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Diffstat (limited to 'prototypes/xgb-image.go')
-rw-r--r--prototypes/xgb-image.go93
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()