From cea179291352b38bec3dd9ea9fac94fc8024da80 Mon Sep 17 00:00:00 2001 From: Přemysl Janouch Date: Sat, 25 Aug 2018 05:51:33 +0200 Subject: xgb-image: add a demo that shows a scaled picture --- prototypes/xgb-image.go | 252 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 prototypes/xgb-image.go diff --git a/prototypes/xgb-image.go b/prototypes/xgb-image.go new file mode 100644 index 0000000..5c3d74a --- /dev/null +++ b/prototypes/xgb-image.go @@ -0,0 +1,252 @@ +package main + +import ( + "encoding/binary" + "github.com/BurntSushi/xgb" + "github.com/BurntSushi/xgb/render" + "github.com/BurntSushi/xgb/xproto" + "log" + "os" + "time" + + "image" + _ "image/gif" + _ "image/jpeg" + _ "image/png" +) + +func F64ToFixed(f float64) render.Fixed { return render.Fixed(f * 65536) } +func FixedToF64(f render.Fixed) float64 { return float64(f) / 65536 } + +func main() { + /* + pf, err := os.Create("pprof.out") + if err != nil { + log.Fatal(err) + } + pprof.StartCPUProfile(pf) + defer pprof.StopCPUProfile() + */ + + // Load a picture from the command line. + f, err := os.Open(os.Args[1]) + if err != nil { + log.Fatalln(err) + } + defer f.Close() + + img, name, err := image.Decode(f) + if err != nil { + log.Fatalln(err) + } + log.Println("image type is", name) + + // Miscellaneous X11 initialization. + X, err := xgb.NewConn() + if err != nil { + log.Fatalln(err) + } + + if err := render.Init(X); err != nil { + log.Fatalln(err) + } + + setup := xproto.Setup(X) + screen := setup.DefaultScreen(X) + + visual, depth := screen.RootVisual, screen.RootDepth + // TODO: We should check that we find it, though we don't /need/ alpha here, + // it's just a minor improvement--affects the backpixel value. + for _, i := range screen.AllowedDepths { + for _, v := range i.Visuals { + // TODO: Could/should check other parameters. + if i.Depth == 32 && v.Class == xproto.VisualClassTrueColor { + visual, depth = v.VisualId, i.Depth + break + } + } + } + + mid, err := xproto.NewColormapId(X) + if err != nil { + log.Fatalln(err) + } + + _ = xproto.CreateColormap( + X, xproto.ColormapAllocNone, mid, screen.Root, visual) + + wid, err := xproto.NewWindowId(X) + if err != nil { + log.Fatalln(err) + } + + // Border pixel and colormap are required when depth differs from parent. + _ = xproto.CreateWindow(X, depth, wid, screen.Root, + 0, 0, 500, 500, 0, xproto.WindowClassInputOutput, + visual, xproto.CwBackPixel|xproto.CwBorderPixel|xproto.CwEventMask| + xproto.CwColormap, []uint32{0x80808080, 0, + xproto.EventMaskStructureNotify | xproto.EventMaskExposure, + uint32(mid)}) + + title := []byte("Image") + _ = xproto.ChangeProperty(X, xproto.PropModeReplace, wid, xproto.AtomWmName, + xproto.AtomString, 8, uint32(len(title)), title) + + _ = xproto.MapWindow(X, wid) + + pformats, err := render.QueryPictFormats(X).Reply() + if err != nil { + log.Fatalln(err) + } + + // Similar to XRenderFindVisualFormat. + // The DefaultScreen is almost certain to be zero. + var pformat render.Pictformat + for _, pd := range pformats.Screens[X.DefaultScreen].Depths { + // This check seems to be slightly extraneous. + if pd.Depth != depth { + continue + } + for _, pv := range pd.Visuals { + if pv.Visual == visual { + pformat = pv.Format + } + } + } + + // Wrap the window's surface in a picture. + pid, err := render.NewPictureId(X) + if err != nil { + log.Fatalln(err) + } + render.CreatePicture(X, pid, xproto.Drawable(wid), pformat, 0, []uint32{}) + + // setup.BitmapFormatScanline{Pad,Unit} and setup.BitmapFormatBitOrder + // don't interest us here since we're only using Z format pixmaps. + for _, pf := range setup.PixmapFormats { + if pf.Depth == 32 { + if pf.BitsPerPixel != 32 || pf.ScanlinePad != 32 { + log.Fatalln("unsuported X server") + } + } + } + + pixid, err := xproto.NewPixmapId(X) + if err != nil { + log.Fatalln(err) + } + _ = xproto.CreatePixmap(X, 32, pixid, xproto.Drawable(screen.Root), + uint16(img.Bounds().Dx()), uint16(img.Bounds().Dy())) + + var bgraFormat render.Pictformat + wanted := render.Directformat{ + RedShift: 16, + RedMask: 0xff, + GreenShift: 8, + GreenMask: 0xff, + BlueShift: 0, + BlueMask: 0xff, + AlphaShift: 24, + AlphaMask: 0xff, + } + for _, pf := range pformats.Formats { + if pf.Depth == 32 && pf.Direct == wanted { + bgraFormat = pf.Id + break + } + } + if bgraFormat == 0 { + log.Fatalln("ARGB format not found") + } + + // We could also look for the inverse pictformat. + var encoding binary.ByteOrder + if setup.ImageByteOrder == xproto.ImageOrderMSBFirst { + encoding = binary.BigEndian + } else { + encoding = binary.LittleEndian + } + + pixpicid, err := render.NewPictureId(X) + if err != nil { + log.Fatalln(err) + } + render.CreatePicture(X, pixpicid, xproto.Drawable(pixid), bgraFormat, + 0, []uint32{}) + + // Do we really need this? :/ + cid, err := xproto.NewGcontextId(X) + if err != nil { + log.Fatalln(err) + } + _ = 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)) + } + _ = xproto.PutImage(X, xproto.ImageFormatZPixmap, + xproto.Drawable(pixid), cid, uint16(bounds.Dx()), 1, + 0, int16(y), + 0, 32, row) + } + + 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() + if xerr != nil { + log.Printf("Error: %s\n", xerr) + return + } + if ev == nil { + return + } + + log.Printf("Event: %s\n", ev) + switch e := ev.(type) { + case xproto.UnmapNotifyEvent: + return + + case xproto.ConfigureNotifyEvent: + w, h := e.Width, e.Height + + scaleX := float64(bounds.Dx()) / float64(w) + scaleY := float64(bounds.Dy()) / float64(h) + + if scaleX < scaleY { + scale = scaleY + } else { + scale = scaleX + } + + _ = render.SetPictureTransform(X, pixpicid, render.Transform{ + F64ToFixed(scale), F64ToFixed(0), F64ToFixed(0), + F64ToFixed(0), F64ToFixed(scale), F64ToFixed(0), + F64ToFixed(0), F64ToFixed(0), F64ToFixed(1), + }) + _ = render.SetPictureFilter(X, pixpicid, 8, "bilinear", nil) + + case xproto.ExposeEvent: + _ = render.Composite(X, render.PictOpSrc, + pixpicid, render.PictureNone, pid, + 0, 0, 0, 0, 0 /* dst-x */, 0, /* dst-y */ + uint16(float64(img.Bounds().Dx())/scale), + uint16(float64(img.Bounds().Dy())/scale)) + } + } +} -- cgit v1.2.3-70-g09d2