[PATCH v2 4/5] gdiplus: Fix hatch brush patterns that require anti-aliasing.

[Esme Povirk (they/them)]

+static ARGB blend_colors_pre(ARGB start, ARGB end, REAL position)
+{
+    const BYTE a = ((start >> 24) & 0xff) * (1 - position) + ((end >>
24) & 0xff) * position;
+    const BYTE r = ((start >> 16) & 0xff) * (1 - position) + ((end >>
16) & 0xff) * position;
+    const BYTE g = ((start >> 8) & 0xff) * (1 - position) + ((end >>
8) & 0xff) * position;
+    const BYTE b = (start & 0xff) * (1 - position) + (end & 0xff) * position;
+
+    return (a << 24) | (r << 16) | (g << 8) | b;
+}

I'm confused by the introduction of this function. It seems to be for
blending PARGB colors, but the hatch brush colors are ARGB.