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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package x11driver
import (
"image"
"image/color"
"image/draw"
"log"
"sync"
"unsafe"
"github.com/BurntSushi/xgb"
"github.com/BurntSushi/xgb/render"
"github.com/BurntSushi/xgb/shm"
"github.com/BurntSushi/xgb/xproto"
"golang.org/x/exp/shiny/driver/internal/swizzle"
)
type bufferUploader interface {
upload(xd xproto.Drawable, xg xproto.Gcontext, depth uint8, dp image.Point, sr image.Rectangle)
}
type bufferImpl struct {
s *screenImpl
addr unsafe.Pointer
buf []byte
rgba image.RGBA
size image.Point
xs shm.Seg
mu sync.Mutex
nUpload uint32
released bool
cleanedUp bool
}
func (b *bufferImpl) degenerate() bool { return b.size.X == 0 || b.size.Y == 0 }
func (b *bufferImpl) Size() image.Point { return b.size }
func (b *bufferImpl) Bounds() image.Rectangle { return image.Rectangle{Max: b.size} }
func (b *bufferImpl) RGBA() *image.RGBA { return &b.rgba }
func (b *bufferImpl) preUpload() {
// Check that the program hasn't tried to modify the rgba field via the
// pointer returned by the bufferImpl.RGBA method. This check doesn't catch
// 100% of all cases; it simply tries to detect some invalid uses of a
// screen.Buffer such as:
// *buffer.RGBA() = anotherImageRGBA
if len(b.buf) != 0 && len(b.rgba.Pix) != 0 && &b.buf[0] != &b.rgba.Pix[0] {
panic("x11driver: invalid Buffer.RGBA modification")
}
b.mu.Lock()
defer b.mu.Unlock()
if b.released {
panic("x11driver: Buffer.Upload called after Buffer.Release")
}
if b.nUpload == 0 {
swizzle.BGRA(b.buf)
}
b.nUpload++
}
func (b *bufferImpl) postUpload() {
b.mu.Lock()
defer b.mu.Unlock()
b.nUpload--
if b.nUpload != 0 {
return
}
if b.released {
go b.cleanUp()
} else {
swizzle.BGRA(b.buf)
}
}
func (b *bufferImpl) Release() {
b.mu.Lock()
defer b.mu.Unlock()
if !b.released && b.nUpload == 0 {
go b.cleanUp()
}
b.released = true
}
func (b *bufferImpl) cleanUp() {
b.mu.Lock()
if b.cleanedUp {
b.mu.Unlock()
panic("x11driver: Buffer clean-up occurred twice")
}
b.cleanedUp = true
b.mu.Unlock()
b.s.mu.Lock()
delete(b.s.buffers, b.xs)
b.s.mu.Unlock()
if b.degenerate() {
return
}
shm.Detach(b.s.xc, b.xs)
if err := shmClose(b.addr); err != nil {
log.Printf("x11driver: shmClose: %v", err)
}
}
func (b *bufferImpl) upload(xd xproto.Drawable, xg xproto.Gcontext, depth uint8, dp image.Point, sr image.Rectangle) {
originalSRMin := sr.Min
sr = sr.Intersect(b.Bounds())
if sr.Empty() {
return
}
dp = dp.Add(sr.Min.Sub(originalSRMin))
b.preUpload()
b.s.mu.Lock()
b.s.nPendingUploads++
b.s.mu.Unlock()
cookie := shm.PutImage(
b.s.xc, xd, xg,
uint16(b.size.X), uint16(b.size.Y), // TotalWidth, TotalHeight,
uint16(sr.Min.X), uint16(sr.Min.Y), // SrcX, SrcY,
uint16(sr.Dx()), uint16(sr.Dy()), // SrcWidth, SrcHeight,
int16(dp.X), int16(dp.Y), // DstX, DstY,
depth, xproto.ImageFormatZPixmap,
1, b.xs, 0, // 1 means send a completion event, 0 means a zero offset.
)
completion := make(chan struct{})
b.s.mu.Lock()
b.s.uploads[cookie.Sequence] = completion
b.s.nPendingUploads--
b.s.handleCompletions()
b.s.mu.Unlock()
<-completion
b.postUpload()
}
func fill(xc *xgb.Conn, xp render.Picture, dr image.Rectangle, src color.Color, op draw.Op) {
r, g, b, a := src.RGBA()
c := render.Color{
Red: uint16(r),
Green: uint16(g),
Blue: uint16(b),
Alpha: uint16(a),
}
x, y := dr.Min.X, dr.Min.Y
if x < -0x8000 || 0x7fff < x || y < -0x8000 || 0x7fff < y {
return
}
dx, dy := dr.Dx(), dr.Dy()
if dx < 0 || 0xffff < dx || dy < 0 || 0xffff < dy {
return
}
render.FillRectangles(xc, renderOp(op), xp, c, []xproto.Rectangle{{
X: int16(x),
Y: int16(y),
Width: uint16(dx),
Height: uint16(dy),
}})
}