[已解决]求解关于C++写ghostview画图程序的问题

丶不离不弃

我们老师布置了一个作业就是利用C++来写ghostview（或者adobe）的指令，生成一个test.ps文件来画各种图形，然后来填充颜色。填充颜色是setrgbcolor,分别画出一个填充红色的矩形，画一个边框为红色的矩形，
连续画6个填充红色的矩形，接着画一个绿色边框的圆，直线，和6边形。里面的数据分别是起始点x，y，宽，高。polygon中时外接圆圆心的左边，外接圆半径以及边的数目。
然后我遇到个问题就是，我这个程序setrgbcolor只是在最开始出现2个语句，并不是在画每个图形的时候都出现，这导致绿色把红色都覆盖了，请问哪位大神能帮我把程序改改？谢谢！！

1. #include <iostream>
   
2. #include <fstream>
   
3. #include <vector>
   
4. #include <cmath>
   
5. const double PI=3.141592653;
   
6. using namespace std;
   
7. 
   
8. class Shape{
   
9. private:
   
10.     double r, g, b;
    
11.     ofstream f;
    
12. public:
    
13.     void setrgb(double r, double g, double b){
    
14.         f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
15.     }
    
16.     virtual void draw(ostream& s) = 0;
    
17. };
    
18. 
    
19. class Circle:public Shape{
    
20. private:
    
21.     double x,y,radius;
    
22. public:
    
23.     Circle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
24.     void draw(ostream& f){
    
25.         f<<x<<' '<<y<<' '<<radius<<" 0 360 arc stroke"<<endl;
    
26.     }
    
27. };
    
28. 
    
29. class Line:public Shape{
    
30. private:
    
31.     double x1, x2,y1, y2;
    
32. public:
    
33.     Line(double x1, double y1,double x2, double y2):x1(x1),y1(y1),x2(x2),y2(y2){}
    
34.     void draw(ostream& f){
    
35.         f<<x1<<' '<<y1<<" moveto "<<'\n'<<x2<<' '<<y2<<" lineto"<<'\n'<< "stroke " <<endl;
    
36.     }
    
37. };
    
38. 
    
39. class Rect:public Shape{
    
40. private:
    
41.     double x, y, width, height;
    
42. public:
    
43.     Rect(double x, double y, double width, double height):x(x),y(y),width(width),height(height){}
    
44.     void draw(ostream& f){
    
45.         f<<x<<' '<<y<<" moveto "<<'\n'<<x+width<<' '<<y<<" lineto "<<'\n'<<x+width
    
46.          <<' '<<y+height<<" lineto "<<'\n'<<x<<' '<<y+height<<" lineto"<<'\n'<< "closepath stroke"<<endl;
    
47.     }
    
48. };
    
49. class Polygon:public Shape{
    
50. private:
    
51.     double x, y, radius,side;
    
52. public:
    
53.     Polygon(double x, double y, double radius, double side):x(x),y(y),radius(radius),side(side){}
    
54.     void draw(ostream& f){
    
55.         f<<x+radius<<' '<<y<<" moveto "<<endl;
    
56.         for(int i=1; i<side; i++){
    
57.             f<<x+radius*cos(2*i*PI/side)<<' '<<y+radius*sin(PI*2*i/side)<<" lineto "<<'\n';
    
58.         }
    
59.         f<<"closepath stroke"<<endl;
    
60. 
    
61.     }
    
62. 
    
63. };
    
64. 
    
65. class FilledRect:public Shape{
    
66. private:
    
67.     double x, y, width,height ;
    
68. public:
    
69.     FilledRect(double x, double y, double width, double height)
    
70.             :x(x),y(y),width(width),height(height){}
    
71.     void draw(ostream& f){
    
72.         f <<x << ' ' << y << " moveto " <<'\n'<< x+width
    
73.           << ' ' << y<< " lineto " <<'\n'<< x + width << ' ' << y + height
    
74.           << " lineto " <<'\n'<< x<< ' ' << y +height << " lineto"<<'\n'<< "closepath fill"<<endl;
    
75. 
    
76.     }
    
77. };
    
78. 
    
