also store the remainder of the sensitivity division, as it smooths movement for low sensitivity values

2 files changed, 23 insertions, 20 deletions

diff --git a/mousetsr.c b/mousetsr.c
index f5caf59..68929af 100644
--- a/mousetsr.c
+++ b/mousetsr.c
@@ -71,17 +71,11 @@ static void bound_position_to_window(void)
  *  I am going with f(x) = x(x+32)/4096 since it looks round and fits decently,
  *  even with integer math (we don't divide by 4096 until after multiplying by delta).
  *  @see INT33_SET_MOUSE_SENSITIVITY for what the factor should look like. */
-int16_t apply_sensitivity(int16_t x, uint8_t sens)
+int16_t apply_sensitivity(int16_t x, uint8_t sens, int16_t *rem)
 {
 	uint16_t factor = (sens * (sens + 32));
-#if 1
-	// use shift by 12 rather than divide by 4096
-	// unsigned math, otherwise negative values would round down when shifted
-	uint16_t scaled = scaleu_shift(abs(x), 12 /*4096*/, factor);
-	return x < 0 ? -scaled : scaled;
-#else
-	return scalei(x, 4096, factor);
-#endif
+	// TODO Actually use a shift instead of division
+	return scalei_rem(x, 4096, factor, rem);
 }
 
 /** Constraints coordinate value to the desired granularity,
@@ -648,8 +642,10 @@ static void handle_mouse_event(uint16_t buttons, bool absolute, int x, int y, ch
 			// Set the new absolute position
 			data.pos.x = x;
 			data.pos.y = y;
-			data.pos_frac.x = 0;
-			data.pos_frac.y = 0;
+			data.pos_pixel_frac.x = 0;
+			data.pos_pixel_frac.y = 0;
+			data.pos_sens_frac.x = 0;
+			data.pos_sens_frac.y = 0;
 		}
 	} else if (x || y) {
 		// Relative movement: x,y are in mickeys
@@ -671,8 +667,8 @@ static void handle_mouse_event(uint16_t buttons, bool absolute, int x, int y, ch
 		data.total_motion += ax * ax + ay * ay;
 
 		// Apply sensitivity now, since unlike acceleration/speed, it affects the raw mickey counters
-		x = apply_sensitivity(x, data.sensitivity_x);
-		y = apply_sensitivity(y, data.sensitivity_y);
+		x = apply_sensitivity(x, data.sensitivity_x, &data.pos_sens_frac.x);
+		y = apply_sensitivity(y, data.sensitivity_y, &data.pos_sens_frac.y);
 
 		// Update the raw mickey counters
 		data.delta.x += x;
@@ -692,8 +688,8 @@ static void handle_mouse_event(uint16_t buttons, bool absolute, int x, int y, ch
 		}
 
 		// Apply mickeysPerLine. Keep the fractional part for the next movement!
-		data.pos.x += scalei_rem(x, data.mickeysPerLine.x, 8, &data.pos_frac.x);
-		data.pos.y += scalei_rem(y, data.mickeysPerLine.y, 8, &data.pos_frac.y);
+		data.pos.x += scalei_rem(x, data.mickeysPerLine.x, 8, &data.pos_pixel_frac.x);
+		data.pos.y += scalei_rem(y, data.mickeysPerLine.y, 8, &data.pos_pixel_frac.y);
 	}
 
 	bound_position_to_window();
@@ -1226,8 +1222,10 @@ static void reset_mouse_state()
 	int i;
 	data.pos.x = data.min.x + (data.max.x - data.min.x) / 2;
 	data.pos.y = data.min.y + (data.max.y - data.min.y) / 2;
-	data.pos_frac.x = 0;
-	data.pos_frac.y = 0;
+	data.pos_pixel_frac.x = 0;
+	data.pos_pixel_frac.y = 0;
+	data.pos_sens_frac.x = 0;
+	data.pos_sens_frac.y = 0;
 	data.delta.x = 0;
 	data.delta.y = 0;
 	data.abs_pos.x = -1;
@@ -1348,8 +1346,10 @@ static void int33_handler(union INTPACK r)
 #endif
 		data.pos.x = r.w.cx;
 		data.pos.y = r.w.dx;
-		data.pos_frac.x = 0;
-		data.pos_frac.y = 0;
+		data.pos_pixel_frac.x = 0;
+		data.pos_pixel_frac.y = 0;
+		data.pos_sens_frac.x = 0;
+		data.pos_sens_frac.y = 0;
 		data.delta.x = 0;
 		data.delta.y = 0;
 		bound_position_to_window();
diff --git a/mousetsr.h b/mousetsr.h
index 93503c5..e190805 100644
--- a/mousetsr.h
+++ b/mousetsr.h
@@ -192,7 +192,10 @@ typedef struct tsrdata {
 	struct point pos;
 	/** Current remainder of movement that does not yet translate to an entire pixel
 	 *  (8ths of pixel). */
-	struct point pos_frac;
+	struct point pos_pixel_frac;
+	/** Current remainder of movement that does not yet translate to one sensitivity unit (4096)
+	 *  @see apply_sensitivity */
+	struct point pos_sens_frac;
 	/** Current delta movement (in mickeys) since the last report. */
 	struct point delta;
 	/** Last absolute position (to compute a delta for relative motion emulation). Using -1 for "none". */