op: add package op for operations

Extract operation types from package ui into package op.

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

ui/ui.go

@@ -3,12 +3,7 @@
 package ui
 
 import (
-	"encoding/binary"
-	"math"
 	"time"
-
-	"gioui.org/f32"
-	"gioui.org/internal/opconst"
 )
 
 // Config define the essential properties of
@@ -19,60 +14,3 @@ type Config interface {
 	// Px converts a Value to pixels.
 	Px(v Value) int
 }
-
-// InvalidateOp requests a redraw at the given time. Use
-// the zero value to request an immediate redraw.
-type InvalidateOp struct {
-	At time.Time
-}
-
-// TransformOp applies a transform to the current transform.
-type TransformOp struct {
-	// TODO: general transformations.
-	offset f32.Point
-}
-
-func (r InvalidateOp) Add(o *Ops) {
-	data := make([]byte, opconst.TypeRedrawLen)
-	data[0] = byte(opconst.TypeInvalidate)
-	bo := binary.LittleEndian
-	// UnixNano cannot represent the zero time.
-	if t := r.At; !t.IsZero() {
-		nanos := t.UnixNano()
-		if nanos > 0 {
-			bo.PutUint64(data[1:], uint64(nanos))
-		}
-	}
-	o.Write(data)
-}
-
-// Offset the transformation.
-func (t TransformOp) Offset(o f32.Point) TransformOp {
-	return t.Multiply(TransformOp{o})
-}
-
-// Invert the transformation.
-func (t TransformOp) Invert() TransformOp {
-	return TransformOp{offset: t.offset.Mul(-1)}
-}
-
-// Transform a point.
-func (t TransformOp) Transform(p f32.Point) f32.Point {
-	return p.Add(t.offset)
-}
-
-// Multiply by a transformation.
-func (t TransformOp) Multiply(t2 TransformOp) TransformOp {
-	return TransformOp{
-		offset: t.offset.Add(t2.offset),
-	}
-}
-
-func (t TransformOp) Add(o *Ops) {
-	data := make([]byte, opconst.TypeTransformLen)
-	data[0] = byte(opconst.TypeTransform)
-	bo := binary.LittleEndian
-	bo.PutUint32(data[1:], math.Float32bits(t.offset.X))
-	bo.PutUint32(data[5:], math.Float32bits(t.offset.Y))
-	o.Write(data)
-}