79. class FilledCircle:public Shape{
    
80. private:
    
81.     double x, y, radius;
    
82. public:
    
83.     FilledCircle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
84.     void draw(ostream& f){
    
85.         f<<x<<' '<<y<<' '<<radius
    
86.          <<" 0 360 arc fill"<<endl;
    
87.     }
    
88. };
    
89. 
    
90. class Drawing {
    
91. private:
    
92.     ofstream f;
    
93.     vector<Shape*> shapes;
    
94.     int r, g, b;
    
95. public:
    
96.     void setrgb(double r, double g, double b){
    
97.         f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
98.     }
    
99.     Drawing(string filename) : f(filename.c_str()), shapes() {
    
100.     }
     
101.     void add( Shape* s ) {
     
102.         shapes.push_back(s);
     
103.     }
     
104.     void draw() {
     
105.         for (int i = 0; i <shapes.size(); i++)
     
106.             shapes[i]->draw(f);
     
107.     }
     
108. 
     
109. };
     
110. int main() {
     
111.     ofstream f();
     
112.     Drawing d("../test2.txt");
     
113.     d.setrgb(1,0,0); // set drawing color to be bright red:  1 0 0 setrgbcolor
     
114.     d.add(new FilledRect(100.0, 150.0, 200.0, 50)); // x y moveto x y lineto ... fill
     
115.     d.add(new Rect(100.0, 150.0, 200.0, 50));       // x y moveto x y lineto ... stroke
     
116.     for (int x = 0; x < 600; x += 100)
     
117.         d.add(new FilledCircle(x,200,50.0)); // x y r 0 360 arc fill
     
118.     d.setrgb(0,1,0); // the rest are green
     
119.     d.add(new Circle(0,0, 100)); // 0 0 100 0 360 stroke
     
120.     d.add(new Line(400,500, 600,550));
     
121.     d.add(new Polygon(200,200, 50, 6));
     
122.     d.draw();
     
123. 
     
124. }

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最佳答案

月排行榜 / 总排行榜

superbe

2019-10-16 23:49:42

重新修改过了，试试可以吗

1. #include <iostream>
   
2. #include <fstream>
   
3. #include <vector>
   
4. #include <cmath>
   
5. const double PI=3.141592653;
   
6. using namespace std;
   
7. 
   
8. class Shape{
   
9. private:
   
10.     double r, g, b;
    
11.     //ofstream f;
    
12. public:
    
13.     void setrgb(double r, double g, double b){  //修改的函数
    
14.         //f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
15.         this->r = r;
    
16.         this->g = g;
    
17.         this->b = b;
    
18.     }
    
19.     void writergb(ostream& f){  //增加的函数
    
20.         f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
21.     }
    
22.     virtual void draw(ostream& s) = 0;
    
23. };
    
24. 
    
25. class Circle:public Shape{
    
26. private:
    
27.     double x,y,radius;
    
28. public:
    
29.     Circle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
30.     void draw(ostream& f){
    
31.         f<< x << ' ' << y <<' '<< radius <<" 0 360 arc stroke"<< endl;
    
32.     }
    
33. };
    
34. 
    
35. class Line:public Shape{
    
36. private:
    
37.     double x1, x2,y1, y2;
    
38. public:
    
39.     Line(double x1, double y1,double x2, double y2):x1(x1),y1(y1),x2(x2),y2(y2){}
    
40.     void draw(ostream& f){
    
41.         f<<x1<<' '<<y1<<" moveto "<<'\n'<<x2<<' '<<y2<<" lineto"<<'\n'<<"stroke "<<endl;
    
42.     }
    
43. };
    
44. 
    
45. class Rect:public Shape{
    
46. private:
    
47.     double x, y, width, height;
    
48. public:
    
49.     Rect(double x, double y, double width, double height):x(x),y(y),width(width),height(height){}
    
50.     void draw(ostream& f){
    
51.         f<<x<<' '<<y<<" moveto "<<'\n'<<x+width<<' '<<y<<" lineto "<<'\n'<<x+width
    
52.          <<' '<<y+height<<" lineto "<<'\n'<<x<<' '<<y+height<<" lineto"<<'\n'<< "closepath stroke"<<endl;
    
53.     }
    
54. };
    
55. 
    
