labAssignmentTriangles.cpp

// lab assignment 
 // Triangles Pattern
 // Also included is Varying Sizes.
#include <windows.h> // for MS Windows
#include <GL/glut.h> // GLUT, include glu.h and gl.h
#include <GL/gl.h>

/* Initialize OpenGL Graphics */

void initGL();
void display ();

void initGL() {
// Set "clearing" or background color
	glClearColor(1.0f, 1.0f, 1.0f, 1.0f); // Black and opaque BackGround

	gluOrtho2D(80.0, 380.0, 0.0, 160.0); // World View gluOrtho2d(left, right, bottom, top);
	glViewport(0, 0, 640, 480); // Is the View Port glViewport(left, bottom, width, height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

}




void display() {
	glClear(GL_COLOR_BUFFER_BIT); 
	GLdouble offset = 30;
	GLdouble x, y;
	glColor3f(0.0, 0.0, 0.0);
	
	for (y = 0.0; y <= 160.0; y += 40.0) {
		
		if (offset == 0) {
			offset = 30;
		} else {
			offset = 0;
		}
		for (x = 50.0; x <= 380.0; x += 60.0) {
			glBegin(GL_TRIANGLES);
				glVertex2d(x + offset, y);
				glVertex2d(x + 60.0 + offset, y);
				glVertex2d(x + 30.0 + offset, y + 40.0);
			glEnd();
		}
	
}
	glEnd();
	glFlush();
	
	
}
/* Main function: GLUT runs as a console application starting at main() */
int main(int argc, char** argv) {
	glutInit(&argc, argv); // Initialize GLUT
	glutCreateWindow(" Triangles Assignment"); // Create window with the given title
	glutInitWindowSize(640, 480); // Set the window's initial width & height
	glutInitWindowPosition(50, 50); // Position the window's initial top-left corner
	glutDisplayFunc(display); // Register callback handler for window re-paint event
	initGL(); // Our own OpenGL initialization
	glutMainLoop(); // Enter the event-processing loop
	return 0;
}