关于cocos2d-x 3.1.1 版本的绘图方法有两种
1、使用DrawNode类绘制自定义图形。
2、继承Layer类重写draw()方法。
以上两种方法都可以绘制自定义图形，根据自己的需要选择合适的方法。
一、使用DrawNode类绘制自定义图形
使用DrawNode 类绘制图形是最简单的方法，create一个DrawNode类，然后添加进场景。然后就可以愉快的绘图了。
1 auto s = Director::getInstance()->getWinSize(); 2 //创建 3 auto draw = DrawNode::create(); 4 addChild(draw, 10); 5 6 // 画圆 7 for( int i=0; i < 10; i++) 8 { 9 draw->drawDot(Vec2(s.width/2, s.height/2), 10*(10-i), Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 1)); 10 } 11 12 // 画多边形 13 Vec2 points[] = { Vec2(s.height/4,0), Vec2(s.width,s.height/5), Vec2(s.width/3*2,s.height) }; 14 draw->drawPolygon(points, sizeof(points)/sizeof(points[0]), Color4F(1,0,0,0.5), 4, Color4F(0,0,1,1)); 15 16 // 画线 17 draw->drawSegment(Vec2(20,s.height), Vec2(20,s.height/2), 10, Color4F(0, 1, 0, 1)); 18 19 draw->drawSegment(Vec2(10,s.height/2), Vec2(s.width/2, s.height/2), 40, Color4F(1, 0, 1, 0.5)); 20 21 // 画三角形 22 draw->drawTriangle(Vec2(10, 10), Vec2(70, 30), Vec2(100, 140), Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 0.5)); 23 24 // 画贝赛尔曲线 25 draw->drawQuadraticBezier(Vec2(s.width - 150, s.height - 150), Vec2(s.width - 70, s.height - 10), Vec2(s.width - 10, s.height - 10), 10, Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 0.5)); 26 27 draw->drawCubicBezier(Vec2(s.width - 250, 40), Vec2(s.width - 70, 100), Vec2(s.width - 30, 250), Vec2(s.width - 10, s.height - 50), 10, Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 0.5));
根据需要可以用这些api创造出自己需要的图像。
二、继承Layer类重写draw()方法
这种方式可以自定义一个绘图类，用于创作自己需要的图形。
#ifndef __HELLOWORLD_SCENE_H__ #define __HELLOWORLD_SCENE_H__ #include "cocos2d.h" USING_NS_CC; class HelloWorld : public cocos2d::Layer { public: virtual void draw(Renderer *renderer, const Mat4 &transform, bool transformUpdated) override; protected: void onDraw(const kmMat4 &transform, bool transformUpdated); CustomCommand _customCommand; }; #endif
#include "HelloWorldScene.h" #include "VisibleRect.h" void HelloWorld::draw(cocos2d::Renderer *renderer, const kmMat4 &transform, bool transformUpdated) { return; _customCommand.init(1); _customCommand.func = CC_CALLBACK_0(HelloWorld::onDraw, this,transform,transformUpdated); renderer->addCommand(&_customCommand); } void HelloWorld::onDraw(const kmMat4 &transform, bool transformUpdated) { kmGLPushMatrix(); kmGLLoadMatrix(&transform); /*直线*/ CHECK_GL_ERROR_DEBUG(); DrawPrimitives::drawLine(VisibleRect::leftBottom(), VisibleRect::rightTop()); CHECK_GL_ERROR_DEBUG(); glLineWidth( 5.0f ); DrawPrimitives::setDrawColor4B(255,0,0,255); DrawPrimitives::drawLine( Point(0, 0), Point(100, 100) ); // draw big point in the center DrawPrimitives::setPointSize(64); DrawPrimitives::setDrawColor4B(100, 0, 255, 128); DrawPrimitives::drawPoint(VisibleRect::center()); CHECK_GL_ERROR_DEBUG(); // draw 4 small points Point points[] = { Point(60,60), Point(70,70), Point(160,70), Point(170,60) }; DrawPrimitives::setPointSize(10); DrawPrimitives::setDrawColor4B(0,10,255,255); DrawPrimitives::drawPoints( points, 4); CHECK_GL_ERROR_DEBUG(); // draw a green circle with 10 segments glLineWidth(16); DrawPrimitives::setDrawColor4B(0, 255, 0, 255); DrawPrimitives::drawCircle( VisibleRect::center(), 100, 0, 10, false); CHECK_GL_ERROR_DEBUG(); // draw a green circle with 50 segments with line to center glLineWidth(2); DrawPrimitives::setDrawColor4B(0, 255, 255, 255); DrawPrimitives::drawCircle( VisibleRect::center(), 150, CC_DEGREES_TO_RADIANS(90), 50, false); CHECK_GL_ERROR_DEBUG(); // draw a pink solid circle with 50 segments glLineWidth(2); DrawPrimitives::setDrawColor4B(255, 0, 255, 255); DrawPrimitives::drawSolidCircle( VisibleRect::center() + Point(140,0), 