ui: basic map scroller

client/world/primitive.go

@@ -0,0 +1,63 @@
+package world
+
+import (
+	"github.com/google/uuid"
+)
+
+// MapItem is the common interface implemented by all world primitives.
+type MapItem interface {
+	ID() uuid.UUID
+}
+
+// Point is a point primitive in fixed-point world coordinates.
+type Point struct {
+	Id   uuid.UUID
+	X, Y int
+}
+
+// Line is a line segment primitive in fixed-point world coordinates.
+type Line struct {
+	Id     uuid.UUID
+	X1, Y1 int
+	X2, Y2 int
+}
+
+// Circle is a circle primitive in fixed-point world coordinates.
+type Circle struct {
+	Id     uuid.UUID
+	X, Y   int
+	Radius int
+}
+
+// ID returns the point identifier.
+func (p Point) ID() uuid.UUID { return p.Id }
+
+// ID returns the line identifier.
+func (l Line) ID() uuid.UUID { return l.Id }
+
+// ID returns the circle identifier.
+func (c Circle) ID() uuid.UUID { return c.Id }
+
+// MinX returns the minimum X endpoint coordinate of the line.
+func (l Line) MinX() int { return min(l.X1, l.X2) }
+
+// MaxX returns the maximum X endpoint coordinate of the line.
+func (l Line) MaxX() int { return max(l.X1, l.X2) }
+
+// MinY returns the minimum Y endpoint coordinate of the line.
+func (l Line) MinY() int { return min(l.Y1, l.Y2) }
+
+// MaxY returns the maximum Y endpoint coordinate of the line.
+func (l Line) MaxY() int { return max(l.Y1, l.Y2) }
+
+// MinX returns the minimum X coordinate of the circle bbox.
+func (c Circle) MinX() int { return c.X - c.Radius }
+
+// MaxX returns the maximum X coordinate of the circle bbox.
+func (c Circle) MaxX() int { return c.X + c.Radius }
+
+// MinY returns the minimum Y coordinate of the circle bbox.
+func (c Circle) MinY() int { return c.Y - c.Radius }
+
+// MaxY returns the maximum Y coordinate of the circle bbox.
+func (c Circle) MaxY() int { return c.Y + c.Radius }