1 files changed, 149 insertions, 0 deletions
diff --git a/libs/hwui/CanvasTransform.cpp b/libs/hwui/CanvasTransform.cpp
new file mode 100644
index 000000000000..06e937ab66f4
--- /dev/null
+++ b/libs/hwui/CanvasTransform.cpp
@@ -0,0 +1,149 @@
+/*
+ * 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 "utils/Color.h"
+
+#include <SkColorFilter.h>
+#include <SkGradientShader.h>
+#include <SkPaint.h>
+#include <SkShader.h>
+#include <ui/ColorSpace.h>
+
+#include <algorithm>
+#include <cmath>
+
+#include <log/log.h>
+#include <SkHighContrastFilter.h>
+
+namespace android::uirenderer {
+
+static SkColor makeLight(SkColor color) {
+    Lab lab = sRGBToLab(color);
+    float invertedL = std::min(110 - lab.L, 100.0f);
+    if (invertedL > lab.L) {
+        lab.L = invertedL;
+        return LabToSRGB(lab, SkColorGetA(color));
+    } else {
+        return color;
+    }
+}
+
+static SkColor makeDark(SkColor color) {
+    Lab lab = sRGBToLab(color);
+    float invertedL = std::min(110 - lab.L, 100.0f);
+    if (invertedL < lab.L) {
+        lab.L = invertedL;
+        return LabToSRGB(lab, SkColorGetA(color));
+    } else {
+        return color;
+    }
+}
+
+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.getShader()) {
+        SkShader::GradientInfo info;
+        std::array<SkColor, 10> _colorStorage;
+        std::array<SkScalar, _colorStorage.size()> _offsetStorage;
+        info.fColorCount = _colorStorage.size();
+        info.fColors = _colorStorage.data();
+        info.fColorOffsets = _offsetStorage.data();
+        SkShader::GradientType type = paint.getShader()->asAGradient(&info);
+
+        if (info.fColorCount <= 10) {
+            switch (type) {
+                case SkShader::kLinear_GradientType:
+                    for (int i = 0; i < info.fColorCount; i++) {
+                        info.fColors[i] = transformColor(transform, info.fColors[i]);
+                    }
+                    paint.setShader(SkGradientShader::MakeLinear(info.fPoint, info.fColors,
+                                                                 info.fColorOffsets, info.fColorCount,
+                                                                 info.fTileMode, info.fGradientFlags, nullptr));
+                    break;
+                default:break;
+            }
+
+        }
+    }
+
+    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));
+        }
+    }
+}
+
+static BitmapPalette paletteForColorHSV(SkColor color) {
+    float hsv[3];
+    SkColorToHSV(color, hsv);
+    return hsv[2] >= .5f ? BitmapPalette::Light : BitmapPalette::Dark;
+}
+
+static BitmapPalette filterPalette(const SkPaint* paint, BitmapPalette palette) {
+    if (palette == BitmapPalette::Unknown || !paint || !paint->getColorFilter()) {
+        return palette;
+    }
+
+    SkColor color = palette == BitmapPalette::Light ? SK_ColorWHITE : SK_ColorBLACK;
+    color = paint->getColorFilter()->filterColor(color);
+    return paletteForColorHSV(color);
+}
+
+bool transformPaint(ColorTransform transform, SkPaint* paint) {
+    // TODO
+    applyColorTransform(transform, *paint);
+    return true;
+}
+
+bool transformPaint(ColorTransform transform, SkPaint* paint, BitmapPalette palette) {
+    palette = filterPalette(paint, 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