Diamond Pattern Using OpenGL in C++

diamondPattern.cpp

/*
	The Code Below is used to develop a Diamond Pattern.
	
	
	1. Start with Identifying the First Diamond
	2. Put in the coordinates for the First Diamind
	3. Create a for-loop to to create diamonds at the same time
	4. Introduce an outer for-loop to cater for the y - axis.
	
*/


#include <windows.h> // for MS Windows
#include <GL/glut.h> // GLUT, include glu.h and gl.h




/* Initialize OpenGL Graphics */

void initGL() {
  
// Set "clearing" or background color
  glClearColor(0.333, 0.420, 0.184, 0.0f); 

  //Enabling Use Of 'glVertex2i()'
  glMatrixMode(GL_PROJECTION);	 
  glLoadIdentity();
  gluOrtho2D(0.0, 640.0, 0.0, 480.0);

}


void display() {
	glClear(GL_COLOR_BUFFER_BIT); 


	//initialize the variables.
	GLint x = 50;
	GLint y = 50;
	GLint colorCode = 1;
	
	//imagine a diamond pattern
	
	/*
								(x, y + 25)
							/				\	
						/						\
													\			
					/								\
														\
				/											\
			/												\
		/
  (x - 25, y)		(x, y)   	(x + 25, y)
			\	
			  \												/
				\										/	
				  \									/		
					\							/
					  \						/		
						 \				/
						   \		/
								(x - 25, y)
	*/ 
	
	
	//setting the (x, y)
	GLint jump = 4;

for(y = 50; y <= 350; y += jump * 2) {

	for(x = 50; x <= 350; x += jump * 2) {
		
	
		//Initiate The First Diamond
		glBegin(GL_QUADS); 
		glColor3f(0.392, 0.584, 0.929); 
		glVertex2i(x - jump, y);
		glVertex2i(x, y + jump);
		glVertex2i(x + jump, y);
		glVertex2i(x, y - jump);
		glEnd();

	}

}


	glFlush(); // Render now
}




/* Main function: GLUT runs as a console application starting at main() */
int main(int argc, char** argv) {
	glutInit(&argc, argv); // Initialize GLUT
	glutCreateWindow("Diamond Pattern"); // 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;
}