An Output resolution larger than the window (3840x2160 in a 2560x1440 window, 5120x2880 on a 4K screen) is drawn
bigger, then scaled down to the window. The window pass read its Catmull-Rom or Lanczos 2 over 4 x 4 of the picture's
pixels whatever the shrink, so it skipped most of them, and detail finer than the window can show came out as shimmer
and moire: worse than the plain linear copy. With the filter Off and Sharpness 0 the picture took that copy, a blit
whose linear filter reads 2 x 2 pixels, which aliases too.

Shrinking, each filter is now stretched by the picture's pixels per window pixel (up to 4), and the pass runs whenever
the picture is larger than the window, Off as a stretched linear (tent) filter. A window as large as the picture, or
larger, is filtered as before.

Assisted-by: Claude Opus 5.5
Co-Authored-By: Claude Opus 5.5 <[email protected]>

@@ -35,3 +45,3 @@
 vec3 filtered(vec2 uv) {
-    if (pc.mode == 0) return textureLod(src, uv, 0.0).rgb;
     const vec2 size = vec2(textureSize(src, 0));
+    const vec2 s = clamp(size / vec2(imageSize(dst)), vec2(1.0), vec2(kMaxStretch));

@@ -599,1 +598,4 @@
     if (!source.w || !source.h) return VK_NULL_HANDLE;
+    // (a picture larger than the window takes the pass even with the filter Off: the blit's linear filter reads 2 x 2 of the
+    // picture whatever the shrink, and fine detail shimmered)
+    const bool shrink = source.w > dw || source.h > dh;