Auto-dark mode prototype

Experimental force_dark prototype mode. Enabled
by setting debug.hwui.force_dark to true.

Test: verified nothing changes without prop being set

Change-Id: Ib02f3f1a9c591cab1f312b827451f04c782c2f41

8 files changed, 180 insertions, 1 deletions

diff --git a/libs/hwui/Android.bp b/libs/hwui/Android.bp
index 0db779906545..111094bb6a2b 100644
--- a/libs/hwui/Android.bp
+++ b/libs/hwui/Android.bp
@@ -198,6 +198,7 @@ cc_defaults {
         "AnimatorManager.cpp",
         "Caches.cpp",
         "CanvasState.cpp",
+        "CanvasTransform.cpp",
         "ClipArea.cpp",
         "DamageAccumulator.cpp",
         "DeferredLayerUpdater.cpp",
diff --git a/libs/hwui/CanvasTransform.cpp b/libs/hwui/CanvasTransform.cpp
new file mode 100644
index 000000000000..bac7a4d17a49
--- /dev/null
+++ b/libs/hwui/CanvasTransform.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "CanvasTransform.h"
+#include "Properties.h"
+
+#include <SkColorFilter.h>
+#include <SkPaint.h>
+#include <log/log.h>
+
+namespace android::uirenderer {
+
+static SkColor makeLight(SkColor color) {
+    SkScalar hsv[3];
+    SkColorToHSV(color, hsv);
+    if (hsv[1] > .2f) return color;
+    // hsv[1] *= .85f;
+    // hsv[2] = std::min(1.0f, std::max(hsv[2], 1 - hsv[2]) * 1.3f);
+    hsv[2] = std::max(hsv[2], 1.1f - hsv[2]);
+    return SkHSVToColor(SkColorGetA(color), hsv);
+}
+
+static SkColor makeDark(SkColor color) {
+    SkScalar hsv[3];
+    SkColorToHSV(color, hsv);
+    if (hsv[1] > .2f) return color;
+    // hsv[1] *= .85f;
+    // hsv[2] = std::max(0.0f, std::min(hsv[2], 1 - hsv[2]) * .7f);
+    hsv[2] = std::min(hsv[2], 1.1f - hsv[2]);
+    return SkHSVToColor(SkColorGetA(color), hsv);
+}
+
+static SkColor transformColor(ColorTransform transform, SkColor color) {
+    switch (transform) {
+        case ColorTransform::Light:
+            return makeLight(color);
+        case ColorTransform::Dark:
+            return makeDark(color);
+        default:
+            return color;
+    }
+}
+
+static void applyColorTransform(ColorTransform transform, SkPaint& paint) {
+    if (transform == ColorTransform::None) return;
+
+    SkColor newColor = transformColor(transform, paint.getColor());
+    paint.setColor(newColor);
+
+    if (paint.getColorFilter()) {
+        SkBlendMode mode;
+        SkColor color;
+        // TODO: LRU this or something to avoid spamming new color mode filters
+        if (paint.getColorFilter()->asColorMode(&color, &mode)) {
+            color = transformColor(transform, color);
+            paint.setColorFilter(SkColorFilter::MakeModeFilter(color, mode));
+        }
+    }
+}
+
+class ColorFilterCanvas : public SkPaintFilterCanvas {
+public:
+    ColorFilterCanvas(ColorTransform transform, SkCanvas* canvas)
+            : SkPaintFilterCanvas(canvas), mTransform(transform) {}
+
+    bool onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type type) const override {
+        if (*paint) {
+            applyColorTransform(mTransform, *(paint->writable()));
+        }
+        return true;
+    }
+
+private:
+    ColorTransform mTransform;
+};
+
+std::unique_ptr<SkCanvas> makeTransformCanvas(SkCanvas* inCanvas, ColorTransform transform) {
+    switch (transform) {
+        case ColorTransform::Light:
+            return std::make_unique<ColorFilterCanvas>(ColorTransform::Light, inCanvas);
+        case ColorTransform::Dark:
+            return std::make_unique<ColorFilterCanvas>(ColorTransform::Dark, inCanvas);
+        default:
+            return nullptr;
+    }
+}
+
+std::unique_ptr<SkCanvas> makeTransformCanvas(SkCanvas* inCanvas, UsageHint usageHint) {
+    if (Properties::forceDarkMode) {
+        switch (usageHint) {
+            case UsageHint::Unknown:
+                return makeTransformCanvas(inCanvas, ColorTransform::Light);
+            case UsageHint::Background:
+                return makeTransformCanvas(inCanvas, ColorTransform::Dark);
+        }
+    }
+    return nullptr;
+}
+
+};  // namespace android::uirenderer
\ No newline at end of file
diff --git a/libs/hwui/CanvasTransform.h b/libs/hwui/CanvasTransform.h
new file mode 100644
index 000000000000..f71fdfaf3fba
--- /dev/null
+++ b/libs/hwui/CanvasTransform.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <SkCanvas.h>
+#include <SkPaintFilterCanvas.h>
+
+#include <memory>
+
+namespace android::uirenderer {
+
+enum class UsageHint {
+    Unknown = 0,
+    Background = 1,
+};
+
+enum class ColorTransform {
+    None,
+    Light,
+    Dark,
+};
+
+std::unique_ptr<SkCanvas> makeTransformCanvas(SkCanvas* inCanvas, ColorTransform transform);
+std::unique_ptr<SkCanvas> makeTransformCanvas(SkCanvas* inCanvas, UsageHint usageHint);
+
+}  // namespace android::uirenderer;
\ No newline at end of file
diff --git a/libs/hwui/Properties.cpp b/libs/hwui/Properties.cpp
index 0338a3aba97d..17bec1934490 100644
--- a/libs/hwui/Properties.cpp
+++ b/libs/hwui/Properties.cpp
@@ -60,6 +60,7 @@ bool Properties::forceDrawFrame = false;
 bool Properties::filterOutTestOverhead = false;
 bool Properties::disableVsync = false;
 bool Properties::skpCaptureEnabled = false;
+bool Properties::forceDarkMode = false;
 bool Properties::enableRTAnimations = true;
 
