added implementation in GO lang

internal/modes/geometry.go

@@ -0,0 +1,180 @@
+package modes
+
+import (
+	"image/color"
+	"math"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
+
+	"kidskeyboard/internal/ui"
+)
+
+type shapeKind int
+
+const (
+	shapeCircle shapeKind = iota
+	shapeRect
+	shapeTriangle
+	shapeLine
+	shapeStar
+)
+
+type shape struct {
+	kind  shapeKind
+	x     float32
+	y     float32
+	w     float32
+	h     float32
+	size  float32
+	color color.NRGBA
+}
+
+type GeometryMode struct {
+	ctx    Context
+	shapes map[ebiten.Key]*shape
+	order  []ebiten.Key
+}
+
+func NewGeometryMode(ctx Context) *GeometryMode {
+	return &GeometryMode{ctx: ctx, shapes: map[ebiten.Key]*shape{}}
+}
+
+func (m *GeometryMode) Name() string { return "CTRL+F2 Geometry" }
+func (m *GeometryMode) OnEnter()     {}
+func (m *GeometryMode) OnLeave()     {}
+
+func (m *GeometryMode) HandleInput() {
+	if inpututil.IsKeyJustPressed(ebiten.KeyDelete) {
+		m.shapes = map[ebiten.Key]*shape{}
+		m.order = nil
+		return
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyArrowLeft) {
+		m.moveLast(-20, 0)
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyArrowRight) {
+		m.moveLast(20, 0)
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyArrowUp) {
+		m.moveLast(0, -20)
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyArrowDown) {
+		m.moveLast(0, 20)
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyEqual) || inpututil.IsKeyJustPressed(ebiten.KeyNumpadAdd) {
+		m.scaleLast(1.12)
+	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyMinus) || inpututil.IsKeyJustPressed(ebiten.KeyNumpadSubtract) {
+		m.scaleLast(0.88)
+	}
+
+	for _, key := range justPressedKeys() {
+		if !childKey(key) || geometryControlKey(key) {
+			continue
+		}
+		if _, ok := m.shapes[key]; ok {
+			delete(m.shapes, key)
+			m.removeOrder(key)
+			continue
+		}
+		m.shapes[key] = m.randomShape()
+		m.order = append(m.order, key)
+	}
+}
+
+func (m *GeometryMode) Update() {}
+
+func (m *GeometryMode) Draw(screen *ebiten.Image) {
+	screen.Fill(color.Black)
+	for _, key := range m.order {
+		if s := m.shapes[key]; s != nil {
+			drawShape(screen, s)
+		}
+	}
+	ui.Text(screen, "CTRL+F2", 20, 20, color.White, 2)
+}
+
+func (m *GeometryMode) randomShape() *shape {
+	w, h := 1280, 720
+	x := float32(80 + m.ctx.RNG.Intn(max(1, w-160)))
+	y := float32(80 + m.ctx.RNG.Intn(max(1, h-160)))
+	size := float32(35 + m.ctx.RNG.Intn(100))
+	return &shape{
+		kind: shapeKind(m.ctx.RNG.Intn(5)),
+		x:    x,
+		y:    y,
+		w:    size + float32(m.ctx.RNG.Intn(90)),
+		h:    size + float32(m.ctx.RNG.Intn(90)),
+		size: size,
+		color: color.NRGBA{
+			R: uint8(80 + m.ctx.RNG.Intn(176)),
+			G: uint8(80 + m.ctx.RNG.Intn(176)),
+			B: uint8(80 + m.ctx.RNG.Intn(176)),
+			A: 255,
+		},
+	}
+}
+
+func drawShape(screen *ebiten.Image, s *shape) {
+	switch s.kind {
+	case shapeCircle:
+		ui.Circle(screen, s.x, s.y, s.size, s.color)
+	case shapeRect:
+		ui.Rect(screen, s.x-s.w/2, s.y-s.h/2, s.w, s.h, s.color)
+	case shapeTriangle:
+		ui.Triangle(screen, s.x, s.y-s.h/2, s.x-s.w/2, s.y+s.h/2, s.x+s.w/2, s.y+s.h/2, s.color)
+	case shapeLine:
+		ui.Line(screen, s.x-s.w/2, s.y-s.h/2, s.x+s.w/2, s.y+s.h/2, float32(math.Max(4, float64(s.size/8))), s.color)
+	case shapeStar:
+		ui.Star(screen, s.x, s.y, s.size, s.size*0.45, 5, s.color)
+	}
+}
+
+func (m *GeometryMode) moveLast(dx, dy float32) {
+	last := m.last()
+	if last == nil {
+		return
+	}
+	last.x += dx
+	last.y += dy
+}
+
+func (m *GeometryMode) scaleLast(factor float32) {
+	last := m.last()
+	if last == nil {
+		return
+	}
+	last.w *= factor
+	last.h *= factor
+	last.size *= factor
+}
+
+func (m *GeometryMode) last() *shape {
+	for i := len(m.order) - 1; i >= 0; i-- {
+		if s := m.shapes[m.order[i]]; s != nil {
+			return s
+		}
+	}
+	return nil
+}
+
+func (m *GeometryMode) removeOrder(key ebiten.Key) {
+	next := m.order[:0]
+	for _, k := range m.order {
+		if k != key {
+			next = append(next, k)
+		}
+	}
+	m.order = next
+}
+
+func geometryControlKey(key ebiten.Key) bool {
+	switch key {
+	case ebiten.KeyDelete, ebiten.KeyArrowLeft, ebiten.KeyArrowRight, ebiten.KeyArrowUp, ebiten.KeyArrowDown,
+		ebiten.KeyEqual, ebiten.KeyMinus, ebiten.KeyNumpadAdd, ebiten.KeyNumpadSubtract:
+		return true
+	default:
+		return false
+	}
+}