1 files changed, 368 insertions, 0 deletions
diff --git a/libs/hwui/ClipArea.cpp b/libs/hwui/ClipArea.cpp
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--- /dev/null
+++ b/libs/hwui/ClipArea.cpp
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+/*
+ * Copyright (C) 2015 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 "ClipArea.h"
+
+#include <SkPath.h>
+#include <limits>
+
+#include "Rect.h"
+
+namespace android {
+namespace uirenderer {
+
+static bool intersect(Rect& r, const Rect& r2) {
+    bool hasIntersection = r.intersect(r2);
+    if (!hasIntersection) {
+        r.setEmpty();
+    }
+    return hasIntersection;
+}
+
+static void handlePoint(Rect& transformedBounds, const Matrix4& transform, float x, float y) {
+    Vertex v;
+    v.x = x;
+    v.y = y;
+    transform.mapPoint(v.x, v.y);
+    transformedBounds.expandToCoverVertex(v.x, v.y);
+}
+
+Rect transformAndCalculateBounds(const Rect& r, const Matrix4& transform) {
+    const float kMinFloat = std::numeric_limits<float>::lowest();
+    const float kMaxFloat = std::numeric_limits<float>::max();
+    Rect transformedBounds = { kMaxFloat, kMaxFloat, kMinFloat, kMinFloat };
+    handlePoint(transformedBounds, transform, r.left, r.top);
+    handlePoint(transformedBounds, transform, r.right, r.top);
+    handlePoint(transformedBounds, transform, r.left, r.bottom);
+    handlePoint(transformedBounds, transform, r.right, r.bottom);
+    return transformedBounds;
+}
+
+/*
+ * TransformedRectangle
+ */
+
+TransformedRectangle::TransformedRectangle() {
+}
+
+TransformedRectangle::TransformedRectangle(const Rect& bounds,
+        const Matrix4& transform)
+        : mBounds(bounds)
+        , mTransform(transform) {
+}
+
+bool TransformedRectangle::canSimplyIntersectWith(
+        const TransformedRectangle& other) const {
+
+    return mTransform == other.mTransform;
+}
+
+bool TransformedRectangle::intersectWith(const TransformedRectangle& other) {
+    Rect translatedBounds(other.mBounds);
+    return intersect(mBounds, translatedBounds);
+}
+
+bool TransformedRectangle::isEmpty() const {
+    return mBounds.isEmpty();
+}
+
+/*
+ * RectangleList
+ */
+
+RectangleList::RectangleList()
+        : mTransformedRectanglesCount(0) {
+}
+
+bool RectangleList::isEmpty() const {
+    if (mTransformedRectanglesCount < 1) {
+        return true;
+    }
+
+    for (int i = 0; i < mTransformedRectanglesCount; i++) {
+        if (mTransformedRectangles[i].isEmpty()) {
+            return true;
+        }
+    }
+    return false;
+}
+
+int RectangleList::getTransformedRectanglesCount() const {
+    return mTransformedRectanglesCount;
+}
+
+const TransformedRectangle& RectangleList::getTransformedRectangle(int i) const {
+    return mTransformedRectangles[i];
+}
+
+void RectangleList::setEmpty() {
+    mTransformedRectanglesCount = 0;
+}
+
+void RectangleList::set(const Rect& bounds, const Matrix4& transform) {
+    mTransformedRectanglesCount = 1;
+    mTransformedRectangles[0] = TransformedRectangle(bounds, transform);
+}
+
+bool RectangleList::intersectWith(const Rect& bounds,
+        const Matrix4& transform) {
+    TransformedRectangle newRectangle(bounds, transform);
+
+    // Try to find a rectangle with a compatible transformation
+    int index = 0;
+    for (; index < mTransformedRectanglesCount; index++) {
+        TransformedRectangle& tr(mTransformedRectangles[index]);
+        if (tr.canSimplyIntersectWith(newRectangle)) {
+            tr.intersectWith(newRectangle);
+            return true;
+        }
+    }
+
+    // Add it to the list if there is room
+    if (index < kMaxTransformedRectangles) {
