diff --git a/wled00/cfg.cpp b/wled00/cfg.cpp
index 1cc01a4f..55b4db34 100644
--- a/wled00/cfg.cpp
+++ b/wled00/cfg.cpp
@@ -366,16 +366,20 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
CJSON(gammaCorrectVal, light["gc"]["val"]); // default 2.8
float light_gc_bri = light["gc"]["bri"];
float light_gc_col = light["gc"]["col"];
+ float light_gc_prev = light["gc"]["prev"]; // WLEDMM
if (light_gc_bri > 1.0f) gammaCorrectBri = true;
else gammaCorrectBri = false;
if (light_gc_col > 1.0f) gammaCorrectCol = true;
else gammaCorrectCol = false;
+ if (light_gc_prev > 1.0f) gammaCorrectPreview = true; // WLEDMM
+ else gammaCorrectPreview = false; // WLEDMM
if (gammaCorrectVal > 1.0f && gammaCorrectVal <= 3) {
if (gammaCorrectVal != 2.8f) calcGammaTable(gammaCorrectVal);
} else {
gammaCorrectVal = 1.0f; // no gamma correction
gammaCorrectBri = false;
gammaCorrectCol = false;
+ gammaCorrectPreview = false; // WLEDMM
}
JsonObject light_tr = light["tr"];
@@ -877,6 +881,7 @@ void serializeConfig() {
JsonObject light_gc = light.createNestedObject("gc");
light_gc["bri"] = (gammaCorrectBri) ? gammaCorrectVal : 1.0f; // keep compatibility
light_gc["col"] = (gammaCorrectCol) ? gammaCorrectVal : 1.0f; // keep compatibility
+ light_gc["prev"] = (gammaCorrectPreview) ? gammaCorrectVal : 1.0f; // WLEDMM
light_gc["val"] = gammaCorrectVal;
JsonObject light_tr = light.createNestedObject("tr");
diff --git a/wled00/colors.cpp b/wled00/colors.cpp
index e8a3b37d..eca8cf74 100644
--- a/wled00/colors.cpp
+++ b/wled00/colors.cpp
@@ -347,6 +347,24 @@ static const byte gammaT[256] = {
245, 247, 250, 252, 255 };
#endif
+// WLEDMM begin
+static uint8_t gammaTinv[256] = { 0 };
+static void calcInvGammaTable(float gamma)
+{
+ float gammaInv = 1.0f / 2.4f; // surprise surprise: WLED palettes use a fixed gamma of 2.4 !!!
+ //float gammaInv = 1.0f / gamma; // if we go by the book, 1.0/gamma will revert gamma corrections
+ for (size_t i = 0; i < 256; i++) {
+ gammaTinv[i] = (int)(powf((float)i / 255.0f, gammaInv) * 255.0f + 0.5f);
+ }
+}
+uint8_t unGamma8(uint8_t value) {
+ if (!gammaCorrectCol || (value == 0) || (value == 255)) return value;
+ if ((gammaCorrectVal <= 1.0f) || (gammaCorrectVal > 3.0f)) return value;
+ if (gammaTinv[255] == 0) calcInvGammaTable(gammaCorrectVal);
+ return gammaTinv[value];
+}
+// wleDMM end
+
uint8_t gamma8_cal(uint8_t b, float gamma)
{
return (int)(powf((float)b / 255.0f, gamma) * 255.0f + 0.5f);
@@ -360,6 +378,7 @@ void calcGammaTable(float gamma)
gammaT[i] = gamma8_cal(i, gamma);
}
#endif
+ calcInvGammaTable(gamma); // WLEDMM
}
// used for individual channel or brightness gamma correction
diff --git a/wled00/data/settings_leds.htm b/wled00/data/settings_leds.htm
index 96805c6c..184c46d2 100644
--- a/wled00/data/settings_leds.htm
+++ b/wled00/data/settings_leds.htm
@@ -657,6 +657,7 @@ Length: WLEDMM experimental )