properly implement msmouse-like sensitivity, separate from speed

1 files changed, 31 insertions, 5 deletions

diff --git a/int33.h b/int33.h
index df870be..f9191ce 100644
--- a/int33.h
+++ b/int33.h
@@ -114,12 +114,38 @@ enum INT33_API {
 	INT33_SAVE_MOUSE_STATUS = 0x16,
 	INT33_LOAD_MOUSE_STATUS = 0x17,
 
-	/** Sets both speed and speed-doubling threshold in one call.
-	 *  @param bx horizontal speed, cx vertical speed
-	 *  @param dx doubling threshold (mickeys per second). */
+	/** Sets both sensitivity and speed-doubling threshold in one call.
+	 *  @param bx horizontal sensitivity, cx vertical sensitivity
+	 *         these are values from 5..100.
+	 *  @param dx speed doubling threshold (mickeys per second?).
+	 *  Unlike set_mouse_speed, this value is persistent, and survives a reset.
+	 *  MS doesn't define what "sensitivity" means here, however MSD does print
+	 *  a table of common sensitivity values and their equivalent "factor",
+	 *  which is applied to the mouse deltas:
+	 *  100 - 3.5    (i.e. mouse is 3.5x faster)
+	 *  95  - 3.25
+	 *  90  - 3
+	 *  85  - 2.75
+	 *  80  - 2.5
+	 *  75  - 2.25
+	 *  70  - 2
+	 *  65  - 1.75
+	 *  60  - 1.5
+	 *  55  - 1.25
+	 *  50  - 1     (default value, mouse is 1x)
+	 *  45  - 0.875
+	 *  40  - 0.75
+	 *  35  - 0.625
+	 *  30  - 0.5
+	 *  25  - 0.375
+	 *  20  - 0.25
+	 *  15  - 0.125
+	 *  10  - 0.062
+	 *  5   - 0.031  (MSD prints 0.31 though? looks buggy as hell).
+	 *  @todo verify if the doubling threshold here is in the same units. */
 	INT33_SET_MOUSE_SENSITIVITY = 0x1A,
-	/** Gets current speed and speed-doubling threshold.
-	 *  @return bx horizontal speed, cx vertical speed
+	/** Gets current sensitivity and speed-doubling threshold.
+	 *  @return bx horizontal sensitivity, cx vertical sensitivity
 	 *  @return dx doubling threshold (mickeys per second). */
 	INT33_GET_MOUSE_SENSITIVITY = 0x1B,