| // 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. |
| |
| // +build windows |
| |
| package windriver |
| |
| import ( |
| "image" |
| "image/draw" |
| "sync" |
| "syscall" |
| |
| "golang.org/x/exp/shiny/driver/internal/swizzle" |
| ) |
| |
| type bufferImpl struct { |
| hbitmap syscall.Handle |
| buf []byte |
| rgba image.RGBA |
| size image.Point |
| |
| mu sync.Mutex |
| nUpload uint32 |
| released bool |
| cleanedUp bool |
| } |
| |
| 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("windriver: invalid Buffer.RGBA modification") |
| } |
| |
| b.mu.Lock() |
| defer b.mu.Unlock() |
| |
| if b.released { |
| panic("windriver: 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("windriver: Buffer clean-up occurred twice") |
| } |
| b.cleanedUp = true |
| b.mu.Unlock() |
| |
| b.rgba.Pix = nil |
| _DeleteObject(b.hbitmap) |
| } |
| |
| func (b *bufferImpl) blitToDC(dc syscall.Handle, dp image.Point, sr image.Rectangle) error { |
| b.preUpload() |
| defer b.postUpload() |
| |
| dr := sr.Add(dp.Sub(sr.Min)) |
| return copyBitmapToDC(dc, dr, b.hbitmap, sr, draw.Src) |
| } |