bigger commits

Camera.h

@@ -16,6 +16,10 @@
 
 const glm::vec3 worldUp = { 0.0f, 1.0f, 0.0f };
 
+// Mouse sensitivity asked at startup (see main.cpp). 0 = keep the camera's built-in default.
+inline float StartupCmPer360 = 0.0f;
+inline float StartupMouseDpi = 800.0f;
+
 class Camera {
 public:
     bool  lockedcursor = true;
@@ -28,7 +32,15 @@ public:
     float FOV = 110.0f;
     float screenshake = 0.0f;
 
-    Camera() {}
+    Camera() {
+        if (StartupCmPer360 > 0.0f) SetSensitivityCm(StartupCmPer360, StartupMouseDpi);
+    }
+
+    // Turn sensitivity into "this many cm of mouse travel per full 360 degree turn" for a mouse
+    // of the given DPI (mouse counts per inch).
+    void SetSensitivityCm(float cmPer360, float dpi) {
+        sensitivity = 6.2831853f / (cmPer360 / 2.54f * dpi);
+    }
 
     void AddScreenshake(float amount) {
         screenshake += amount;