/* 
 * This function puts letters on the OpenGL window
 * Usage of the parameters are specified as follows:
 *     x: the start x position of the text, range = -1 ~ +1
 *     y: the start y position of the text, range = -1 ~ +1
 *     text: char array that you want it to be showed on the screen
 *     font: specified in glut.h line 307~317
 *           GLUT_BITMAP_9_BY_15
 *           GLUT_BITMAP_8_BY_13
 *           GLUT_BITMAP_TIMES_ROMAN_10
 *           GLUT_BITMAP_TIMES_ROMAN_24
 *           GLUT_BITMAP_HELVETICA_10
 *           GLUT_BITMAP_HELVETICA_12
 *           GLUT_BITMAP_HELVETICA_18
 *     r, g, b, a : the color of the text
 */


void myGlPutText(float x, float y, char* text, LPVOID font, float r, float g, float b, float a) 
{ 
	if(!text || !strlen(text)) return; 

	/* Projectoin and Modelview Matrix store then clear */
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();
	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();

	/* blending and lighting status storing then swap to text putting mode */
	bool blending = false; 
	if(glIsEnabled(GL_BLEND))	blending = true; 
	else	glEnable(GL_BLEND); 
	bool lighting = true; 
	if(glIsEnabled(GL_LIGHTING)) glDisable(GL_LIGHTING);
	else	lighting = false;
	
	/* Start to put text */
	glColor4f(r,g,b,a); 
	glRasterPos2f(x,y); 
	while (*text) { 
        	glutBitmapCharacter(font, *text); 
        	text++; 
	} 

	/* blending and lighting status resume */
	if(!blending)	glDisable(GL_BLEND); 
	if(lighting)	glEnable(GL_LIGHTING);
	

	/* Projectoin and Modelview Matrix restore */
	glMatrixMode(GL_PROJECTION);
	glPopMatrix();
	glMatrixMode(GL_MODELVIEW);
	glPopMatrix();
}