Cap workers at half the cores to stop host freezes

ppl2psd.py

@@ -219,7 +219,6 @@ def render_bitmap(ly: dict, img_path: Path, cw: int, ch: int
                            Image.LANCZOS)
     L, T = math.floor(l), math.floor(t)
     layer = layer.crop((ix0 - L, iy0 - T, ix1 - L, iy1 - T))
-    apply_opacity(layer, ly.get("alpha", 255))
     return layer, (ix0, iy0)
 
 
@@ -269,7 +268,6 @@ def render_shape(ly: dict, cw: int, ch: int) -> Optional[Tuple[Image.Image, Tupl
                                                    outline=255, width=thickness)
             img.paste(stroke_img, (0, 0), ring)
 
-    apply_opacity(img, ly.get("alpha", 255))
     # shadow (ppl renders a soft offset shadow per layer)
     sd = float(ly.get("shadowDistance", "0") or 0)
     sb = float(ly.get("shadowBlur", "0") or 0)
@@ -352,7 +350,11 @@ def render_text(ly: dict, cw: int, ch: int) -> Optional[Tuple[Image.Image, Tuple
         return adv * c
 
     grad = parse_gradient(ly.get("textColor", ""))
-    fill = grad["colors"][0][1] if grad["colors"] else (0, 0, 0, 255)
+    if grad["type"] == "gradient":
+        fill = (255, 255, 255, 255)  # base color; gradient is applied after
+        grad = grad  # keep for the mask pass
+    else:
+        fill = grad["colors"][0][1] if grad["colors"] else (0, 0, 0, 255)
 
     # --- measure natural text size (multi-line aware, per-char spacing) ---
     lines = text.split("\n")
@@ -428,7 +430,11 @@ def render_text(ly: dict, cw: int, ch: int) -> Optional[Tuple[Image.Image, Tuple
         return None
     img = img.crop((ix0 - left, iy0 - top, ix1 - left, iy1 - top))
 
-    apply_opacity(img, ly.get("alpha", 255))
+
+    # text gradient fill: paint a gradient over the glyph alpha
+    if grad["type"] == "gradient":
+        gimg = make_linear_gradient(img.width, img.height, grad)
+        img.paste(gimg, (0, 0), img.getchannel("A"))
 
     # soft shadow (used by rasterized output / previews)
     sd = float(ly.get("shadowDistance", "0") or 0)
@@ -453,6 +459,16 @@ def apply_opacity(img: Image.Image, alpha: str) -> None:
     img.putalpha(alpha_ch)
 
 
+def _opacity_paste(canvas: Image.Image, img: Image.Image, pos, opacity: int) -> None:
+    """Composite a layer onto the merged/preview canvas, applying the layer
+    opacity (PSD opacity field is applied by Photoshop itself, but the
+    in-tool merged preview must apply it manually)."""
+    if opacity < 255:
+        img = img.copy()
+        img.putalpha(img.getchannel("A").point(lambda p: p * opacity // 255))
+    canvas.paste(img, pos, img)
+
+
 # --------------------------------------------------------------------------
 # PSD writer
 # --------------------------------------------------------------------------
@@ -744,7 +760,7 @@ def build_psd(layers, width: int, height: int, out_path: str, workers: int,
     for layer in layers:
         name, opacity, visible, (lx, ly), img = layer[:5]
         if img is not None and visible and opacity > 0:
-            merged.paste(img, (lx, ly), img)
+            _opacity_paste(merged, img, (lx, ly), opacity)
     merged_rgb = None  # keep the RGBA merged image for the 4-channel output
     # Merged image data is written RAW with a single compression field and
     # all planes in planar order (R G B A). 4 channels because the document
@@ -784,9 +800,10 @@ def build_psd(layers, width: int, height: int, out_path: str, workers: int,
 # Main
 # --------------------------------------------------------------------------
 def _safe_workers(workers: int) -> int:
-    """Never use every CPU core: leave one for the system, otherwise the
+    """Keep at least half the CPU cores free - on phones the RLE-encoding
-    RLE-encoding workers can stall the whole device."""
+    workers plus PIL's internal threading can otherwise stall the whole
-    available = max(1, (os.cpu_count() or 2) - 1)
+    device (a previous cores-1 cap still froze the host)."""
+    available = max(1, (os.cpu_count() or 2) // 2)
     return max(1, min(workers, available))
 
 
@@ -919,7 +936,7 @@ def convert(ppl_path: str, out_path: str, preview_path: Optional[str] = None,
             for layer in rendered:
                 name, opacity, visible, (lx, ly), img = layer[:5]
                 if img is not None and visible and opacity > 0:
-                    canvas.paste(img, (lx, ly), img)
+                    _opacity_paste(canvas, img, (lx, ly), opacity)
             # downscale for easy viewing
             preview = canvas.convert("RGB")
             if preview.width > 2000:
@@ -937,8 +954,8 @@ def main():
     ap.add_argument("-o", "--output", help="output .psd path")
     ap.add_argument("--preview", help="also write a downscaled composite PNG")
     ap.add_argument("-j", "--workers", type=int,
-                    default=max(1, (os.cpu_count() or 2) - 1),
+                    default=max(1, (os.cpu_count() or 2) // 2),
-                    help="parallel workers for RLE encoding (default: cores-1)")
+                    help="parallel workers for RLE encoding (default: cores/2)")
     ap.add_argument("--type-layer", action="store_true",
                     help="convert text layers to editable TypeLayers (TySh) "
                          "instead of rasterized pixels")