hunk.code_window:     }
       onHide() {
           this.setState({
               serverError: ''
           });
           this.props.onHide();
       }
  
hunk.labels: keep keep keep keep replace keep keep keep keep
hunk.after_edit:             serverError: '',
               header: this.props.channel.header
  
hunk.file_path: web/react/components/edit_channel_header_modal.jsx
hunk.type: replace
file: package imaging
  
  import (
  	"image"
  	"testing"
  )
  
  func TestCrop(t *testing.T) {
  	td := []struct {
  		desc string
  		src  image.Image
  		r    image.Rectangle
  		want *image.NRGBA
  	}{
  		{
  			"Crop 2x3 2x1",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			image.Rect(-1, 0, 1, 1),
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 1),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  				},
  			},
  		},
  	}
  	for _, d := range td {
  		got := Crop(d.src, d.r)
  		want := d.want
  		if !compareNRGBA(got, want, 0) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  
  func TestCropCenter(t *testing.T) {
  	td := []struct {
  		desc string
  		src  image.Image
  		w, h int
  		want *image.NRGBA
  	}{
  		{
  			"CropCenter 2x3 2x1",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			2, 1,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 1),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  				},
  			},
  		},
  		{
  			"CropCenter 2x3 0x1",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			0, 1,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 0, 0),
  				Stride: 0,
  				Pix:    []uint8{},
  			},
  		},
  		{
  			"CropCenter 2x3 5x5",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			5, 5,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 3),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  		},
  	}
  	for _, d := range td {
  		got := CropCenter(d.src, d.w, d.h)
  		want := d.want
  		if !compareNRGBA(got, want, 0) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  
  func TestCropAnchor(t *testing.T) {
  	td := []struct {
  		desc   string
  		src    image.Image
  		w, h   int
  		anchor Anchor
  		want   *image.NRGBA
  	}{
  		{
  			"CropAnchor 4x4 2x2 TopLeft",
  			&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,
  			TopLeft,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
  					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 Top",
  			&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,
  			Top,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
  					0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 TopRight",
  			&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,
  			TopRight,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
  					0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 Left",
  			&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,
  			Left,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
  					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 Center",
  			&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,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b,
  					0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 Right",
  			&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,
  			Right,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
  					0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 BottomLeft",
  			&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,
  			BottomLeft,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
  					0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 Bottom",
  			&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,
  			Bottom,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  					0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 2x2 BottomRight",
  			&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,
  			BottomRight,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
  					0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 0x0 BottomRight",
  			&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, 0,
  			BottomRight,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 0, 0),
  				Stride: 0,
  				Pix:    []uint8{},
  			},
  		},
  		{
  			"CropAnchor 4x4 100x100 BottomRight",
  			&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,
  				},
  			},
  			100, 100,
  			BottomRight,
  			&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,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 1x100 BottomRight",
  			&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, 100,
  			BottomRight,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 1, 4),
  				Stride: 1 * 4,
  				Pix: []uint8{
  					0x0c, 0x0d, 0x0e, 0x0f,
  					0x1c, 0x1d, 0x1e, 0x1f,
  					0x2c, 0x2d, 0x2e, 0x2f,
  					0x3c, 0x3d, 0x3e, 0x3f,
  				},
  			},
  		},
  		{
  			"CropAnchor 4x4 0x100 BottomRight",
  			&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, 100,
  			BottomRight,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 0, 0),
  				Stride: 0,
  				Pix:    []uint8{},
  			},
  		},
  	}
  	for _, d := range td {
  		got := CropAnchor(d.src, d.w, d.h, d.anchor)
  		want := d.want
  		if !compareNRGBA(got, want, 0) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  
  func TestPaste(t *testing.T) {
  	td := []struct {
  		desc string
  		src1 image.Image
  		src2 image.Image
  		p    image.Point
  		want *image.NRGBA
  	}{
  		{
  			"Paste 2x3 2x1",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			&image.NRGBA{
  				Rect:   image.Rect(1, 1, 3, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  				},
  			},
  			image.Pt(-1, 0),
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 3),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  		},
  	}
  	for _, d := range td {
  		got := Paste(d.src1, d.src2, d.p)
  		want := d.want
  		if !compareNRGBA(got, want, 0) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  
  func TestPasteCenter(t *testing.T) {
  	td := []struct {
  		desc string
  		src1 image.Image
  		src2 image.Image
  		want *image.NRGBA
  	}{
  		{
  			"PasteCenter 2x3 2x1",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			&image.NRGBA{
  				Rect:   image.Rect(1, 1, 3, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  				},
  			},
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 3),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  		},
  	}
  	for _, d := range td {
  		got := PasteCenter(d.src1, d.src2)
  		want := d.want
  		if !compareNRGBA(got, want, 0) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  
  func TestOverlay(t *testing.T) {
  	td := []struct {
  		desc string
  		src1 image.Image
  		src2 image.Image
  		p    image.Point
  		a    float64
  		want *image.NRGBA
  	}{
  		{
  			"Overlay 2x3 2x1 1.0",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0x60, 0x00, 0x90, 0xff, 0xff, 0x00, 0x99, 0x7f,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  			&image.NRGBA{
  				Rect:   image.Rect(1, 1, 3, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x20, 0x40, 0x80, 0x7f, 0xaa, 0xbb, 0xcc, 0xff,
  				},
  			},
  			image.Pt(-1, 0),
  			1.0,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 3),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0x00, 0x11, 0x22, 0x33, 0xcc, 0xdd, 0xee, 0xff,
  					0x40, 0x1f, 0x88, 0xff, 0xaa, 0xbb, 0xcc, 0xff,
  					0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,
  				},
  			},
  		},
  		{
  			"Overlay 2x2 2x2 0.5",
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 1),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0xff, 0x00, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff,
  					0x00, 0x00, 0xff, 0xff, 0x20, 0x20, 0x20, 0x00,
  				},
  			},
  			&image.NRGBA{
  				Rect:   image.Rect(-1, -1, 1, 1),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00,
  					0xff, 0xff, 0x00, 0xff, 0x20, 0x20, 0x20, 0xff,
  				},
  			},
  			image.Pt(-1, -1),
  			0.5,
  			&image.NRGBA{
  				Rect:   image.Rect(0, 0, 2, 2),
  				Stride: 2 * 4,
  				Pix: []uint8{
  					0xff, 0x7f, 0x7f, 0xff, 0x00, 0xff, 0x00, 0xff,
  					0x7f, 0x7f, 0x7f, 0xff, 0x20, 0x20, 0x20, 0x7f,
  				},
  			},
  		},
  	}
  	for _, d := range td {
  		got := Overlay(d.src1, d.src2, d.p, d.a)
  		want := d.want
  		if !compareNRGBA(got, want, 1) {
  			t.Errorf("test [%s] failed: %#v", d.desc, got)
  		}
  	}
  }
  