C++ Programming Code Examples
C++ > Computer Graphics Code Examples
Program for 3-D Transformation
/* Program for 3-D Transformation */
#include<iostream.h>
#include<dos.h>
#include<stdio.h>
#include<math.h>
#include<conio.h>
#include<graphics.h>
#include<process.h>
int gd=DETECT,gm;
double x1,x2,y1,y2;
void show_message()
{
char *mess[]={"-","=","["," ","3","D","-","T","r","a","n","s",
"f","o","r","m","a","t","i","o","n"," ","]","=","-"};
int xx=28,xxx=52,i,j;
_setcursortype(_NOCURSOR);
for(i=0,j=24;i<15,j>=12;i++,j--)
{
gotoxy(xx,1);
cout<<mess[i];
xx++;
gotoxy(xxx,1);
cout<<mess[j];
xxx--;
delay(50);
}
_setcursortype(_NORMALCURSOR);
}
void draw_cube(double edge[20][3])
{
initgraph(&gd,&gm,"..\bgi");
int i;
clearviewport();
for(i=0;i<19;i++)
{
x1=edge[i][0]+edge[i][2]*(cos(2.3562));
y1=edge[i][1]-edge[i][2]*(sin(2.3562));
x2=edge[i+1][0]+edge[i+1][2]*(cos(2.3562));
y2=edge[i+1][1]-edge[i+1][2]*(sin(2.3562));
line(x1+320,240-y1,x2+320,240-y2);
}
line(320,240,320,25);
line(320,240,550,240);
line(320,240,150,410);
getch();
closegraph();
}
void scale(double edge[20][3])
{
double a,b,c;
int i;
cout<<"
" Enter The Scaling Factors ":=";
cin>>a>>b>>c;
initgraph(&gd,&gm,"..\bgi");
clearviewport();
for(i=0;i<20;i++)
{
edge[i][0]=edge[i][0]*a;
edge[i][1]=edge[i][1]*b;
edge[i][2]=edge[i][2]*c;
}
draw_cube(edge);
closegraph();
}
void translate(double edge[20][3])
{
int a,b,c;
int i;
cout<<"
" Enter The Translation Factors ":=";
cin>>a>>b>>c;
initgraph(&gd,&gm,"..\bgi");
clearviewport();
for(i=0;i<20;i++)
{
edge[i][0]+=a;
edge[i][0]+=b;
edge[i][0]+=c;
}
draw_cube(edge);
closegraph();
}
void rotate(double edge[20][3])
{
int ch;
int i;
double temp,theta,temp1;
clrscr();
cout<<"
-=[ Rotation About ]=-";
cout<<"
1:==>" X-Axis "";
cout<<"
2:==>" Y-Axis "";
cout<<"
3:==>" Z-Axis "";
cout<<"
" Enter Your Choice ":=";
cin>>ch;
switch(ch)
{
case 1:
cout<<"
" Enter The Angle ":=";
cin>>theta;
theta=(theta*3.14)/180;
for(i=0;i<20;i++)
{
edge[i][0]=edge[i][0];
temp=edge[i][1];
temp1=edge[i][2];
edge[i][1]=temp*cos(theta)-temp1*sin(theta);
edge[i][2]=temp*sin(theta)+temp1*cos(theta);
}
draw_cube(edge);
break;
case 2:
cout<<"
" Enter The Angle ":=";
cin>>theta;
theta=(theta*3.14)/180;
for(i=0;i<20;i++)
{
edge[i][1]=edge[i][1];
temp=edge[i][0];
temp1=edge[i][2];
edge[i][0]=temp*cos(theta)+temp1*sin(theta);
edge[i][2]=-temp*sin(theta)+temp1*cos(theta);
}
draw_cube(edge);
break;
case 3:
cout<<"
" Enter The Angle ":=";
cin>>theta;
theta=(theta*3.14)/180;
for(i=0;i<20;i++)
{
edge[i][2]=edge[i][2];
temp=edge[i][0];
temp1=edge[i][1];
edge[i][0]=temp*cos(theta)-temp1*sin(theta);
edge[i][1]=temp*sin(theta)+temp1*cos(theta);
}
draw_cube(edge);
break;
}
}
void reflect(double edge[20][3])
{
int ch;
int i;
clrscr();
cout<<"
-=[ Reflection About ]=-";
cout<<"
1:==>" X-Axis "";
cout<<"
2:==>" Y-Axis "";
cout<<"
3:==>" Z-Axis "";
