Y = rboard.Min.Y + lev[j]*pcsz
r.Max.Y = r.Min.Y + pcsz
draw.Draw(screen, r, draw.White, whitemask, draw.ZP)
draw.DrawMask(screen, r, draw.White, draw.ZP, whitemask, draw.ZP, draw.SoverD)
display.FlushImage()
}
PlaySound(whoosh)
......@@ -457,7 +457,7 @@ func horiz() bool {
for j := 0; j < h; j++ {
r.Min.Y = rboard.Min.Y + lev[j]*pcsz
r.Max.Y = r.Min.Y + pcsz
draw.Draw(screen, r, draw.White, whitemask, draw.ZP)
draw.DrawMask(screen, r, draw.White, draw.ZP, whitemask, draw.ZP, draw.SoverD)
}
display.FlushImage()
}
......@@ -467,9 +467,9 @@ func horiz() bool {
score(250 + 10*i*i)
r.Min.Y = rboard.Min.Y
r.Max.Y = rboard.Min.Y + lev[j]*pcsz
draw.Draw(screen, r.Add(draw.Pt(0, pcsz)), screen, nil, r.Min)
draw.Draw(screen, r.Add(draw.Pt(0, pcsz)), screen, r.Min)
r.Max.Y = rboard.Min.Y + pcsz
draw.Draw(screen, r, draw.White, nil, draw.ZP)
draw.Draw(screen, r, draw.White, draw.ZP)
for k := lev[j] - 1; k >= 0; k-- {
board[k+1] = board[k]
}
......@@ -703,7 +703,7 @@ func redraw(new bool) {
bb2r = draw.Rect(0, 0, N*pcsz, N*pcsz+DY)
bb2 = image.NewRGBA(bb2r.Dx(), bb2r.Dy())
bb2mask = image.NewRGBA(bb2r.Dx(), bb2r.Dy()) // actually just a bitmap
draw.Draw(screen, screenr, draw.White, nil, draw.ZP)
draw.Draw(screen, screenr, draw.White, draw.ZP)
drawboard()
setpiece(piece)
if piece != nil {
......
src/pkg/exp/draw/draw.go
View file @ 4e2035bd
......@@ -12,32 +12,37 @@ package draw
import "image"
// A Porter-Duff compositing operator.
type Op int
const SoverD Op = 0
// 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)
}
// Draw aligns r.Min in dst with pt in src and mask
// and then replaces the rectangle r in dst with the
// result of the Porter-Duff compositing operation
// ``(src in mask) over dst.'' If mask is nil, the operation
// simplifies to ``src over dst.''
// The implementation is simple and slow.
func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
// Plenty of room for optimizations here.
// Draw calls DrawMask with a nil mask and an SoverD op.
func Draw(dst Image, r Rectangle, src image.Image, sp Point) {
DrawMask(dst, r, src, sp, nil, ZP, SoverD)
}
dx, dy := src.Width(), src.Height()
// DrawMask aligns r.Min in dst with sp in src and mp in mask and then replaces the rectangle r
// in dst with the result of a Porter-Duff composition. For the SoverD operator, the result
// is ``(src in mask) over dst''. If mask is nil, this simplifies to ``src over dst''.
// The implementation is simple and slow.
// TODO(nigeltao): Optimize this.
func DrawMask(dst Image, r Rectangle, src image.Image, sp Point, mask image.Image, mp Point, op Op) {
dx, dy := src.Width()-sp.X, src.Height()-sp.Y
if mask != nil {
if dx > mask.Width() {
dx = mask.Width()
if dx > mask.Width()-mp.X {
dx = mask.Width() - mp.X
}
if dy > mask.Height() {
dy = mask.Height()
if dy > mask.Height()-mp.Y {
dy = mask.Height() - mp.Y
}
}
dx -= pt.X
dy -= pt.Y
if r.Dx() > dx {
r.Max.X = r.Min.X + dx
}
......@@ -45,26 +50,31 @@ func Draw(dst Image, r Rectangle, src, mask image.Image, pt Point) {
r.Max.Y = r.Min.Y + dy
}
// TODO(nigeltao): Clip r to dst's bounding box, and handle the case when sp or mp has negative X or Y.
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))) {
if image.Image(dst) == src && r.Overlaps(r.Add(sp.Sub(r.Min))) {
// Rectangles overlap: process backward?
if pt.Y < r.Min.Y || pt.Y == r.Min.Y && pt.X < r.Min.X {
if sp.Y < r.Min.Y || sp.Y == r.Min.Y && sp.X < r.Min.X {
x0, x1, dx = x1-1, x0-1, -1
y0, y1, dy = y1-1, y0-1, -1
}
}
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
sy := sp.Y + y0 - r.Min.Y
my := mp.Y + y0 - r.Min.Y
for y := y0; y != y1; y, sy, my = y+dy, sy+dy, my+dy {
sx := sp.X + x0 - r.Min.X
mx := mp.X + x0 - r.Min.X
for x := x0; x != x1; x, sx, mx = x+dx, sx+dx, mx+dx {
// TODO(nigeltao): Check that op == SoverD.
if mask == nil {
dst.Set(x, y, src.At(sx, sy))
continue
}
_, _, _, ma := mask.At(sx, sy).RGBA()
_, _, _, ma := mask.At(mx, my).RGBA()
switch ma {
case 0:
continue
......@@ -109,17 +119,17 @@ func Border(dst Image, r Rectangle, w int, src image.Image, sp Point) {
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
Draw(dst, Rect(r.Min.X, r.Min.Y, r.Max.X, r.Min.Y+i), src, sp) // top
Draw(dst, Rect(r.Min.X, r.Min.Y+i, r.Min.X+i, r.Max.Y-i), src, 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, 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, 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
Draw(dst, Rect(r.Min.X-i, r.Min.Y-i, r.Max.X+i, r.Min.Y), src, sp.Add(Pt(-i, -i))) // top
Draw(dst, Rect(r.Min.X-i, r.Min.Y, r.Min.X, r.Max.Y), src, sp.Add(Pt(-i, 0))) // left
Draw(dst, Rect(r.Max.X, r.Min.Y, r.Max.X+i, r.Max.Y), src, 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, sp.Add(Pt(-i, 0))) // bottom
}
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