Add support for multiple types of button/axis specification.

docs/readme.md

@@ -15,7 +15,7 @@ Each entry in `devices` must have a couple of parameters:
 
 `virtual` devices must additionally define these parameters:
 
-* `buttons` - a number between 0 and 80. Linux may not recognize buttons greater than 56.
+* `buttons` - a number between 0 and 74. Linux may not recognize buttons greater than 56.
 * `axes` - a number between 0 and 8.
 
 Virtual devices can also define a `relative_axes` parameter; this must be a list of `REL_` event keycodes, and can be useful for a simulated mouse device. Some environments will only register mouse events if the device *only* supports mouse-like events, so it can be useful to isolate your `relative_axes` to their own virtual device.
@@ -35,13 +35,20 @@ Configuration options for each rule type vary. See <examples/ruletypes.yml> for
 
 ### Keycodes
 
-Currently, there is only one way to specify a button or axis: using evdev's Keycodes. These look like `ABS_X` for axes and `BTN_TRIGGER`
-for buttons. See <https://github.com/holoplot/go-evdev/blob/master/codes.go> for a full list of these codes, but note that Joyful's virtual devices currently only uses a subset. Specifically, the axes from `ABS_X` to `ABS_RUDDER`, and the buttons from `BTN_JOYSTICK` to `BTN_DEAD`, as well as all of the `BTN_TRIGGER_HAPPY*` codes.
+Keycodes are the values that identify buttons and axes. There are several ways to configure keycodes. All of them are case-insensitive.
+
+Ways to specify keycodes are:
+
+* Using evdev's Keycodes. This is the best way to be absolutely certain about which axis you're referencing. You can specify these keycodes in two forms:
+  * Using the code's identifier from <https://github.com/holoplot/go-evdev/blob/master/codes.go>. e.g., `ABS_X`, `REL_WHEEL`, `BTN_TRIGGER`.
+  * Alternately, you can omit the `ABS_` type prefix, and Joyful will automatically add it from context. So for a button input, you can simply specify `button: trigger` instead of `BTN_TRIGGER`.
+* You can use the hexadecimal value of the keycode directly, via `0x<numeric value>`. This can be useful if you want to force a specific numeric value that isn't represented by a Linux keycode directly. Note however that not all keycodes will work. Only the first 8 axes are available, and see <internal/config/variables.go> for a list of valid button outputs.
+* For buttons, you can specify the button number, as in `button: 3`. There are 74 buttons available, and the first button is button number `0`. As a result, valid values are 0-73. Note that buttons 12-14 and buttons 55-73 may not work in all Linux-native games.
 
 For input, you can figure out what keycodes your device is emitting by running the Linux utility `evtest`. `evtest` works well with `grep`, so if you just want to see button inputs, you can do:
 
 ```
-evtest | grep KEY_
+evtest | grep BTN_
 ```
 
 The authors of this tool recognize that this is currently a pain in the ass. Easier ways to represent keycodes (as well as outputting additional keycodes) is planned for the future.

internal/config/make_rule_targets.go

@@ -3,6 +3,8 @@ package config
 import (
 	"errors"
 	"fmt"
+	"strconv"
+	"strings"
 
 	"git.annabunches.net/annabunches/joyful/internal/mappingrules"
 	"github.com/holoplot/go-evdev"
@@ -14,9 +16,39 @@ func makeRuleTargetButton(targetConfig RuleTargetConfig, devs map[string]*evdev.
 		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
 	}
 
-	eventCode, ok := evdev.KEYFromString[targetConfig.Button]
+	var eventCode evdev.EvCode
+	buttonConfig := strings.ToUpper(targetConfig.Button)
+	switch {
+	case strings.HasPrefix(buttonConfig, "BTN_"):
+		eventCode, ok = evdev.KEYFromString[buttonConfig]
 		if !ok {
-		return nil, fmt.Errorf("invalid button code '%s'", targetConfig.Button)
+			return nil, fmt.Errorf("invalid button specification '%s'", buttonConfig)
+		}
+
+	case strings.HasPrefix(buttonConfig, "0X"):
+		codeInt, err := strconv.ParseUint(buttonConfig[2:], 16, 32)
+		if err != nil {
+			return nil, err
+		}
+		eventCode = evdev.EvCode(codeInt)
+
+	case !hasError(strconv.Atoi(buttonConfig)):
+		index, err := strconv.Atoi(buttonConfig)
+		if err != nil {
+			return nil, err
+		}
+
+		if index >= len(ButtonFromIndex) {
+			return nil, fmt.Errorf("button index '%d' out of bounds", index)
+		}
+
+		eventCode = ButtonFromIndex[index]
+
+	default:
+		eventCode, ok = evdev.KEYFromString["BTN_"+buttonConfig]
+		if !ok {
+			return nil, fmt.Errorf("invalid button specification '%s'", buttonConfig)
+		}
 	}
 
 	return mappingrules.NewRuleTargetButton(
@@ -33,9 +65,27 @@ func makeRuleTargetAxis(targetConfig RuleTargetConfig, devs map[string]*evdev.In
 		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
 	}
 
