Introduce a stable ABI

The current mtdev is not ABI stable, and the upcoming additions
to the kernel api will break ABI. This patch starts the process
of keeping binary compatibility with old programs, by moving the
abi-specific parts under a special flag, MTDEV_NO_LEGACY_API,
and makes sure the internal parts compiles with MTDEV_NO_LEGACY_API
set. This way, older programs will still work, old programs will
still compile, and new programs will be able to use the additions.

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

1 files changed, 26 insertions, 1 deletions

diff --git a/src/state.h b/src/state.h
index df12139..4e98a08 100644
--- a/src/state.h
+++ b/src/state.h
@@ -37,9 +37,29 @@
  * @abs: current values of ABS_MT axes for this slot
  */
 struct mtdev_slot {
-        int abs[MT_ABS_SIZE];
+        int touch_major;
+        int touch_minor;
+        int width_major;
+        int width_minor;
+        int orientation;
+        int position_x;
+        int position_y;
+        int tool_type;
+        int blob_id;
+        int tracking_id;
+        int pressure;
 };
 
+static inline int get_sval(const struct mtdev_slot *slot, int ix)
+{
+        return (&slot->touch_major)[ix];
+}
+
+static inline void set_sval(struct mtdev_slot *slot, int ix, int value)
+{
+        (&slot->touch_major)[ix] = value;
+}
+
 /*
  * struct mtdev_state - MT slot parsing
  * @inbuf: input event buffer
@@ -50,10 +70,15 @@ struct mtdev_slot {
  * @lastid: last used tracking id
  */
 struct mtdev_state {
+
+        int has_ext_abs[MT_ABS_SIZE - 11];
+        struct input_absinfo ext_abs[MT_ABS_SIZE - 11];
+
         struct mtdev_iobuf iobuf;
         struct mtdev_evbuf inbuf;
         struct mtdev_evbuf outbuf;
         struct mtdev_slot data[DIM_FINGER];
+
         bitmask_t used;
         bitmask_t slot;
         bitmask_t lastid;