56. class Polygon:public Shape{
    
57. private:
    
58.     double x, y, radius,side;
    
59. public:
    
60.     Polygon(double x, double y, double radius, double side):x(x),y(y),radius(radius),side(side){}
    
61.     void draw(ostream& f){
    
62.         f<<x+radius<<' '<<y<<" moveto "<<endl;
    
63.         for(int i=1; i<side; i++){
    
64.             f<<x+radius*cos(2*i*PI/side)<<' '<<y+radius*sin(PI*2*i/side)<<" lineto "<<'\n';
    
65.         }
    
66.         f<<"closepath stroke"<<endl;
    
67.     }
    
68. };
    
69. 
    
70. class FilledRect:public Shape{
    
71. private:
    
72.     double x, y, width,height ;
    
73. public:
    
74.     FilledRect(double x, double y, double width, double height)
    
75.             :x(x),y(y),width(width),height(height){}
    
76.     void draw(ostream& f){
    
77.         f <<x << ' ' << y << " moveto " <<'\n'<< x+width
    
78.           << ' ' << y<< " lineto " <<'\n'<< x + width << ' ' << y + height
    
79.           << " lineto " <<'\n'<< x<< ' ' << y +height << " lineto"<<'\n'<< "closepath fill"<<endl;
    
80. 
    
81.     }
    
82. };
    
83. 
    
84. class FilledCircle:public Shape{
    
85. private:
    
86.     double x, y, radius;
    
87. public:
    
88.     FilledCircle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
89.     void draw(ostream& f){
    
90.         f<<x<<' '<<y<<' '<<radius<<" 0 360 arc fill"<<endl;
    
91.     }
    
92. };
    
93. 
    
94. class Drawing {
    
95. private:
    
96.     ofstream f;
    
97.     vector<Shape*> shapes;
    
98.     double r, g, b;
    
99. public:
    
100.     void setrgb(double r, double g, double b){  //修改的函数
     
101.         //f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
     
102.         this->r = r;
     
103.         this->g = g;
     
104.         this->b = b;
     
105.     }
     
106.     Drawing(string filename) : f(filename.c_str()), shapes() {
     
107.     }
     
108.     void add( Shape *s ) {  //修改的函数
     
109.         s->setrgb(r, g, b);
     
110.         shapes.push_back(s);
     
111.     }
     
112.     void draw() {    //修改的函数
     
113.         for (int i = 0; i <shapes.size(); i++){
     
114.             shapes[i]->writergb(f);
     
115.             shapes[i]->draw(f);
     
116.         }
     
117.     }
     
118. };
     
119. 
     
120. int main() {   //main未改动
     
121.     ofstream f();
     
122.     Drawing d("../test2.txt");
     
123.     d.setrgb(1,0,0); // set drawing color to be bright red:  1 0 0 setrgbcolor
     
124.     d.add(new FilledRect(100.0, 150.0, 200.0, 50)); // x y moveto x y lineto ... fill
     
125.     d.add(new Rect(100.0, 150.0, 200.0, 50));       // x y moveto x y lineto ... stroke
     
126.     for (int x = 0; x < 600; x += 100)
     
127.         d.add(new FilledCircle(x,200,50.0)); // x y r 0 360 arc fill
     
128.     d.setrgb(0,1,0); // the rest are green
     
129.     d.add(new Circle(0,0, 100)); // 0 0 100 0 360 stroke
     
130.     d.add(new Line(400,500, 600,550));
     
131.     d.add(new Polygon(200,200, 50, 6));
     
132.     d.draw();
     
133. 
     
