1 files changed, 69 insertions, 0 deletions
diff --git a/common/accel-base.hpp b/common/accel-base.hpp
new file mode 100644
index 0000000..da2c96b
--- /dev/null
+++ b/common/accel-base.hpp
@@ -0,0 +1,69 @@
+#pragma once
+
+#include "vec2.h"
+
+namespace rawaccel {
+
+    // Error throwing calls std libraries which are unavailable in kernel mode.
+    void error(const char* s);
+
+    using milliseconds = double;
+
+    /// <summary> Struct to hold arguments for an acceleration function. </summary>
+    struct accel_args {
+        double offset = 0;
+        double accel = 0;
+        double limit = 2;
+        double exponent = 2;
+        double midpoint = 0;
+        double power_scale = 1;
+        vec2d weight = { 1, 1 };
+    };
+
+    /// <summary>
+    /// Struct to hold common acceleration curve implementation details.
+    /// </summary>
+    struct accel_base {
+
+        /// <summary> Coefficients applied to acceleration per axis.</summary>
+        vec2d weight = { 1, 1 };
+
+        /// <summary> Generally, the acceleration ramp rate.
+        double speed_coeff = 0;
+
+        accel_base(const accel_args& args) {
+            verify(args);
+
+            speed_coeff = args.accel;
+            weight = args.weight;
+        }
+
+        /// <summary> 
+        /// Default transformation of speed -> acceleration.
+        /// </summary>
+        inline double accelerate(double speed) const { 
+            return speed_coeff * speed; 
+        }
+
+        /// <summary> 
+        /// Default transformation of acceleration -> mouse input multipliers.
+        /// </summary>
+        inline vec2d scale(double accel_val) const {
+            return {
+                weight.x * accel_val + 1,
+                weight.y * accel_val + 1
+            };
+        }
+
+        /// <summary>
+        /// Verifies arguments as valid. Errors if not.
+        /// </summary>
+        /// <param name="args">Arguments to verified.</param>
+        void verify(const accel_args& args) const {
+            if (args.accel < 0) error("accel can not be negative, use a negative weight to compensate");
+        }
+
+        accel_base() = default;
+    };
+
+}