cocos_lib/cocos/math/Geometry.cpp

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#include "math/Geometry.h"

#include <algorithm>
#include <cmath>
#include "base/Macros.h"

// implementation of Vec2
namespace cc {

// implementation of Size

Size::Size() = default;

Size::Size(float w, float h) : width(w),
                               height(h) {
}

Size::Size(const Size &other) = default;

Size::Size(const Vec2 &point) : width(point.x),
                                height(point.y) {
}

Size &Size::operator=(const Size &other) {
    setSize(other.width, other.height);
    return *this;
}

Size &Size::operator=(const Vec2 &point) {
    setSize(point.x, point.y);
    return *this;
}

Size Size::operator+(const Size &right) const {
    return Size(this->width + right.width, this->height + right.height);
}

Size Size::operator-(const Size &right) const {
    return Size(this->width - right.width, this->height - right.height);
}

Size Size::operator*(float a) const {
    return Size(this->width * a, this->height * a);
}

Size Size::operator/(float a) const {
    CC_ASSERT_NE(a, 0);
    float inv = 1.0F / a;
    return Size(this->width * inv, this->height * inv);
}

void Size::setSize(float w, float h) {
    this->width = w;
    this->height = h;
}

bool Size::equals(const Size &target) const {
    return (std::abs(this->width - target.width) < FLT_EPSILON) && (std::abs(this->height - target.height) < FLT_EPSILON);
}

const Size Size::ZERO = Size(0, 0);

// implementation of Rect

Rect::Rect() {
    setRect(0.0F, 0.0F, 0.0F, 0.0F);
}

Rect::Rect(float x, float y, float width, float height) {
    setRect(x, y, width, height);
}
Rect::Rect(const Vec2 &pos, const Size &dimension) {
    setRect(pos.x, pos.y, dimension.width, dimension.height);
}

Rect::Rect(const Rect &other) {
    setRect(other.x, other.y, other.width, other.height);
}

Rect &Rect::operator=(const Rect &other) {
    setRect(other.x, other.y, other.width, other.height);
    return *this;
}

void Rect::setRect(float x, float y, float width, float height) {
    // CGRect can support width<0 or height<0
    // CC_ASSERT(width >= 0.0f && height >= 0.0f);

    this->x = x;
    this->y = y;
    this->width = width;
    this->height = height;
}

bool Rect::equals(const Rect &rect) const {
    return (std::abs(this->x - rect.x) < FLT_EPSILON) && (std::abs(this->y - rect.y) < FLT_EPSILON) && (std::abs(this->width - rect.width) < FLT_EPSILON) && (std::abs(this->height - rect.height) < FLT_EPSILON);
}

float Rect::getMaxX() const {
    return this->x + this->width;
}

float Rect::getMidX() const {
    return this->x + this->width / 2.0F;
}

float Rect::getMinX() const {
    return this->x;
}

float Rect::getMaxY() const {
    return this->y + this->height;
}

float Rect::getMidY() const {
    return this->y + this->height / 2.0F;
}

float Rect::getMinY() const {
    return this->y;
}

bool Rect::containsPoint(const Vec2 &point) const {
    bool bRet = false;

    if (point.x >= getMinX() && point.x <= getMaxX() && point.y >= getMinY() && point.y <= getMaxY()) {
        bRet = true;
    }

    return bRet;
}

bool Rect::intersectsRect(const Rect &rect) const {
    return !(getMaxX() < rect.getMinX() ||
             rect.getMaxX() < getMinX() ||
             getMaxY() < rect.getMinY() ||
             rect.getMaxY() < getMinY());
}

bool Rect::intersectsCircle(const Vec2 &center, float radius) const {
    Vec2 rectangleCenter((this->x + this->width / 2),
                         (this->y + this->height / 2));

    float w = this->width / 2;
    float h = this->height / 2;

    float dx = std::abs(center.x - rectangleCenter.x);
    float dy = std::abs(center.y - rectangleCenter.y);

    if (dx > (radius + w) || dy > (radius + h)) {
        return false;
    }

    Vec2 circleDistance(std::abs(center.x - this->x - w),
                        std::abs(center.y - this->y - h));

    if (circleDistance.x <= (w)) {
        return true;
    }

    if (circleDistance.y <= (h)) {
        return true;
    }

    float cornerDistanceSq = powf(circleDistance.x - w, 2) + powf(circleDistance.y - h, 2);

    return (cornerDistanceSq <= (powf(radius, 2)));
}

void Rect::merge(const Rect &rect) {
    float minX = std::min(getMinX(), rect.getMinX());
    float minY = std::min(getMinY(), rect.getMinY());
    float maxX = std::max(getMaxX(), rect.getMaxX());
    float maxY = std::max(getMaxY(), rect.getMaxY());
    setRect(minX, minY, maxX - minX, maxY - minY);
}

Rect Rect::unionWithRect(const Rect &rect) const {
    float thisLeftX = this->x;
    float thisRightX = this->x + this->width;
    float thisTopY = this->y + this->height;
    float thisBottomY = this->y;

    if (thisRightX < thisLeftX) {
        std::swap(thisRightX, thisLeftX); // This rect has negative width
    }

    if (thisTopY < thisBottomY) {
        std::swap(thisTopY, thisBottomY); // This rect has negative height
    }

    float otherLeftX = rect.x;
    float otherRightX = rect.x + rect.width;
    float otherTopY = rect.y + rect.height;
    float otherBottomY = rect.y;

    if (otherRightX < otherLeftX) {
        std::swap(otherRightX, otherLeftX); // Other rect has negative width
    }

    if (otherTopY < otherBottomY) {
        std::swap(otherTopY, otherBottomY); // Other rect has negative height
    }

    float combinedLeftX = std::min(thisLeftX, otherLeftX);
    float combinedRightX = std::max(thisRightX, otherRightX);
    float combinedTopY = std::max(thisTopY, otherTopY);
    float combinedBottomY = std::min(thisBottomY, otherBottomY);

    return Rect(combinedLeftX, combinedBottomY, combinedRightX - combinedLeftX, combinedTopY - combinedBottomY);
}

const Rect Rect::ZERO = Rect(0, 0, 0, 0);

} // namespace cc