/*
 * Copyright (c) 1996-1999  Silicon Graphics, Inc.  All rights reserved.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF THE
 * POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* text.c - render strings using an X Window System bitmap 
 *      font and a stroke font 
 *
 *	Escape key 	- exit the program
 */

#include <GL/glut.h>	/* includes gl.h, glu.h */
#include <stdio.h>
#include "axes.h"

/*  Function Prototypes  */

GLvoid  initgfx( GLvoid );
GLvoid  drawScene( GLvoid );
GLvoid  animate( GLvoid );
GLvoid  visibility( int );
GLvoid  reshape( GLsizei, GLsizei );
GLvoid  keyboard( GLubyte, GLint, GLint );

void printHelp( char * );

/* Global Definitions */

#define KEY_ESC	27	/* ascii value for the escape key */

/* Global Variables */
	 
static GLdouble	left, right, bottom, top;
static void   	*fixedFont, *strokeFont;
static char    	*charStr = "A text string.";

GLvoid
main( int argc, char *argv[] )
{
	GLsizei width, height;

	glutInit( &argc, argv );

	width = glutGet( GLUT_SCREEN_WIDTH ); 
	height = glutGet( GLUT_SCREEN_HEIGHT );
	glutInitWindowPosition( 0, height / 4 );
	glutInitWindowSize( (width / 2) - 4, height / 2 );
	glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
	glutCreateWindow( argv[0] );

	initgfx();

	glutIdleFunc( animate );
	glutVisibilityFunc( visibility );
	glutKeyboardFunc( keyboard );
	glutReshapeFunc( reshape );
	glutDisplayFunc( drawScene ); 

	printHelp( argv[0] );

	glutMainLoop();
}

void
printHelp( char *progname )
{
	fprintf(stdout, "\n%s - render a bitmap font string and a "
		"stroke font string\n\n"
		"Escape Key		- exit the program\n\n",
		progname);
}

GLvoid
initgfx( GLvoid )
{
	glClearColor( 0.0, 0.0, 0.0, 1.0 );
	glShadeModel( GL_FLAT );

	/* Set up two fonts to use for rendering */
	fixedFont = GLUT_BITMAP_TIMES_ROMAN_24;
	strokeFont = GLUT_STROKE_ROMAN;
}

GLvoid 
keyboard( GLubyte key, GLint x, GLint y )
{
	switch (key) {
	case KEY_ESC:	/* Exit whenever the Escape key is pressed */
		exit(0);
	}
}

GLvoid
reshape( GLsizei width, GLsizei height )
{
	GLdouble	aspect;

	glViewport( 0, 0, width, height );

	aspect = (GLdouble) width / (GLdouble) height;
	if ( aspect < 1.0 ) {
		left = -2.0;
		right = 2.0;
		bottom = -2.0 * ( 1.0 / aspect );
		top = 2.0 * ( 1.0 / aspect );
	} else {
		left = -2.0 * aspect;
		right = 2.0 * aspect;
		bottom = -2.0;
		top = 2.0;
	}

	glMatrixMode( GL_PROJECTION );
	glLoadIdentity();
	glOrtho( left, right, bottom, top, -1.0, 1.0 );
	glMatrixMode( GL_MODELVIEW );
}

GLvoid 
animate( GLvoid )
{
	/* Tell GLUT to redraw the scene */
	glutPostRedisplay();
}

GLvoid
visibility( int state ) 
{
	if (state == GLUT_VISIBLE) {
		glutIdleFunc( animate );
	} else {
		glutIdleFunc( NULL );
	}
}

GLvoid
renderBitmapString( void *font, char *string )
{
        int i;
        int len = (int) strlen(string);
        for (i = 0; i < len; i++) {
                glutBitmapCharacter(font, string[i]);
        }
}

GLvoid
renderStrokeString( void *font, char *string )
{
        int i;
        int len = (int) strlen(string);
        for (i = 0; i < len; i++) {
                glutStrokeCharacter(font, string[i]);
        }
}


GLvoid
drawScene( GLvoid )
{
	char              str[16];
	static GLfloat    whiteColor[] = { 1.0f, 1.0f, 1.0f };
	static GLfloat    x = 3.0f;

	glClear( GL_COLOR_BUFFER_BIT );

	XYaxes();

	/* update the x position each time we're called;
	 * wrap when we go off the screen */
	x -= 0.02f;
	if ( x <= left )
		x = right ;

	glColor3fv( whiteColor );	

	glPushMatrix();
		/* Bitmap characters ARE NOT affected by 
		 * modeling transformations 
		 */
		glRotatef( 15.0f, 0.0f, 0.0f, 1.0f );
		glScalef( 2.0f, 2.0f, 2.0f );

		/* Set position for the left end of the baseline for
		 *  our text string */
		glRasterPos2f( x, 0.0f );
		renderBitmapString( fixedFont, charStr );

		/* show the baseline */
		glBegin( GL_LINES );
		       glVertex2f( x, 0.0f );
		       glVertex2f( x+1.0f, 0.0f );
		glEnd();
	glPopMatrix();

	glPushMatrix(); 
		/* Stroke characters ARE affected by 
		 * modeling transformations 
		 */
		glTranslatef( -1.0f, 0.0f, 0.0f );
		glRotatef( 15.0f, 0.0f, 0.0f, 1.0f );
		glScalef(0.003f, 0.003f, 0.003f );
		sprintf( str, "x = %5.2f", x );
		renderStrokeString( strokeFont, str );
	glPopMatrix();

	glutSwapBuffers();
}