1 files changed, 187 insertions, 0 deletions
diff --git a/shiny/example/basic/main.go b/shiny/example/basic/main.go
new file mode 100644
index 0000000..8a35268
--- /dev/null
+++ b/shiny/example/basic/main.go
@@ -0,0 +1,187 @@
+// 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.
+
+//go:build example
+// +build example
+
+//
+// This build tag means that "go install golang.org/x/exp/shiny/..." doesn't
+// install this example program. Use "go run main.go" to run it or "go install
+// -tags=example" to install it.
+
+// Basic is a basic example of a graphical application.
+package main
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+	"log"
+	"math"
+
+	"golang.org/x/exp/shiny/driver"
+	"golang.org/x/exp/shiny/imageutil"
+	"golang.org/x/exp/shiny/screen"
+	"golang.org/x/image/math/f64"
+	"golang.org/x/mobile/event/key"
+	"golang.org/x/mobile/event/lifecycle"
+	"golang.org/x/mobile/event/paint"
+	"golang.org/x/mobile/event/size"
+)
+
+var (
+	blue0    = color.RGBA{0x00, 0x00, 0x1f, 0xff}
+	blue1    = color.RGBA{0x00, 0x00, 0x3f, 0xff}
+	darkGray = color.RGBA{0x3f, 0x3f, 0x3f, 0xff}
+	green    = color.RGBA{0x00, 0x7f, 0x00, 0x7f}
+	red      = color.RGBA{0x7f, 0x00, 0x00, 0x7f}
+	yellow   = color.RGBA{0x3f, 0x3f, 0x00, 0x3f}
+
+	cos30 = math.Cos(math.Pi / 6)
+	sin30 = math.Sin(math.Pi / 6)
+)
+
+func main() {
+	driver.Main(func(s screen.Screen) {
+		w, err := s.NewWindow(&screen.NewWindowOptions{
+			Title: "Basic Shiny Example",
+		})
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer w.Release()
+
+		size0 := image.Point{256, 256}
+		b, err := s.NewBuffer(size0)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer b.Release()
+		drawGradient(b.RGBA())
+
+		t0, err := s.NewTexture(size0)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer t0.Release()
+		t0.Upload(image.Point{}, b, b.Bounds())
+
+		size1 := image.Point{32, 20}
+		t1, err := s.NewTexture(size1)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer t1.Release()
+		t1.Fill(t1.Bounds(), green, screen.Src)
+		t1.Fill(t1.Bounds().Inset(2), red, screen.Over)
+		t1.Fill(t1.Bounds().Inset(4), red, screen.Src)
+
+		var sz size.Event
+		for {
+			e := w.NextEvent()
+
+			// This print message is to help programmers learn what events this
+			// example program generates. A real program shouldn't print such
+			// messages; they're not important to end users.
+			format := "got %#v\n"
+			if _, ok := e.(fmt.Stringer); ok {
+				format = "got %v\n"
+			}
+			fmt.Printf(format, e)
+
+			switch e := e.(type) {
+			case lifecycle.Event:
+				if e.To == lifecycle.StageDead {
+					return
+				}
+
+			case key.Event:
+				if e.Code == key.CodeEscape {
+					return
+				}
+
+			case paint.Event:
+				const inset = 10
+				for _, r := range imageutil.Border(sz.Bounds(), inset) {
+					w.Fill(r, blue0, screen.Src)
+				}
+				w.Fill(sz.Bounds().Inset(inset), blue1, screen.Src)
+				w.Upload(image.Point{20, 0}, b, b.Bounds())
+				w.Fill(image.Rect(50, 50, 350, 120), red, screen.Over)
+
+				// By default, draw the entirety of the texture using the Over
+				// operator. Uncomment one or both of the lines below to see
+				// their different effects.
+				op := screen.Over
+				// op = screen.Src
+				t0Rect := t0.Bounds()
+				// t0Rect = image.Rect(16, 0, 240, 100)
+
+				// Draw the texture t0 twice, as a 1:1 copy and under the
+				// transform src2dst.
+				w.Copy(image.Point{150, 100}, t0, t0Rect, op, nil)
+				src2dst := f64.Aff3{
+					+0.5 * cos30, -1.0 * sin30, 100,
+					+0.5 * sin30, +1.0 * cos30, 200,
+				}
+				w.Draw(src2dst, t0, t0Rect, op, nil)
+				w.DrawUniform(src2dst, yellow, t0Rect.Inset(30), screen.Over, nil)
+
+				// Draw crosses at the transformed corners of t0Rect.
+				for _, sx := range []int{t0Rect.Min.X, t0Rect.Max.X} {
+					for _, sy := range []int{t0Rect.Min.Y, t0Rect.Max.Y} {
+						dx := int(src2dst[0]*float64(sx) + src2dst[1]*float64(sy) + src2dst[2])
+						dy := int(src2dst[3]*float64(sx) + src2dst[4]*float64(sy) + src2dst[5])
+						w.Fill(image.Rect(dx-0, dy-1, dx+1, dy+2), darkGray, screen.Src)
+						w.Fill(image.Rect(dx-1, dy-0, dx+2, dy+1), darkGray, screen.Src)
+					}
+				}
+
+				// Draw t1.
+				w.Copy(image.Point{400, 50}, t1, t1.Bounds(), screen.Src, nil)
+
+				w.Publish()
+
+			case size.Event:
+				sz = e
+
+			case error:
+				log.Print(e)
+			}
+		}
+	})
+}
+
+func drawGradient(m *image.RGBA) {
+	b := m.Bounds()
+	for y := b.Min.Y; y < b.Max.Y; y++ {
+		for x := b.Min.X; x < b.Max.X; x++ {
+			if x%64 == 0 || y%64 == 0 {
+				m.SetRGBA(x, y, color.RGBA{0xff, 0xff, 0xff, 0xff})
+			} else if x%64 == 63 || y%64 == 63 {
+				m.SetRGBA(x, y, color.RGBA{0x00, 0x00, 0xff, 0xff})
+			} else {
+				m.SetRGBA(x, y, color.RGBA{uint8(x), uint8(y), 0x00, 0xff})
+			}
+		}
+	}
+
+	// Round off the corners.
+	const radius = 64
+	lox := b.Min.X + radius - 1
+	loy := b.Min.Y + radius - 1
+	hix := b.Max.X - radius
+	hiy := b.Max.Y - radius
+	for y := 0; y < radius; y++ {
+		for x := 0; x < radius; x++ {
+			if x*x+y*y <= radius*radius {
+				continue
+			}
+			m.SetRGBA(lox-x, loy-y, color.RGBA{})
+			m.SetRGBA(hix+x, loy-y, color.RGBA{})
+			m.SetRGBA(lox-x, hiy+y, color.RGBA{})
+			m.SetRGBA(hix+x, hiy+y, color.RGBA{})
+		}
+	}
+}