Fix evdev relative axes, add detect option

5 files changed, 75 insertions, 13 deletions

diff --git a/TODO b/TODO
index 2a97c30..5f4ce91 100644
--- a/TODO
+++ b/TODO
@@ -3,5 +3,4 @@ Note source in channel value struct
 Optimize core channel search (store backend offset)
 Printing backend / Verbose mode
 
-evdev relative axis size
 mm_managed_fd.impl is not freed currently
diff --git a/backends/evdev.c b/backends/evdev.c
index ca8469a..565eb17 100644
--- a/backends/evdev.c
+++ b/backends/evdev.c
@@ -27,6 +27,12 @@ typedef union {
 	uint64_t label;
 } evdev_channel_ident;
 
+static struct {
+	uint8_t detect;
+} evdev_config = {
+	.detect = 0
+};
+
 int init(){
 	backend evdev = {
 		.name = BACKEND_NAME,
@@ -49,7 +55,15 @@ int init(){
 }
 
 static int evdev_configure(char* option, char* value) {
-	fprintf(stderr, "The evdev backend does not take any global configuration\n");
+	if(!strcmp(option, "detect")){
+		evdev_config.detect = 1;
+		if(!strcmp(value, "off")){
+			evdev_config.detect = 0;
+		}
+		return 0;
+	}
+
+	fprintf(stderr, "Unknown configuration option %s for evdev backend\n", option);
 	return 1;
 }
 
@@ -185,6 +199,22 @@ static int evdev_configure_instance(instance* inst, char* option, char* value) {
 		data->exclusive = 1;
 		return 0;
 	}
+	else if(!strncmp(option, "relaxis.", 8)){
+		data->relative_axis = realloc(data->relative_axis, (data->relative_axes + 1) * sizeof(evdev_relaxis_config));
+		if(!data->relative_axis){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return 1;
+		}
+		data->relative_axis[data->relative_axes].code = libevdev_event_code_from_name(EV_REL, option + 8);
+		data->relative_axis[data->relative_axes].max = strtoul(value, &next_token, 0);
+		data->relative_axis[data->relative_axes].current = strtoul(next_token, NULL, 0);
+		if(data->relative_axis[data->relative_axes].code < 0){
+			fprintf(stderr, "Failed to configure relative axis extents for %s.%s\n", inst->name, option + 8);
+			return 1;
+		}
+		data->relative_axes++;
+		return 0;
+	}
 #ifndef EVDEV_NO_UINPUT
 	else if(!strcmp(option, "output")){
 		data->output_enabled = 1;
@@ -214,7 +244,7 @@ static int evdev_configure_instance(instance* inst, char* option, char* value) {
 		return 0;
 	}
 #endif
-	fprintf(stderr, "Unknown configuration parameter %s for evdev backend\n", option);
+	fprintf(stderr, "Unknown instance configuration parameter %s for evdev instance %s\n", option, inst->name);
 	return 1;
 }
 
@@ -275,21 +305,32 @@ static int evdev_push_event(instance* inst, evdev_instance_data* data, struct in
 		.fields.code = event.code
 	};
 	channel* chan = mm_channel(inst, ident.label, 0);
+	size_t axis;
 
 	if(chan){
 		val.raw.u64 = event.value;
 		switch(event.type){
 			case EV_REL:
-				val.normalised = 0.5 + ((event.value < 0) ? 0.5 : -0.5);
+				for(axis = 0; axis < data->relative_axes; axis++){
+					if(data->relative_axis[axis].code == event.code){
+						data->relative_axis[axis].current = clamp(data->relative_axis[axis].current + event.value, data->relative_axis[axis].max, 0);
+						val.normalised = (double) data->relative_axis[axis].current / (double) data->relative_axis[axis].max;
+						break;
+					}
+				}
+				if(axis == data->relative_axes){
+					val.normalised = 0.5 + ((event.value < 0) ? 0.5 : -0.5);
+					break;
+				}
 				break;
 			case EV_ABS:
 				range = libevdev_get_abs_maximum(data->input_ev, event.code) - libevdev_get_abs_minimum(data->input_ev, event.code);
-				val.normalised = (event.value - libevdev_get_abs_minimum(data->input_ev, event.code)) / (double) range;
+				val.normalised = clamp((event.value - libevdev_get_abs_minimum(data->input_ev, event.code)) / (double) range, 1.0, 0.0);
 				break;
 			case EV_KEY:
 			case EV_SW:
 			default:
-				val.normalised = 1.0 * event.value;
+				val.normalised = clamp(1.0 * event.value, 1.0, 0.0);
 				break;
 		}
 
@@ -299,6 +340,10 @@ static int evdev_push_event(instance* inst, evdev_instance_data* data, struct in
 		}
 	}
 
