11 OpenGL Program to Perform 2D Transformation: 1) Reflection and 2)Shearing on a Polygon ~ Coding Atharva

Program:

#include<GL/glut.h>
#include<math.h>

double parr[8];

void init()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glClearColor(0,0,0,1);
	glColor3f(1,0,1);
	gluOrtho2D(-500,500,-500,500); // Left,right,bottom,top
	
	// Polygon Defaut
	parr[0] = 10;  //x
	parr[1] = 10;  //y
	
	parr[2] = 200;
	parr[3] = 10;
	
	parr[4] = 150;
	parr[5] = 150;
	

}


void polygon()
{
	glColor3f(1,0,0);
	glBegin(GL_LINE_LOOP);
		glVertex2f(parr[0],parr[1]);
		glVertex2f(parr[2],parr[3]);
		
		glVertex2f(parr[4],parr[5]);

	glEnd();
	
	glFlush();
}


void drawCorodinates()
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(1,1,1);
	glPointSize(4);
	
	glBegin(GL_LINES);
		glVertex2f(-500,0);
		glVertex2f(500,0);
		
		glVertex2f(0,500);
		glVertex2f(0,-500);
	glEnd();
	
	glColor3f(1,0,0);
	
	glBegin(GL_POINTS);
		glVertex2f(0,0);
	glEnd();
	
	glFlush();
}


// Reflection About Origin
void reflection_origin()
{
    for(int i=0;i<6;i++)
    {
    	parr[i] = -parr[i];
    }
    
    polygon();
}


// Reflection About X-axis
void reflection_x()
{
    for(int i=1;i<6;i=i+2)
    {
    	parr[i] = -parr[i];
    }
    
    polygon();
}


// Reflection About Y-axis
void reflection_y()
{
    for(int i=0;i<6;i=i+2)
    {
    	parr[i] = -parr[i];
    }
    
    polygon();
}


// Reflection About X=Y
void reflection_xy()
{
    double temp;
    for(int i=0;i<6;i=i+2)
    {
    	temp = parr[i];
    	parr[i] = parr[i+1];
    	parr[i+1] = temp;
    }
    
    polygon();
}

// Shearing About X-Axis
void shearing_x()
{
     int shx = 2;
	
    for(int i=0;i<6;i=i+2)
    {
    	parr[i] = parr[i] + shx*parr[i+1];
    }	

    polygon();
}


// Shearing About Y-Axis
void shearing_y()
{
     int shy = 2;
	
    for(int i=1;i<6;i=i+2)
    {
    	parr[i] = parr[i] + shy*parr[i-1];
    }	

    polygon();
}

// Shearing About X Y-Axis
void shearing_xy()
{
     int shx = 2,shy = 2,temp;
	
    for(int i=0;i<6;i=i+2)
    {
    	temp = parr[i] + shx * parr[i+1];
    	parr[i+1] = parr[i]*shy + parr[i+1];
    	parr[i] = temp;
    }	

    polygon();
}

void menu(int ch)
{
        drawCorodinates();
	switch(ch)
	{
		case 1: polygon();
			break;
		
		case 2: reflection_origin();
			break;
		case 3: reflection_x();
			break;
		case 4: reflection_y();
			break;	
		case 5: reflection_xy();
			break;	
		case 6: shearing_x();
			break;	
		case 7: shearing_y();
			break;	
		case 8: shearing_xy();
			break;	
	}
}


int main(int argc,char **argv)
{
	glutInit(&argc,argv);
	glutInitWindowSize(500,500);
	glutInitWindowPosition(100,100);
	
	glutCreateWindow("2D Transformation");
	init();
	glutDisplayFunc(drawCorodinates);
	
	glutCreateMenu(menu);
		glutAddMenuEntry("1 Display Polygon",1);
		
		glutAddMenuEntry("2 Reflection About Origin",2);
		glutAddMenuEntry("3 Reflection About X-Axis",3);
		glutAddMenuEntry("4 Reflection About Y-Axiis",4);
		glutAddMenuEntry("5 Reflection About X=Y",5);
		
		glutAddMenuEntry("6 Shearing About X-Axis",6);
		glutAddMenuEntry("7 Shearing About Y-Axiis",7);
		glutAddMenuEntry("8 Shearing About XandY",8);			
	glutAttachMenu(GLUT_RIGHT_BUTTON);
	
	glutMainLoop();	
	return 0;
}
Output:
11 OpenGL Program to Perform 2D Transformation: 1) Reflection and 2)Shearing on a Polygon

Program:

Related Post
