Getting two of the four rules (sorta) working

with some gnarly and probably way too big scoring code.

conway/go/conway_test.go

@@ -21,7 +21,7 @@ func init() {
 
 func TestNewGameOfLifeHasCorrectDimensions(t *testing.T) {
 	game := NewGameOfLife(16, 16)
-	if game.Height != 16 || game.Width != 16 {
+	if game.State.Height() != 16 || game.State.Width() != 16 {
 		t.Fail()
 	}
 }
@@ -40,7 +40,7 @@ func TestNewGameOfLifeHasGameStateOfSameDimensions(t *testing.T) {
 
 func TestGameStateCanImportState(t *testing.T) {
 	game := NewGameOfLife(16, 16)
-	err := game.State.ImportState(TEST_SIMPLE_INITIAL_STATE)
+	err := game.State.Import(TEST_SIMPLE_INITIAL_STATE)
 	if err != nil {
 		t.Fail()
 	}
@@ -68,9 +68,10 @@ func TestGameStateCanImportState(t *testing.T) {
 
 func TestLiveCellWithFewerThanTwoLiveNeighborsDies(t *testing.T) {
 	game := NewGameOfLife(16, 16)
-	err := game.State.ImportState(TEST_SIMPLE_INITIAL_STATE)
+	err := game.State.Import(TEST_SIMPLE_INITIAL_STATE)
 	if err != nil {
 		t.Error(err)
+		return
 	}
 
 	game.EvaluateGeneration()
@@ -78,10 +79,35 @@ func TestLiveCellWithFewerThanTwoLiveNeighborsDies(t *testing.T) {
 	value, err := game.State.Get(2, 2)
 	if err != nil {
 		t.Error(err)
+		return
 	}
 
 	if value != 0 {
 		t.Errorf("%v != 0", value)
+		return
+	}
+}
+
+func TestLiveCellWithTwoOrThreeLiveNeighborsLivesOn(t *testing.T) {
+	game := NewGameOfLife(16, 16)
+	err := game.ImportState(TEST_SIMPLE_INITIAL_STATE)
+
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	game.EvaluateGeneration()
+
+	value, err := game.State.Get(0, 0)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	if value != 1 {
+		t.Errorf("%v != 1", value)
+		return
 	}
 }
 
@@ -144,3 +170,45 @@ func TestGameStateCanDeadenCellsByCoords(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestNewGenerationScoreCardIsAllZeros(t *testing.T) {
+	gen := NewGenerationScoreCard(4, 4)
+
+	for y := 0; y < gen.Height(); y++ {
+		for x := 0; x < gen.Width(); x++ {
+			if value, err := gen.Get(x, y); err != nil || value != 0 {
+				t.Fail()
+			}
+		}
+	}
+}
+
+func TestGenerationScoreCardCalculateResultsInCorrectNeighborCounts(t *testing.T) {
+	genScore := NewGenerationScoreCard(16, 16)
+	state := NewGameState(16, 16)
+
+	err := state.Import(TEST_SIMPLE_INITIAL_STATE)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	genScore.Calculate(state)
+	value, err := genScore.Get(0, 0)
+	if err != nil {
+		t.Error(err)
+		return
+	} else if value != 3 {
+		t.Errorf("[0, 0] value %v != 3", value)
+		return
+	}
+
+	value, err = genScore.Get(2, 2)
+	if err != nil {
+		t.Error(err)
+		return
+	} else if value != 1 {
+		t.Errorf("[2, 2] value %d != 1", value)
+		return
+	}
+}

conway/go/game_of_life.go

@@ -2,11 +2,10 @@ package conway
 
 import (
 	"errors"
+	"fmt"
 )
 
 type GameOfLife struct {
-	Height int
-	Width  int
 	State *GameState
 }
 
@@ -18,6 +17,10 @@ type GameState struct {
 	Rows []*gameGridRow
 }
 
+type GenerationScoreCard struct {
+	GameState
+}
+
 func NewGameState(height, width int) *GameState {
 	state := &GameState{}
 	for i := 0; i < height; i++ {
@@ -30,8 +33,19 @@ func NewGameState(height, width int) *GameState {
 	return state
 }
 
