How can i create menu

system · January 25, 2001, 6:24pm

Hi,
I want to create two menu’s(color,with 8 colors & tools, with four tools)Just like microsoft paint.So whenever i click the color menu the selection window should pop up so that i can select a color.Same with the tools menu.Could somebody help me with the code please.
Thanks,
Xhang

rIO · January 26, 2001, 9:01am

It’s not a beginner thing, U need to do everything by yourself.
Just some hints to start from :

Find some examples/docs on BILLBOARDING (it also helps displaying texts).

And find some samples/docs on PICKING.

The rest should come himself, u have the routines to draw rectangles/texts and routines to chek where the user clicked.

rIO.sK http://www.spinningkids.org/umine

ZeeBoy · January 28, 2001, 4:44am

Hi I have a sample code for just that copy paste and compile.

have fun Zee

#pragma hdrstop
#include <condefs.h>

#include <windows.h>
#include <glut.h>
/* ========== ========== ========== ========== ========== ========== */

/*

A demonstration painting program for IM211 and MA8
Based on Interactive Computer Graphics
E. Angel
Chapter 3 and Appendix A.3
1. How to set up menus and submenus.
1. How to set up colours.
1. How to determine and use the position of the mouse.
  */

USELIB(“Glut32.lib”);
//---------------------------------------------------------------------------
void ColourMenu( int id ) ;
void Display ( void ) ;
void DrawSquare( int x, int y ) ;
void FillMenu ( int id ) ;
void Mouse ( int btn, int state, int x, int y ) ;
void MyInit ( void ) ;
int Pick ( int x, int y ) ;
void PixelMenu ( int id ) ;
void Reshape ( int w, int h ) ;
void RightMenu ( int id ) ;
void ScreenBox ( int x, int y, int size ) ;

/* end of function prototypes */

/* global variables */

int fill = 0 ;
GLfloat r = 1.0,
g = 1.0,
b = 1.0 ;
GLfloat size = 3.0 ; /* half side of square /
GLsizei wh = 250 ; / initial height of window */
GLsizei ww = 250 ;

void ColourMenu( int id ) {

/*
 * sets the red, green, and blue components
 *for the appropriate menu selection.
 */

if ( 1 == id )
	{ r = 1.0 ; g = 0.0 ; b = 0.0 ; }
else if ( 2 == id )
	{ r = 0.0 ; g = 1.0 ; b = 0.0 ; }
else if ( 3 == id )
	{ r = 0.0 ; g = 0.0 ; b = 1.0 ; }
else if ( 4 == id )
	{ r = 0.0 ; g = 1.0 ; b = 1.0 ; }
else if ( 5 == id )
	{ r = 1.0 ; g = 0.0 ; b = 1.0 ; }
else if ( 6 == id )
	{ r = 1.0 ; g = 1.0 ; b = 0.0 ; }
else if ( 7 == id )
	{ r = 1.0 ; g = 1.0 ; b = 1.0 ; }
else if ( 8 == id )
	{ r = 0.0 ; g = 0.0 ; b = 0.0 ; }

} /* end of function ColourMenu */

void Display( void ) {

/*
 * sets up a cleared display window with
 * the tool bar containing icons.
 */

glPushAttrib( GL_ALL_ATTRIB_BITS ) ;  /* save attributes */

glClearColor( 0.0, 0.0, 0.0, 1.0 ) ;
glClear     ( GL_COLOR_BUFFER_BIT ) ;

/* place tool bar */
glColor3f( 1.0, 1.0, 1.0 ) ;
ScreenBox( 0, wh - ww/10, ww/10 ) ;

glColor3f( 1.0, 0.0, 0.0 ) ;
ScreenBox( ww/10, wh - ww/10, ww/10 ) ;

glColor3f( 0.0, 1.0, 0.0 ) ;
ScreenBox( ww/5, wh - ww/10, ww/10 ) ;

glColor3f( 0.0, 0.0, 1.0 ) ;
ScreenBox( 3*ww/10, wh - ww/10, ww/10 ) ;

