Move a piece

example/blocks/field.go

@@ -13,11 +13,49 @@ func NewField() *Field {
 	return &Field{}
 }
 
+func (f *Field) IsBlocked(x, y int) bool {
+	if x < 0 || fieldBlockNumX <= x {
+		return true
+	}
+	if y < 0 {
+		return false
+	}
+	if fieldBlockNumX <= y {
+		return true
+	}
+	return f.blocks[x][y] != BlockTypeNone
+}
+
+func (f *Field) collides(piece *Piece, x, y int, angle Angle) bool {
+	return piece.collides(f, x, y, angle)
+}
+
+func (f *Field) MovePieceToLeft(piece *Piece, x, y int, angle Angle) int {
+	if f.collides(piece, x-1, y, angle) {
+		return x
+	}
+	return x - 1
+}
+
+func (f *Field) MovePieceToRight(piece *Piece, x, y int, angle Angle) int {
+	if f.collides(piece, x+1, y, angle) {
+		return x
+	}
+	return x + 1
+}
+
+func (f *Field) RotatePieceRight(piece *Piece, x, y int, angle Angle) Angle {
+	if f.collides(piece, x, y, angle.RotateRight()) {
+		return angle
+	}
+	return angle.RotateRight()
+}
+
 func (f *Field) Draw(context graphics.Context, geo matrix.Geometry) {
 	blocks := make([][]BlockType, len(f.blocks))
-	for i, blockLine := range f.blocks {
-		blocks[i] = make([]BlockType, len(blockLine))
-		copy(blocks[i], blockLine[:])
+	for i, blockCol := range f.blocks {
+		blocks[i] = make([]BlockType, len(blockCol))
+		copy(blocks[i], blockCol[:])
 	}
 	drawBlocks(context, blocks, geo)
 }

example/blocks/game_scene.go

@@ -3,6 +3,7 @@ package blocks
 import (
 	"github.com/hajimehoshi/go-ebiten/graphics"
 	"github.com/hajimehoshi/go-ebiten/graphics/matrix"
+	"github.com/hajimehoshi/go-ebiten/ui"
 	"image/color"
 	"math/rand"
 	"time"
@@ -13,10 +14,13 @@ func init() {
 }
 
 type GameScene struct {
-	field        *Field
-	rand         *rand.Rand
-	currentPiece *Piece
-	nextPiece    *Piece
+	field             *Field
+	rand              *rand.Rand
+	currentPiece      *Piece
+	currentPieceX     int
+	currentPieceY     int
+	currentPieceAngle Angle
+	nextPiece         *Piece
 }
 
 func NewGameScene() *GameScene {
@@ -32,15 +36,36 @@ const fieldWidth = blockWidth * fieldBlockNumX
 const fieldHeight = blockHeight * fieldBlockNumY
 
 func (s *GameScene) choosePiece() *Piece {
-	// Omit BlockTypeNone.
-	num := int(BlockTypeMax) - 1
-	blockType := BlockType(s.rand.Intn(num) + 1)
+	//num := NormalBlockTypeNum
+	//blockType := BlockType(s.rand.Intn(num) + 1)
+	blockType := BlockType1
 	return Pieces[blockType]
 }
 
 func (s *GameScene) Update(state *GameState) {
 	if s.currentPiece == nil {
 		s.currentPiece = s.choosePiece()
+		x, y := s.currentPiece.InitialPosition()
+		s.currentPieceX = x
+		s.currentPieceY = y
+		s.currentPieceAngle = Angle0
+	}
+	if state.Input.StateForKey(ui.KeySpace) == 1 {
+		s.currentPieceAngle = s.field.RotatePieceRight(
+			s.currentPiece, s.currentPieceX, s.currentPieceY,
+			s.currentPieceAngle)
+	}
+	l := state.Input.StateForKey(ui.KeyLeft)
+	if l == 1 || (10 <= l && l % 2 == 0) {
+		s.currentPieceX = s.field.MovePieceToLeft(
+			s.currentPiece, s.currentPieceX, s.currentPieceY,
+			s.currentPieceAngle)
+	}
+	r := state.Input.StateForKey(ui.KeyRight)
+	if r == 1 || (10 <= r && r % 2 == 0) {
+		s.currentPieceX = s.field.MovePieceToRight(
+			s.currentPiece, s.currentPieceX, s.currentPieceY,
+			s.currentPieceAngle)
 	}
 }
 