 bool Properties::runningInEmulator = false;
@@ -146,6 +147,8 @@ bool Properties::load() {
 
     runningInEmulator = property_get_bool(PROPERTY_QEMU_KERNEL, false);
 
+    forceDarkMode = property_get_bool(PROPERTY_FORCE_DARK, false);
+
     return (prevDebugLayersUpdates != debugLayersUpdates) || (prevDebugOverdraw != debugOverdraw) ||
            (prevDebugStencilClip != debugStencilClip);
 }
diff --git a/libs/hwui/Properties.h b/libs/hwui/Properties.h
index d640c749d829..ea017a72cd74 100644
--- a/libs/hwui/Properties.h
+++ b/libs/hwui/Properties.h
@@ -190,6 +190,8 @@ enum DebugLevel {
  */
 #define PROPERTY_QEMU_KERNEL "ro.kernel.qemu"
 
+#define PROPERTY_FORCE_DARK "debug.hwui.force_dark"
+
 ///////////////////////////////////////////////////////////////////////////////
 // Misc
 ///////////////////////////////////////////////////////////////////////////////
@@ -263,6 +265,7 @@ public:
     static bool disableVsync;
 
     static bool skpCaptureEnabled;
+    static bool forceDarkMode;
 
     // For experimentation b/68769804
     ANDROID_API static bool enableRTAnimations;
diff --git a/libs/hwui/RenderNode.h b/libs/hwui/RenderNode.h
index dc962f307903..8393288d2ffd 100644
--- a/libs/hwui/RenderNode.h
+++ b/libs/hwui/RenderNode.h
@@ -28,6 +28,7 @@
 #include <androidfw/ResourceTypes.h>
 
 #include "AnimatorManager.h"
+#include "CanvasTransform.h"
 #include "Debug.h"
 #include "DisplayList.h"
 #include "Matrix.h"
@@ -208,6 +209,14 @@ public:
 
     void output(std::ostream& output, uint32_t level);
 
+    void setUsageHint(UsageHint usageHint) {
+        mUsageHint = usageHint;
+    }
+
+    UsageHint usageHint() const {
+        return mUsageHint;
+    }
+
 private:
     void computeOrderingImpl(RenderNodeOp* opState,
                              std::vector<RenderNodeOp*>* compositedChildrenOfProjectionSurface,
@@ -263,6 +272,8 @@ private:
 
     sp<PositionListener> mPositionListener;
 
+    UsageHint mUsageHint = UsageHint::Unknown;
+
     // METHODS & FIELDS ONLY USED BY THE SKIA RENDERER
 public:
     /**
diff --git a/libs/hwui/pipeline/skia/SkiaRecordingCanvas.cpp b/libs/hwui/pipeline/skia/SkiaRecordingCanvas.cpp
index f0da660f17b0..6fb2ee03cb50 100644
--- a/libs/hwui/pipeline/skia/SkiaRecordingCanvas.cpp
+++ b/libs/hwui/pipeline/skia/SkiaRecordingCanvas.cpp
@@ -17,6 +17,7 @@
 #include "SkiaRecordingCanvas.h"
 
 #include <SkImagePriv.h>
+#include "CanvasTransform.h"
 #include "Layer.h"
 #include "LayerDrawable.h"
 #include "NinePatchUtils.h"
@@ -44,13 +45,19 @@ void SkiaRecordingCanvas::initDisplayList(uirenderer::RenderNode* renderNode, in
     }
 
     mDisplayList->attachRecorder(&mRecorder, SkIRect::MakeWH(width, height));
-    SkiaCanvas::reset(&mRecorder);
+    SkCanvas* canvas = &mRecorder;
+    mWrappedCanvas = makeTransformCanvas(&mRecorder, renderNode->usageHint());
+    if (mWrappedCanvas) {
+        canvas = mWrappedCanvas.get();
+    }
+    SkiaCanvas::reset(canvas);
 }
 
 uirenderer::DisplayList* SkiaRecordingCanvas::finishRecording() {
     // close any existing chunks if necessary
     insertReorderBarrier(false);
     mRecorder.restoreToCount(1);
+    mWrappedCanvas = nullptr;
     return mDisplayList.release();
 }
 
diff --git a/libs/hwui/pipeline/skia/SkiaRecordingCanvas.h b/libs/hwui/pipeline/skia/SkiaRecordingCanvas.h
index 93807a5476e6..b69acbf2ffb8 100644
--- a/libs/hwui/pipeline/skia/SkiaRecordingCanvas.h
+++ b/libs/hwui/pipeline/skia/SkiaRecordingCanvas.h
@@ -78,6 +78,7 @@ public:
 private:
     SkLiteRecorder mRecorder;
     std::unique_ptr<SkiaDisplayList> mDisplayList;
+    std::unique_ptr<SkCanvas> mWrappedCanvas;
     StartReorderBarrierDrawable* mCurrentBarrier;
 
     /**