/* place icons */
glColor3f( 0.0, 0.0, 0.0 ) ;
ScreenBox( ww/10 + ww/40, wh - ww/10 + ww/40, ww/20 ) ;

glBegin( GL_LINES ) ;
	glVertex2i( wh/40, wh - ww/20 ) ;
	glVertex2i( wh/40 + ww/20, wh - ww/20 ) ;
glEnd() ;

glBegin( GL_TRIANGLES ) ;
	glVertex2i( ww/5 + ww/40  , wh - ww/10 + ww/40 ) ;
	glVertex2i( ww/5 + ww/20  , wh - ww/40         ) ;
	glVertex2i( ww/5 + 3*ww/40, wh - ww/10 + ww/40 ) ;
glEnd() ;

glPointSize( 5.0 ) ;
glBegin( GL_POINTS ) ;
	glVertex2i( 3*ww/10 + ww/20, wh - ww/20 ) ;
glEnd() ;

glFlush() ;

glPopAttrib() ;  /* restore attributes */

} /* end of function Display */

void DrawSquare( int x, int y ) {

/*
 * draws a square using a randomly chosen colour.
 */

y = wh - y ;
glColor3ub( (GLubyte)rand()%256,
		    (GLubyte)rand()%256,
		    (GLubyte)rand()%256 ) ;

glBegin( GL_POLYGON ) ;
	glVertex2f( x + size, y + size ) ;
	glVertex2f( x - size, y + size ) ;
	glVertex2f( x - size, y - size ) ;
	glVertex2f( x + size, y - size ) ;
glEnd() ;
glFlush() ;

} /* end of function DrawSquare */

void FillMenu( int id ) {

/*
 *sets the global fill flag.
 */

if ( 1 == id )
	fill = 1 ;
else if ( 2 == id )
	fill = 0 ;

} /* end of function FillMenu */

void Mouse( int btn, int state, int x, int y ) {

/*
 * determines the action to be taken based on the
 * position of the mouse.
 *
 * drawMode identifies the tool chosen
 * 1 = line, 2 = square, 3 = triangle, 4 = pixel
 *
 * count marks the number of points already chosen
 * in specifying a square, triangle, etc.
 */

static int count ;
static int drawMode = 0 ;
static int xp[2], yp[2] ;

int where ;

if( GLUT_LEFT_BUTTON == btn && GLUT_DOWN == state ) {
	glPushAttrib( GL_ALL_ATTRIB_BITS ) ;

	where = Pick( x, y ) ;
	glColor3f( r, g, b ) ;

	if ( where != 0 ) {
		count    = 0 ;
		drawMode = where ;
	}
	else if ( 1 == drawMode && 0 == count ) {
		count = 1 ;
		xp[0] = x ;
		yp[0] = y ;
	}
	else if ( 1 == drawMode && 0 != count ) {
		glBegin( GL_LINES ) ;
			glVertex2i( x    , wh - y     ) ;
			glVertex2i( xp[0], wh - yp[0] ) ;
		glEnd() ;
		count    = 0 ;
		drawMode = 0 ;
	}
	else if ( 2 == drawMode && 0 == count ) {
		count = 1 ;
		xp[0] = x ;
		yp[0] = y ;
	}
	else if ( 2 == drawMode && 0 != count ) {
		if ( fill )
			glBegin( GL_POLYGON ) ;
		else
			glBegin( GL_LINE_LOOP ) ;

		glVertex2i( x    , wh - y ) ;
		glVertex2i( x    , wh - yp[0] ) ;
		glVertex2i( xp[0], wh - yp[0] ) ;
		glVertex2i( xp[0], wh - y     ) ;
		glEnd() ;
		count    = 0 ;
		drawMode = 0 ;
	}
	else if ( 3 == drawMode && 0 == count ) {
		count = 1 ;
		xp[0] = x ;
		yp[0] = y ;
	}
	else if ( 3 == drawMode && 1 == count ) {
		count = 2 ;
		xp[1] = x ;
		yp[1] = y ;
	}
	else if ( 3 == drawMode && 2 == count ) {
		if ( fill )
			glBegin( GL_POLYGON ) ;
		else
			glBegin( GL_LINE_LOOP ) ;

		glVertex2i( xp[0], wh - yp[0] ) ;
		glVertex2i( xp[1], wh - yp[1] ) ;
		glVertex2i( x    , wh - y     ) ;
		glEnd() ;
		count    = 0 ;
		drawMode = 0 ;
	}
	else if ( 4 == drawMode ) {
		DrawSquare( x, y ) ;
	}

	glFlush() ;
	glPopAttrib() ;