@@ -49,8 +74,8 @@ func (s *GameScene) Draw(context graphics.Context) {
 
 	field := drawInfo.textures["empty"]
 	geoMat := matrix.IdentityGeometry()
-	geoMat.Scale(float64(fieldWidth) / float64(emptyWidth),
-		float64(fieldHeight) / float64(emptyHeight))
+	geoMat.Scale(float64(fieldWidth)/float64(emptyWidth),
+		float64(fieldHeight)/float64(emptyHeight))
 	geoMat.Translate(20, 20) // magic number?
 	colorMat := matrix.IdentityColor()
 	colorMat.Scale(color.RGBA{0, 0, 0, 0x80})
@@ -61,6 +86,7 @@ func (s *GameScene) Draw(context graphics.Context) {
 	s.field.Draw(context, geoMat)
 
 	if s.currentPiece != nil {
-		s.currentPiece.Draw(context, geoMat)
+		s.currentPiece.Draw(context, 20, 20,
+			s.currentPieceX, s.currentPieceY, s.currentPieceAngle)
 	}
 }

example/blocks/piece.go

@@ -9,6 +9,22 @@ func init() {
 	texturePaths["blocks"] = "images/blocks/blocks.png"
 }
 
+type Angle int
+
+const (
+	Angle0 Angle = iota
+	Angle90
+	Angle180
+	Angle270
+)
+
+func (a Angle) RotateRight() Angle {
+	if a == Angle270 {
+		return Angle0
+	}
+	return a + 1
+}
+
 type BlockType int
 
 const (
@@ -20,9 +36,10 @@ const (
 	BlockType5
 	BlockType6
 	BlockType7
-	BlockTypeMax
 )
 
+const NormalBlockTypeNum = 7
+
 type Piece struct {
 	blockType BlockType
 	blocks    [][]bool
@@ -30,67 +47,70 @@ type Piece struct {
 
 func toBlocks(ints [][]int) [][]bool {
 	blocks := make([][]bool, len(ints))
-	for i, line := range ints {
-		blocks[i] = make([]bool, len(line))
-		for j, v := range line {
-			blocks[i][j] = v != 0
+	for j, row := range ints {
+		blocks[j] = make([]bool, len(row))
+	}
+	// Tranpose the argument matrix.
+	for i, col := range ints {
+		for j, v := range col {
+			blocks[j][i] = v != 0
 		}
 	}
 	return blocks
 }
 
 var Pieces = map[BlockType]*Piece{
-	BlockTypeNone: nil,
 	BlockType1: &Piece{
 		blockType: BlockType1,
 		blocks: toBlocks([][]int{
-			{0, 1, 0, 0},
-			{0, 1, 0, 0},
-			{0, 1, 0, 0},
-			{0, 1, 0, 0},
+			{0, 0, 0, 0},
+			{1, 1, 1, 1},
+			{0, 0, 0, 0},
+			{0, 0, 0, 0},
 		}),
 	},
 	BlockType2: &Piece{
 		blockType: BlockType2,
 		blocks: toBlocks([][]int{
-			{0, 1, 1},
-			{0, 1, 0},
-			{0, 1, 0},
+			{1, 0, 0},
+			{1, 1, 1},
+			{0, 0, 0},
 		}),
 	},
 	BlockType3: &Piece{
 		blockType: BlockType3,
 		blocks: toBlocks([][]int{
 			{0, 1, 0},
-			{0, 1, 1},
-			{0, 1, 0},
+			{1, 1, 1},
+			{0, 0, 0},
 		}),
 	},
 	BlockType4: &Piece{
 		blockType: BlockType4,
 		blocks: toBlocks([][]int{
-			{0, 1, 0},
-			{0, 1, 0},
-			{0, 1, 1},
+			{0, 0, 1},
+			{1, 1, 1},
+			{0, 0, 0},
 		}),
 	},
 	BlockType5: &Piece{
 		blockType: BlockType5,
 		blocks: toBlocks([][]int{
-			{0, 0, 1},
+			{1, 1, 0},
 			{0, 1, 1},
-			{0, 1, 0},
+			{0, 0, 0},
 		}),
 	},
 	BlockType6: &Piece{
 		blockType: BlockType6,
 		blocks: toBlocks([][]int{
-			{0, 1, 0},
 			{0, 1, 1},
-			{0, 0, 1},
+			{1, 1, 0},
+			{0, 0, 0},
 		}),
 	},
 	BlockType7: &Piece{
+		blockType: BlockType7,
 		blocks: toBlocks([][]int{
 			{1, 1},
 			{1, 1},
@@ -105,13 +125,13 @@ const fieldBlockNumY = 20
 