cout<<"
" Enter Your Choice ":=";
cin>>ch;
switch(ch)
{
case 1:
for(i=0;i<20;i++)
{
edge[i][0]=edge[i][0];
edge[i][1]=-edge[i][1];
edge[i][2]=-edge[i][2];
}
draw_cube(edge);
break;
case 2:
for(i=0;i<20;i++)
{
edge[i][1]=edge[i][1];
edge[i][0]=-edge[i][0];
edge[i][2]=-edge[i][2];
}
draw_cube(edge);
break;
case 3:
for(i=0;i<20;i++)
{
edge[i][2]=edge[i][2];
edge[i][0]=-edge[i][0];
edge[i][1]=-edge[i][1];
}
draw_cube(edge);
break;
}
}
void perspect(double edge[20][3])
{
int ch;
int i;
double p,q,r;
clrscr();
cout<<"
-=[ Perspective Projection About ]=-";
cout<<"
1:==>" X-Axis "";
cout<<"
2:==>" Y-Axis "";
cout<<"
3:==>" Z-Axis "";
cout<<"
" Enter Your Choice ":=";
cin>>ch;
switch(ch)
{
case 1:
cout<<"
" Enter P ":=";
cin>>p;
for(i=0;i<20;i++)
{
edge[i][0]=edge[i][0]/(p*edge[i][0]+1);
edge[i][1]=edge[i][1]/(p*edge[i][0]+1);
edge[i][2]=edge[i][2]/(p*edge[i][0]+1);
}
draw_cube(edge);
break;
case 2:
cout<<"
" Enter Q ":=";
cin>>q;
for(i=0;i<20;i++)
{
edge[i][1]=edge[i][1]/(edge[i][1]*q+1);
edge[i][0]=edge[i][0]/(edge[i][1]*q+1);
edge[i][2]=edge[i][2]/(edge[i][1]*q+1);
}
draw_cube(edge);
break;
case 3:
cout<<"
" Enter R ":=";
cin>>r;
for(i=0;i<20;i++)
{
edge[i][2]=edge[i][2]/(edge[i][2]*r+1);
edge[i][0]=edge[i][0]/(edge[i][2]*r+1);
edge[i][1]=edge[i][1]/(edge[i][2]*r+1);
}
draw_cube(edge);
break;
}
closegraph();
}
void main()
{
int choice;
double edge[20][3]=
{
100,0,0,
100,100,0,
0,100,0,
0,100,100,
0,0,100,
0,0,0,
100,0,0,
100,0,100,
100,75,100,
75,100,100,
100,100,75,
100,100,0,
100,100,75,
100,75,100,
75,100,100,
0,100,100,
0,100,0,
0,0,0,
0,0,100,
100,0,100
};
while(1)
{
clrscr();
show_message();
cout<<"
1:==>" Draw Cube "";
cout<<"
2:==>" Scaling "";
cout<<"
3:==>" Rotation "";
cout<<"
4:==>" Reflection "";
cout<<"
5:==>" Translation "";
cout<<"
6:==>" Perspective Projection "";
cout<<"
7:==>" Exit "";
cout<<"
" Enter Your Choice ":=";
cin>>choice;
switch(choice)
{
case 1:
draw_cube(edge);
break;
case 2:
scale(edge);
break;
case 3:
rotate(edge);
break;
case 4:
reflect(edge);
break;
case 5:
translate(edge);
break;
case 6:
perspect(edge);
break;
case 7:
exit(0);
default:
cout<<"
a" Press A Valid Key...!!! "";
getch();
break;
}
closegraph();
}
}
Break statement in C++ is a loop control statement defined using the break keyword. It is used to stop the current execution and proceed with the next one. When a compiler calls the break statement, it immediately stops the execution of the loop and transfers the control outside the loop and executes the other statements. In the case of a nested loop, break the statement stops the execution of the inner loop and proceeds with the outer loop. The statement itself says it breaks the loop. When the break statement is called in the program, it immediately terminates the loop and transfers the flow control to the statement mentioned outside the loop.
