Enhance DaliBase and DaliBridge: add support for logarithmic brightness control in setBright and setBrightPercentage methods

Signed-off-by: Tony <tonylu@tony-cloud.com>

README.md

@@ -27,6 +27,7 @@ Dali dali(comm);
 
 ```cpp
 dali.base.setBright(5, 200);         // direct arc power control
+dali.base.setBright(5, 128, true);   // direct arc power with logarithmic curve
 dali.base.off(5);
 dali.base.dtSelect(8);
 dali.dt8.setColorTemperature(5, 4000); // Kelvin
@@ -71,6 +72,9 @@ DaliBridgeRequest request;
 request.modelID = "line-1-brightness";
 request.value = 180;
 engine.execute(request);
+
+request.value = DaliValue::Object{{"value", 128}, {"logarithmicCurve", true}};
+engine.execute(request); // set_brightness with app-side logarithmic curve
 ```
 
 ### Supported Bridge Operations
@@ -95,6 +99,9 @@ engine.execute(request);
 - `start_emergency_function_test`
 - `stop_emergency_test`
 
+`set_brightness` and `set_brightness_percent` accept optional
+`logarithmicCurve` / `logarithmic_curve` boolean request fields.
+
 Query-style operations return `data` when available and may include decoded flags in `meta`.
 
 ## Notes

include/base.hpp

@@ -50,8 +50,8 @@ class DaliBase {
   // Brightness helpers
   int brightnessToLog(int brightness) const;
   int logToBrightness(int logValue) const;
-  bool setBright(int a, int b);
-  bool setBrightPercentage(int a, double b);
+  bool setBright(int a, int b, bool logarithmicCurve = false);
+  bool setBrightPercentage(int a, double b, bool logarithmicCurve = false);
   bool stopFade(int a);
   bool off(int a);
   bool on(int a);

src/base.cpp

@@ -68,16 +68,18 @@ int DaliBase::logToBrightness(int logValue) const {
   return static_cast<int>(val);
 }
 
-bool DaliBase::setBright(int a, int b) {
-  int bright = std::clamp(b, 0, 254);
+bool DaliBase::setBright(int a, int b, bool logarithmicCurve) {
+  const int inputBright = std::clamp(b, 0, 254);
+  const int bright = logarithmicCurve ? std::clamp(brightnessToLog(inputBright), 0, 254)
+                                      : inputBright;
   const auto addr = encodeArcAddr(a);
   return comm_.sendCmd(addr, static_cast<uint8_t>(bright));
 }
 
-bool DaliBase::setBrightPercentage(int a, double b) {
+bool DaliBase::setBrightPercentage(int a, double b, bool logarithmicCurve) {
   int bright = static_cast<int>(b * 254.0 / 100.0);
   bright = std::clamp(bright, 0, 254);
-  return setBright(a, bright);
+  return setBright(a, bright, logarithmicCurve);
 }
 
 bool DaliBase::stopFade(int a) { return sendCmd(encodeCmdAddr(a), DALI_CMD_STOP_FADE); }

src/bridge.cpp

@@ -649,13 +649,16 @@ DaliBridgeResult DaliBridgeEngine::executeResolved(const DaliBridgeRequest& requ
         result.error = "missing target address";
         return result;
       }
+      const bool logarithmicCurve =
+          boolParam(request, {"logarithmicCurve", "logarithmic_curve", "logCurve", "log_curve"})
+              .value_or(false);
       if (operation == BridgeOperation::setBrightness) {
         const auto value = resolveIntValue(request, model);
         if (!value.has_value()) {
           result.error = "missing value";
           return result;
         }
-        result.ok = base_.setBright(address.value(), value.value());
+        result.ok = base_.setBright(address.value(), value.value(), logarithmicCurve);
         result.data = value.value();
       } else if (operation == BridgeOperation::setBrightnessPercent) {
         const auto value = resolveDoubleValue(request);
@@ -663,7 +666,7 @@ DaliBridgeResult DaliBridgeEngine::executeResolved(const DaliBridgeRequest& requ
           result.error = "missing value";
           return result;
         }
-        result.ok = base_.setBrightPercentage(address.value(), value.value());
+        result.ok = base_.setBrightPercentage(address.value(), value.value(), logarithmicCurve);
         result.data = static_cast<int>(std::lround(value.value()));
       } else if (operation == BridgeOperation::on) {
         result.ok = base_.on(address.value());