134. }

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跳转到最佳答案楼层

superbe

main里面只在最后d.draw()的时候才会输出全部图形，第一个和第二个d.setrgb之间的图形并没有输出，所以等于连续向文件中输出了两个setrgb，这样只是第二个setrgb才会对后面的图形起作用。

你可以在class Drawing里增加一个函数，用来清空shapes。

1. void clear(){
   
2.     shapes.clear();
   
3. }

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在输出前几个红色的图形后，调用clear清空shapes，然后设置绿色再输出后面几个绿色图形。

main函数修改如下，为了图形不重叠，我调整了图形坐标(注释未改)，根据实际情况修改吧：

1. int main() {
   
2.     //ofstream f();
   
3.     Drawing d("../test2.txt");
   
4.     d.setrgb(1, 0, 0); // set drawing color to be bright red:  1 0 0 setrgbcolor
   
5.     d.add(new FilledRect(100.0, 150.0, 200.0, 50)); // x y moveto x y lineto ... fill
   
6.     d.add(new Rect(100.0, 250.0, 200.0, 50));       // x y moveto x y lineto ... stroke
   
7.     for (int x = 50; x < 650; x += 100)
   
8.         d.add(new FilledCircle(x, 400, 50.0)); // x y r 0 360 arc fill
   
9.     d.draw();  //增加的行
   
10.     d.clear();  //增加的行
    
11.     d.setrgb(0, 1, 0); // the rest are green
    
12.     d.add(new Circle(400, 100, 100)); // 0 0 100 0 360 stroke
    
13.     d.add(new Line(400, 500, 550, 550));
    
14.     d.add(new Polygon(200, 500, 50, 6));
    
15.     d.draw();
    
16.     return 0;
    
17. }

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最后的效果是这样的：


生成的ps文件内容如下：

丶不离不弃

superbe 发表于 2019-10-16 20:45
main里面只在最后d.draw()的时候才会输出全部图形，第一个和第二个d.setrgb之间的图形并没有输出，所以等于 ...

我们的main函数是老师先写好的，老师说不可以改，请问你可以说一下不改main函数只在class中编辑的解决方法嘛？谢谢！

superbe

重新修改过了，试试可以吗

1. #include <iostream>
   
2. #include <fstream>
   
3. #include <vector>
   
4. #include <cmath>
   
5. const double PI=3.141592653;
   
6. using namespace std;
   
7. 
   
8. class Shape{
   
9. private:
   
10.     double r, g, b;
    
11.     //ofstream f;
    
12. public:
    
13.     void setrgb(double r, double g, double b){  //修改的函数
    
14.         //f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
15.         this->r = r;
    
16.         this->g = g;
    
17.         this->b = b;
    
18.     }
    
19.     void writergb(ostream& f){  //增加的函数
    
20.         f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
    
21.     }
    
22.     virtual void draw(ostream& s) = 0;
    
23. };
    
24. 
    
25. class Circle:public Shape{
    
26. private:
    
27.     double x,y,radius;
    
28. public:
    
29.     Circle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
30.     void draw(ostream& f){
    
31.         f<< x << ' ' << y <<' '<< radius <<" 0 360 arc stroke"<< endl;
    
32.     }
    
33. };
    
34. 
    
35. class Line:public Shape{
    
36. private:
    
37.     double x1, x2,y1, y2;
    
38. public:
    
39.     Line(double x1, double y1,double x2, double y2):x1(x1),y1(y1),x2(x2),y2(y2){}
    
40.     void draw(ostream& f){
    
41.         f<<x1<<' '<<y1<<" moveto "<<'\n'<<x2<<' '<<y2<<" lineto"<<'\n'<<"stroke "<<endl;
    
42.     }
    
43. };
    
44. 
    
45. class Rect:public Shape{
    
46. private:
    
47.     double x, y, width, height;
    
48. public:
    
49.     Rect(double x, double y, double width, double height):x(x),y(y),width(width),height(height){}
    
50.     void draw(ostream& f){
    
51.         f<<x<<' '<<y<<" moveto "<<'\n'<<x+width<<' '<<y<<" lineto "<<'\n'<<x+width
    
52.          <<' '<<y+height<<" lineto "<<'\n'<<x<<' '<<y+height<<" lineto"<<'\n'<< "closepath stroke"<<endl;
    
53.     }
    
54. };
    
55. 
    
