feat: add 7-bag generation

Author: Broderick-Westrope

bag.go

@@ -0,0 +1,151 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+)
+
+var RotationCoords = map[byte][]Coordinate{
+	'I': {
+		{X: -1, Y: -1},
+		{X: 2, Y: 1},
+		{X: -2, Y: -2},
+		{X: 1, Y: 2},
+	},
+	'O': {
+		{X: 0, Y: 0},
+		{X: 0, Y: 0},
+		{X: 0, Y: 0},
+		{X: 0, Y: 0},
+	},
+	'6': { // All tetriminos with 6 cells (T, S, Z, J, L)
+		{X: 0, Y: 0},
+		{X: 1, Y: 0},
+		{X: -1, Y: -1},
+		{X: 0, Y: 1},
+	},
+}
+
+var startingPositions = map[byte]Coordinate{
+	'I': {X: 3, Y: -1},
+	'O': {X: 4, Y: -2},
+	'6': {X: 3, Y: -2},
+}
+
+var tetriminos = []Tetrimino{
+	{
+		Value: 'I',
+		Cells: [][]bool{
+			{true, true, true, true},
+		},
+		Pos:            startingPositions['I'],
+		RotationCoords: RotationCoords['I'],
+	},
+	{
+		Value: 'O',
+		Cells: [][]bool{
+			{true, true},
+			{true, true},
+		},
+		Pos:            startingPositions['O'],
+		RotationCoords: RotationCoords['O'],
+	},
+	{
+		Value: 'T',
+		Cells: [][]bool{
+			{false, true, false},
+			{true, true, true},
+		},
+		Pos:            startingPositions['6'],
+		RotationCoords: RotationCoords['6'],
+	},
+	{
+		Value: 'S',
+		Cells: [][]bool{
+			{false, true, true},
+			{true, true, false},
+		},
+		Pos:            startingPositions['6'],
+		RotationCoords: RotationCoords['6'],
+	},
+	{
+		Value: 'Z',
+		Cells: [][]bool{
+			{true, true, false},
+			{false, true, true},
+		},
+		Pos:            startingPositions['6'],
+		RotationCoords: RotationCoords['6'],
+	},
+	{
+		Value: 'J',
+		Cells: [][]bool{
+			{true, false, false},
+			{true, true, true},
+		},
+		Pos:            startingPositions['6'],
+		RotationCoords: RotationCoords['6'],
+	},
+	{
+		Value: 'L',
+		Cells: [][]bool{
+			{false, false, true},
+			{true, true, true},
+		},
+		Pos:            startingPositions['6'],
+		RotationCoords: RotationCoords['6'],
+	},
+}
+
+type bag struct {
+	elements        []*Tetrimino
+	playfieldHeight int
+}
+
+func defaultBag(playfieldHeight int) *bag {
+	b := bag{
+		elements:        make([]*Tetrimino, 0, 14),
+		playfieldHeight: playfieldHeight,
+	}
+	b.fillBag()
+	b.fillBag()
+	return &b
+}
+
+func (b *bag) next() *Tetrimino {
+	tet := b.elements[0]
+	b.elements = b.elements[1:]
+
+	if len(b.elements) <= 7 {
+		b.fillBag()
+	}
+
+	tet.Pos.Y += b.playfieldHeight - 20
+	return tet
+}
+
+func (b *bag) fillBag() {
+	perm := rand.Perm(len(tetriminos))
+	for _, i := range perm {
+		if len(b.elements) == 14 {
+			return
+		}
+		b.enqueue(&tetriminos[i])
+	}
+}
+
+// Adds an item to the end of the queue
+func (b *bag) enqueue(value *Tetrimino) {
+	b.elements = append(b.elements, value)
+}
+
+// Removes an item from the front of the queue and returns it
+// If the queue is empty, returns 0 and an error
+func (b *bag) dequeue() (*Tetrimino, error) {
+	if len(b.elements) == 0 {
+		return nil, fmt.Errorf("queue is empty")
+	}
+	element := b.elements[0]    // Get the first element
+	b.elements = b.elements[1:] // Remove it from the queue
+	return element, nil
+}

