VG101 RECITATION 5 By TAs
VG101 RECITATION 5 By TAs
CONTENTS o How to read Vg101Class.h o Samples about graphics o About assignment 5 o Array
CONTENTS How to read Vg101Class.h Samples about graphics About assignment 5 Array
HOW TO READ VG101CLASS.H o This file defines the following classes: o ConsoleT GwindowsT:represent the graphics window oGObjectT:base class for all geometric classes ·LineT ·TriangleT ·RectangleT ArcT:a circle is an arc with an angle of 360 degrees
HOW TO READ VG101CLASS.H This file defines the following classes: ConsoleT GwindowsT: represent the graphics window GObjectT: base class for all geometric classes LineT TriangleT RectangleT ArcT: a circle is an arc with an angle of 360 degrees
HOW TO READ VG101CLASS.H o RandomT:random numbers and colors o PointT:represent a point using (x,y) o PenT:record the current location and color of the pen o MouseT:detect the click event of the mouse,get mouse current location TextT:set text color,style,font...when printing a message to the graphics window (not console window)
HOW TO READ VG101CLASS.H RandomT: random numbers and colors PointT: represent a point using (x, y) PenT: record the current location and color of the pen MouseT: detect the click event of the mouse, get mouse current location TextT: set text color, style, font… when printing a message to the graphics window (not console window)
HOW TO READ VG101CLASS.H o Let's see what's the general structure of a class definition
HOW TO READ VG101CLASS.H Let’s see what’s the general structure of a class definition
class RectangleT:public GObjectT Base class { PointT llp,urp; Data members Private void drawRect ( member constructor public: RectangleT(const double x0=0,const double y0=0, const double x1=0,const double y1=0, const string clr ="Blue",const double fill =0); RectangleT (const PointT &p0,const PointT &p1, const string clr ="Blue",const double fill=0); const PointT &getLocation ()freturn llp; double getWidth const; Public double getHeight const; Get Set member double getArea const; void setLocation(const double x,const double y); void setLocation(const PointT p); void setWidth(const double w); void setHeight(const double h); Function void draw 0; members void draw (const string clr,const double density =0);
class RectangleT : public GObjectT { PointT llp, urp; void drawRect (); public: RectangleT (const double x0 = 0, const double y0 = 0, const double x1 = 0, const double y1 = 0, const string clr = "Blue", const double fill = 0); RectangleT (const PointT &p0, const PointT &p1, const string clr = "Blue", const double fill = 0); const PointT &getLocation () {return llp;} double getWidth () const; double getHeight () const; double getArea () const; void setLocation (const double x, const double y); void setLocation (const PointT p); void setWidth (const double w); void setHeight (const double h); void draw (); void draw (const string clr, const double density = 0); }; Base class Private member Public member constructor Get & Set Data members Function members
HOW TO READ VG101CLASS.H o About constructors Rectangle'T (const double x0=0,const double y0=0, const double x1=0,const double y1=0, const string clr ="Blue",const double fill =0); RectangleT(const PointT &p0,const PointT &p1, const string clr ="Blue",const double fill=0); o Note: 1.No return type,function name is just its class name. 2.You should declare an object using one of its constructors:
HOW TO READ VG101CLASS.H About constructors RectangleT (const double x0 = 0, const double y0 = 0, const double x1 = 0, const double y1 = 0, const string clr = "Blue" , const double fill = 0); RectangleT (const PointT &p0, const PointT &p1, const string clr = "Blue" , const double fill = 0); Note: 1. No return type, function name is just its class name. 2. You should declare an object using one of its constructors:
HOW TO READ VG101CLASS.H o If the constructor gives the default value of a parameter,then you don't need to give that parameter. use RectangleT myRecO;/default position,color,fill or RectangleT myRec(1,1,2,3);/default color,fill or RectangleT myRece(1,l,2,3,“red”,0.5); /p1,p2 are two known PointT object or RectangleT myRec(p1,p2);/default color,fill or RectangleT myRec(pl,p2,“green”,0.8);
HOW TO READ VG101CLASS.H If the constructor gives the default value of a parameter, then you don’t need to give that parameter. use RectangleT myRec(); // default position, color, fill or RectangleT myRec(1, 1, 2, 3); // default color, fill or RectangleT myRec(1, 1, 2, 3, “red” , 0.5); // p1, p2 are two known PointT object or RectangleT myRec(p1, p2); // default color, fill or RectangleT myRec(p1, p2, “green” , 0.8);
HOW TO READ VG101CLASS.H o What are useful to us ·Get and Set functions double getWidth 0 const; void setWidth(const double w); Other public functions void draw 0; void draw (const string clr,const double density =0);/overloaded function Note: 1.You can't access private/protected data or use private/protected functions directly. 2.The get set functions offer you access to some private data. 3.Read function comment carefully
HOW TO READ VG101CLASS.H What are useful to us Get and Set functions double getWidth () const; void setWidth (const double w); Other public functions void draw (); void draw (const string clr, const double density = 0); // overloaded function Note: 1. You can’t access private/protected data or use private/protected functions directly. 2. The get & set functions offer you access to some private data. 3. Read function comment carefully
SAMPLES ABOUT GRAPHICS o Draw a line from (2,1)to (5,3)in red #include #ing' usir 日vo1c d): t}
SAMPLES ABOUT GRAPHICS Draw a line from (2,1) to (5,3) in red