rawinput: reimplement analog relative mode and delay (#674)

## Link to GitHub Issue or related Pull Request, if one exists
#181 

## Description of change
Implement analog relative mode and delay option using a new
millisecond-based algorithm.

## Testing
WIP

src/spice2x/cfg/analog.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <array>
 #include <string>
 #include <cmath>
@@ -34,6 +35,11 @@ struct AnalogMovingAverage {
     float cosine;
 };
 
+struct AnalogDelayEntry {
+    double time_in_ms;
+    float value;
+};
+
 class Analog {
 private:
     std::string name;
@@ -63,6 +69,15 @@ private:
     float divisor_previous_value = 0.5f;
     unsigned short divisor_region = 0;
 
+    // relative input mode
+    float rel_mode_absolute_value = 0.5f;
+    float rel_mode_last_read_time_s = 0.f;
+    bool relative_mode = false;
+
+    // delay
+    uint32_t delay_ms = 0;
+    std::queue<AnalogDelayEntry> delayed_inputs;
+
     float calculateAngularDifference(float old_rads, float new_rads);
     float normalizeAngle(float rads);
     float normalizeAnalogValue(float value);
@@ -83,6 +98,8 @@ public:
     float applyAngularSensitivity(float raw_rads);
     float applyMultiplier(float raw_value);
     float applyDeadzone(float raw_value);
+    float getRelativeModeValue(float raw_value);
+    float getDelayedValue(float raw_value);
 
     inline bool isSet() {
         if (this->override_enabled) {
@@ -98,7 +115,9 @@ public:
         smoothing = false;
         deadzone_mirror = false;
         setMultiplier(1);
+        setRelativeMode(false);
         setLastState(0.5f);
+        setDelayMs(0);
     }
 
     inline void clearBindings() {
@@ -195,6 +214,19 @@ public:
         this->last_state = last_state;
     }
 
+    inline bool isRelativeMode() const {
+        return this->relative_mode;
+    }
+
+    inline void setRelativeMode(bool relative_mode) {
+        if (relative_mode) {
+            this->smoothing = false;
+        }
+        this->relative_mode = relative_mode;
+        this->rel_mode_absolute_value = 0.5f;
+        this->rel_mode_last_read_time_s = 0.f;
+    }
+
     inline GameAPI::Analogs::AnalogType getType() const {
         return this->type;
     }
@@ -202,4 +234,12 @@ public:
     inline void setType(GameAPI::Analogs::AnalogType type) {
         this->type = type;
     }
+
+    inline uint32_t getDelayMs() const {
+        return this->delay_ms;
+    }
+
+    inline void setDelayMs(uint32_t delay_ms) {
+        this->delay_ms = delay_ms;
+    }
 };