support multi-module (#4)

* add multimodule
* re-package modules

server/internal/model/game/ship.go

@@ -0,0 +1,64 @@
+package game
+
+import (
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+type ShipType struct {
+	ID       uuid.UUID `json:"id"`
+	Name     string    `json:"name"`
+	Drive    Float     `json:"drive"`
+	Armament uint      `json:"armament"`
+	Weapons  Float     `json:"weapons"`
+	Shields  Float     `json:"shields"`
+	Cargo    Float     `json:"cargo"`
+}
+
+func (st ShipType) Equal(o ShipType) bool {
+	return st.Drive == o.Drive &&
+		st.Weapons == o.Weapons &&
+		st.Armament == o.Armament &&
+		st.Shields == o.Shields &&
+		st.Cargo == o.Cargo
+}
+
+func (st ShipType) BlockMass(t Tech) float64 {
+	switch t {
+	case TechDrive:
+		return st.DriveBlockMass()
+	case TechWeapons:
+		return st.WeaponsBlockMass()
+	case TechShields:
+		return st.ShieldsBlockMass()
+	case TechCargo:
+		return st.CargoBlockMass()
+	default:
+		panic("BlockMass: unexpectec tech: " + t.String())
+	}
+}
+
+func (st ShipType) DriveBlockMass() float64 {
+	return st.Drive.F()
+}
+
+func (st ShipType) WeaponsBlockMass() float64 {
+	if (st.Armament == 0 && st.Weapons != 0) || (st.Armament != 0 && st.Weapons == 0) {
+		panic(fmt.Sprintf("ship class invalid design: A=%d W=%.03f", st.Armament, st.Weapons))
+	}
+	return float64(st.Armament+1) * (st.Weapons.F() / 2)
+}
+
+func (st ShipType) ShieldsBlockMass() float64 {
+	return st.Shields.F()
+}
+
+func (st ShipType) CargoBlockMass() float64 {
+	return st.Cargo.F()
+}
+
+func (st ShipType) EmptyMass() float64 {
+	shipMass := st.DriveBlockMass() + st.ShieldsBlockMass() + st.CargoBlockMass() + st.WeaponsBlockMass()
+	return shipMass
+}