Cocos2d-x 系列八之绘图API
时间：2014-06-03 11:20:50
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本节来看一下在cocos2d-x中，常用的一些绘图api；
先来看一个工具类，以便于快速指定游戏窗口的一些位置，如左上，右上等；
VisibleRect.h
#ifndef __VISIBLERECT_H__ #define __VISIBLERECT_H__ #include "cocos2d.h" class VisibleRect { public: static cocos2d::Rect getVisibleRect(); static cocos2d::Vec2 left(); static cocos2d::Vec2 right(); static cocos2d::Vec2 top(); static cocos2d::Vec2 bottom(); static cocos2d::Vec2 center(); static cocos2d::Vec2 leftTop(); static cocos2d::Vec2 rightTop(); static cocos2d::Vec2 leftBottom(); static cocos2d::Vec2 rightBottom(); private: static void lazyInit(); static cocos2d::Rect s_visibleRect; }; #endif /* __VISIBLERECT_H__ */
VisibleRect.cpp实现
#include "VisibleRect.h" USING_NS_CC; Rect VisibleRect::s_visibleRect; void VisibleRect::lazyInit() { // no lazy init // Useful if we change the resolution in runtime s_visibleRect = Director::getInstance()->getOpenGLView()->getVisibleRect(); } Rect VisibleRect::getVisibleRect() { lazyInit(); return s_visibleRect; } Vec2 VisibleRect::left() { lazyInit(); return Vec2(s_visibleRect.origin.x, s_visibleRect.origin.y+s_visibleRect.size.height/2); } Vec2 VisibleRect::right() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y+s_visibleRect.size.height/2); } Vec2 VisibleRect::top() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y+s_visibleRect.size.height); } Vec2 VisibleRect::bottom() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y); } Vec2 VisibleRect::center() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width/2, s_visibleRect.origin.y+s_visibleRect.size.height/2); } Vec2 VisibleRect::leftTop() { lazyInit(); return Vec2(s_visibleRect.origin.x, s_visibleRect.origin.y+s_visibleRect.size.height); } Vec2 VisibleRect::rightTop() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y+s_visibleRect.size.height); } Vec2 VisibleRect::leftBottom() { lazyInit(); return s_visibleRect.origin; } Vec2 VisibleRect::rightBottom() { lazyInit(); return Vec2(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y); }
上面的代码不再过多解释，比较简单，也就是获取一些Rect的位置；
下面主要展示两种种形式，一是直接在Layer的构造方法中通过api绘制，另一种是在继承Layer的draw,onDraw方法进行绘制；
一、直接在Layer类构造方法里面绘制图形
DrawNodeTest::DrawNodeTest() { auto s = Director::getInstance()->getWinSize(); auto draw = DrawNode::create(); addChild(draw, 10); // 画10个圆，实际上是画了10个点，指定点的大小，所以看起来就是圆； for( int i=0; i < 10; i++) { draw->drawDot(Vec2(s.width/2, s.height/2), 10*(10-i), Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 1)); } // 画多边形 Vec2 points[] = { Vec2(s.height/4,0), Vec2(s.width,s.height/5), Vec2(s.width/3*2,s.height) }; draw->drawPolygon(points, sizeof(points)/sizeof(points[0]), Color4F(1,0,0,0.5), 4, Color4F(0,0,1,1)); // 多边形(注意，这里会有一些bug) { const float o=80; const float w=20; const float h=50; Vec2 star[] = { Vec2(o+w,o-h), Vec2(o+w*2, o), // lower spike Vec2(o + w*2 + h, o+w ), Vec2(o + w*2, o+w*2), // right spike // {o +w, o+w*2+h}, {o,o+w*2}, // top spike // {o -h, o+w}, {o,o}, // left spike }; draw->drawPolygon(star, sizeof(star)/sizeof(star[0]), Color4F(1,0,0,0.5), 1, Color4F(0,0,1,1)); } // 多边形，此处正常显示，注意此处与上一个多边形的区别:按规律指定点的顺序，相反，上一个多边形的顶点顺序是乱的，所以会有一些bug； { const float o=180; const float w=20; const float h=50; Vec2 star[] = { Vec2(o,o), Vec2(o+w,o-h), Vec2(o+w*2, o), // lower spike Vec2(o + w*2 + h, o+w ), Vec2(o + w*2, o+w*2), // right spike Vec2(o +w, o+w*2+h), Vec2(o,o+w*2), // top spike Vec2(o -h, o+w), // left spike }; draw->drawPolygon(star, sizeof(star)/sizeof(star[0]), Color4F(1,0,0,0.5), 1, Color4F(0,0,1,1)); } // 画片段 draw->drawSegment(Vec2(20,s.height), Vec2(20,s.height/2), 10, Color4F(0, 1, 0, 1)); draw->drawSegment(Vec2(10,s.height/2), Vec2(s.width/2, s.height/2), 40, Color4F(1, 0, 1, 0.5)); // 三角形 draw->drawTriangle(Vec2(10, 10), Vec2(70, 30), Vec2(100, 140), Color4F(CCRANDOM_0_1(), CCRANDOM_0_1(), CCRANDOM_0_1(), 0.5)); // 二次方贝赛尔曲线 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)); 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)); }