40, CC_DEGREES_TO_RADIANS(90), 50, 1.0f, 1.0f); CHECK_GL_ERROR_DEBUG(); // open yellow poly DrawPrimitives::setDrawColor4B(255, 255, 0, 255); glLineWidth(5); Point vertices[] = { Point(10,10), Point(50,50), Point(100,50), Point(150,100), Point(200,150) }; DrawPrimitives::drawPoly( vertices, 5, false); CHECK_GL_ERROR_DEBUG(); // filled poly glLineWidth(1); Point filledVertices[] = { Point(0,120), Point(50,120), Point(50,170), Point(25,200), Point(0,170) }; DrawPrimitives::drawSolidPoly(filledVertices, 5, Color4F(0.5f, 0.5f, 1, 1 ) ); // closed purble poly DrawPrimitives::setDrawColor4B(255, 0, 255, 255); glLineWidth(2); Point vertices2[] = { Point(30,130), Point(30,230), Point(50,200) }; DrawPrimitives::drawPoly( vertices2, 3, true); CHECK_GL_ERROR_DEBUG(); // draw quad bezier path DrawPrimitives::drawQuadBezier(VisibleRect::leftTop(), VisibleRect::center(), VisibleRect::rightTop(), 50); CHECK_GL_ERROR_DEBUG(); // draw cubic bezier path DrawPrimitives::drawCubicBezier(VisibleRect::center(), Point(VisibleRect::center().x+30,VisibleRect::center().y+150), Point(VisibleRect::center().x+60,VisibleRect::center().y-300),Point(VisibleRect::center().x+90,VisibleRect::center().y+150),100); CHECK_GL_ERROR_DEBUG(); //draw a solid polygon Point vertices3[] = {Point(60,160), Point(70,190), Point(100,190), Point(90,160)}; DrawPrimitives::drawSolidPoly( vertices3, 4, Color4F(1,1,0,1) ); CHECK_GL_ERROR_DEBUG(); //end draw kmGLPopMatrix(); }
其中涉及到辅助类VisibleRect类得到获取视口。
1 #ifndef __VISIBLERECT_H__ 2 #define __VISIBLERECT_H__ 3 4 #include "cocos2d.h" 5 6 class VisibleRect 7 { 8 public: 9 static cocos2d::Rect getVisibleRect(); 10 11 static cocos2d::Vec2 left(); 12 static cocos2d::Vec2 right(); 13 static cocos2d::Vec2 top(); 14 static cocos2d::Vec2 bottom(); 15 static cocos2d::Vec2 center(); 16 static cocos2d::Vec2 leftTop(); 17 static cocos2d::Vec2 rightTop(); 18 static cocos2d::Vec2 leftBottom(); 19 static cocos2d::Vec2 rightBottom(); 20 private: 21 static void lazyInit(); 22 static cocos2d::Rect s_visibleRect; 23 }; 24 25 #endif /* __VISIBLERECT_H__ */
1 #include "VisibleRect.h" 2 3 USING_NS_CC; 4 5 Rect VisibleRect::s_visibleRect; 6 7 void VisibleRect::lazyInit() 8 { 9 // no lazy init 10 // Useful if we change the resolution in runtime 11 s_visibleRect = Director::getInstance()->getOpenGLView()->getVisibleRect(); 12 } 13 14 Rect VisibleRect::getVisibleRect() 15 { 16 lazyInit(); 17 return s_visibleRect; 18 } 19 20 Vec2 VisibleRect::left() 21 { 22 lazyInit(); 23 return Vec2(s_visibleRect.origin.x, s_visibleRect.origin.y+s_visibleRect.size.height/2); 24 } 25 26 Vec2 VisibleRect::right() 27 { 28 lazyInit(); 29 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y+s_visibleRect.size.height/2); 30 } 31 32 Vec2 VisibleRect::top() 33 { 34 lazyInit(); 35 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y+s_visibleRect.size.height); 36 } 37 38 Vec2 VisibleRect::bottom() 39 { 40 lazyInit(); 41 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y); 42 } 43 44 Vec2 VisibleRect::center() 45 { 46 lazyInit(); 47 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y+s_visibleRect.size.height/2); 48 } 49 50 Vec2 VisibleRect::leftTop() 51 { 52 lazyInit(); 53 return Vec2(s_visibleRect.origin.x, s_visibleRect.origin.y+s_visibleRect.size.height); 54 } 55 56 Vec2 VisibleRect::rightTop() 57 { 58 lazyInit(); 59 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y+s_visibleRect.size.height); 60 } 61 62 Vec2 VisibleRect::leftBottom() 63 { 64 lazyInit(); 65 return s_visibleRect.origin; 66 } 67 68 Vec2 VisibleRect::rightBottom() 69 { 70 lazyInit(); 71 return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y); 72 }