ExpressionParser: Move FunctionExpression type definitions into another file.

Source/Core/InputCommon/ControlReference/FunctionExpression.cpp

@@ -0,0 +1,261 @@
+// Copyright 2019 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <chrono>
+#include <cmath>
+
+#include "InputCommon/ControlReference/FunctionExpression.h"
+
+namespace ciface
+{
+namespace ExpressionParser
+{
+constexpr int LOOP_MAX_REPS = 10000;
+constexpr ControlState CONDITION_THRESHOLD = 0.5;
+
+// TODO: Return an oscillating value to make it apparent something was spelled wrong?
+class UnknownFunctionExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return false;
+  }
+  ControlState GetValue() const override { return 0.0; }
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "unknown"; }
+};
+
+class ToggleExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 1 == args.size();
+  }
+
+  ControlState GetValue() const override
+  {
+    const ControlState inner_value = GetArg(0).GetValue();
+
+    if (inner_value < CONDITION_THRESHOLD)
+    {
+      m_released = true;
+    }
+    else if (m_released && inner_value > CONDITION_THRESHOLD)
+    {
+      m_released = false;
+      m_state ^= true;
+    }
+
+    return m_state;
+  }
+
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "toggle"; }
+
+  mutable bool m_released{};
+  mutable bool m_state{};
+};
+
+class NotExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 1 == args.size();
+  }
+
+  ControlState GetValue() const override { return 1.0 - GetArg(0).GetValue(); }
+  void SetValue(ControlState value) override { GetArg(0).SetValue(1.0 - value); }
+  std::string GetFuncName() const override { return ""; }
+};
+
+class SinExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 1 == args.size();
+  }
+
+  ControlState GetValue() const override { return std::sin(GetArg(0).GetValue()); }
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "sin"; }
+};
+
+class TimerExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 1 == args.size();
+  }
+
+  ControlState GetValue() const override
+  {
+    const auto now = Clock::now();
+    const auto elapsed = now - m_start_time;
+
+    using FSec = std::chrono::duration<ControlState>;
+
+    const ControlState val = GetArg(0).GetValue();
+
+    ControlState progress = std::chrono::duration_cast<FSec>(elapsed).count() / val;
+
+    if (std::isinf(progress))
+    {
+      // User configured a 0.0 length timer. Reset the timer and return 0.0.
+      progress = 0.0;
+      m_start_time = now;
+    }
+    else if (progress >= 1.0)
+    {
+      const ControlState reset_count = std::floor(progress);
+
+      m_start_time += std::chrono::duration_cast<Clock::duration>(FSec(val * reset_count));
+      progress -= reset_count;
+    }
+
+    return progress;
+  }
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "timer"; }
+
+private:
+  using Clock = std::chrono::steady_clock;
+  mutable Clock::time_point m_start_time = Clock::now();
+};
+
+class IfExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 3 == args.size();
+  }
+
+  ControlState GetValue() const override
+  {
+    return (GetArg(0).GetValue() > CONDITION_THRESHOLD) ? GetArg(1).GetValue() :
+                                                          GetArg(2).GetValue();
+  }
+
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "if"; }
+};
+
+class UnaryMinusExpression : public FunctionExpression
+{
+private:
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 1 == args.size();
+  }
+
+  ControlState GetValue() const override
+  {
+    // Subtraction for clarity:
+    return 0.0 - GetArg(0).GetValue();
+  }
+
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "minus"; }
+};
+
+class WhileExpression : public FunctionExpression
+{
+  virtual bool ValidateArguments(const std::vector<std::unique_ptr<Expression>>& args) override
+  {
+    return 2 == args.size();
+  }
+
+  ControlState GetValue() const override
+  {
+    // Returns 1.0 on successful loop, 0.0 on reps exceeded. Sensible?
+
+    for (int i = 0; i != LOOP_MAX_REPS; ++i)
+    {
+      // Check condition of 1st argument:
+      const ControlState val = GetArg(0).GetValue();
+      if (val < CONDITION_THRESHOLD)
+        return 1.0;
+
+      // Evaluate 2nd argument:
+      GetArg(1).GetValue();
+    }
+
+    // Exceeded max reps:
+    return 0.0;
+  }
+
+  void SetValue(ControlState value) override {}
+  std::string GetFuncName() const override { return "while"; }
+};
+
+std::unique_ptr<FunctionExpression> MakeFunctionExpression(std::string name)
+{
+  if (name.empty())
+    return std::make_unique<NotExpression>();
+  else if ("if" == name)
+    return std::make_unique<IfExpression>();
+  else if ("sin" == name)
+    return std::make_unique<SinExpression>();
+  else if ("timer" == name)
+    return std::make_unique<TimerExpression>();
+  else if ("toggle" == name)
+    return std::make_unique<ToggleExpression>();
+  else if ("while" == name)
+    return std::make_unique<WhileExpression>();
+  else if ("minus" == name)
+    return std::make_unique<UnaryMinusExpression>();
+  else
+    return std::make_unique<UnknownFunctionExpression>();
+}
+
+int FunctionExpression::CountNumControls() const
+{
+  int result = 0;
+
+  for (auto& arg : m_args)
+    result += arg->CountNumControls();
+
+  return result;
+}
+
+void FunctionExpression::UpdateReferences(ControlEnvironment& env)
+{
+  for (auto& arg : m_args)
+    arg->UpdateReferences(env);
+}
+
+FunctionExpression::operator std::string() const
+{
+  std::string result = '!' + GetFuncName();
+
+  for (auto& arg : m_args)
+    result += ' ' + static_cast<std::string>(*arg);
+
+  return result;
+}
+
+bool FunctionExpression::SetArguments(std::vector<std::unique_ptr<Expression>>&& args)
+{
+  m_args = std::move(args);
+
+  return ValidateArguments(m_args);
+}
+
+Expression& FunctionExpression::GetArg(u32 number)
+{
+  return *m_args[number];
+}
+
+const Expression& FunctionExpression::GetArg(u32 number) const
+{
+  return *m_args[number];
+}
+
+}  // namespace ExpressionParser
+}  // namespace ciface