上面的代码画出来的多图形如下:
二、继承Layer，在onDraw/draw方法中绘制图形
void DrawPrimitivesTest::draw(Renderer *renderer, const Mat4 &transform, bool transformUpdated) { _customCommand.init(_globalZOrder); // _customCommand为DrawPrimitivesTest的一个字段(CustomCommand)； _customCommand.func = CC_CALLBACK_0(DrawPrimitivesTest::onDraw, this, transform, transformUpdated); renderer->addCommand(&_customCommand); } void DrawPrimitivesTest::onDraw(const Mat4 &transform, bool transformUpdated) { Director* director = Director::getInstance(); CCASSERT(nullptr != director, "Director is null when seting matrix stack"); director->pushMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW); director->loadMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW, transform); //draw CHECK_GL_ERROR_DEBUG(); // 画线，默认宽度1,白色， DrawPrimitives::drawLine( VisibleRect::leftBottom(), VisibleRect::rightTop() ); CHECK_GL_ERROR_DEBUG(); // 画线: 指定颜色和宽度，当宽度大于1时，GL_LINE_SMOOTH无效果// GL_SMOOTH_LINE_WIDTH_RANGE = (1,1) on iPhone // glDisable(GL_LINE_SMOOTH); glLineWidth( 5.0f ); DrawPrimitives::setDrawColor4B(255,0,0,255); DrawPrimitives::drawLine( VisibleRect::leftTop(), VisibleRect::rightBottom() ); CHECK_GL_ERROR_DEBUG(); // 画点 DrawPrimitives::setPointSize(64); DrawPrimitives::setDrawColor4B(0,0,255,128); DrawPrimitives::drawPoint( VisibleRect::center() ); CHECK_GL_ERROR_DEBUG(); // draw 4 small points Vec2 points[] = { Vec2(60,60), Vec2(70,70), Vec2(60,70), Vec2(70,60) }; DrawPrimitives::setPointSize(4); DrawPrimitives::setDrawColor4B(0,255,255,255); 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(), 50, CC_DEGREES_TO_RADIANS(90), 50, true); CHECK_GL_ERROR_DEBUG(); // 画一个填充的圆， glLineWidth(2); DrawPrimitives::setDrawColor4B(255, 0, 255, 255); DrawPrimitives::drawSolidCircle( VisibleRect::center() + Vec2(140,0), 40, CC_DEGREES_TO_RADIANS(90), 50, 1.0f, 1.0f); CHECK_GL_ERROR_DEBUG(); // 未关闭的多边形(画出来的效果其实就是一条折线) DrawPrimitives::setDrawColor4B(255, 255, 0, 255); glLineWidth(10); Vec2 vertices[] = { Vec2(0,0), Vec2(50,50), Vec2(100,50), Vec2(100,100), Vec2(50,100) }; DrawPrimitives::drawPoly( vertices, 5, false); CHECK_GL_ERROR_DEBUG(); // 填充的多边形 glLineWidth(1); Vec2 filledVertices[] = { Vec2(0,120), Vec2(50,120), Vec2(50,170), Vec2(25,200), Vec2(0,170) }; DrawPrimitives::drawSolidPoly(filledVertices, 5, Color4F(0.5f, 0.5f, 1, 1 ) ); // closed purble poly DrawPrimitives::setDrawColor4B(255, 0, 255, 255); glLineWidth(2); Vec2 vertices2[] = { Vec2(30,130), Vec2(30,230), Vec2(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(), Vec2(VisibleRect::center().x+30,VisibleRect::center().y+50), Vec2(VisibleRect::center().x+60,VisibleRect::center().y-50),VisibleRect::right(),100); CHECK_GL_ERROR_DEBUG(); //draw a solid polygon Vec2 vertices3[] = {Vec2(60,160), Vec2(70,190), Vec2(100,190), Vec2(90,160)}; DrawPrimitives::drawSolidPoly( vertices3, 4, Color4F(1,1,0,1) ); // 还原画笔为原始状态 glLineWidth(1); DrawPrimitives::setDrawColor4B(255,255,255,255); DrawPrimitives::setPointSize(1); CHECK_GL_ERROR_DEBUG(); //end draw director->popMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW); }
上述代码所画出的效果为
注:上面的一些画图形的方法未对部分参数注释，下边做一个简单禅述；
// 矩形 DrawPrimitives::setDrawCooolor4B(255, 0, 0, 255); DrawPrimitives::drawRect(Point(0, 0), Point(100, 100)); // 填充的矩形 DrawPrimitives::drawSolidRect(Point(0, 0), Point(100, 100), Color4F(0, 0, 1, 1)); // 圆形，5个参数分别是圆心，半径，角度，切割片段(实际上计算机无法画圆，圆实际是点的组合，这里把圆分为50个点)， DrawPrimitives::drawCircle(Point(0, 0), 50, M_PI * 2, 50, true); // 填充圆形，5个参数分别是圆心，半径，角度，切割片段， DrawPrimitives::drawSolidCircle(Point(0, 0), 50, M_PI * 2, 50); Point ps[3]; ps[0] = Point(0, 0); ps[1] = Point(100, 0); ps[2] = Point(0, 50); // 多边形；第二个参数表示顶点个数 DrawPrimitives::drawPoly(ps, 3, true); // 填充多边形 DrawPrimitives::drawSolidPoly(ps, 3, Color4F(0, 0, 1, 1)); // 线 DrawPrimitives::drawLine(Point(0, 0), Point(50, 50)); // 点 DrawPrimitives::drawPoint(Point(0, 0));
完：本人Cocos2d-x新手，如有错误，还请指教！
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