NeHe Productions: OpenGL Lesson #13

#include <windows.h>						 // Header File For Windows
#include <math.h>						 // Header File For Windows Math Library		( ADD )
#include <stdio.h>						 // Header File For Standard Input/Output	( ADD )
#include <stdarg.h>						 // Header File For Variable Argument Routines	( ADD )
#include <gl\gl.h>						 // Header File For The OpenGL32 Library
#include <gl\glu.h>						 // Header File For The GLu32 Library
#include <gl\glaux.h>						 // Header File For The GLaux Library
HDC		hDC=NULL;					 // Private GDI Device Context
HGLRC		hRC=NULL;					 // Permanent Rendering Context
HWND		hWnd=NULL;					 // Holds Our Window Handle
HINSTANCE	hInstance;					 // Holds The Instance Of The Application

GLuint	base;							 // Base Display List For The Font Set
GLfloat	cnt1;							 // 1st Counter Used To Move Text & For Coloring
GLfloat	cnt2;							 // 2nd Counter Used To Move Text & For Coloring
bool	keys[256];						 // Array Used For The Keyboard Routine
bool	active=TRUE;						 // Window Active Flag Set To TRUE By Default
bool	fullscreen=TRUE;					 // Fullscreen Flag Set To Fullscreen Mode By Default
LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);		 // Declaration For WndProc

GLvoid BuildFont(GLvoid)					 // Build Our Bitmap Font
{
	HFONT	font;						 // Windows Font ID
	HFONT	oldfont;					 // Used For Good House Keeping
	base = glGenLists(96);					 // Storage For 96 Characters ( NEW )

	font = CreateFont(	-24,				 // Height Of Font ( NEW )

				0,				 // Width Of Font

				0,				 // Angle Of Escapement
				0,				 // Orientation Angle

				FW_BOLD,			 // Font Weight

				FALSE,				 // Italic
				FALSE,				 // Underline
				FALSE,				 // Strikeout

				ANSI_CHARSET,			 // Character Set Identifier

				OUT_TT_PRECIS,			 // Output Precision

				CLIP_DEFAULT_PRECIS,		 // Clipping Precision

				ANTIALIASED_QUALITY,		 // Output Quality

				FF_DONTCARE|DEFAULT_PITCH,	 // Family And Pitch

				"Courier New");			 // Font Name

	oldfont = (HFONT)SelectObject(hDC, font);		 // Selects The Font We Want
	wglUseFontBitmaps(hDC, 32, 96, base);			 // Builds 96 Characters Starting At Character 32
	SelectObject(hDC, oldfont);				 // Selects The Font We Want
	DeleteObject(font);					 // Delete The Font
}

GLvoid KillFont(GLvoid)						 // Delete The Font List
{
 	glDeleteLists(base, 96);				 // Delete All 96 Characters ( NEW )
}

GLvoid glPrint(const char *fmt, ...)				 // Custom GL "Print" Routine
{

	char		text[256];				 // Holds Our String
	va_list		ap;					 // Pointer To List Of Arguments

	if (fmt == NULL)					 // If There's No Text
		return;						 // Do Nothing

	va_start(ap, fmt);					 // Parses The String For Variables
	 vsprintf(text, fmt, ap);				 // And Converts Symbols To Actual Numbers
	va_end(ap);						 // Results Are Stored In Text

	glPushAttrib(GL_LIST_BIT);				 // Pushes The Display List Bits		( NEW )
	glListBase(base - 32);					 // Sets The Base Character to 32	( NEW )

	glCallLists(strlen(text), GL_UNSIGNED_BYTE, text);	 // Draws The Display List Text	( NEW )
	glPopAttrib();						 // Pops The Display List Bits	( NEW )
}

int InitGL(GLvoid)						 // All Setup For OpenGL Goes Here
{
	glShadeModel(GL_SMOOTH);				 // Enable Smooth Shading
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);			 // Black Background
	glClearDepth(1.0f);					 // Depth Buffer Setup
	glEnable(GL_DEPTH_TEST);				 // Enables Depth Testing
	glDepthFunc(GL_LEQUAL);					 // The Type Of Depth Testing To Do
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	 // Really Nice Perspective Calculations
	BuildFont();						 // Build The Font
	return TRUE;						 // Initialization Went OK
}

int DrawGLScene(GLvoid)						 // Here's Where We Do All The Drawing
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	 // Clear The Screen And The Depth Buffer
	glLoadIdentity();					 // Reset The View
	glTranslatef(0.0f,0.0f,-1.0f);				 // Move One Unit Into The Screen

	 // Pulsing Colors Based On Text Position
	glColor3f(1.0f*float(cos(cnt1)),1.0f*float(sin(cnt2)),1.0f-0.5f*float(cos(cnt1+cnt2)));

	 // Position The Text On The Screen
	glRasterPos2f(-0.45f+0.05f*float(cos(cnt1)), 0.35f*float(sin(cnt2)));

 	glPrint("Active OpenGL Text With NeHe - %7.2f", cnt1);	 // Print GL Text To The Screen

	cnt1+=0.051f;						 // Increase The First Counter
	cnt2+=0.005f;						 // Increase The Second Counter
	return TRUE;						 // Everything Went OK
}

	if (!UnregisterClass("OpenGL",hInstance))		 // Are We Able To Unregister Class
	{
		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hInstance=NULL;					 // Set hInstance To NULL
	}
	KillFont();						 // Destroy The Font
}