hash_test.go

package disgo

import (
	"image"
	"testing"
)

func TestHashDistance(t *testing.T) {
	tests := []struct {
		hash1            PHash
		hash2            PHash
		expectedDistance int
	}{
		{0x00, 0xff, 8},
		{0xf0, 0x0f, 8},
		{0xff, 0xfe, 1},
	}

	for i, test := range tests {
		distance := test.hash1.Distance(test.hash2)
		if distance != test.expectedDistance {
			t.Errorf("tests[%d] expected %d got %d", i, test.expectedDistance, distance)
		}

		distance = test.hash2.Distance(test.hash1)
		if distance != test.expectedDistance {
			t.Errorf("tests[%d] expected %d got %d", i, test.expectedDistance, distance)
		}
	}
}

func TestHash(t *testing.T) {
	tests := []struct {
		expectedHash   PHash
		expectedString string
		img            image.Image
	}{
		{
			expectedHash:   0x00ff00ff00ff00ff,
			expectedString: "0x00ff00ff00ff00ff   0000000011111111000000001111111100000000111111110000000011111111",
			img: &image.Gray{
				Pix: []byte{
					0x00, 0x03, 0x07, 0x0a, 0x0e, 0x11, 0x15, 0x18, 0x1c,
					0xdf, 0xdb, 0xd8, 0xd4, 0xd0, 0xcd, 0xc9, 0xc6, 0xc2,
					0x3f, 0x43, 0x46, 0x4a, 0x4d, 0x51, 0x55, 0x58, 0x5c,
					0x9f, 0x9b, 0x98, 0x94, 0x91, 0x8d, 0x8a, 0x86, 0x83,
					0x7f, 0x83, 0x86, 0x8a, 0x8d, 0x91, 0x94, 0x98, 0x9b,
					0x5f, 0x5c, 0x58, 0x54, 0x51, 0x4d, 0x4a, 0x46, 0x43,
					0xbf, 0xc2, 0xc6, 0xc9, 0xcd, 0xd0, 0xd4, 0xd8, 0xdb,
					0x1f, 0x1c, 0x18, 0x15, 0x11, 0x0e, 0x0a, 0x07, 0x03,
				},
				Stride: 9,
				Rect:   image.Rect(0, 0, 9, 8),
			},
		},
		{
			expectedHash:   0,
			expectedString: "0x0000000000000000   0000000000000000000000000000000000000000000000000000000000000000",
			img: &image.Gray{
				Pix: []byte{
					0x03, 0x07, 0x0a, 0x0e, 0x11, 0x15, 0x18, 0x1c, 0x1f,
					0x23, 0x26, 0x2a, 0x2e, 0x31, 0x35, 0x38, 0x3c, 0x3f,
					0x43, 0x46, 0x4a, 0x4d, 0x51, 0x55, 0x58, 0x5c, 0x5f,
					0x63, 0x66, 0x6a, 0x6d, 0x71, 0x74, 0x78, 0x7b, 0x7f,
					0x83, 0x86, 0x8a, 0x8d, 0x91, 0x94, 0x98, 0x9b, 0x9f,
					0xa2, 0xa6, 0xaa, 0xad, 0xb1, 0xb4, 0xb8, 0xbb, 0xbf,
					0xc2, 0xc6, 0xc9, 0xcd, 0xd0, 0xd4, 0xd8, 0xdb, 0xdf,
					0xe2, 0xe6, 0xe9, 0xed, 0xf0, 0xf4, 0xf7, 0xfb, 0xff,
				},
				Stride: 9,
				Rect:   image.Rect(0, 0, 9, 8),
			},
		},
		{
			expectedHash:   0xffffffffffffffff,
			expectedString: "0xffffffffffffffff   1111111111111111111111111111111111111111111111111111111111111111",
			img: &image.Gray{
				Pix: []byte{
					0xff, 0xfb, 0xf7, 0xf4, 0xf0, 0xed, 0xe9, 0xe6, 0xe2,
					0xdf, 0xdb, 0xd8, 0xd4, 0xd0, 0xcd, 0xc9, 0xc6, 0xc2,
					0xbf, 0xbb, 0xb8, 0xb4, 0xb1, 0xad, 0xa9, 0xa6, 0xa2,
					0x9f, 0x9b, 0x98, 0x94, 0x91, 0x8d, 0x8a, 0x86, 0x83,
					0x7f, 0x7b, 0x78, 0x74, 0x71, 0x6d, 0x6a, 0x66, 0x63,
					0x5f, 0x5c, 0x58, 0x55, 0x51, 0x4d, 0x4a, 0x46, 0x43,
					0x3f, 0x3c, 0x38, 0x35, 0x31, 0x2e, 0x2a, 0x26, 0x23,
					0x1f, 0x1c, 0x18, 0x15, 0x11, 0x0e, 0x0a, 0x07, 0x03,
				},
				Stride: 9,
				Rect:   image.Rect(0, 0, 9, 8),
			},
		},
	}

	for i, test := range tests {
		hash, _ := Hash(test.img)
		if hash != test.expectedHash {
			t.Errorf("tests[%d] expected %x got %x", i, test.expectedHash, hash)
		}

		if hash.String() != test.expectedString {
			t.Errorf("tests[%d] expected %q got %q", i, test.expectedString, hash.String())
		}
	}
}