model.go

@@ -21,6 +21,7 @@ type Model struct {
 	holdTet    *Tetrimino
 	fall       *Fall
 	scoring    *scoring
+	bag        *bag
 }
 
 type Fall struct {
@@ -69,8 +70,13 @@ func InitialModel() *Model {
 			Value: 0,
 		},
 	}
+	m.bag = defaultBag(len(m.playfield))
 	m.fall = defaultFall(m.scoring.level)
-	m.currentTet = m.playfield.NewTetrimino()
+	m.currentTet = m.bag.next()
+	err := m.playfield.AddTetrimino(m.currentTet)
+	if err != nil {
+		panic(fmt.Errorf("failed to add tetrimino to playfield: %w", err))
+	}
 	return m
 }
 
@@ -112,7 +118,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				if !m.currentTet.canMoveDown(m.playfield) {
 					action := m.playfield.removeCompletedLines(m.currentTet)
 					m.scoring.processAction(action)
-					m.currentTet = m.playfield.NewTetrimino()
+					m.currentTet = m.bag.next()
+					err := m.playfield.AddTetrimino(m.currentTet)
+					if err != nil {
+						panic(fmt.Errorf("failed to add tetrimino to playfield: %w", err))
+					}
 					break
 				}
 
@@ -128,7 +138,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if !m.currentTet.canMoveDown(m.playfield) {
 			action := m.playfield.removeCompletedLines(m.currentTet)
 			m.scoring.processAction(action)
-			m.currentTet = m.playfield.NewTetrimino()
+			m.currentTet = m.bag.next()
+			err := m.playfield.AddTetrimino(m.currentTet)
+			if err != nil {
+				panic(fmt.Errorf("failed to add tetrimino to playfield: %w", err))
+			}
 			break
 		}
 		err := m.currentTet.MoveDown(&m.playfield)

playfield.go

@@ -34,7 +34,7 @@ func (p *Playfield) removeCells(tetrimino *Tetrimino) error {
 	return nil
 }
 
-func (p *Playfield) addCells(tetrimino *Tetrimino) error {
+func (p *Playfield) AddTetrimino(tetrimino *Tetrimino) error {
 	for row := range tetrimino.Cells {
 		for col := range tetrimino.Cells[row] {
 			if tetrimino.Cells[row][col] {
@@ -48,12 +48,6 @@ func (p *Playfield) addCells(tetrimino *Tetrimino) error {
 	return nil
 }
 
-func (p *Playfield) NewTetrimino() *Tetrimino {
-	tet := RandomTetrimino(len(p))
-	p.addCells(tet)
-	return tet
-}
-
 func (p *Playfield) removeCompletedLines(tet *Tetrimino) action {
 	lines := 0
 	for row := range tet.Cells {

tetrimino.go

@@ -2,101 +2,8 @@ package main
 
 import (
 	"fmt"
-	"math/rand"
 )
 
