Add macOS backdrop blur and preserve PDF ink opacity

1 files changed, 15 insertions, 6 deletions

diff --git a/test/macos_e2e.swift b/test/macos_e2e.swift
index 5427c3ad..5efc366c 100644
--- a/test/macos_e2e.swift
+++ b/test/macos_e2e.swift
@@ -687,13 +687,22 @@ private final class Driver: PardesViewDelegate {
             throw ScriptError(message: "PDF: placement is outside its physical-pixel viewport")
         }
         let backing = CGFloat(rep.pixelsWide) / view.bounds.width
-        var matched = 0
-        for fraction in [CGFloat(0.2), 0.4, 0.6, 0.8] {
-            if let c = rep.colorAt(x: Int((x + width * fraction) * backing),
-                                  y: Int((y + height * fraction) * backing)), abs(c.alphaComponent - view.backgroundAlpha) < 2.0 / 255 { matched += 1 }
+        guard image.paper_bg != UInt32(PARDES_COLOR_DEFAULT) else {
+            throw ScriptError(message: "PDF: missing separate paper background")
         }
-        guard matched == 4 else { throw ScriptError(message: "PDF: raster opacity does not match WindowOpacity") }
-        output += "== pdf \(label) native page opacity verified\n"
+        var lowest: CGFloat = 1, highest: CGFloat = 0
+        for py in stride(from: Int(y * backing) + 2, to: Int((y + height) * backing) - 2, by: 2) {
+            for px in stride(from: Int(x * backing) + 2, to: Int((x + width) * backing) - 2, by: 2) {
+                if let c = rep.colorAt(x: px, y: py) {
+                    lowest = min(lowest, c.alphaComponent)
+                    highest = max(highest, c.alphaComponent)
+                }
+            }
+        }
+        guard abs(lowest - view.backgroundAlpha) < 2.0 / 255, highest > 0.98 else {
+            throw ScriptError(message: "PDF: expected translucent paper and opaque ink, got alpha \(lowest)...\(highest)")
+        }
+        output += "== pdf \(label) paper opacity and opaque ink verified\n"
     }
 
     // MARK: - the script