-	eventCode, ok := evdev.ABSFromString[targetConfig.Axis]
+	var eventCode evdev.EvCode
+	axisConfig := strings.ToUpper(targetConfig.Axis)
+	switch {
+	case strings.HasPrefix(axisConfig, "ABS_"):
+		eventCode, ok = evdev.ABSFromString[axisConfig]
 		if !ok {
-		return nil, fmt.Errorf("invalid button code '%s'", targetConfig.Button)
+			return nil, fmt.Errorf("invalid axis code '%s'", axisConfig)
+		}
+
+	case strings.HasPrefix(axisConfig, "0X"):
+		codeInt, err := strconv.ParseUint(axisConfig[2:], 16, 32)
+		if err != nil {
+			return nil, err
+		}
+		eventCode = evdev.EvCode(codeInt)
+
+	default:
+		eventCode, ok = evdev.ABSFromString["ABS_"+axisConfig]
+		if !ok {
+			return nil, fmt.Errorf("invalid axis code '%s'", axisConfig)
+		}
 	}
 
 	return mappingrules.NewRuleTargetAxis(
@@ -54,11 +104,28 @@ func makeRuleTargetRelaxis(targetConfig RuleTargetConfig, devs map[string]*evdev
 		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
 	}
 
-	eventCode, ok := evdev.RELFromString[targetConfig.Axis]
+	var eventCode evdev.EvCode
+	axisConfig := strings.ToUpper(targetConfig.Axis)
+	switch {
+	case strings.HasPrefix(axisConfig, "REL_"):
+		eventCode, ok = evdev.RELFromString[axisConfig]
 		if !ok {
-		return nil, fmt.Errorf("invalid button code '%s'", targetConfig.Button)
+			return nil, fmt.Errorf("invalid axis code '%s'", axisConfig)
 		}
 
+	case strings.HasPrefix(axisConfig, "0X"):
+		codeInt, err := strconv.ParseUint(axisConfig[2:], 16, 32)
+		if err != nil {
+			return nil, err
+		}
+		eventCode = evdev.EvCode(codeInt)
+
+	default:
+		eventCode, ok = evdev.ABSFromString["REL_"+axisConfig]
+		if !ok {
+			return nil, fmt.Errorf("invalid axis code '%s'", axisConfig)
+		}
+	}
 	return mappingrules.NewRuleTargetRelaxis(
 		targetConfig.Device,
 		device,
@@ -74,3 +141,8 @@ func makeRuleTargetModeSelect(targetConfig RuleTargetConfig, allModes []string)
 
 	return mappingrules.NewRuleTargetModeSelect(targetConfig.Modes)
 }
+
+// hasError exists solely to switch on errors in case statements
+func hasError(_ interface{}, err error) bool {
+	return err != nil
+}

internal/config/variables.go

@@ -31,6 +31,10 @@ var (
 		evdev.BTN_BASE4,
 		evdev.BTN_BASE5,
 		evdev.BTN_BASE6,
+		evdev.EvCode(0x12c),
+		evdev.EvCode(0x12d),
+		evdev.EvCode(0x12e),
+		evdev.BTN_DEAD,
 		evdev.BTN_TRIGGER_HAPPY1,
 		evdev.BTN_TRIGGER_HAPPY2,
 		evdev.BTN_TRIGGER_HAPPY3,
@@ -71,5 +75,23 @@ var (
 		evdev.BTN_TRIGGER_HAPPY38,
 		evdev.BTN_TRIGGER_HAPPY39,
 		evdev.BTN_TRIGGER_HAPPY40,
+		evdev.EvCode(0x2e8),
+		evdev.EvCode(0x2e9),
+		evdev.EvCode(0x2f0),
+		evdev.EvCode(0x2f1),
+		evdev.EvCode(0x2f2),
+		evdev.EvCode(0x2f3),
+		evdev.EvCode(0x2f4),
+		evdev.EvCode(0x2f5),
+		evdev.EvCode(0x2f6),
+		evdev.EvCode(0x2f7),
+		evdev.EvCode(0x2f8),
+		evdev.EvCode(0x2f9),
+		evdev.EvCode(0x2fa),
+		evdev.EvCode(0x2fb),
+		evdev.EvCode(0x2fc),
+		evdev.EvCode(0x2fd),
+		evdev.EvCode(0x2fe),
+		evdev.EvCode(0x2ff),
 	}
 )