soft_palettegen_test.go

Documentation: github.com/lucasb-eyer/go-colorful

     1  package colorful
     2  
     3  import (
     4  	"fmt"
     5  	"testing"
     6  )
     7  
     8  // This is really difficult to test, if you've got a good idea, pull request!
     9  
    10  // Check if it returns all valid and enough colors.
    11  func TestColorCount(t *testing.T) {
    12  	fmt.Printf("Testing up to %v palettes may take a while...\n", 100)
    13  	for i := 0; i < 100; i++ {
    14  		//pal, err := SoftPaletteEx(i, SoftPaletteGenSettings{nil, 50, true})
    15  		pal, err := SoftPalette(i)
    16  		if err != nil {
    17  			t.Errorf("Error: %v", err)
    18  		}
    19  
    20  		// Check the color count of the palette
    21  		if len(pal) != i {
    22  			t.Errorf("Requested %v colors but got %v", i, len(pal))
    23  		}
    24  
    25  		// Also check whether all colors exist in RGB space.
    26  		for icol, col := range pal {
    27  			if !col.IsValid() {
    28  				t.Errorf("Color %v in palette of %v is invalid: %v", icol, len(pal), col)
    29  			}
    30  		}
    31  	}
    32  	fmt.Println("Done with that, but more tests to run.")
    33  }
    34  
    35  // Check if it errors-out on an impossible constraint
    36  func TestImpossibleConstraint(t *testing.T) {
    37  	never := func(l, a, b float64) bool { return false }
    38  
    39  	pal, err := SoftPaletteEx(10, SoftPaletteSettings{never, 50, true})
    40  	if err == nil || pal != nil {
    41  		t.Error("Should error-out on impossible constraint!")
    42  	}
    43  }
    44  
    45  // Check whether the constraint is respected
    46  func TestConstraint(t *testing.T) {
    47  	octant := func(l, a, b float64) bool { return l <= 0.5 && a <= 0.0 && b <= 0.0 }
    48  
    49  	pal, err := SoftPaletteEx(100, SoftPaletteSettings{octant, 50, true})
    50  	if err != nil {
    51  		t.Errorf("Error: %v", err)
    52  	}
    53  
    54  	// Check ALL the colors!
    55  	for icol, col := range pal {
    56  		if !col.IsValid() {
    57  			t.Errorf("Color %v in constrained palette is invalid: %v", icol, col)
    58  		}
    59  
    60  		l, a, b := col.Lab()
    61  		if l > 0.5 || a > 0.0 || b > 0.0 {
    62  			t.Errorf("Color %v in constrained palette violates the constraint: %v (lab: %v)", icol, col, [3]float64{l, a, b})
    63  		}
    64  	}
    65  }
    66
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