+	if(evdev_config.detect){
+		fprintf(stderr, "Incoming evdev data for channel %s.%s.%s\n", inst->name, libevdev_event_type_get_name(event.type), libevdev_event_code_get_name(event.type, event.code));
+	}
+
 	return 0;
 }
 
@@ -470,6 +515,8 @@ static int evdev_shutdown(){
 
 		libevdev_free(data->output_proto);
 #endif
+		data->relative_axes = 0;
+		free(data->relative_axis);
 		free(data);
 	}
 
diff --git a/backends/evdev.h b/backends/evdev.h
index c6e3a25..d719631 100644
--- a/backends/evdev.h
+++ b/backends/evdev.h
@@ -24,10 +24,18 @@ static int evdev_shutdown();
 	#define UINPUT_MAX_NAME_SIZE 512
 #endif
 
+typedef struct /*_evdev_relative_axis_config*/ {
+	int code;
+	int64_t max;
+	int64_t current;
+} evdev_relaxis_config;
+
 typedef struct /*_evdev_instance_model*/ {
 	int input_fd;
 	struct libevdev* input_ev;
 	int exclusive;
+	size_t relative_axes;
+	evdev_relaxis_config* relative_axis;
 
 	int output_enabled;
 #ifndef EVDEV_NO_UINPUT
diff --git a/backends/evdev.md b/backends/evdev.md
index d750f1e..995b44c 100644
--- a/backends/evdev.md
+++ b/backends/evdev.md
@@ -7,7 +7,9 @@ This functionality may require elevated privileges (such as special group member
 
 #### Global configuration
 
-This backend does not take any global configuration.
+| Option        | Example value         | Default value         | Description           |
+|---------------|-----------------------|-----------------------|-----------------------|
+| `detect`      | `on`                  | `off`                 | Output the channel specification for all events coming in on configured instances to help with configuration. |
 
 #### Instance configuration
 
@@ -18,7 +20,8 @@ This backend does not take any global configuration.
 | `output`	| `My Input Device`	| none		| Output device presentation name. Setting this option enables the instance for output	|
 | `exclusive`	| `1`			| `0`		| Prevent other processes from using the device		|
 | `id`		| `0x1 0x2 0x3`		| none		| Set output device bus identification (Vendor, Product and Version), optional |
-| `axis.AXISNAME`| `34300 0 65536 255 4095` | none	| Specify absolute axis details (see below) for output. This is required for any absolute axis to be output.
+| `axis.AXISNAME`| `34300 0 65536 255 4095` | none	| Specify absolute axis details (see below) for output. This is required for any absolute axis to be output. | 
+| `relaxis.AXISNAME`| `65534 32767` | none	| Specify relative axis details (extent and optional initial value) for output and input (see below). |
 
 The absolute axis details configuration (e.g. `axis.ABS_X`) is required for any absolute axis on output-enabled
 instances. The configuration value contains, space-separated, the following values:
@@ -34,6 +37,13 @@ If an axis is not used for output, this configuration can be omitted.
 
 For real devices, all of these parameters for every axis can be found by running `evtest` on the device.
 
+To use the input from relative axes in absolute-value based protocols, the backend needs a reference frame to
+convert the relative movements to absolute values.
+
+If relative axes are used without specifying their extents, the channel will generate normalized values
+of `0`, `0.5` and `1` for any input less than, equal to and greater than `0`, respectively. As for output, only
+the values `-1`, `0` and `1` are generated for the same interval.
+
 #### Channel specification
 
 A channel is specified by its event type and event code, separated by `.`. For a complete list of event types and codes
@@ -64,10 +74,6 @@ Input devices may synchronize logically connected event types (for example, X an
 events. The MIDIMonster also generates these events after processing channel events, but may not keep the original
 event grouping.
 
-Relative axes (`EV_REL`-type events), such as generated by mouses, are currently handled in a very basic fashion,
-generating only the normalized channel values of `0`, `0.5` and `1` for any input less than, equal to and greater
-than `0`, respectively. As for output, only the values `-1`, `0` and `1` are generated for the same interval.
-
 `EV_KEY` key-down events are sent for normalized channel values over `0.9`.
 
 Extended event type values such as `EV_LED`, `EV_SND`, etc are recognized in the MIDIMonster configuration file
diff --git a/monster.cfg b/monster.cfg
index 7db3ec3..2e6f76f 100644
--- a/monster.cfg
+++ b/monster.cfg
@@ -1,6 +1,8 @@
 [backend artnet]
 bind = 0.0.0.0
 
+[backend evdev]
+
 [artnet art]
 universe = 0
 dest = 255.255.255.255
@@ -11,6 +13,6 @@ input = TPPS
 [loopback loop]
 
 [map]
+mouse.EV_REL.REL_X > loop.chan0
 art.{3..4}{4..3} > loop.chan{4..3}{3..4}
 art.{1..10} > loop.data{1..10}
-art.{500..599} > loop.test{500..599}