-var RotationCoords = map[byte][]Coordinate{
-	'I': {
-		{X: -1, Y: -1},
-		{X: 2, Y: 1},
-		{X: -2, Y: -2},
-		{X: 1, Y: 2},
-	},
-	'O': {
-		{X: 0, Y: 0},
-		{X: 0, Y: 0},
-		{X: 0, Y: 0},
-		{X: 0, Y: 0},
-	},
-	'6': { // All tetriminos with 6 cells (T, S, Z, J, L)
-		{X: 0, Y: 0},
-		{X: 1, Y: 0},
-		{X: -1, Y: -1},
-		{X: 0, Y: 1},
-	},
-}
-
-var startingPositions = map[byte]Coordinate{
-	'I': {X: 3, Y: -1},
-	'O': {X: 4, Y: -2},
-	'6': {X: 3, Y: -2},
-}
-
-var tetriminos = []Tetrimino{
-	{
-		Value: 'I',
-		Cells: [][]bool{
-			{true, true, true, true},
-		},
-		Pos:            startingPositions['I'],
-		RotationCoords: RotationCoords['I'],
-	},
-	{
-		Value: 'O',
-		Cells: [][]bool{
-			{true, true},
-			{true, true},
-		},
-		Pos:            startingPositions['O'],
-		RotationCoords: RotationCoords['O'],
-	},
-	{
-		Value: 'T',
-		Cells: [][]bool{
-			{false, true, false},
-			{true, true, true},
-		},
-		Pos:            startingPositions['6'],
-		RotationCoords: RotationCoords['6'],
-	},
-	{
-		Value: 'S',
-		Cells: [][]bool{
-			{false, true, true},
-			{true, true, false},
-		},
-		Pos:            startingPositions['6'],
-		RotationCoords: RotationCoords['6'],
-	},
-	{
-		Value: 'Z',
-		Cells: [][]bool{
-			{true, true, false},
-			{false, true, true},
-		},
-		Pos:            startingPositions['6'],
-		RotationCoords: RotationCoords['6'],
-	},
-	{
-		Value: 'J',
-		Cells: [][]bool{
-			{true, false, false},
-			{true, true, true},
-		},
-		Pos:            startingPositions['6'],
-		RotationCoords: RotationCoords['6'],
-	},
-	{
-		Value: 'L',
-		Cells: [][]bool{
-			{false, false, true},
-			{true, true, true},
-		},
-		Pos:            startingPositions['6'],
-		RotationCoords: RotationCoords['6'],
-	},
-}
-
 type Coordinate struct {
 	X, Y int
 }
@@ -109,15 +16,6 @@ type Tetrimino struct {
 	RotationCoords  []Coordinate
 }
 
-// TODO: update to be private. Change tests to be on NewTetrimino instead.
-// randomTetrimino returns a random tetrimino.
-// The tetrimino will be positioned just above the playfield.
-func RandomTetrimino(playfieldHeight int) *Tetrimino {
-	t := tetriminos[rand.Intn(len(tetriminos))]
-	t.Pos.Y += playfieldHeight - 20
-	return &t
-}
-
 // MoveDown moves the tetrimino down one row.
 // If the tetrimino cannot move down, it will be added to the playfield and a new tetrimino will be returned.
 func (t *Tetrimino) MoveDown(playfield *Playfield) error {
@@ -126,7 +24,7 @@ func (t *Tetrimino) MoveDown(playfield *Playfield) error {
 		return fmt.Errorf("failed to remove cells: %w", err)
 	}
 	t.Pos.Y++
-	err = playfield.addCells(t)
+	err = playfield.AddTetrimino(t)
 	if err != nil {
 		return fmt.Errorf("failed to add cells: %w", err)
 	}
@@ -144,7 +42,7 @@ func (t *Tetrimino) MoveLeft(playfield *Playfield) error {
 		return fmt.Errorf("failed to remove cells: %w", err)
 	}
 	t.Pos.X--
-	err = playfield.addCells(t)
+	err = playfield.AddTetrimino(t)
 	if err != nil {
 		return fmt.Errorf("failed to add cells: %w", err)
 	}
@@ -162,7 +60,7 @@ func (t *Tetrimino) MoveRight(playfield *Playfield) error {
 		return fmt.Errorf("failed to remove cells: %w", err)
 	}
 	t.Pos.X++
-	err = playfield.addCells(t)
+	err = playfield.AddTetrimino(t)
 	if err != nil {
 		return fmt.Errorf("failed to add cells: %w", err)
 	}
@@ -239,7 +137,7 @@ func (t *Tetrimino) Rotate(playfield *Playfield, clockwise bool) error {
 		t.Cells = rotated.Cells
 	}
 
-	err = playfield.addCells(t)
+	err = playfield.AddTetrimino(t)
 	if err != nil {
 		return fmt.Errorf("failed to add cells: %w", err)
 	}