Added tests for Fill function

resize_test.go

@@ -200,6 +200,180 @@ func TestFit(t *testing.T) {
 	}
 }
 
+func TestFill(t *testing.T) {
+	td := []struct {
+		desc string
+		src  image.Image
+		w, h int
+		a    Anchor
+		f    ResampleFilter
+		want *image.NRGBA
+	}{
+		{
+			"Fill 4x4 2x2 Center Nearest",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			2, 2,
+			Center,
+			NearestNeighbor,
+			&image.NRGBA{
+				Rect:   image.Rect(0, 0, 2, 2),
+				Stride: 2 * 4,
+				Pix: []uint8{
+					0x14, 0x15, 0x16, 0x17, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x34, 0x35, 0x36, 0x37, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+		},
+		{
+			"Fill 4x4 1x4 TopLeft Nearest",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			1, 4,
+			TopLeft,
+			NearestNeighbor,
+			&image.NRGBA{
+				Rect:   image.Rect(0, 0, 1, 4),
+				Stride: 1 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03,
+					0x10, 0x11, 0x12, 0x13,
+					0x20, 0x21, 0x22, 0x23,
+					0x30, 0x31, 0x32, 0x33,
+				},
+			},
+		},
+		{
+			"Fill 4x4 8x2 Bottom Nearest",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			8, 2,
+			Bottom,
+			NearestNeighbor,
+			&image.NRGBA{
+				Rect:   image.Rect(0, 0, 8, 2),
+				Stride: 8 * 4,
+				Pix: []uint8{
+					0x30, 0x31, 0x32, 0x33, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x3c, 0x3d, 0x3e, 0x3f,
+					0x30, 0x31, 0x32, 0x33, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+		},
+		{
+			"Fill 4x4 2x8 Top Nearest",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			2, 8,
+			Top,
+			NearestNeighbor,
+			&image.NRGBA{
+				Rect:   image.Rect(0, 0, 2, 8),
+				Stride: 2 * 4,
+				Pix: []uint8{
+					0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
+					0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
+					0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b,
+					0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b,
+					0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
+					0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
+					0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+					0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+				},
+			},
+		},
+		{
+			"Fill 4x4 4x4 TopRight Box",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			4, 4,
+			TopRight,
+			Box,
+			&image.NRGBA{
+				Rect:   image.Rect(0, 0, 4, 4),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+		},
+		{
+			"Fill 4x4 0x4 Left Box",
+			&image.NRGBA{
+				Rect:   image.Rect(-1, -1, 3, 3),
+				Stride: 4 * 4,
+				Pix: []uint8{
+					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+				},
+			},
+			0, 4,
+			Left,
+			Box,
+			&image.NRGBA{},
+		},
+		{
+			"Fill 0x0 4x4 Right Box",
+			&image.NRGBA{},
+			4, 4,
+			Right,
+			Box,
+			&image.NRGBA{},
+		},
+	}
+	for _, d := range td {
+		got := Fill(d.src, d.w, d.h, d.a, d.f)
+		want := d.want
+		if !compareNRGBA(got, want, 0) {
+			t.Errorf("test [%s] failed: %#v", d.desc, got)
+		}
+	}
+}
+
 func TestThumbnail(t *testing.T) {
 	td := []struct {
 		desc string