Add rotation gesture

Moving two fingers around a center point will trigger the gesture.
This patch computes the rotation gesture and maps it to mouse buttons
14 and 15.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

4 files changed, 28 insertions, 6 deletions

diff --git a/src/gestures.c b/src/gestures.c
index 03ec96d..2dafe79 100644
--- a/src/gestures.c
+++ b/src/gestures.c
@@ -74,7 +74,8 @@ static void extract_movement(struct Gestures *gs, struct MTouch* mt)
 	float xm[DIM_FINGER], ym[DIM_FINGER];
 	float xpos = 0, ypos = 0;
 	float move, xmove = 0, ymove = 0;
-	float rad, rad2 = 0, scale = 0;
+	float rad, rad2 = 0, scale = 0, rot = 0;
+
 
 	if (!nmove || nmove != npoint)
 		return;
@@ -116,13 +117,23 @@ static void extract_movement(struct Gestures *gs, struct MTouch* mt)
 		rad2 += yp[i] * yp[i];
 		scale += xp[i] * xm[i];
 		scale += yp[i] * ym[i];
+		rot += xp[i] * ym[i];
+		rot -= yp[i] * xm[i];
 	}
 	rad2 /= nmove;
 	scale /= nmove;
+	rot /= nmove;
 	rad = sqrt(rad2);
 	scale /= rad;
+	rot /= rad;
 
-	if (abs(scale) > move) {
+	if (abs(rot) > move && abs(rot) > abs(scale)) {
+		gs->rot = rot;
+		if (gs->rot) {
+			if (nmove == 2)
+				SETBIT(gs->type, GS_ROTATE);
+		}
+	} else if (abs(scale) > move) {
 		gs->scale = scale;
 		if (gs->scale) {
 			if (nmove == 2)
diff --git a/src/gestures.h b/src/gestures.h
index 5739d45..2866ba4 100644
--- a/src/gestures.h
+++ b/src/gestures.h
@@ -31,10 +31,11 @@
 #define GS_VSWIPE 4
 #define GS_HSWIPE 5
 #define GS_SCALE 6
+#define GS_ROTATE 7
 
 struct Gestures {
 	unsigned type, btmask, btdata;
-	int same_fingers, dx, dy, scale;
+	int same_fingers, dx, dy, scale, rot;
 };
 
 void extract_gestures(struct Gestures *gs, struct MTouch* mt);
diff --git a/src/hwdata.h b/src/hwdata.h
index 867a295..42d0a19 100644
--- a/src/hwdata.h
+++ b/src/hwdata.h
@@ -24,7 +24,7 @@
 
 #include "common.h"
 
-#define DIM_BUTTON 13
+#define DIM_BUTTON 15
 
 #define MT_BUTTON_LEFT 0
 #define MT_BUTTON_MIDDLE 1
@@ -39,6 +39,8 @@
 #define MT_BUTTON_SWIPE_RIGHT 10
 #define MT_BUTTON_SCALE_DOWN 11
 #define MT_BUTTON_SCALE_UP 12
+#define MT_BUTTON_ROTATE_LEFT 13
+#define MT_BUTTON_ROTATE_RIGHT 14
 
 #define BIT_MT_TOUCH_MAJOR 0
 #define BIT_MT_TOUCH_MINOR 1
diff --git a/src/multitouch.c b/src/multitouch.c
index 6281a5b..3dde667 100644
--- a/src/multitouch.c
+++ b/src/multitouch.c
@@ -32,6 +32,7 @@ static const float hscroll_fraction = 0.05;
 static const float vswipe_fraction = 0.25;
 static const float hswipe_fraction = 0.25;
 static const float scale_fraction = 0.05;
+static const float rot_fraction = 0.05;
 
 /* flip these to enable event debugging */
 #if 1
@@ -85,6 +86,8 @@ static void initButtonLabels(Atom map[DIM_BUTTON])
 	/* how to map scale and rotate? */
 	PROPMAP(map, MT_BUTTON_SCALE_DOWN, BTN_LABEL_PROP_BTN_4);
 	PROPMAP(map, MT_BUTTON_SCALE_UP, BTN_LABEL_PROP_BTN_5);
+	PROPMAP(map, MT_BUTTON_ROTATE_LEFT, BTN_LABEL_PROP_BTN_6);
+	PROPMAP(map, MT_BUTTON_ROTATE_RIGHT, BTN_LABEL_PROP_BTN_7);
 }
 #endif
 
@@ -92,7 +95,7 @@ static int device_init(DeviceIntPtr dev, LocalDevicePtr local)
 {
 	struct MTouch *mt = local->private;
 	unsigned char btmap[DIM_BUTTON + 1] = {
-		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
+		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
 	};
 #if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 7
 	Atom axes_labels[2], btn_labels[DIM_BUTTON];
@@ -213,12 +216,13 @@ static void handle_gestures(LocalDevicePtr local,
 			    const struct Gestures *gs,
 			    const struct Capabilities *caps)
 {
-	static int vscroll, hscroll, vswipe, hswipe, scale;
+	static int vscroll, hscroll, vswipe, hswipe, scale, rot;
 	int vscrollstep = 1 + vscroll_fraction * get_cap_ysize(caps);
 	int hscrollstep = 1 + hscroll_fraction * get_cap_xsize(caps);
 	int vswipestep = 1 + vswipe_fraction * get_cap_ysize(caps);
 	int hswipestep = 1 + hswipe_fraction * get_cap_xsize(caps);
 	int scalestep = 1 + scale_fraction * get_cap_xsize(caps);
+	int rotstep = 1 + rot_fraction * get_cap_xsize(caps);
 	int i;
 	if (!gs->same_fingers) {
 		vscroll = 0;
@@ -258,6 +262,10 @@ static void handle_gestures(LocalDevicePtr local,
 		button_scroll(local, 12, 13, &scale, scalestep, gs->scale);
 		TRACE1("scale: %d\n", gs->scale);
 	}
+	if (GETBIT(gs->type, GS_ROTATE)) {
+		button_scroll(local, 14, 15, &rot, rotstep, gs->rot);
+		TRACE1("rotate: %d\n", gs->rot);
+	}
 }
 
 /* called for each full received packet from the touchpad */