libs/hwui/Rect.h

/*
 * Copyright (C) 2010 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 "Vertex.h"

#include <utils/Log.h>

#include <SkRect.h>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <ostream>

namespace android {
namespace uirenderer {

#define RECT_STRING "%5.2f %5.2f %5.2f %5.2f"
#define RECT_ARGS(r) (r).left, (r).top, (r).right, (r).bottom
#define SK_RECT_ARGS(r) (r).left(), (r).top(), (r).right(), (r).bottom()

///////////////////////////////////////////////////////////////////////////////
// Structs
///////////////////////////////////////////////////////////////////////////////

class Rect {
public:
    float left;
    float top;
    float right;
    float bottom;

    // Used by Region
    typedef float value_type;

    // we don't provide copy-ctor and operator= on purpose
    // because we want the compiler generated versions

    inline Rect() : left(0), top(0), right(0), bottom(0) {}

    inline Rect(float left, float top, float right, float bottom)
            : left(left), top(top), right(right), bottom(bottom) {}

    inline Rect(float width, float height) : left(0.0f), top(0.0f), right(width), bottom(height) {}

    inline Rect(const SkIRect& rect) // NOLINT(google-explicit-constructor)
            :
            left(rect.fLeft)
            , top(rect.fTop)
            , right(rect.fRight)
            , bottom(rect.fBottom) {}

    inline Rect(const SkRect& rect) // NOLINT(google-explicit-constructor)
            :
            left(rect.fLeft)
            , top(rect.fTop)
            , right(rect.fRight)
            , bottom(rect.fBottom) {}

    friend int operator==(const Rect& a, const Rect& b) { return !memcmp(&a, &b, sizeof(a)); }

    friend int operator!=(const Rect& a, const Rect& b) { return memcmp(&a, &b, sizeof(a)); }

    inline void clear() { left = top = right = bottom = 0.0f; }

    inline bool isEmpty() const {
        // this is written in such way this it'll handle NANs to return
        // true (empty)
        return !((left < right) && (top < bottom));
    }

    inline void setEmpty() { left = top = right = bottom = 0.0f; }

    inline void set(float left, float top, float right, float bottom) {
        this->left = left;
        this->right = right;
        this->top = top;
        this->bottom = bottom;
    }

    inline void set(const Rect& r) { set(r.left, r.top, r.right, r.bottom); }

    inline void set(const SkIRect& r) { set(r.left(), r.top(), r.right(), r.bottom()); }

    inline float getWidth() const { return right - left; }

    inline float getHeight() const { return bottom - top; }

    bool intersects(float l, float t, float r, float b) const {
        float tempLeft = std::max(left, l);
        float tempTop = std::max(top, t);
        float tempRight = std::min(right, r);
        float tempBottom = std::min(bottom, b);

        return ((tempLeft < tempRight) && (tempTop < tempBottom));  // !isEmpty
    }

    bool intersects(const Rect& r) const { return intersects(r.left, r.top, r.right, r.bottom); }

    /**
     * This method is named 'doIntersect' instead of 'intersect' so as not to be confused with
     * SkRect::intersect / android.graphics.Rect#intersect behavior, which do not modify the object
     * if the intersection of the rects would be empty.
     */
    void doIntersect(float l, float t, float r, float b) {
        left = std::max(left, l);
        top = std::max(top, t);
        right = std::min(right, r);
        bottom = std::min(bottom, b);
    }

    void doIntersect(const Rect& r) { doIntersect(r.left, r.top, r.right, r.bottom); }

    inline bool contains(float l, float t, float r, float b) const {
        return l >= left && t >= top && r <= right && b <= bottom;
    }

    inline bool contains(const Rect& r) const { return contains(r.left, r.top, r.right, r.bottom); }

    bool unionWith(const Rect& r) {
        if (r.left < r.right && r.top < r.bottom) {
            if (left < right && top < bottom) {
                if (left > r.left) left = r.left;
                if (top > r.top) top = r.top;
                if (right < r.right) right = r.right;
                if (bottom < r.bottom) bottom = r.bottom;
                return true;
            } else {
                left = r.left;
                top = r.top;
                right = r.right;
                bottom = r.bottom;
                return true;
            }
        }
        return false;
    }

    void translate(float dx, float dy) {
        left += dx;
        right += dx;
        top += dy;
        bottom += dy;
    }

    void inset(float delta) { outset(-delta); }

    void outset(float delta) {
        left -= delta;
        top -= delta;
        right += delta;
        bottom += delta;
    }

    void outset(float xdelta, float ydelta) {
        left -= xdelta;
        top -= ydelta;
        right += xdelta;
        bottom += ydelta;
    }

