Make auto-dark a bit better

Handles transform of basic bitmaps
Tweak to always treat text as foreground

Test: builds, poked around with force_dark
Change-Id: I733d39e05067438335da5a7eac06111f66f1228d
diff --git a/libs/hwui/CanvasTransform.cpp b/libs/hwui/CanvasTransform.cpp
index adcdc18..a03b317 100644
--- a/libs/hwui/CanvasTransform.cpp
+++ b/libs/hwui/CanvasTransform.cpp
@@ -28,6 +28,7 @@
 #include <cmath>
 
 #include <log/log.h>
+#include <SkHighContrastFilter.h>
 
 namespace android::uirenderer {
 
@@ -113,4 +114,20 @@
     return true;
 }
 
+bool transformPaint(ColorTransform transform, SkPaint* paint, BitmapPalette palette) {
+    bool shouldInvert = false;
+    if (palette == BitmapPalette::Light && transform == ColorTransform::Dark) {
+        shouldInvert = true;
+    }
+    if (palette == BitmapPalette::Dark && transform == ColorTransform::Light) {
+        shouldInvert = true;
+    }
+    if (shouldInvert) {
+        SkHighContrastConfig config;
+        config.fInvertStyle = SkHighContrastConfig::InvertStyle::kInvertLightness;
+        paint->setColorFilter(SkHighContrastFilter::Make(config)->makeComposed(paint->refColorFilter()));
+    }
+    return shouldInvert;
+}
+
 };  // namespace android::uirenderer
\ No newline at end of file