Cocos2d-Lua-Community/cocos/2d/CCClippingRectangleNode.cpp

/****************************************************************************
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
 Copyright (c) 2020-2021 cocos2d-lua.org
 
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#include "2d/CCClippingRectangleNode.h"
#include "base/CCDirector.h"
#include "renderer/CCRenderer.h"
#include "math/Vec2.h"
#include "platform/CCGLView.h"

NS_CC_BEGIN

ClippingRectangleNode* ClippingRectangleNode::create(const Rect& clippingRegion)
{
    ClippingRectangleNode* node = new (std::nothrow) ClippingRectangleNode();
    if (node && node->init()) {
        // ClippingRectangleNode mostly use for UI, enable below two attributes.
        node->setCascadeColorEnabled(true);
        node->setCascadeOpacityEnabled(true);
        node->setClippingRegion(clippingRegion);
        node->autorelease();
    } else {
        CC_SAFE_DELETE(node);
    }
    return node;
}

ClippingRectangleNode* ClippingRectangleNode::create()
{
    ClippingRectangleNode* node = new (std::nothrow) ClippingRectangleNode();
    if (node && node->init()) {
        // ClippingRectangleNode mostly use for UI, enable below two attributes.
        node->setCascadeColorEnabled(true);
        node->setCascadeOpacityEnabled(true);
        node->autorelease();
    } else {
        CC_SAFE_DELETE(node);
    }
    return node;
}

void ClippingRectangleNode::setClippingRegion(const Rect &clippingRegion)
{
    _clippingRegion = clippingRegion;
}

void ClippingRectangleNode::onBeforeVisitScissor()
{
    if (_clippingEnabled) {
		// get this ClipRegion
		const Point pos1 = convertToWorldSpace(Point(_clippingRegion.origin.x, _clippingRegion.origin.y));
		const Point pos2 = convertToWorldSpace(Point(_clippingRegion.origin.x + _clippingRegion.size.width, _clippingRegion.origin.y + _clippingRegion.size.height));
		float px = pos1.x;
		float py = pos1.y;
		float width = pos2.x - pos1.x;
		float height = pos2.y - pos1.y;
		if (width < 0) {
			width = 0; //ClippingRectangle should not be rotated
		}
		if (height < 0) {
			height = 0; //ClippingRectangle should not be rotated
		}

        // record old ClipRegion
        GLView* glView = Director::getInstance()->getOpenGLView();
        if (glView->isScissorEnabled()) {
			_preClipRegion = glView->getScissorRect();
			// check collision
			float centerXdelta = (width + _preClipRegion.size.width) / 2;
			float centerYdelta = (height + _preClipRegion.size.height) / 2;
			if (std::abs((px + width / 2) - (_preClipRegion.origin.x + _preClipRegion.size.width / 2)) <= centerXdelta
				&& std::abs((py + height / 2) - (_preClipRegion.origin.y + _preClipRegion.size.height / 2)) <= centerYdelta)
			{
				// get Intersecting rectangle
				px = std::max(px, _preClipRegion.origin.x);
				py = std::max(py, _preClipRegion.origin.y);
				width = std::min(pos1.x + width - px, _preClipRegion.origin.x + _preClipRegion.size.width - px);
				height = std::min(pos1.y + height - py, _preClipRegion.origin.y + _preClipRegion.size.height- py);
			} else {
				//ZERO rect will auto disable Scissor clip, cheat with below code.
				px = -1;
				py = -1;
				width = 1;
				height = 1;
			}
        } else {
            _preClipRegion = Rect::ZERO;
            auto renderer = Director::getInstance()->getRenderer();
            renderer->setScissorTest(true);
        }
        
        glView->setScissorInPoints(px, py, width, height);
    }
}

void ClippingRectangleNode::onAfterVisitScissor()
{
    if (_clippingEnabled) {
        // rollback to old ClipRegion
        if (!_preClipRegion.equals(Rect::ZERO)) {
            auto glview = Director::getInstance()->getOpenGLView();
            glview->setScissorInPoints(_preClipRegion.origin.x,
                      _preClipRegion.origin.y,
                      _preClipRegion.size.width,
                      _preClipRegion.size.height);
        } else {
            // revert scissor test
            auto renderer = Director::getInstance()->getRenderer();
            renderer->setScissorTest(false);
        }
    }
}

void ClippingRectangleNode::visit(Renderer *renderer, const Mat4 &parentTransform, uint32_t parentFlags)
{
    if (!_visible) {
        return;
    }
    
    if (isVisitableByVisitingCamera()) {
        _beforeVisitCmdScissor.init(_globalZOrder);
        _beforeVisitCmdScissor.func = CC_CALLBACK_0(ClippingRectangleNode::onBeforeVisitScissor, this);
        renderer->addCommand(&_beforeVisitCmdScissor);
        
        Node::visit(renderer, parentTransform, parentFlags);
        
        _afterVisitCmdScissor.init(_globalZOrder);
        _afterVisitCmdScissor.func = CC_CALLBACK_0(ClippingRectangleNode::onAfterVisitScissor, this);
        renderer->addCommand(&_afterVisitCmdScissor);
    }
}

NS_CC_END