Added clock time

SHADER_CONTRACT.md

@@ -122,6 +122,8 @@ struct ShaderContext
     float2 inputResolution;
     float2 outputResolution;
     float time;
+    float utcTimeSeconds;
+    float utcOffsetSeconds;
     float frameCount;
     float mixAmount;
     float bypass;
@@ -137,6 +139,8 @@ Fields:
 - `inputResolution`: decoded input video resolution in pixels.
 - `outputResolution`: shader render resolution in pixels. The current pipeline renders the shader stack at input resolution, then scales the final frame to the configured DeckLink output mode.
 - `time`: elapsed runtime time in seconds.
+- `utcTimeSeconds`: current UTC time of day from the host PC clock, expressed as seconds since UTC midnight.
+- `utcOffsetSeconds`: host PC local UTC offset in seconds. Add this to `utcTimeSeconds` and wrap to `0..86400` to get local time of day.
 - `frameCount`: incrementing frame counter.
 - `mixAmount`: runtime mix amount.
 - `bypass`: `1.0` when the layer is bypassed, otherwise `0.0`.