github.com/Kintar/etxt@v0.0.0-20221224033739-2fc69f000137/emask/shape_test.go (about)

     1  package emask
     2  
     3  import "image/color"
     4  import "testing"
     5  
     6  import "golang.org/x/image/math/fixed"
     7  
     8  func TestShape(t *testing.T) {
     9  	shape := NewShape(5)
    10  
    11  	shape.MoveTo(0, 50)
    12  	shape.CubeTo(-25, -25, -25, 25, 0, -50)
    13  	shape.QuadTo(-50, 0, 0, 50)
    14  
    15  	shape.MoveTo(0, 50)
    16  	shape.CubeTo(25, -25, 25, 25, 0, -50)
    17  	shape.QuadTo(50, 0, 0, 50)
    18  
    19  	shape.MoveTo(0, -50)
    20  	shape.LineTo(0, 50)
    21  	shape.LineTo(50, 50)
    22  	shape.LineTo(50, -50)
    23  	shape.LineTo(0, -50)
    24  
    25  	mask, err := Rasterize(shape.Segments(), &DefaultRasterizer{}, fixed.P(0, 0))
    26  	if err != nil {
    27  		panic(err)
    28  	}
    29  
    30  	gotSize := mask.Rect.Dx()
    31  	if gotSize != 100 {
    32  		t.Fatalf("expected mask rect.Dx == 100, got %d", gotSize)
    33  	}
    34  	gotSize = mask.Rect.Dy()
    35  	if gotSize != 100 {
    36  		t.Fatalf("expected mask rect.Dx == 100, got %d", gotSize)
    37  	}
    38  
    39  	posSum := 0
    40  	negSum := 0
    41  	for _, value := range mask.Pix {
    42  		intValue := int(value)
    43  		posSum += intValue
    44  		negSum += 255 - intValue
    45  	}
    46  	halfSum := 255 * 100 * 50
    47  
    48  	posSumDist := halfSum - posSum
    49  	if posSumDist < -halfSum/1000 || posSumDist > halfSum/1000 {
    50  		t.Fatalf("expected posSum (%d) around %d", posSum, halfSum)
    51  	}
    52  
    53  	negSumDist := halfSum - negSum
    54  	if negSumDist < -halfSum/1000 || negSumDist > halfSum/1000 {
    55  		t.Fatalf("expected negSum (%d) around %d", negSum, halfSum)
    56  	}
    57  
    58  	rgbSum := 0
    59  	img := shape.Paint(color.White, color.Black)
    60  	for i := 0; i < len(img.Pix); i += 4 {
    61  		rgbSum += int(img.Pix[i]) + int(img.Pix[i+1]) + int(img.Pix[i+2])
    62  	}
    63  	avgColorChanValue := rgbSum / (100 * 100 * 3)
    64  	if avgColorChanValue < 127 || avgColorChanValue > 129 {
    65  		t.Fatalf("expected avg color (%d) around 128", avgColorChanValue)
    66  	}
    67  
    68  	shape.Reset()
    69  	if len(shape.Segments()) != 0 {
    70  		t.Fatal("expected zero segments after reset")
    71  	}
    72  }