}

} /* end of function Mouse */

void MyInit( void ) {

glViewport( 0, 0, ww, wh ) ;

glMatrixMode( GL_PROJECTION ) ;
glLoadIdentity() ;
gluOrtho2D( 0.0, (GLdouble)ww, 0.0, (GLdouble)wh ) ;

glMatrixMode( GL_MODELVIEW ) ;
glLoadIdentity() ;

glClearColor( 0.0, 0.0, 0.0, 1.0 ) ;
glClear( GL_COLOR_BUFFER_BIT ) ;

glFlush() ;

} /* end of function MyInit */

int Pick ( int x, int y ) {

/*
 * returns token picked by mouse.
 *
 * 0 =&gt; no selection
 * 1 - 4 identify the tools from left to right.
 */

y = wh - y ;
if ( y &lt; wh - ww/10 )
    return 0 ;
else if ( x &lt; ww/10 )
    return 1 ;
else if ( x &lt; ww/5 )
    return 2 ;
else if ( x &lt; 3*ww/10 )
    return 3 ;
else if ( x &lt; 2*ww/5 )
    return 4 ;
else
    return 0 ;

} /* end of function Pick */

void PixelMenu( int id ) {

if ( 1 == id )
	size = size * 2.0 ;
else if ( 2 == id )
	size = size / 2.0 ;

} /* end of function PixelMenu */

void Reshape( int w, int h ) {

glMatrixMode( GL_PROJECTION ) ;
glLoadIdentity() ;
gluOrtho2D( 0.0, (GLdouble)w, 0.0, (GLdouble)h ) ;

glMatrixMode( GL_MODELVIEW ) ;
glLoadIdentity() ;

glViewport( 0, 0, w, h ) ;
glClearColor( 1.0, 1.0, 1.0, 1.0 ) ;
glClear( GL_COLOR_BUFFER_BIT ) ;

glFlush() ;

wh = h ;
ww = w ;

} /* end of function Reshape */

void RightMenu( int id ) {

if( 1 == id )
	exit( 0 ) ;
else if ( 2 == id )
	glutPostRedisplay() ;

} /* end of function RightMenu */

void ScreenBox( int x, int y, int size ) {

glBegin( GL_POLYGON ) ;
	glVertex2i( x       , y        ) ;
	glVertex2i( x + size, y        ) ;
	glVertex2i( x + size, y + size ) ;
	glVertex2i( x       , y + size ) ;
glEnd() ;

} /* end of function ScreenBox */

#pragma argsused
int main(int argc, char **argv)
{
int cMenu ; // handle for colour menu
int pMenu ;
int fMenu ;

glutInit               ( &argc, argv ) ;
glutInitDisplayMode    ( GLUT_SINGLE | GLUT_RGB ) ;
glutInitWindowSize     ( ww, wh ) ;
glutInitWindowPosition ( 50, 50 ) ;
glutCreateWindow       ( "Graphic Paint" ) ;

glutDisplayFunc        ( Display ) ;

cMenu = glutCreateMenu( ColourMenu ) ;
glutAddMenuEntry( "Red"     , 1 ) ;
glutAddMenuEntry( "Green"   , 2 ) ;
glutAddMenuEntry( "Blue"    , 3 ) ;
glutAddMenuEntry( "Cyan"    , 4 ) ;
glutAddMenuEntry( "Magenta" , 5 ) ;
glutAddMenuEntry( "Yellow"  , 6 ) ;
glutAddMenuEntry( "White"   , 7 ) ;
glutAddMenuEntry( "Black"   , 8 ) ;

pMenu = glutCreateMenu( PixelMenu ) ;
glutAddMenuEntry( "Increase size", 1 ) ;
glutAddMenuEntry( "Decrease size", 2 ) ;

fMenu = glutCreateMenu( FillMenu ) ;
glutAddMenuEntry( "Fill on"  , 1 ) ;
glutAddMenuEntry( "Fill off" , 2 ) ;

glutCreateMenu( RightMenu ) ;
glutAddMenuEntry( "Quit"  , 1 ) ;
glutAddMenuEntry( "Clear" , 2 ) ;
glutAddSubMenu( "Colours"    , cMenu ) ;
glutAddSubMenu( "Pixel size" , pMenu ) ;
glutAddSubMenu( "Fill"       , fMenu ) ;
glutAttachMenu( GLUT_RIGHT_BUTTON ) ;

MyInit() ;

glutReshapeFunc ( Reshape ) ;
glutMouseFunc   ( Mouse ) ;

glutMainLoop() ;

return 0;

}

ZeeBoy · January 28, 2001, 4:45am

P.S

It was done in borland C++
u may have to modify abit.