To create a program in Graphics Mode, the first step would be to include the header file graphics.h. This file is required for Graphics programming. After this, the graphics have to be initialized. C Language supports 16 Bit's MS-DOS environment. Initializing the Graphics mode is to call various functions, one such is called initgraph. initgraph initializes the graphics system by loading a graphics driver from disk (or validating a registered driver), and putting the system into graphics mode. To start the graphics system, first call the initgraph function. initgraph loads the graphics driver and puts the system into graphics mode. You can tell initgraph to use a particular graphics driver and mode, or to autodetect the attached video adapter at run time and pick the corresponding driver. If you tell initgraph to autodetect, it calls detectgraph to select a graphics driver and mode. initgraph also resets all graphics settings to their defaults (current position, palette, color, viewport, and so on)
The exit function terminates the program normally. Automatic objects are not destroyed, but static objects are. Then, all functions registered with atexit are called in the opposite order of registration. The code is returned to the operating system. An exit code of 0 or EXIT_SUCCESS means successful completion. If code is EXIT_FAILURE, an indication of program failure is returned to the operating system. Other values of code are implementation-defined. Calls all functions registered with the atexit() function, and destroys C++ objects with static storage duration, all in last-in-first-out (LIFO) order. C++ objects with static storage duration are destroyed in the reverse order of the completion of their constructor. (Automatic objects are not destroyed as a result of calling exit().)
The cin object is used to accept input from the standard input device i.e. keyboard. It is defined in the iostream header file. C++ cin statement is the instance of the class istream and is used to read input from the standard input device which is usually a keyboard. The extraction operator(>>) is used along with the object cin for reading inputs. The extraction operator extracts the data from the object cin which is entered using the keyboard. The "c" in cin refers to "character" and "in" means "input". Hence cin means "character input". The cin object is used along with the extraction operator >> in order to receive a stream of characters.
As the name already suggests, these operators help in assigning values to variables. These operators help us in allocating a particular value to the operands. The main simple assignment operator is '='. We have to be sure that both the left and right sides of the operator must have the same data type. We have different levels of operators. Assignment operators are used to assign the value, variable and function to another variable. Assignment operators in C are some of the C Programming Operator, which are useful to assign the values to the declared variables. Let's discuss the various types of the assignment operators such as =, +=, -=, /=, *= and %=. The following table lists the assignment operators supported by the C language:
Compute cosine. Returns the cosine of an angle of x radians. cos() function is a library function of cmath header, it is used to find the cosine of the given number (angle), it accepts a number (x) and returns the cosine of angle x radians. In trigonometry, the cos function of a right-angled triangle is defined as the length of the adjacent side over the longest side, i.e., the hypotenuse. The cos function in C++ works precisely like the cosine function in trigonometry. The return value of the cos function is the cosine of an angle given in radian. Function returns cosine of x radians.
An array is a collection of data items, all of the same type, accessed using a common name. A one-dimensional array is like a list; A two dimensional array is like a table; The C++ language places no limits on the number of dimensions in an array, though specific implementations may. Some texts refer to one-dimensional arrays as vectors, two-dimensional arrays as matrices, and use the general term arrays when the number of dimensions is unspecified or unimportant. (2D) array in C++ programming is also known as matrix. A matrix can be represented as a table of rows and columns. In C/C++, we can define multi dimensional arrays in simple words as array of arrays. Data in multi dimensional arrays are stored in tabular form (in row major order).
#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.
Positions cursor in text window. The gotoxy() function places the cursor at the desired location on the screen. This means it is possible to change the cursor location on the screen using the gotoxy() function. It is basically used to print text wherever the cursor is moved. If the coordinates are in any way invalid the call to gotoxy is ignored. Neither argument to gotoxy can be zero.
A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.
In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.
The header file graphics.h contains line() function which is used to draw a line from a point(x1, y1) to point(x2, y2) i.e. (x1, y1) and (x2, y2) are end points of the line. The function line() draws a line on the graphics screen between two specified points. So this function requires four parameters namely x1, y1, x2, and y2 to represent two points. This function draws a line from (x1, y1) coordinates to (x2, y2) coordinates on the graphics screen.
