all: initial import

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/ui.go

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package ui
+
+import (
+	"time"
+
+	"gioui.org/ui/f32"
+)
+
+type Config struct {
+	PxPerDp float32
+	PxPerSp float32
+	Now     time.Time
+}
+
+type Op interface {
+	ImplementsOp()
+}
+
+type OpLayer struct {
+	Op Op
+}
+
+type OpRedraw struct {
+	At time.Time
+}
+
+type Ops []Op
+
+type OpTransform struct {
+	Transform Transform
+	Op        Op
+}
+
+type Transform struct {
+	// TODO: general transforms.
+	offset f32.Point
+}
+
+func (t Transform) InvTransform(p f32.Point) f32.Point {
+	return p.Sub(t.offset)
+}
+
+func (t Transform) Transform(p f32.Point) f32.Point {
+	return p.Add(t.offset)
+}
+
+func (t Transform) Mul(t2 Transform) Transform {
+	return Transform{
+		offset: t.offset.Add(t2.offset),
+	}
+}
+
+func (t OpTransform) ChildOp() Op {
+	return t.Op
+}
+
+func (o OpLayer) ChildOp() Op {
+	return o.Op
+}
+
+func Offset(o f32.Point) Transform {
+	return Transform{o}
+}
+
+// Inf is the int value that represents an unbounded maximum constraint.
+const Inf = int(^uint(0) >> 1)
+
+func (Ops) ImplementsOp()         {}
+func (OpLayer) ImplementsOp()     {}
+func (OpTransform) ImplementsOp() {}
+func (OpRedraw) ImplementsOp()    {}