using namespace std;


#include <GL/glut.h>
#include <iostream>
#include <cmath>

// Definición de los vértices de los objetos
float triangleVertices[3][2] = {{1.0, 0.0}, {2.0, 0.0}, {0.0, 3.0}};
float trapezoidVertices[4][2] = {{-5.0, 1.0}, {-1.0, 1.0}, {-2.0, 2.0}, {-4.0, 2.0}};
float octagonVertices[8][2] = {{0.0, -4.0}, {1.0, -5.0}, {2.0, -5.0}, {3.0, -4.0}, {3.0, -3.0}, {2.0, -2.0}, {1.0, -2.0}, {0.0, -3.0}};
float (*objectToTransform)[2];

// Variables de control
int currentObject = 0;  // 0 para triángulo, 1 para trapecio, 2 para octágono
float angle = 0.0;
float scaleFactor = 1.0;
float translationX = 0.0;
float translationY = 0.0;

void drawObject() {
    if (currentObject == 0) {
        objectToTransform = triangleVertices;
    } else if (currentObject == 1) {
        objectToTransform = trapezoidVertices;
    } else if (currentObject == 2) {
        objectToTransform = octagonVertices;
    }
    
    // Aplicar transformaciones aquí
    glPushMatrix();
    glTranslatef(translationX, translationY, 0.0);
    glRotatef(angle, 0.0, 0.0, 1.0);
    glScalef(scaleFactor, scaleFactor, 1.0);
    
    glBegin(GL_POLYGON);
    for (int i = 0; i < 8; i++) {
        glVertex2f(objectToTransform[i][0], objectToTransform[i][1]);
    }
    glEnd();
    glPopMatrix();
}

void display() {
    glClear(GL_COLOR_BUFFER_BIT);
    drawObject();
    glFlush();
}

void keyboard(unsigned char key, int x, int y) {
    switch (key) {
        case '1':
            currentObject = 0;
            break;
        case '2':
            currentObject = 1;
            break;
        case '3':
            currentObject = 2;
            break;
        case 'r':
            angle += 10.0;
            break;
        case 'R':
            angle -= 10.0;
            break;
        case 's':
            scaleFactor += 0.1;
            break;
        case 'S':
            scaleFactor -= 0.1;
            break;
        case 't':
            std::cout << "Introduce la nueva posición X: ";
            std::cin >> translationX;
            std::cout << "Introduce la nueva posición Y: ";
            std::cin >> translationY;
            break;
        default:
            break;
    }
    glutPostRedisplay();
}

int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(400, 400);
    glutInitWindowPosition(100, 100);
    glutCreateWindow("Transformaciones Geométricas 2D");
    glClearColor(1.0, 1.0, 1.0, 1.0);
    gluOrtho2D(-10.0, 10.0, -10.0, 10.0);
    glutDisplayFunc(display);
    glutKeyboardFunc(keyboard);
    glutMainLoop();
    return 0;
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is 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 compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

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);

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. Function gets run only when it is called.

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
}