Processing介绍PPT学习课件

Processing介绍,一种快捷的图形表达工具,介绍,Processing是由BenFry和CaseyReas开发的开源软件.它由Java发展而来，为艺术家和设计师所设计.简单。它使得我们可以直接专注于图形和交互的程序，而不需要考虑很多麻烦的任务，比如建立类的路径和编译参数，或者建立窗口和图形环境这样辅助性的图形环境。友好。有非常活跃的社区和用户，非常容易得到支持。,使用环境,坐标系统左上角为原点。,三种模式,基础型（Basic）画静态图像。活动型（Continuous）setup()初始设置。draw()不断的运行，直到停止。Java型。最复杂，最灵活，写java程序。,注释,/*或者/*结束*/./*多行注释可以说明程序结构，使得更为清晰可读,调试（debugging）,print()println()此两个函数在调试窗口输出参数,变量variables,变量是程序的核心通过指定名称来读写内存中的数据变量包括name和type.接收外部输入创造通用解决方案输入的细小变化引起输出巨大改变,命名,name/identifier名字/识别符有限长度的字母或数字不能java的保留词以字母或_开头Validnames有效foo,foo_bar,f00,_foo,xpositionInvalidnames无效35foo,$bar,245,(,true,int,驼峰命名camelCasing小写开头易读,数据类型type,变量存储的类别。取值的范围。int:非负自然数.InProcessing,范围-2147483648,2147483647操作符operators:+,-,*,DIV,MOD浮点数floatInProcessing,范围-3.40282347E+38,3.40282347E+38操作符:+,-,*,/,squareroot,.boolean:两个值:trueandfalse操作符:AND,OR,NOT,.,usingvariables使用变量,变量首先要声明（declared）表示让程序为它保留一些内存空间,好的编程习惯初始化变量后立即赋值赋值运算符=,变量只能初始化一次但值可以多次赋予,变量可以读出,variablesformodularity变量的模块性,画一个点,另一种方式,每隔二十个像素画一个点丑陋，hardcoding,漂亮,内建变量built-invariables,只读，不能赋值mouseX/mouseY:当前鼠标值width/height:当前窗口的长宽frameCount:当前帧的数量，从程序开始.,/setthesizeofthedisplaysize(200,200);/setthebackgroundcolortowhitebackground(255);/drawthreepointsalongthehorizontalaxisintspacing=20;intxPos=width/2;intyPos=height/2;point(xPos-spacing,yPos);point(xPos,yPos);point(xPos+spacing,yPos);,functions函数,函数是特定名称的一系列代码，在一个更大的程序里面执行某种任务在面向对象编程中，也被称为方法method黑箱模型,函数的作用,定义一次，多次使用。Theyallowaprogramtoemployasequenceofcodemultipletimesfromasingledefinition.把大段程序重构为有意义的子单元。Theyprovideameansofdeconstructingaprogramintomeaningfulsub-units.代码易读，易维护和易再用Theyhelpinwritingcodethatisreadable,maintainableandreusable,使用函数usingfunctions,TodeclareordefineafunctioninProcessing,youusethefollowingformat:,例子,call调用,调用变量类型相同数量相同,调用的例子,variablescope变量范围,global全局变量local局部变量应该把大段代码编程小段的函数，从而易于理解全局变量尽量少用,/globalvariables,accessiblethroughouttheprogramintcircleSize=25;voidsetup()size(400,400);smooth();background(255);stroke(0);/xPosandyPosarelocalvariablesintxPos=200;intyPos=100;circle(xPos,yPos);,fill(255,0,0);ellipse(width/2,height/2,circleSize,circleSize);voiddraw()/mouseXandmouseYareglobalbuilt-invariablescircle(mouseX,mouseY);/xandyarelocalvariablespassedasparametersvoidcircle(intx,inty)/fillColorisalocalvariableintfillColor=255;fill(fillColor);ellipse(x,y,circleSize,circleSize);,built-infunctions内在函数,很多内在函数，参考Reference,shapes,/drawalinefrom(200,10)to(210,380)line(200,10,210,380);/usefill()tospecifywhatcolorshouldbeinsidetheshapefill(100,100,200);/blue/drawarectanglewiththeupperleft-handcornerat(25,50)/anditswidthandheightbothequalto100rect(25,50,100,100);/usefill()tospecifywhatcolorshouldbeinsidetheshapefill(255,100,0);/orange/usestroke()tospecifythecoloroftheoutlinestroke(100,100,255);/blue,/drawanellipsecenteredat(280,150),with/itswidthequalto100,anditsheightequalto75ellipse(280,150,100,75);/usestrokeWeight()tospecifythewidthoftheoutlinestrokeWeight(3);/drawatrianglewithpointsat(30,275),(58,225),and(186,350)triangle(30,275,58,225,186,350);/usenoStroke()tonotdrawanoutlinenoStroke();/usefill()tospecifywhatcolorshouldbeinsidetheshapefill(185,17,39);/red/drawaquadwithpointsat(240,240),(390,320),/(360,380),and(220,350)quad(240,240,390,320,360,380,220,350);,customshapes自定义形状,vertex()放在beginShape()和endShape()中间,voidsetup()size(400,400);smooth();noStroke();voiddraw()background(0);/drawastaratthecurrentmousepositionfill(216,61,4);drawStar(mouseX,mouseY,100);,voiddrawStar(intxPos,intyPos,intstarSize)beginShape();vertex(xPos,yPos-starSize/2);vertex(xPos-starSize/3,yPos+starSize/2);vertex(xPos+starSize/2,yPos-starSize/8);vertex(xPos-starSize/2,yPos-starSize/8);vertex(xPos+starSize/3,yPos+starSize/2);vertex(xPos,yPos-starSize/2);endShape();,compositeexpressions复合表达式,数字运算numericaloperators10+500变量variablesa+width-10函数functionsrandom()+myAngle()数学运算mathematicaloperators(whicharealsofunctions)log(500)+b,常用函数round()abs()ceil()floor()random()sqrt(),intminSize=50;intmaxSize=100;voidsetup()size(400,400);smooth();rectMode(CENTER);strokeWeight(2);voiddraw()drawSquares(random(width),random(height),random(minSize,maxSize);,voiddrawSquares(floatxPos,floatyPos,floatsqSize)/drawtheoutersquarefirstfill(254,255,0);stroke(255,166,0);drawSquare(xPos,yPos,sqSize);/drawtheinnersquarenextfill(252,233,8);stroke(216,61,4);drawSquare(xPos,yPos,sqSize/2);voiddrawSquare(floatxPos,floatyPos,floatsqSize)rect(xPos,yPos,sqSize,sqSize);,一些短的操作符a+=b;isequivalenttoa=a+b;a-=b;isequivalenttoa=a-b;a*=b;isequivalenttoa=a*b;a/=b;isequivalenttoa=a/b;a+;isequivalenttoa=a+1;a-;isequivalenttoa=a-1;,实际x=x+1;x+;x+=1;:adds1tothevalueofxandmakestheresultthenewvalueofxx=x+25;x+=25;:adds25tothevalueofxandmakestheresultthenewvalueofxx=x-1;x-;x-=1;:subtracts1fromthevalueofxandmakestheresultthenewvalueofx,operatorprecedence操作符的优先级,inta=10;intb=5;intc=12;intd=2;andevaluatethefollowingexpressions:a+b*c/d10+5*12/210+60/210+3040,(a+b)*c/d(10+5)*12/215*12/2180/290(a+(b*c)/d(10+(5*12)/2(10+60)/270/235,datatypeconversion数据类型转换,有时候会出错加int运算符,原来程序加入abs()跟踪鼠标速度,voidsetup()size(400,400);smooth();noStroke();voiddraw()background(0);/drawastaratthecurrentmousepositionwithsizerelativetothemousemovementfill(216,61,4);intavgMove=int(abs(pmouseX-mouseX)+abs(pmouseY-mouseY)/2);drawStar(mouseX,mouseY,avgMove*5);,voiddrawStar(intxPos,intyPos,intstarSize)beginShape();vertex(xPos,yPos-starSize/2);vertex(xPos-starSize/3,yPos+starSize/2);vertex(xPos+starSize/2,yPos-starSize/8);vertex(xPos-starSize/2,yPos-starSize/8);vertex(xPos+starSize/3,yPos+starSize/2);vertex(xPos,yPos-starSize/2);endShape();,color色彩,默认的色彩空间是RGB/255。RGB三通道0-255的值color(red,green,blue)函数color(val)函数灰度值0-255大于255，作为RGB值也可以用16进制hexadecimal,色彩模式转化,colorMode(mode)(RGBorHSB)colorMode(mode,range)指定色彩范围,transparency透明度,色彩带透明度属性，Alpha通道color(),fill(),andstroke(),butNOTbackground()./drawaredcirclefill(1.0,0,0,0.5);ellipse(125,125,100,100);/drawagreencirclefill(0,1.0,0,0.5);ellipse(150,175,100,100);/drawabluecirclefill(0,0,1.0,0.5);ellipse(175,125,100,100);,运动模糊效果motionblureffect.把background()用半透明的rect()覆盖整个画面,练习一个脸,脸必须要有眼，鼻子和嘴巴Thefacem