    /**
     * Similar to snapToPixelBoundaries, but estimates bounds conservatively to handle GL rounding
     * errors.
     *
     * This function should be used whenever estimating the damage rect of geometry already mapped
     * into layer space.
     */
    void snapGeometryToPixelBoundaries(bool snapOut) {
        if (snapOut) {
            /* For AA geometry with a ramp perimeter, don't snap by rounding - AA geometry will have
             * a 0.5 pixel perimeter not accounted for in its bounds. Instead, snap by
             * conservatively rounding out the bounds with floor/ceil.
             *
             * In order to avoid changing integer bounds with floor/ceil due to rounding errors
             * inset the bounds first by the fudge factor. Very small fraction-of-a-pixel errors
             * from this inset will only incur similarly small errors in output, due to transparency
             * in extreme outside of the geometry.
             */
            left = floorf(left + Vertex::GeometryFudgeFactor());
            top = floorf(top + Vertex::GeometryFudgeFactor());
            right = ceilf(right - Vertex::GeometryFudgeFactor());
            bottom = ceilf(bottom - Vertex::GeometryFudgeFactor());
        } else {
            /* For other geometry, we do the regular rounding in order to snap, but also outset the
             * bounds by a fudge factor. This ensures that ambiguous geometry (e.g. a non-AA Rect
             * with top left at (0.5, 0.5)) will err on the side of a larger damage rect.
             */
            left = floorf(left + 0.5f - Vertex::GeometryFudgeFactor());
            top = floorf(top + 0.5f - Vertex::GeometryFudgeFactor());
            right = floorf(right + 0.5f + Vertex::GeometryFudgeFactor());
            bottom = floorf(bottom + 0.5f + Vertex::GeometryFudgeFactor());
        }
    }

    void snapToPixelBoundaries() {
        left = floorf(left + 0.5f);
        top = floorf(top + 0.5f);
        right = floorf(right + 0.5f);
        bottom = floorf(bottom + 0.5f);
    }

    void roundOut() {
        left = floorf(left);
        top = floorf(top);
        right = ceilf(right);
        bottom = ceilf(bottom);
    }

    /*
     * Similar to unionWith, except this makes the assumption that both rects are non-empty
     * to avoid both emptiness checks.
     */
    void expandToCover(const Rect& other) {
        left = std::min(left, other.left);
        top = std::min(top, other.top);
        right = std::max(right, other.right);
        bottom = std::max(bottom, other.bottom);
    }

    void expandToCover(float x, float y) {
        left = std::min(left, x);
        top = std::min(top, y);
        right = std::max(right, x);
        bottom = std::max(bottom, y);
    }

    SkRect toSkRect() const { return SkRect::MakeLTRB(left, top, right, bottom); }

    SkIRect toSkIRect() const { return SkIRect::MakeLTRB(left, top, right, bottom); }

    void dump(const char* label = nullptr) const {
        ALOGD("%s[l=%.2f t=%.2f r=%.2f b=%.2f]", label ? label : "Rect", left, top, right, bottom);
    }

    friend std::ostream& operator<<(std::ostream& os, const Rect& rect) {
        if (rect.isEmpty()) {
            // Print empty, but continue, since empty rects may still have useful coordinate info
            os << "(empty)";
        }

        if (rect.left == 0 && rect.top == 0) {
            return os << "[" << rect.right << " x " << rect.bottom << "]";
        }

        return os << "[" << rect.left << " " << rect.top << " " << rect.right << " " << rect.bottom
                  << "]";
    }
};  // class Rect

}  // namespace uirenderer
}  // namespace android