diff options
| -rw-r--r-- | prototypes/xgb-image.go | 93 |
1 files changed, 77 insertions, 16 deletions
diff --git a/prototypes/xgb-image.go b/prototypes/xgb-image.go index 5c3d74a..2da37d6 100644 --- a/prototypes/xgb-image.go +++ b/prototypes/xgb-image.go @@ -4,10 +4,13 @@ import ( "encoding/binary" "github.com/BurntSushi/xgb" "github.com/BurntSushi/xgb/render" + "github.com/BurntSushi/xgb/shm" "github.com/BurntSushi/xgb/xproto" "log" "os" + "reflect" "time" + "unsafe" "image" _ "image/gif" @@ -15,6 +18,10 @@ import ( _ "image/png" ) +// #include <sys/ipc.h> +// #include <sys/shm.h> +import "C" + func F64ToFixed(f float64) render.Fixed { return render.Fixed(f * 65536) } func FixedToF64(f render.Fixed) float64 { return float64(f) / 65536 } @@ -182,30 +189,84 @@ func main() { _ = xproto.CreateGC(X, cid, xproto.Drawable(pixid), xproto.GcGraphicsExposures, []uint32{0}) - // Load data into the pixmap. Also see xgbutil/xgraphics/xsurface.go. - // We're being lazy and resolve the 1<<16 limit of requests by sending - // a row at a time. The encoding is also done inefficiently. bounds := img.Bounds() - Lstart := time.Now() - row := make([]byte, bounds.Dx()*4) - for y := bounds.Min.Y; y < bounds.Max.Y; y++ { - for x := bounds.Min.X; x < bounds.Max.X; x++ { - r, g, b, a := img.At(x, y).RGBA() - encoding.PutUint32(row[x*4:], - (a>>8)<<24|(r>>8)<<16|(g>>8)<<8|(b>>8)) + if err := shm.Init(X); err != nil { + log.Println("MIT-SHM unavailable") + + // We're being lazy and resolve the 1<<16 limit of requests by sending + // a row at a time. The encoding is also done inefficiently. + // Also see xgbutil/xgraphics/xsurface.go. + row := make([]byte, bounds.Dx()*4) + for y := bounds.Min.Y; y < bounds.Max.Y; y++ { + for x := bounds.Min.X; x < bounds.Max.X; x++ { + r, g, b, a := img.At(x, y).RGBA() + encoding.PutUint32(row[x*4:], + (a>>8)<<24|(r>>8)<<16|(g>>8)<<8|(b>>8)) + } + _ = xproto.PutImage(X, xproto.ImageFormatZPixmap, + xproto.Drawable(pixid), cid, uint16(bounds.Dx()), 1, + 0, int16(y), + 0, 32, row) + } + } else { + rep, err := shm.QueryVersion(X).Reply() + if err != nil { + log.Fatalln(err) + } + if rep.PixmapFormat != xproto.ImageFormatZPixmap || + !rep.SharedPixmaps { + log.Fatalln("MIT-SHM configuration unfit") + } + + shmSize := bounds.Dx() * bounds.Dy() * 4 + + // As a side note, to clean up unreferenced segments (orphans): + // ipcs -m | awk '$6 == "0" { print $2 }' | xargs ipcrm shm + shmID := int(C.shmget(C.IPC_PRIVATE, + C.size_t(shmSize), C.IPC_CREAT|0777)) + if shmID == -1 { + // TODO: We should handle this case by falling back to PutImage, + // if only because the allocation may hit a system limit. + log.Fatalln("memory allocation failed") } - _ = xproto.PutImage(X, xproto.ImageFormatZPixmap, - xproto.Drawable(pixid), cid, uint16(bounds.Dx()), 1, - 0, int16(y), - 0, 32, row) + + dataRaw := C.shmat(C.int(shmID), nil, 0) + defer C.shmdt(dataRaw) + defer C.shmctl(C.int(shmID), C.IPC_RMID, nil) + + data := *(*[]byte)(unsafe.Pointer(&reflect.SliceHeader{ + Data: uintptr(dataRaw), Len: shmSize, Cap: shmSize})) + for y := bounds.Min.Y; y < bounds.Max.Y; y++ { + row := data[y*bounds.Dx()*4:] + for x := bounds.Min.X; x < bounds.Max.X; x++ { + r, g, b, a := img.At(x, y).RGBA() + encoding.PutUint32(row[x*4:], + (a>>8)<<24|(r>>8)<<16|(g>>8)<<8|(b>>8)) + } + } + + segid, err := shm.NewSegId(X) + if err != nil { + log.Fatalln(err) + } + + // Need to have it attached on the server before we unload the segment. + c := shm.AttachChecked(X, segid, uint32(shmID), true /* RO */) + if err := c.Check(); err != nil { + log.Fatalln(err) + } + + _ = shm.PutImage(X, xproto.Drawable(pixid), cid, + uint16(bounds.Dx()), uint16(bounds.Dy()), 0, 0, + uint16(bounds.Dx()), uint16(bounds.Dy()), 0, 0, + 32, xproto.ImageFormatZPixmap, + 0 /* SendEvent */, segid, 0 /* Offset */) } log.Println("uploading took", time.Now().Sub(Lstart)) - // TODO: SHM, for an example see https://github.com/BurntSushi/xgb/issues/28 - var scale float64 = 1 for { ev, xerr := X.WaitForEvent() |