First commit

vendor/github.com/tdewolff/parse/css/util.go

@@ -0,0 +1,47 @@
+package css // import "github.com/tdewolff/parse/css"
+
+import "github.com/tdewolff/parse/buffer"
+
+// IsIdent returns true if the bytes are a valid identifier.
+func IsIdent(b []byte) bool {
+	l := NewLexer(buffer.NewReader(b))
+	l.consumeIdentToken()
+	l.r.Restore()
+	return l.r.Pos() == len(b)
+}
+
+// IsURLUnquoted returns true if the bytes are a valid unquoted URL.
+func IsURLUnquoted(b []byte) bool {
+	l := NewLexer(buffer.NewReader(b))
+	l.consumeUnquotedURL()
+	l.r.Restore()
+	return l.r.Pos() == len(b)
+}
+
+// HSL2RGB converts HSL to RGB with all of range [0,1]
+// from http://www.w3.org/TR/css3-color/#hsl-color
+func HSL2RGB(h, s, l float64) (float64, float64, float64) {
+	m2 := l * (s + 1)
+	if l > 0.5 {
+		m2 = l + s - l*s
+	}
+	m1 := l*2 - m2
+	return hue2rgb(m1, m2, h+1.0/3.0), hue2rgb(m1, m2, h), hue2rgb(m1, m2, h-1.0/3.0)
+}
+
+func hue2rgb(m1, m2, h float64) float64 {
+	if h < 0.0 {
+		h += 1.0
+	}
+	if h > 1.0 {
+		h -= 1.0
+	}
+	if h*6.0 < 1.0 {
+		return m1 + (m2-m1)*h*6.0
+	} else if h*2.0 < 1.0 {
+		return m2
+	} else if h*3.0 < 2.0 {
+		return m1 + (m2-m1)*(2.0/3.0-h)*6.0
+	}
+	return m1
+}