input: add support for precise scroll axes

Support horizontal and vertical axes of input devices.

If the input device support precise scrolling with an input value then it
should first be scaled to a standard multiplier, where 1.0 is the default.

The multiplier will then applied to the following commands if possible:
 * MP_CMD_SEEK
 * MP_CMD_SPEED_MULT
 * MP_CMD_ADD

All other commands will triggered on every axis event, without change the
values specified in the config file.

1 files changed, 5 insertions, 0 deletions

diff --git a/mpvcore/input/input.h b/mpvcore/input/input.h
index 2c8441c7c0..022ebb3881 100644
--- a/mpvcore/input/input.h
+++ b/mpvcore/input/input.h
@@ -146,6 +146,7 @@ typedef struct mp_cmd {
     bool mouse_move;
     int mouse_x, mouse_y;
     struct mp_cmd *queue_next;
+    double scale;                             // for scaling numeric arguments
 } mp_cmd_t;
 
 
@@ -181,6 +182,10 @@ void mp_input_put_key(struct input_ctx *ictx, int code);
 // string as key events.
 void mp_input_put_key_utf8(struct input_ctx *ictx, int mods, struct bstr t);
 
+// Process scrolling input. Support for precise scrolling. Scales the given
+// scroll amount add multiplies it with the command (seeking, sub-delay, etc)
+void mp_input_put_axis(struct input_ctx *ictx, int direction, double value);
+
 // Update mouse position (in window coordinates).
 void mp_input_set_mouse_pos(struct input_ctx *ictx, int x, int y);