1 files changed, 68 insertions, 4 deletions

diff --git a/src/state.c b/src/state.c
index 46b7fef..fc3580d 100644
--- a/src/state.c
+++ b/src/state.c
@@ -1,4 +1,5 @@
 #include "state.h"
+#include <stdlib.h>
 
 /******************************************************/
 
@@ -9,11 +10,58 @@ void init_state(struct State *s)
 
 /******************************************************/
 
+inline int fincomp(const struct FingerState* a,const struct FingerState* b)
+{
+        return a->id - b->id;
+}
+
+inline float dist2(const struct FingerData* a,const struct FingerData* b)
+{
+        float dx = a->position_x - b->position_x;
+        float dy = a->position_y - b->position_y;
+
+        return dx * dx + dy * dy;
+}
+
 void modify_state(struct State *s, const struct HWData* hw)
 {
-        int i;
-        if (s->button[0] != hw->button[0])
-                xf86Msg(X_INFO, "multitouch: button changed\n");
+        float A[DIM2_FINGER], *row;
+        int id[DIM_FINGER], index[DIM_FINGER], i, j;
+
+        for (j = 0; j < s->nfinger; j++) {
+                id[j] = s->finger[j].id;
+                row = A + hw->nfinger * j;
+                for (i = 0; i < hw->nfinger; i++)
+                        row[i] = dist2(&hw->finger[i], &s->finger[j].hw);
+        }
+
+        match_fingers(index, A, hw->nfinger, s->nfinger);
+
+        s->nfinger = 0;
+
+        /* update matched fingers */
+        for (i = 0; i < hw->nfinger; i++) {
+                if ((j = index[i]) >= 0) {
+                        s->finger[s->nfinger].id = id[j];
+                        s->finger[s->nfinger].hw = hw->finger[i];
+                        s->nfinger++;
+                }
+        }
+
+        /* create new fingers */
+        for (i = 0; i < hw->nfinger; i++) {
+                if (index[i] < 0) {
+                        s->finger[s->nfinger].id = ++s->lastid;
+                        s->finger[s->nfinger].hw = hw->finger[i];
+                        s->nfinger++;
+                }
+        }
+
+        /* sort fingers in touching order */
+        qsort(s->finger, s->nfinger, sizeof(struct FingerState),
+              (int (*)(const void*,const void*))fincomp);
+
+        /* copy buttons */
         for (i = 0; i < DIM_BUTTON; i++)
                 s->button[i] = hw->button[i];
 }
@@ -23,9 +71,11 @@ void modify_state(struct State *s, const struct HWData* hw)
 const struct FingerState *find_finger(const struct State *s, int id)
 {
         int i;
+
         for (i = 0; i < s->nfinger; i++)
                 if (s->finger[i].id == id)
-                        return s->finger+i;
+                        return s->finger + i;
+
         return NULL;
 }
 
@@ -33,6 +83,20 @@ const struct FingerState *find_finger(const struct State *s, int id)
 
 void output_state(const struct State *s)
 {
+        int i;
+        printf("buttons: %d%d%d\n", s->button[0], s->button[1], s->button[2]);
+        printf("fingers: %d\n", s->nfinger);
+        for (i = 0; i < s->nfinger; i++) {
+                printf("  %+02d %+05d:%+05d +%05d:%+05d %+05d %+05d:%+05d\n",
+                       s->finger[i].id,
+                       s->finger[i].hw.touch_major,
+                       s->finger[i].hw.touch_minor,
+                       s->finger[i].hw.width_major,
+                       s->finger[i].hw.width_minor,
+                       s->finger[i].hw.orientation,
+                       s->finger[i].hw.position_x,
+                       s->finger[i].hw.position_y);
+        }
 }
 
 /******************************************************/