+func (state *GameState) Height() int {
+	return len(state.Rows)
+}
+
+func (state *GameState) Width() int {
+	if len(state.Rows) < 1 {
+		return -1
+	}
+	return len(state.Rows[0].Cols)
+}
+
 func (state *GameState) GetRow(y int) (*gameGridRow, error) {
-	if len(state.Rows) < y+1 {
+	if y+1 > len(state.Rows) {
 		return nil, errors.New("y coordinate is out of bounds!")
 	}
 
@@ -39,13 +53,19 @@ func (state *GameState) GetRow(y int) (*gameGridRow, error) {
 }
 
 func (state *GameState) Set(x, y, value int) error {
+	if x < 0 || y < 0 {
+		errMsg := fmt.Sprintf("coordinates (%v, %v) are out of bounds!", x, y)
+		return errors.New(errMsg)
+	}
+
 	row, err := state.GetRow(y)
 	if err != nil {
 		return err
 	}
 
-	if len(row.Cols) < x+1 {
-		return errors.New("x coordinate is out of bounds!")
+	if x+1 > len(row.Cols) {
+		errMsg := fmt.Sprintf("x coordinate %v is out of bounds!", x)
+		return errors.New(errMsg)
 	}
 
 	row.Cols[x] = value
@@ -73,7 +93,7 @@ func (state *GameState) Deaden(x, y int) error {
 	return state.Set(x, y, 0)
 }
 
-func (state *GameState) ImportState(other *GameState) (err error) {
+func (state *GameState) Import(other *GameState) (err error) {
 	for y, row := range other.Rows {
 		for x, cell := range row.Cols {
 			if err = state.Set(x, y, cell); err != nil {
@@ -86,12 +106,91 @@ func (state *GameState) ImportState(other *GameState) (err error) {
 
 func NewGameOfLife(height, width int) *GameOfLife {
 	return &GameOfLife{
-		Height: height,
-		Width:  width,
 		State: NewGameState(height, width),
 	}
 }
 
-func (game *GameOfLife) EvaluateGeneration() {
-	return
+func (game *GameOfLife) EvaluateGeneration() error {
+	height, width := game.State.Height(), game.State.Width()
+
+	genScore := NewGenerationScoreCard(height, width)
+	genScore.Calculate(game.State)
+
+	for y := 0; y < height-1; y++ {
+		for x := 0; x < width-1; x++ {
+			score, err := genScore.Get(x, y)
+			if err != nil {
+				return err
+			}
+
+			if score < 2 {
+				err = game.State.Deaden(x, y)
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (game *GameOfLife) ImportState(state *GameState) error {
+	return game.State.Import(state)
+}
+
+func NewGenerationScoreCard(height, width int) *GenerationScoreCard {
+	genScore := &GenerationScoreCard{}
+	for i := 0; i < height; i++ {
+		row := &gameGridRow{}
+		for j := 0; j < width; j++ {
+			row.Cols = append(row.Cols, 0)
+		}
+		genScore.Rows = append(genScore.Rows, row)
+	}
+	return genScore
+}
+
+func (genScore *GenerationScoreCard) Calculate(state *GameState) error {
+	stateHeight, stateWidth := state.Height(), state.Width()
+	for y := 0; y < stateHeight-1; y++ {
+		for x := 0; x < stateWidth-1; x++ {
+			value, err := state.Get(x, y)
+			if err != nil {
+				return err
+			}
+
+			if value == 1 {
+				for yOffset := -1; yOffset < 2; yOffset++ {
+					for xOffset := -1; xOffset < 2; xOffset++ {
+						xTarget := x + xOffset
+						yTarget := y + yOffset
+
+						if xTarget < 0 || yTarget < 0 {
+							continue
+						}
+
+						if xTarget+1 > stateWidth || yTarget+1 > stateWidth {
+							continue
+						}
+
+						if xTarget == x && yTarget == y {
+							continue
+						}
+
+						curScore, err := genScore.Get(xTarget, yTarget)
+						if err != nil {
+							continue // assume out of bounds, which is stinky
+						}
+						err = genScore.Set(xTarget, yTarget, curScore+1)
+						if err != nil {
+							return err
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return nil
 }