Initial release

engine/plugins/guidance/cfg_pp.lua

@@ -0,0 +1,21 @@
+-- cfg_pp.lua: CFG++ — Step-scaled guidance for large steps
+-- Reduces effective scale by the step-size-to-sigma ratio.
+-- Routes through native APG (momentum + projection + norm thresholding).
+
+guidance = {
+    name        = "cfg_pp",
+    display     = "CFG++",
+    description = "Step-scaled guidance for few-step models",
+}
+
+function guide(pred_cond, pred_uncond, guidance_scale, result, Oc, T, norm_threshold)
+    -- Effective scale adjusted by step ratio (t_curr and dt are globals)
+    local effective_scale = guidance_scale
+    if t_curr and t_curr > 1e-6 and dt then
+        local step_scale = math.abs(dt) / t_curr
+        effective_scale = 1.0 + (guidance_scale - 1.0) * step_scale
+    end
+
+    -- Route through native APG with the adjusted scale
+    apg(pred_cond, pred_uncond, effective_scale, result, Oc, T, norm_threshold)
+end