Add scale gesture

Moving two fingers apart or closer together will trigger the gesture.
This patch computes the scaling gesture and maps it to mouse buttons
12 and 13.

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

4 files changed, 49 insertions, 5 deletions

diff --git a/src/gestures.c b/src/gestures.c
index 977655c..03ec96d 100644
--- a/src/gestures.c
+++ b/src/gestures.c
@@ -70,22 +70,32 @@ static void extract_movement(struct Gestures *gs, struct MTouch* mt)
 	int npoint = bitcount(mt->mem.pointing);
 	int nmove = bitcount(mt->mem.moving);
 	int i;
+	float xp[DIM_FINGER], yp[DIM_FINGER];
 	float xm[DIM_FINGER], ym[DIM_FINGER];
-	float xmove = 0, ymove = 0;
+	float xpos = 0, ypos = 0;
+	float move, xmove = 0, ymove = 0;
+	float rad, rad2 = 0, scale = 0;
 
 	if (!nmove || nmove != npoint)
 		return;
 
 	foreach_bit(i, mt->mem.moving) {
+		xp[i] = mt->state.finger[i].hw.position_x - xpos;
+		yp[i] = mt->state.finger[i].hw.position_y - ypos;
 		xm[i] = mt->mem.dx[i];
 		ym[i] = mt->mem.dy[i];
 		mt->mem.dx[i] = 0;
 		mt->mem.dy[i] = 0;
+		xpos += xp[i];
+		ypos += yp[i];
 		xmove += xm[i];
 		ymove += ym[i];
 	}
+	xpos /= nmove;
+	ypos /= nmove;
 	xmove /= nmove;
 	ymove /= nmove;
+	move = sqrt(xmove * xmove + ymove * ymove);
 
 	if (nmove == 1) {
 		if (mt->mem.moving & mt->mem.thumb) {
@@ -96,6 +106,28 @@ static void extract_movement(struct Gestures *gs, struct MTouch* mt)
 		gs->dy = ymove;
 		if (gs->dx || gs->dy)
 			SETBIT(gs->type, GS_MOVE);
+		return;
+	}
+
+	foreach_bit(i, mt->mem.moving) {
+		xp[i] -= xpos;
+		yp[i] -= ypos;
+		rad2 += xp[i] * xp[i];
+		rad2 += yp[i] * yp[i];
+		scale += xp[i] * xm[i];
+		scale += yp[i] * ym[i];
+	}
+	rad2 /= nmove;
+	scale /= nmove;
+	rad = sqrt(rad2);
+	scale /= rad;
+
+	if (abs(scale) > move) {
+		gs->scale = scale;
+		if (gs->scale) {
+			if (nmove == 2)
+				SETBIT(gs->type, GS_SCALE);
+		}
 	} else {
 		if (mt->mem.moving & mt->mem.thumb) {
 			mt_skip_movement(mt, FINGER_THUMB_MS);
diff --git a/src/gestures.h b/src/gestures.h
index 5630d4c..5739d45 100644
--- a/src/gestures.h
+++ b/src/gestures.h
@@ -30,10 +30,11 @@
 #define GS_HSCROLL 3
 #define GS_VSWIPE 4
 #define GS_HSWIPE 5
+#define GS_SCALE 6
 
 struct Gestures {
 	unsigned type, btmask, btdata;
-	int same_fingers, dx, dy;
+	int same_fingers, dx, dy, scale;
 };
 
 void extract_gestures(struct Gestures *gs, struct MTouch* mt);
diff --git a/src/hwdata.h b/src/hwdata.h
index 5dd99cf..867a295 100644
--- a/src/hwdata.h
+++ b/src/hwdata.h
@@ -24,7 +24,7 @@
 
 #include "common.h"
 
-#define DIM_BUTTON 11
+#define DIM_BUTTON 13
 
 #define MT_BUTTON_LEFT 0
 #define MT_BUTTON_MIDDLE 1
@@ -37,6 +37,8 @@
 #define MT_BUTTON_SWIPE_DOWN 8
 #define MT_BUTTON_SWIPE_LEFT 9
 #define MT_BUTTON_SWIPE_RIGHT 10
+#define MT_BUTTON_SCALE_DOWN 11
+#define MT_BUTTON_SCALE_UP 12
 
 #define BIT_MT_TOUCH_MAJOR 0
 #define BIT_MT_TOUCH_MINOR 1
diff --git a/src/multitouch.c b/src/multitouch.c
index a11b8da..6281a5b 100644
--- a/src/multitouch.c
+++ b/src/multitouch.c
@@ -31,6 +31,7 @@ static const float vscroll_fraction = 0.05;
 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;
 
 /* flip these to enable event debugging */
 #if 1
@@ -81,6 +82,9 @@ static void initButtonLabels(Atom map[DIM_BUTTON])
 	PROPMAP(map, MT_BUTTON_SWIPE_DOWN, BTN_LABEL_PROP_BTN_1);
 	PROPMAP(map, MT_BUTTON_SWIPE_LEFT, BTN_LABEL_PROP_BTN_2);
 	PROPMAP(map, MT_BUTTON_SWIPE_RIGHT, BTN_LABEL_PROP_BTN_3);
+	/* 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);
 }
 #endif
 
@@ -88,7 +92,7 @@ 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
+		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
 	};
 #if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 7
 	Atom axes_labels[2], btn_labels[DIM_BUTTON];
@@ -209,11 +213,12 @@ static void handle_gestures(LocalDevicePtr local,
 			    const struct Gestures *gs,
 			    const struct Capabilities *caps)
 {
-	static int vscroll, hscroll, vswipe, hswipe;
+	static int vscroll, hscroll, vswipe, hswipe, scale;
 	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 i;
 	if (!gs->same_fingers) {
 		vscroll = 0;
@@ -249,6 +254,10 @@ static void handle_gestures(LocalDevicePtr local,
 		button_scroll(local, 10, 11, &hswipe, hswipestep, gs->dx);
 		TRACE1("hswipe: %d\n", gs->dx);
 	}
+	if (GETBIT(gs->type, GS_SCALE)) {
+		button_scroll(local, 12, 13, &scale, scalestep, gs->scale);
+		TRACE1("scale: %d\n", gs->scale);
+	}
 }
 
 /* called for each full received packet from the touchpad */