56. class Polygon:public Shape{
    
57. private:
    
58.     double x, y, radius,side;
    
59. public:
    
60.     Polygon(double x, double y, double radius, double side):x(x),y(y),radius(radius),side(side){}
    
61.     void draw(ostream& f){
    
62.         f<<x+radius<<' '<<y<<" moveto "<<endl;
    
63.         for(int i=1; i<side; i++){
    
64.             f<<x+radius*cos(2*i*PI/side)<<' '<<y+radius*sin(PI*2*i/side)<<" lineto "<<'\n';
    
65.         }
    
66.         f<<"closepath stroke"<<endl;
    
67.     }
    
68. };
    
69. 
    
70. class FilledRect:public Shape{
    
71. private:
    
72.     double x, y, width,height ;
    
73. public:
    
74.     FilledRect(double x, double y, double width, double height)
    
75.             :x(x),y(y),width(width),height(height){}
    
76.     void draw(ostream& f){
    
77.         f <<x << ' ' << y << " moveto " <<'\n'<< x+width
    
78.           << ' ' << y<< " lineto " <<'\n'<< x + width << ' ' << y + height
    
79.           << " lineto " <<'\n'<< x<< ' ' << y +height << " lineto"<<'\n'<< "closepath fill"<<endl;
    
80. 
    
81.     }
    
82. };
    
83. 
    
84. class FilledCircle:public Shape{
    
85. private:
    
86.     double x, y, radius;
    
87. public:
    
88.     FilledCircle(double x, double y, double radius):x(x),y(y),radius(radius){}
    
89.     void draw(ostream& f){
    
90.         f<<x<<' '<<y<<' '<<radius<<" 0 360 arc fill"<<endl;
    
91.     }
    
92. };
    
93. 
    
94. class Drawing {
    
95. private:
    
96.     ofstream f;
    
97.     vector<Shape*> shapes;
    
98.     double r, g, b;
    
99. public:
    
100.     void setrgb(double r, double g, double b){  //修改的函数
     
101.         //f<<r<<' '<<g<<' '<<b<<" setrgbcolor "<<endl;
     
102.         this->r = r;
     
103.         this->g = g;
     
104.         this->b = b;
     
105.     }
     
106.     Drawing(string filename) : f(filename.c_str()), shapes() {
     
107.     }
     
108.     void add( Shape *s ) {  //修改的函数
     
109.         s->setrgb(r, g, b);
     
110.         shapes.push_back(s);
     
111.     }
     
112.     void draw() {    //修改的函数
     
113.         for (int i = 0; i <shapes.size(); i++){
     
114.             shapes[i]->writergb(f);
     
115.             shapes[i]->draw(f);
     
116.         }
     
117.     }
     
118. };
     
119. 
     
120. int main() {   //main未改动
     
121.     ofstream f();
     
122.     Drawing d("../test2.txt");
     
123.     d.setrgb(1,0,0); // set drawing color to be bright red:  1 0 0 setrgbcolor
     
124.     d.add(new FilledRect(100.0, 150.0, 200.0, 50)); // x y moveto x y lineto ... fill
     
125.     d.add(new Rect(100.0, 150.0, 200.0, 50));       // x y moveto x y lineto ... stroke
     
126.     for (int x = 0; x < 600; x += 100)
     
127.         d.add(new FilledCircle(x,200,50.0)); // x y r 0 360 arc fill
     
128.     d.setrgb(0,1,0); // the rest are green
     
129.     d.add(new Circle(0,0, 100)); // 0 0 100 0 360 stroke
     
130.     d.add(new Line(400,500, 600,550));
     
131.     d.add(new Polygon(200,200, 50, 6));
     
132.     d.draw();
     
133. 
     
134. }

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superbe

解决思路是这样的：
调用d.setrgb时把rgb值存储在d中，以后添加每个图形时把rgb值设置到图形中。
最后输出时，先调用图形的writergb将其rgb值写到文件，接着再调用该图形的draw方法写入画图的命令。

丶不离不弃

superbe 发表于 2019-10-17 00:13
解决思路是这样的：
调用d.setrgb时把rgb值存储在d中，以后添加每个图形时把rgb值设置到图形中。
最后输 ...

奥，我明白啦，谢谢你，你真厉害哇~~！我要是有你学的这么好就好了-。-