adjustments to control and stack saving

shaders/white-balance-correction/shader.json

@@ -0,0 +1,49 @@
+{
+  "id": "white-balance-correction",
+  "name": "White Balance Correction",
+  "description": "Operator-friendly tint, color balance, and exposure correction intended to pair with the white match probe.",
+  "category": "Color",
+  "entryPoint": "shadeVideo",
+  "parameters": [
+    {
+      "id": "warmCool",
+      "label": "Warm / Cool",
+      "type": "float",
+      "default": 0.0,
+      "min": -1.0,
+      "max": 1.0,
+      "step": 0.001,
+      "description": "Moves the image cooler at negative values and warmer at positive values."
+    },
+    {
+      "id": "greenMagenta",
+      "label": "Green / Magenta",
+      "type": "float",
+      "default": 0.0,
+      "min": -1.0,
+      "max": 1.0,
+      "step": 0.001,
+      "description": "Moves the image toward magenta at negative values and toward green at positive values."
+    },
+    {
+      "id": "exposure",
+      "label": "Exposure",
+      "type": "float",
+      "default": 0.0,
+      "min": -4.0,
+      "max": 4.0,
+      "step": 0.01,
+      "description": "Exposure offset in stop units, using a Blender-style 2^exposure brightness scale."
+    },
+    {
+      "id": "strength",
+      "label": "Strength",
+      "type": "float",
+      "default": 1.0,
+      "min": 0.0,
+      "max": 1.0,
+      "step": 0.01,
+      "description": "Blends the correction with the original image."
+    }
+  ]
+}

shaders/white-balance-correction/shader.slang

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+float3 applyWhiteBalanceOnly(float3 color)
+{
+    float warmAmount = clamp(warmCool, -1.0, 1.0);
+    float tintAmount = clamp(greenMagenta, -1.0, 1.0);
+
+    // Warm/cool pivots red against blue while keeping green more stable.
+    float3 warmCoolGain = float3(
+        exp2(warmAmount * 0.35),
+        exp2(-abs(warmAmount) * 0.08),
+        exp2(-warmAmount * 0.35));
+
+    // Green/magenta pivots green against the average of red and blue.
+    float3 tintGain = float3(
+        exp2(-tintAmount * 0.22),
+        exp2(tintAmount * 0.35),
+        exp2(-tintAmount * 0.22));
+
+    return color * warmCoolGain * tintGain;
+}
+
+float3 applyExposureLikeBlender(float3 color)
+{
+    // Match the compositor-style exposure model: every +1.0 stop doubles the
+    // image and every -1.0 stop halves it.
+    return color * exp2(exposure);
+}
+
+float4 shadeVideo(ShaderContext context)
+{
+    float4 source = context.sourceColor;
+    float3 balanced = applyWhiteBalanceOnly(source.rgb);
+    float3 corrected = applyExposureLikeBlender(balanced);
+    source.rgb = lerp(source.rgb, corrected, saturate(strength));
+    return source;
+}