The cout is a predefined object of ostream class. It is connected with the standard output device, which is usually a display screen. The cout is used in conjunction with stream insertion operator (<<) to display the output on a console. On most program environments, the standard output by default is the screen, and the C++ stream object defined to access it is cout. The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output". The cout object is used along with the insertion operator << in order to display a stream of characters.
It is a predefined function in "conio.h" (console input output header file) used to clear the console screen. It is a predefined function, by using this function we can clear the data from console (Monitor). Using of clrscr() is always optional but it should be place after variable or function declaration only. It is often used at the beginning of the program (mostly after variable declaration but not necessarily) so that the console is clear for our output.
Rotate left the elements in range. Rotates the order of the elements in the range [first,last), in such a way that the element pointed by middle becomes the new first element. rotate() function is a library function of algorithm header, it is used to rotate left the elements of a sequence within a given range, it accepts the range (start, end) and a middle point, it rotates the elements in such way that the element pointed by the middle iterator becomes the new first element. ForwardIterator shall point to a type for which swap is properly defined and which is both move-constructible and move-assignable. Function returns an iterator pointing to the element that now contains the value previously pointed by first.
delay() function is used to hold the program's execution for given number of milliseconds, it is declared in dos.h header file. There can be many instances when we need to create a delay in our programs. C++ provides us with an easy way to do so. We can use a delay() function for this purpose in our code. We can run the code after a specific time in C++ using delay() function.
The getch() is a predefined non-standard function that is defined in conio.h header file. It is mostly used by the Dev C/C++, MS- DOS's compilers like Turbo C to hold the screen until the user passes a single value to exit from the console screen. It can also be used to read a single byte character or string from the keyboard and then print. It does not hold any parameters. It has no buffer area to store the input character in a program. The getch() function does not accept any parameter from the user. It returns the ASCII value of the key pressed by the user as an input.
clearviewport() function clears the current viewport. setviewport will create a new viewport by accepting left, top, right and bottom coordinates. clearviewport() function will erase the drawing done on the view port only and not the whole screen. Cleardevice is the function used to clear the whole screen with the background color.
Switch statement in C tests the value of a variable and compares it with multiple cases. Once the case match is found, a block of statements associated with that particular case is executed. Each case in a block of a switch has a different name/number which is referred to as an identifier. The value provided by the user is compared with all the cases inside the switch block until the match is found. If a case match is NOT found, then the default statement is executed, and the control goes out of the switch block. • The expression can be integer expression or a character expression. • Value-1, 2, n are case labels which are used to identify each case individually. Remember that case labels should not be same as it may create a problem while executing a program. Suppose we have two cases with the same label as '1'. Then while executing the program, the case that appears first will be executed even though you want the program to execute a second case. This creates problems in the program and
Compute sine. Returns the sine of an angle of x radians. sin() function is a library function of cmath header, it is used to find the sine of the given number (angle), it accepts a number (x) and returns the sine of angle x radians. Additional overloads are provided in this header (<cmath>) for the integral types: These overloads effectively cast x to a double before calculations (defined for T being any integral type). This function is also overloaded in <complex> and <valarray> (see complex sin and valarray sin).
In while loop, condition is evaluated first and if it returns true then the statements inside while loop execute, this happens repeatedly until the condition returns false. When condition returns false, the control comes out of loop and jumps to the next statement in the program after while loop. The important point to note when using while loop is that we need to use increment or decrement statement inside while loop so that the loop variable gets changed on each iteration, and at some point condition returns false. This way we can end the execution of while loop otherwise the loop would execute indefinitely. A while loop that never stops is said to be the infinite while loop, when we give the condition in such a way so that it never returns false, then the loops becomes infinite and repeats itself indefinitely.
The header file graphics.h contains closegraph() function which closes the graphics mode, deallocates all memory allocated by graphics system and restores the screen to the mode it was in before you called initgraph. closegraph() function is used to re-enter in the text mode and exit from the graphics mode. If you want to use both text mode and graphics mode in the program then you have to use both initgraph() and closegraph() function in the program. This function deallocates all memory allocated by graphics system and restores the screen to that mode in which it was presented before you called the initgraph() function.
To reverse an array in C++ programming, you have to ask to the user to enter the array size and array elements. Now start swapping the array elements. Make a variable say temp of
Following C++ program first ask to the user to enter the value of n and then ask to enter the n Number to add them. This program add all n numbers entered. To add n numbers in C++
