initialize git

libsnake/libsnake.go

@@ -0,0 +1,121 @@
+package libsnake
+
+import (
+	"fmt"
+	"errors"
+	"slices"
+	"math/rand"
+)
+
+type Entity struct {
+	Id int
+	Name string
+	Type string
+	XDirection int
+	YDirection int
+
+	ConsumedFood int
+}
+
+type SnakeGame struct {
+	PlayField [][]int
+	Entities []Entity
+}
+
+type StepStatus struct {
+	EliminatedEntities []Entity
+}
+
+func remove_entity(s []Entity, i int) []Entity {
+  s[i] = s[len(s)-1]
+  return s[:len(s)-1]
+}
+
+func (sg *SnakeGame) StepGame() StepStatus {
+	status := StepStatus {
+		EliminatedEntities: []Entity {},
+	}
+
+	for entity_index, entity := range sg.Entities {
+		if entity.Type == "player" {
+			for playfield_row_index, playfield_row := range sg.PlayField {
+				for playfield_col_index, playfield_col := range playfield_row {
+					if playfield_col == entity.Id {
+						sg.PlayField[playfield_row_index][playfield_col_index] = 0
+
+						next_row_direction := playfield_row_index + entity.XDirection
+						next_col_direction := playfield_col_index + entity.YDirection
+
+						if next_row_direction > len(sg.PlayField) || next_col_direction > len(playfield_row) {
+							entity = sg.Entities[entity_index]
+							sg.Entities = remove_entity(sg.Entities, entity_index)
+
+							status.EliminatedEntities = append(status.EliminatedEntities, entity)
+							continue
+						} else if next_row_direction < 0 || next_col_direction < 0 {
+							entity = sg.Entities[entity_index]
+							sg.Entities = remove_entity(sg.Entities, entity_index)
+
+							status.EliminatedEntities = append(status.EliminatedEntities, entity)
+							continue
+						} else if sg.PlayField[next_row_direction][next_col_direction] != 0 {
+							entity_id := sg.PlayField[next_row_direction][next_col_direction]
+							entity_index := slices.IndexFunc(sg.Entities, func(e Entity) bool { return e.Id == entity_id })
+
+							if entity_index == -1 {
+								fmt.Println("FIXME: entity is in field, but could not be found? wtf?")
+								continue
+							}
+
+							found_entity := sg.Entities[entity_index]
+							
+							if found_entity.Type == "food" {
+								entity.ConsumedFood += 1
+								sg.PlayField[rand.Intn(len(sg.PlayField))][rand.Intn(len(playfield_row))] = entity_id
+							} else {
+								entity = sg.Entities[entity_index]
+								sg.Entities = remove_entity(sg.Entities, entity_index)
+
+								status.EliminatedEntities = append(status.EliminatedEntities, entity)
+								continue
+							}
+
+							sg.PlayField[next_row_direction][next_col_direction] = entity.Id
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return status;
+}
+
+func (sg *SnakeGame) AddEntity(en_id int, en_name string, en_type string) error {
+	if en_type != "player" && en_type != "food" {
+		return errors.New("invalid entity type")
+	}
+
+	if en_id == 0 {
+		return errors.New("reserved ID (cannot be 0!)")
+	}
+
+	for _, entity := range sg.Entities {
+		if entity.Id == en_id {
+			return errors.New("entity already exists")
+		}
+	}
+
+	entity := Entity {
+		Id: en_id,
+		Name: en_name,
+		Type: en_type,
+		XDirection: 0,
+		YDirection: 0,
+		ConsumedFood: 0,
+	}
+
+	sg.Entities = append(sg.Entities, entity)
+
+	return nil
+}