package main

import (
	"image/color"
	"testing"
)

func TestNoop(t *testing.T) {
	c := noOp(0, 0, color.White)
	r, g, b, a := c.RGBA()
	if r != 0xffff || g != 0xffff || b != 0xffff || a != 0xffff {
		t.Log("noop did not return input")
		t.Fail()
	}
}

func TestLuminence(t *testing.T) {
	l := luminence(color.White)
	if l != 1 {
		t.Logf("white input did not output 1, instead %f", l)
		t.Fail()
	}
	l = luminence(color.Black)
	if l != 0 {
		t.Logf("black input did not output 0, instead %f", l)
		t.Fail()
	}
	l = luminence(color.Gray16{0x8000})
	if l < 0.5 {
		t.Logf("white-leaning gray input was not above 0.5, instead %f", l)
		t.Fail()
	}
	l = luminence(color.Gray16{0x7fff})
	if l > 0.5 {
		t.Logf("black-leaning gray input not below 0.5, instead %f", l)
		t.Fail()
	}
}