Initial release

engine/vendor/vst3sdk/vstgui4/vstgui/lib/algorithm.h

@@ -0,0 +1,97 @@
+// This file is part of VSTGUI. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this
+// distribution and at http://github.com/steinbergmedia/vstgui/LICENSE
+
+#pragma once
+
+#include "optional.h"
+#include "vstguidebug.h"
+#include <cstdint>
+#include <algorithm>
+
+//------------------------------------------------------------------------
+namespace VSTGUI {
+
+//------------------------------------------------------------------------
+/** Returns the index of the value */
+template <typename Iter, typename Type, typename ResultType = int32_t>
+Optional<ResultType> indexOf (Iter first, Iter last, const Type& value)
+{
+	auto it = std::find (first, last, value);
+	if (it == last)
+		return {};
+	return {static_cast<ResultType> (std::distance (first, it))};
+}
+
+//------------------------------------------------------------------------
+/** Returns the index of the element for which predicate p returns true */
+template <typename Iter, typename Proc, typename ResultType = int32_t>
+Optional<ResultType> indexOfTest (Iter first, Iter last, Proc p)
+{
+	auto it = std::find_if (first, last, p);
+	if (it == last)
+		return {};
+	return {static_cast<ResultType> (std::distance (first, it))};
+}
+
+//------------------------------------------------------------------------
+/** Returns the value clamped to min and max */
+template <typename T>
+T clamp (T value, T min, T max)
+{
+	return std::min (max, std::max (value, min));
+}
+
+//------------------------------------------------------------------------
+/** Returns the value clamped to zero and one */
+template <typename T>
+T clampNorm (T value)
+{
+	static_assert (std::is_floating_point<T>::value, "Only floating point types allowed");
+	return clamp (value, static_cast<T> (0), static_cast<T> (1));
+}
+
+//------------------------------------------------------------------------
+/** Returns the value projected lineary between stepOffset and stepOffset + steps */
+template<typename NormT, typename StepT = int32_t>
+StepT normalizedToSteps (NormT value, StepT numSteps, StepT stepStart = static_cast<StepT> (0))
+{
+	static_assert (std::is_integral<StepT>::value, "Step type must be integral");
+	vstgui_assert (value >= 0. && value <= 1., "Only normalized values are allowed");
+	return std::min<StepT> (numSteps, static_cast<StepT> ((numSteps + 1) * value)) + stepStart;
+}
+
+//------------------------------------------------------------------------
+/** Returns the normalized value from the step value */
+template<typename NormT, typename StepValueT, typename StepT>
+NormT stepsToNormalized (StepValueT value, StepT steps, StepT stepOffset = static_cast<StepT> (0))
+{
+	static_assert (std::is_integral<StepT>::value, "Step type must be integral");
+	vstgui_assert ((value - stepOffset) <= steps, "Value must be smaller or equal then steps");
+	return static_cast<NormT> (value - stepOffset) / static_cast<NormT> (steps);
+}
+
+//------------------------------------------------------------------------
+/** Returns the normalized value from a plain one */
+template<typename NormT, typename PlainT>
+NormT plainToNormalized (PlainT value, PlainT minValue, PlainT maxValue)
+{
+	static_assert (std::is_floating_point<NormT>::value,
+				   "Only floating point types for NormT allowed");
+	vstgui_assert (maxValue - minValue != 0., "min and max value must be different");
+	return (value - minValue) / static_cast<NormT> (maxValue - minValue);
+}
+
+//------------------------------------------------------------------------
+/** Returns the plain value from a normalized one */
+template<typename PlainT, typename NormT>
+PlainT normalizedToPlain (NormT value, PlainT minValue, PlainT maxValue)
+{
+	static_assert (std::is_floating_point<NormT>::value,
+				   "Only floating point types for NormT allowed");
+	vstgui_assert (maxValue - minValue != 0., "min and max value must be different");
+	return static_cast<PlainT> ((maxValue - minValue) * value + minValue);
+}
+
+//------------------------------------------------------------------------
+} // VSTGUI