#include <stdio.h>
#include <math.h>
#include <string.h>
#include <unistd.h>

float A,B,C;

float cubeWidth = 14;
int width = 160, height = 44;
float zBuffer[160 * 44];
char buffer[160 * 44];
int backgroundASCIICode = ' ';
int distanceFromCam = 100;
float K1 = 40;

float incrementSpeed = 1;

float x, y, z;
float ooz;
int xp, yp;
int idx;

float calculateX(int i, int j, int k){
    return j * sin(A) * sin(B) * cos(C)
     - k * cos(A) * sin(B) * cos(C) + j
      * cos(A) * sin(C) + k * sin(A) * sin(C)
       + i * cos(B) * cos(C); 
}

float calculateY(int i,int j, int k){
    return j * cos(A) * cos(C) + k * sin(A) * cos(C)
     - j * sin(A) * sin(B) * sin(C) + k * cos(A) * sin(B)
      * sin(C) - i * cos(B) * sin(C);
}

float calculateZ(int i, int j, int k){
     return k * cos(A) * cos(B)
     - j * sin(A) * cos(B) + i * sin(B);
}

void calculateForSurface(float cubeX, float cubeY, float cubeZ, int ch){
    x =  calculateX(cubeX,cubeY,cubeZ);
    y =  calculateY(cubeX,cubeY,cubeZ);
    z =  calculateZ(cubeX,cubeY,cubeZ) + distanceFromCam;

    ooz = 1 / z;

    xp = (int)(width / 2 - 2 * cubeWidth + K1 * ooz * x * 2);
    yp = (int)(height / 2 + K1 * ooz * y * 2);

    idx = xp + yp * width;
    if(idx >= 0 && idx < width * height) {
        if(ooz > zBuffer[idx]) {
            zBuffer[idx] = ooz;
            buffer[idx] = ch;
        }
    }
}

int main(){
    printf("\x1b[2J");
    while(1){
        memset(buffer,backgroundASCIICode, width * height);
        memset(zBuffer, 0, width * height * 4);
        for(float cubeX = -cubeWidth; cubeX < cubeWidth; cubeX += incrementSpeed){
           for(float cubeY = -cubeWidth; cubeY < cubeWidth; cubeY += incrementSpeed){
            calculateForSurface(cubeX, cubeY, -cubeWidth,'.');
            calculateForSurface(cubeWidth, cubeY, cubeX ,'$');
            calculateForSurface(-cubeWidth, cubeY, -cubeX ,'~');
            calculateForSurface(-cubeX, cubeY, cubeWidth ,'#');
            calculateForSurface(cubeX, -cubeWidth, -cubeY,';');
            calculateForSurface(cubeX, cubeWidth, cubeY,'+');
           } 
        }
        printf("\x1b[H");
        for (int k = 0; k < width * height; k++){
            putchar(k % width ? buffer[k] : 10);
        }

        A += 0.02;
        B += 0.02;
        usleep(1000);
    }
    return 0;
}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}