Refactor the Tile to a full Atlas

This atlas is a set of chunks and supports resizing

pkg/game/atlas_test.go

@@ -0,0 +1,136 @@
+package game
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAtlas_NewAtlas(t *testing.T) {
+	a := NewAtlas(1, 1) // "radius" of 1, each chunk just one tile
+	assert.NotNil(t, a)
+	// Tiles should look like: 2 | 3
+	//  -----
+	//  0 | 1
+	assert.Equal(t, 4, len(a.Chunks))
+
+	a = NewAtlas(2, 1) // "radius" of 2
+	assert.NotNil(t, a)
+	// Tiles should look like: 2 | 3
+	//  -----
+	//  0 | 1
+	assert.Equal(t, 16, len(a.Chunks))
+}
+
+func TestAtlas_ToChunk(t *testing.T) {
+	a := NewAtlas(1, 1)
+	assert.NotNil(t, a)
+	// Tiles should look like: 2 | 3
+	//  -----
+	//  0 | 1
+	tile := a.ToChunk(Vector{0, 0})
+	assert.Equal(t, 3, tile)
+	tile = a.ToChunk(Vector{0, -1})
+	assert.Equal(t, 1, tile)
+	tile = a.ToChunk(Vector{-1, -1})
+	assert.Equal(t, 0, tile)
+	tile = a.ToChunk(Vector{-1, 0})
+	assert.Equal(t, 2, tile)
+
+	a = NewAtlas(1, 2)
+	assert.NotNil(t, a)
+	// Tiles should look like:
+	// 2 | 3
+	// -----
+	// 0 | 1
+	tile = a.ToChunk(Vector{1, 1})
+	assert.Equal(t, 3, tile)
+	tile = a.ToChunk(Vector{1, -2})
+	assert.Equal(t, 1, tile)
+	tile = a.ToChunk(Vector{-2, -2})
+	assert.Equal(t, 0, tile)
+	tile = a.ToChunk(Vector{-2, 1})
+	assert.Equal(t, 2, tile)
+
+	a = NewAtlas(2, 2)
+	assert.NotNil(t, a)
+	// Tiles should look like:
+	//  12| 13|| 14| 15
+	// ----------------
+	//  8 | 9 || 10| 11
+	// ================
+	//  4 | 5 || 6 | 7
+	// ----------------
+	//  0 | 1 || 2 | 3
+	tile = a.ToChunk(Vector{1, 3})
+	assert.Equal(t, 14, tile)
+	tile = a.ToChunk(Vector{1, -3})
+	assert.Equal(t, 2, tile)
+	tile = a.ToChunk(Vector{-1, -1})
+	assert.Equal(t, 5, tile)
+	tile = a.ToChunk(Vector{-2, 2})
+	assert.Equal(t, 13, tile)
+}
+
+func TestAtlas_GetSetTile(t *testing.T) {
+	a := NewAtlas(2, 10)
+	assert.NotNil(t, a)
+
+	// Set the origin tile to 1 and test it
+	assert.NoError(t, a.SetTile(Vector{0, 0}, 1))
+	tile, err := a.GetTile(Vector{0, 0})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(1), tile)
+
+	// Set another tile to 1 and test it
+	assert.NoError(t, a.SetTile(Vector{5, -2}, 2))
+	tile, err = a.GetTile(Vector{5, -2})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(2), tile)
+}
+
+func TestAtlas_Grown(t *testing.T) {
+	// Start with a small example
+	a := NewAtlas(1, 2)
+	assert.NotNil(t, a)
+	assert.Equal(t, 4, len(a.Chunks))
+
+	// Set a few tiles to values
+	assert.NoError(t, a.SetTile(Vector{0, 0}, 1))
+	assert.NoError(t, a.SetTile(Vector{-1, -1}, 2))
+	assert.NoError(t, a.SetTile(Vector{1, -2}, 3))
+
+	// Grow once to just double it
+	a, err := a.Grown(2)
+	assert.NoError(t, err)
+	assert.Equal(t, 16, len(a.Chunks))
+
+	tile, err := a.GetTile(Vector{0, 0})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(1), tile)
+
+	tile, err = a.GetTile(Vector{-1, -1})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(2), tile)
+
+	tile, err = a.GetTile(Vector{1, -2})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(3), tile)
+
+	// Grow it again even bigger
+	a, err = a.Grown(5)
+	assert.NoError(t, err)
+	assert.Equal(t, 100, len(a.Chunks))
+
+	tile, err = a.GetTile(Vector{0, 0})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(1), tile)
+
+	tile, err = a.GetTile(Vector{-1, -1})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(2), tile)
+
+	tile, err = a.GetTile(Vector{1, -2})
+	assert.NoError(t, err)
+	assert.Equal(t, Kind(3), tile)
+}