InputCommon: Simplified StickGate interface and moved class into its own file. Changed default input radius to perform no resizing. Tweaked the indicator colors a bit to improve visibility. Cleaned up some math and code.

Source/Core/InputCommon/ControllerEmu/StickGate.cpp

@@ -0,0 +1,47 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "InputCommon/ControllerEmu/StickGate.h"
+
+#include <cmath>
+
+#include "Common/MathUtil.h"
+
+namespace ControllerEmu
+{
+OctagonStickGate::OctagonStickGate(ControlState radius) : m_radius(radius)
+{
+}
+
+ControlState OctagonStickGate::GetRadiusAtAngle(double ang) const
+{
+  constexpr int sides = 8;
+  constexpr double sum_int_angles = (sides - 2) * MathUtil::PI;
+  constexpr double half_int_angle = sum_int_angles / sides / 2;
+
+  ang = std::fmod(ang, MathUtil::TAU / sides);
+  // Solve ASA triangle using The Law of Sines:
+  return m_radius / std::sin(MathUtil::PI - ang - half_int_angle) * std::sin(half_int_angle);
+}
+
+RoundStickGate::RoundStickGate(ControlState radius) : m_radius(radius)
+{
+}
+
+ControlState RoundStickGate::GetRadiusAtAngle(double) const
+{
+  return m_radius;
+}
+
+SquareStickGate::SquareStickGate(ControlState half_width) : m_half_width(half_width)
+{
+}
+
+ControlState SquareStickGate::GetRadiusAtAngle(double ang) const
+{
+  constexpr double section_ang = MathUtil::TAU / 4;
+  return m_half_width / std::cos(std::fmod(ang + section_ang / 2, section_ang) - section_ang / 2);
+}
+
+}  // namespace ControllerEmu