+        mTransformedRectangles[index] = newRectangle;
+        mTransformedRectanglesCount += 1;
+        return true;
+    }
+
+    // This rectangle list is full
+    return false;
+}
+
+Rect RectangleList::calculateBounds() const {
+    Rect bounds;
+    for (int index = 0; index < mTransformedRectanglesCount; index++) {
+        const TransformedRectangle& tr(mTransformedRectangles[index]);
+        if (index == 0) {
+            bounds = tr.transformedBounds();
+        } else {
+            bounds.intersect(tr.transformedBounds());
+        }
+    }
+    return bounds;
+}
+
+static SkPath pathFromTransformedRectangle(const Rect& bounds,
+        const Matrix4& transform) {
+    SkPath rectPath;
+    SkPath rectPathTransformed;
+    rectPath.addRect(bounds.left, bounds.top, bounds.right, bounds.bottom);
+    SkMatrix skTransform;
+    transform.copyTo(skTransform);
+    rectPath.transform(skTransform, &rectPathTransformed);
+    return rectPathTransformed;
+}
+
+SkRegion RectangleList::convertToRegion(const SkRegion& clip) const {
+    SkRegion rectangleListAsRegion;
+    for (int index = 0; index < mTransformedRectanglesCount; index++) {
+        const TransformedRectangle& tr(mTransformedRectangles[index]);
+        SkPath rectPathTransformed = pathFromTransformedRectangle(
+                tr.getBounds(), tr.getTransform());
+        if (index == 0) {
+            rectangleListAsRegion.setPath(rectPathTransformed, clip);
+        } else {
+            SkRegion rectRegion;
+            rectRegion.setPath(rectPathTransformed, clip);
+            rectangleListAsRegion.op(rectRegion, SkRegion::kIntersect_Op);
+        }
+    }
+    return rectangleListAsRegion;
+}
+
+/*
+ * ClipArea
+ */
+
+ClipArea::ClipArea()
+        : mMode(kModeRectangle) {
+}
+
+/*
+ * Interface
+ */
+
+void ClipArea::setViewportDimensions(int width, int height) {
+    mViewportBounds.set(0, 0, width, height);
+    mClipRect = mViewportBounds;
+}
+
+void ClipArea::setEmpty() {
+    mMode = kModeRectangle;
+    mClipRect.setEmpty();
+    mClipRegion.setEmpty();
+    mRectangleList.setEmpty();
+}
+
+void ClipArea::setClip(float left, float top, float right, float bottom) {
+    mMode = kModeRectangle;
+    mClipRect.set(left, top, right, bottom);
+    mClipRegion.setEmpty();
+}
+
+bool ClipArea::clipRectWithTransform(float left, float top, float right,
+        float bottom, const mat4* transform, SkRegion::Op op) {
+    Rect r(left, top, right, bottom);
+    return clipRectWithTransform(r, transform, op);
+}
+
+bool ClipArea::clipRectWithTransform(const Rect& r, const mat4* transform,
+        SkRegion::Op op) {
+    switch (mMode) {
+    case kModeRectangle:
+        return rectangleModeClipRectWithTransform(r, transform, op);
+    case kModeRectangleList:
+        return rectangleListModeClipRectWithTransform(r, transform, op);
+    case kModeRegion:
+        return regionModeClipRectWithTransform(r, transform, op);
+    }
+    return false;
+}
+
+bool ClipArea::clipRegion(const SkRegion& region, SkRegion::Op op) {
+    enterRegionMode();
+    mClipRegion.op(region, op);
+    setClipRectToRegionBounds();
+    return true;
+}
+
+bool ClipArea::clipPathWithTransform(const SkPath& path, const mat4* transform,
+        SkRegion::Op op) {
+    SkMatrix skTransform;
+    transform->copyTo(skTransform);
+    SkPath transformed;
+    path.transform(skTransform, &transformed);
+    SkRegion region;
+    regionFromPath(transformed, region);
+    return clipRegion(region, op);
+}
+
+/*
+ * Rectangle mode
+ */
+
+void ClipArea::enterRectangleMode() {
+    // Entering rectangle mode discards any
+    // existing clipping information from the other modes.