 func drawBlocks(context graphics.Context, blocks [][]BlockType, geo matrix.Geometry) {
 	parts := []graphics.TexturePart{}
-	for i, blockLine := range blocks {
-		for j, block := range blockLine {
+	for i, blockCol := range blocks {
+		for j, block := range blockCol {
 			if block == BlockTypeNone {
 				continue
 			}
-			locationX := j * blockWidth
-			locationY := i * blockHeight
+			locationX := i * blockWidth
+			locationY := j * blockHeight
 			source := graphics.Rect{
 				(int(block) - 1) * blockWidth, 0,
 				blockWidth, blockHeight}
@@ -127,15 +147,68 @@ func drawBlocks(context graphics.Context, blocks [][]BlockType, geo matrix.Geome
 	context.DrawTextureParts(blocksTexture, parts, geo, matrix.IdentityColor())
 }
 
-func (p *Piece) Draw(context graphics.Context, geo matrix.Geometry) {
-	blocks := make([][]BlockType, len(p.blocks))
-	for i, blockLine := range p.blocks {
-		blocks[i] = make([]BlockType, len(blockLine))
-		for j, v := range blockLine {
-			if v {
+func (p *Piece) InitialPosition() (int, int) {
+	size := len(p.blocks)
+	x := (fieldBlockNumX - size) / 2
+	y := 0
+Loop:
+	for j := 0; j < size; j++ {
+		for i := 0; i < size; i++ {
+			if p.blocks[i][j] {
+				break Loop
+			}
+		}
+		y--
+	}
+	return x, y
+}
+
+func (p *Piece) isBlocked(i, j int, angle Angle) bool {
+	size := len(p.blocks)
+	i2, j2 := i, j
+	switch angle {
+	case Angle0:
+	case Angle90:
+		i2 = j
+		j2 = size-1-i
+	case Angle180:
+		i2 = size-1-i
+		j2 = size-1-j
+	case Angle270:
+		i2 = size-1-j
+		j2 = i
+	}
+	return p.blocks[i2][j2]
+}
+
+func (p *Piece) collides(field *Field, x, y int, angle Angle) bool {
+	size := len(p.blocks)
+	for i := 0; i < size; i++ {
+		for j := 0; j < size; j++ {
+			if field.IsBlocked(x+i, y+j) && p.isBlocked(i, j, angle) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (p *Piece) Draw(context graphics.Context, fieldX, fieldY int, pieceX, pieceY int, angle Angle) {
+	size := len(p.blocks)
+	blocks := make([][]BlockType, size)
+	for i, _ := range p.blocks {
+		blocks[i] = make([]BlockType, size)
+		for j, _ := range blocks[i] {
+			if p.isBlocked(i, j, angle) {
 				blocks[i][j] = p.blockType
 			}
 		}
 	}
-	drawBlocks(context, blocks, geo)
+
+	geoMat := matrix.IdentityGeometry()
+	x := fieldX + pieceX * blockWidth
+	y := fieldY + pieceY * blockHeight
+	geoMat.Translate(float64(x), float64(y))
+
+	drawBlocks(context, blocks, geoMat)
 }