add zero/inf/nan guards

3 files changed, 49 insertions, 28 deletions

diff --git a/common/rawaccel.hpp b/common/rawaccel.hpp
index 67b4e61..f6bc0fd 100644
--- a/common/rawaccel.hpp
+++ b/common/rawaccel.hpp
@@ -218,8 +218,12 @@ namespace rawaccel {
                     movement.y *= scale;
                 }
                 else {
-                    movement.x *= accels.x.apply(fabs(movement.x) * norm);
-                    movement.y *= accels.y.apply(fabs(movement.y) * norm);
+                    if (movement.x != 0) {
+                        movement.x *= accels.x.apply(fabs(movement.x) * norm);
+                    }
+                    if (movement.y != 0) {
+                        movement.y *= accels.y.apply(fabs(movement.y) * norm);
+                    }
                 }
             }
         }
diff --git a/common/utility.hpp b/common/utility.hpp
index 40bc7c4..d7b63cf 100644
--- a/common/utility.hpp
+++ b/common/utility.hpp
@@ -28,3 +28,15 @@ inline constexpr double maxsd(double a, double b) {
 inline constexpr double clampsd(double v, double lo, double hi) {
     return minsd(maxsd(v, lo), hi);
 }
+
+// returns the unbiased exponent of x if x is normal 
+inline int ilogb(double x)
+{
+	union { double f; unsigned long long i; } u = { x };
+	return static_cast<int>((u.i >> 52) & 0x7ff) - 0x3ff;
+}
+
+inline bool infnan(double x)
+{
+	return ilogb(x) == 0x400;
+}
diff --git a/driver/driver.cpp b/driver/driver.cpp
index 235571c..5b9eca4 100644
--- a/driver/driver.cpp
+++ b/driver/driver.cpp
@@ -67,40 +67,45 @@ Arguments:
 
         auto it = InputDataStart;
         do {
-            vec2d input = {
-                static_cast<double>(it->LastX),
-                static_cast<double>(it->LastY)
-            };
-
-            global.modifier.apply_rotation(input);
-            global.modifier.apply_angle_snap(input);
-
-            if (enable_accel) {
-                auto time_supplier = [=] {
-                    counter_t now = KeQueryPerformanceCounter(NULL).QuadPart;
-                    counter_t ticks = now - devExt->counter;
-                    devExt->counter = now;
-                    milliseconds time = ticks * global.tick_interval;
-                    return clampsd(time, global.args.time_min, 100);
+            if (it->LastX || it->LastY) {
+                vec2d input = {
+                    static_cast<double>(it->LastX),
+                    static_cast<double>(it->LastY)
                 };
 
-                global.modifier.apply_acceleration(input, time_supplier);
-            }
+                global.modifier.apply_rotation(input);
+                global.modifier.apply_angle_snap(input);
+
+                if (enable_accel) {
+                    auto time_supplier = [=] {
+                        counter_t now = KeQueryPerformanceCounter(NULL).QuadPart;
+                        counter_t ticks = now - devExt->counter;
+                        devExt->counter = now;
+                        milliseconds time = ticks * global.tick_interval;
+                        return clampsd(time, global.args.time_min, 100);
+                    };
 
-            global.modifier.apply_sensitivity(input);
+                    global.modifier.apply_acceleration(input, time_supplier);
+                }
 
-            double carried_result_x = input.x + devExt->carry.x;
-            double carried_result_y = input.y + devExt->carry.y;
+                global.modifier.apply_sensitivity(input);
 
-            LONG out_x = static_cast<LONG>(carried_result_x);
-            LONG out_y = static_cast<LONG>(carried_result_y);
+                double carried_result_x = input.x + devExt->carry.x;
+                double carried_result_y = input.y + devExt->carry.y;
 
-            devExt->carry.x = carried_result_x - out_x;
-            devExt->carry.y = carried_result_y - out_y;
+                LONG out_x = static_cast<LONG>(carried_result_x);
+                LONG out_y = static_cast<LONG>(carried_result_y);
 
-            it->LastX = out_x;
-            it->LastY = out_y;
+                double carry_x = carried_result_x - out_x;
+                double carry_y = carried_result_y - out_y;
 
+                if (!infnan(carry_x + carry_y)) {
+                    devExt->carry.x = carried_result_x - out_x;
+                    devExt->carry.y = carried_result_y - out_y;
+                    it->LastX = out_x;
+                    it->LastY = out_y;
+                }
+            }
         } while (++it != InputDataEnd);
 
     }