+    // The only way this occurs is by a clip setting operation.
+    mMode = kModeRectangle;
+}
+
+bool ClipArea::rectangleModeClipRectWithTransform(const Rect& r,
+        const mat4* transform, SkRegion::Op op) {
+
+    if (op != SkRegion::kIntersect_Op) {
+        enterRegionMode();
+        return regionModeClipRectWithTransform(r, transform, op);
+    }
+
+    if (transform->rectToRect()) {
+        Rect transformed(r);
+        transform->mapRect(transformed);
+        bool hasIntersection = mClipRect.intersect(transformed);
+        if (!hasIntersection) {
+            mClipRect.setEmpty();
+        }
+        return true;
+    }
+
+    enterRectangleListMode();
+    return rectangleListModeClipRectWithTransform(r, transform, op);
+}
+
+bool ClipArea::rectangleModeClipRectWithTransform(float left, float top,
+        float right, float bottom, const mat4* transform, SkRegion::Op op) {
+    Rect r(left, top, right, bottom);
+    bool result = rectangleModeClipRectWithTransform(r, transform, op);
+    mClipRect = mRectangleList.calculateBounds();
+    return result;
+}
+
+/*
+ * RectangleList mode implementation
+ */
+
+void ClipArea::enterRectangleListMode() {
+    // Is is only legal to enter rectangle list mode from
+    // rectangle mode, since rectangle list mode cannot represent
+    // all clip areas that can be represented by a region.
+    ALOG_ASSERT(mMode == kModeRectangle);
+    mMode = kModeRectangleList;
+    mRectangleList.set(mClipRect, Matrix4::identity());
+}
+
+bool ClipArea::rectangleListModeClipRectWithTransform(const Rect& r,
+        const mat4* transform, SkRegion::Op op) {
+    if (op != SkRegion::kIntersect_Op
+            || !mRectangleList.intersectWith(r, *transform)) {
+        enterRegionMode();
+        return regionModeClipRectWithTransform(r, transform, op);
+    }
+    return true;
+}
+
+bool ClipArea::rectangleListModeClipRectWithTransform(float left, float top,
+        float right, float bottom, const mat4* transform, SkRegion::Op op) {
+    Rect r(left, top, right, bottom);
+    return rectangleListModeClipRectWithTransform(r, transform, op);
+}
+
+/*
+ * Region mode implementation
+ */
+
+void ClipArea::enterRegionMode() {
+    if (mMode != kModeRegion) {
+        if (mMode == kModeRectangle) {
+            mClipRegion.setRect(mClipRect.left, mClipRect.top,
+                    mClipRect.right, mClipRect.bottom);
+        } else {
+            mClipRegion = mRectangleList.convertToRegion(createViewportRegion());
+            setClipRectToRegionBounds();
+        }
+        mMode = kModeRegion;
+    }
+}
+
+bool ClipArea::regionModeClipRectWithTransform(const Rect& r,
+        const mat4* transform, SkRegion::Op op) {
+    SkPath transformedRect = pathFromTransformedRectangle(r, *transform);
+    SkRegion transformedRectRegion;
+    regionFromPath(transformedRect, transformedRectRegion);
+    mClipRegion.op(transformedRectRegion, op);
+    setClipRectToRegionBounds();
+    return true;
+}
+
+bool ClipArea::regionModeClipRectWithTransform(float left, float top,
+        float right, float bottom, const mat4* transform, SkRegion::Op op) {
+    return regionModeClipRectWithTransform(Rect(left, top, right, bottom),
+            transform, op);
+}
+
+void ClipArea::setClipRectToRegionBounds() {
+    if (!mClipRegion.isEmpty()) {
+        mClipRect.set(mClipRegion.getBounds());
+
+        if (mClipRegion.isRect()) {
+            mClipRegion.setEmpty();
+        }
+    } else {
+        mClipRect.setEmpty();
+    }
+}
+
+} /* namespace uirenderer */
+} /* namespace android */