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 */