galaxy-game/pkg/bitmap/bitmap_test.go

package bitmap_test

import (
	"fmt"
	"math/rand"
	"os"
	"strings"
	"testing"

	"bitmap"
)

func TestBitVectorSize(t *testing.T) {
	type testCase struct {
		width, height uint32
		expectSize    int
	}
	for _, tc := range []testCase{
		{
			width:      10,
			height:     10,
			expectSize: 4,
		},
		{
			width:      1,
			height:     1,
			expectSize: 1,
		},
		{
			width:      32,
			height:     32,
			expectSize: 32,
		},
	} {
		t.Run(fmt.Sprintf("w=%d h=%d s=%d", tc.width, tc.height, tc.expectSize), func(t *testing.T) {
			bm := bitmap.NewBitmap(tc.width, tc.height)
			l := len(bitmap.Value(bm))
			if tc.expectSize != l {
				t.Errorf("expected bitmap size: %d, got: %d", tc.expectSize, l)
			}
		})
	}
}

func TestSetPixel(t *testing.T) {
	type coord struct {
		x, y int
	}
	type testCase struct {
		width, height uint32
		pixels        []coord
		bits          []int
	}
	asMap := func(bits []int) map[int]bool {
		result := make(map[int]bool)
		for i := range bits {
			if _, ok := result[bits[i]]; ok {
				t.Fatalf("source bits duplicate at idx=%d", i)
			} else {
				result[bits[i]] = true
			}
		}
		return result
	}
	asUint32 := func(v bool) uint32 { return map[bool]uint32{true: 1, false: 0}[v] }
	for i, tc := range []testCase{
		{
			width:  5,
			height: 5,
			pixels: []coord{{0, 0}},
			bits:   []int{0},
		},
		{
			width:  5,
			height: 5,
			pixels: []coord{{1, 0}},
			bits:   []int{1},
		},
		{
			width:  5,
			height: 5,
			pixels: []coord{{2, 0}},
			bits:   []int{2},
		},
		{
			width:  5,
			height: 5,
			pixels: []coord{{0, 1}},
			bits:   []int{5},
		},
		{
			width:  5,
			height: 5,
			pixels: []coord{{4, 4}},
			bits:   []int{24},
		},
		{
			width:  8,
			height: 8,
			pixels: []coord{{7, 7}},
			bits:   []int{63},
		},
	} {
		t.Run(fmt.Sprintf("tc#%d", i), func(t *testing.T) {
			bm := bitmap.NewBitmap(tc.width, tc.height)
			for _, c := range tc.pixels {
				if bm.IsSet(c.x, c.y) {
					t.Errorf("expected pixel to be clear at x=%d y=%d", c.x, c.y)
				}
				bm.Set(c.x, c.y)
				if !bm.IsSet(c.x, c.y) {
					t.Errorf("expected pixel to be set at x=%d y=%d", c.x, c.y)
				}
			}
			bitVector := bitmap.Value(bm)
			bitNum := 0
			expected := asMap(tc.bits)
			for bi := range bitVector {
				for ; bitNum < (bi+1)*32; bitNum++ {
					if (bitVector[bi]>>(bitNum%32))&1 != asUint32(expected[bitNum]) {
						t.Errorf("expected: bit #%d to be %t, got %v", bitNum, expected[bitNum], uint32(1<<(bitNum%32)))
					}
				}
			}
		})
	}
}

func TestClear(t *testing.T) {
	var bm = bitmap.NewBitmap(10, 10)
	for range 50 {
		bm.Set(rand.Intn(10), rand.Intn(10))
	}
	var acc uint32
	for _, holder := range bitmap.Value(bm) {
		acc |= holder
	}
	if acc == 0 {
		t.Errorf("some pixels should be set")
	}
	bm.Clear()
	acc = 0
	for _, holder := range bitmap.Value(bm) {
		acc |= holder
	}
	if acc != 0 {
		t.Errorf("all pixels should be clear")
	}
}

func TestCircle5x5(t *testing.T) {
	type testCase struct {
		x, y   int
		r      float64
		filled bool
	}
	bm := bitmap.NewBitmap(80, 80)
	for i, tc := range []testCase{
		{3, 3, 0.9, false},
	} {
		file := fmt.Sprintf("assets_test/circle_case_%02d.txt", i)
		_ = file
		t.Run(file, func(t *testing.T) {
			bm.CircleAdjacent(tc.x, tc.y, tc.r)
			b, err := os.ReadFile(file)
			if err != nil {
				t.Fatal(err)
			}
			expect := strings.TrimSpace(string(b))
			if expect != bm.String() {
				t.Errorf("expect:\n%s\ngot:\n%s\n", expect, bm.String())
			}
		})
	}
}

func TestCircle(t *testing.T) {
	var size int = 40
	var bm1 = bitmap.NewBitmap(uint32(size), uint32(size))
	bm1.Circle(size/2+5, size/2-5, float64(size/2)-3)
	fmt.Println(bm1)
	var bm2 = bitmap.NewBitmap(uint32(size), uint32(size))
	bm2.CircleAdjacent(size/2+20, size/2, float64(size/2)-5)
}