/* surface.c 1.1 */
/*
    Copyright 1992, 1993 O'Reilly and Associates, Inc.  Permission to
    use, copy, and modify this program is hereby granted, as long as
    this copyright notice appears in each copy of the program source
    code.
*/

#include "book_utils.h"

/* The surface knots and control points. */
static	float		uknots[] = { 0, 0, 0, 1, 1, 1 };
static	float		vknots[] = { 0, 0, 0, 0, 1, 1, 1, 1 };
static	PEXCoord	control_points[] = {
    {0.0, 0.5, 0.0}, {0.0, 0.6, 0.5}, {0.0, 0.5, 1.0},
    {0.3, 0.5, 0.0}, {0.3, 1.0, 0.5}, {0.3, 0.5, 1.0},
    {0.6, 0.4, 0.0}, {0.6, 0.5, 0.5}, {0.6, 0.4, 1.0},
    {0.9, 0.5, 0.0}, {0.9, 0.3, 0.5}, {0.9, 0.2, 1.0}};

static void
redraw( dpy, window, renderer )
    Display	*dpy;
    Window	window;
    PEXRenderer	renderer;
{
    int			uorder = 3, vorder = 4;
    unsigned int	num_u_points = 3, num_v_points = 4;
    PEXArrayOfCoord	grid;
    PEXColor		color;
    PEXPSCData		psc;
    
    XClearWindow( dpy, window );
    PEXBeginRendering( dpy, window, renderer ); {
    
	/* Use the view defined by set_view(). */
	PEXSetViewIndex( dpy, renderer, PEXOCRender, 1 );
    
	/* Set the interior style. */
	PEXSetInteriorStyle( dpy, renderer, PEXOCRender,
			     PEXInteriorStyleEmpty );
	
	/* Set the color of the isoparametric curves. */
	SET_COLOR( 1, 1, 1, color );
	PEXSetLineColor( dpy, renderer, PEXOCRender,
			 PEXColorTypeRGB, &color );
    
	/* Set the parametric surface characteristics. */
	psc.iso_curves.placement_type = PEXUniformPlacement;
	psc.iso_curves.u_count = 20;
	psc.iso_curves.v_count = 20;
	PEXSetParaSurfCharacteristics( dpy, renderer, PEXOCRender,
				       PEXPSCIsoCurves, &psc );

	/* Set the surface approximation criteria. */
	PEXSetSurfaceApprox( dpy, renderer, PEXOCRender,
			     PEXApproxConstantBetweenKnots,
			     (double)10, (double)10 );

	/* Create the surface. */
	grid.point = control_points;
	PEXNURBSurface( dpy, renderer, PEXOCRender, PEXNonRational,
		        uorder, vorder, uknots, vknots,
		        num_u_points, num_v_points, grid,
		        0, (PEXListOfTrimCurve *) NULL );
    }
    PEXEndRendering( dpy, renderer, True );
    XFlush( dpy );
}

static void
set_view( dpy, view_table )
    Display		*dpy;
    PEXLookupTable	view_table;
{
    PEXViewEntry	view;
    PEXCoord2D		window[2];
    double		view_plane, front_plane, back_plane;
    PEXCoord		prp;
    PEXNPCSubVolume	viewport;

    /* The view orientation parameters. */
    static PEXCoord	view_ref_pt = {0.5, 0.5, 0.5};
    static PEXVector	view_plane_normal = {0.5643, 0.4775, 0.6735};
    static PEXVector	view_up_vec = {0,1,0};

    /* Compute the view orientation transform. */
    PEXViewOrientationMatrix( &view_ref_pt, &view_plane_normal,
			      &view_up_vec, view.orientation );
    
    /* The view mapping parameters. */
    prp.x = 0; prp.y = 0; prp.z = 10;
    window[0].x = -0.78; window[1].x = 0.7;
    window[0].y = -0.78; window[1].y = 0.7;
    front_plane = 1; view_plane = 0; back_plane = -1;
    viewport.min.x = 0; viewport.max.x = 1;
    viewport.min.y = 0; viewport.max.y = 1;
    viewport.min.z = 0; viewport.max.z = 1;
    
    /* Compute the view mapping transform. */
    PEXViewMappingMatrix( window, &viewport, False, &prp,
			  view_plane, back_plane, front_plane,
			  view.mapping );
    
    /* The view clipping parameters. */
    view.clip_flags = PEXClippingAll;
    view.clip_limits = viewport;
    
    /* Set view 1. */
    PEXSetTableEntries( dpy, view_table, 1, 1, PEXLUTView,
		        (PEXPointer) &view );
}

#define WIN_GEOM	"500x500+50+50"

main( argc, argv )
    int		argc;
    char	*argv[];
{
    Display			*dpy;
    Window			window;
    XEvent			event;
    XVisualInfo			vis_info;
    XColor			bkgd_color;
    XStandardColormap		cmap_info;
    PEXColorApproxEntry		capx_info;
    PEXRenderer			renderer;
    PEXRendererAttributes	rattrs;
    PEXExtensionInfo		*pexinfo;
    int				done = 0;
    
    /* Open a display and initialize PEX. */
    dpy = ora_init_pex( argv, &pexinfo );
    if ( !dpy ) exit(1);
    
    /* Determine the best visual to use. */
    ora_find_best_visual( dpy, &vis_info );
    
    /* Get a standard colormap for the visual. */
    if ( !ora_get_standard_colormap( dpy, &vis_info, &cmap_info ) ) {
	fprintf ( stderr, "Cannot find a standard colormap\n" );
	exit(1);
    }
    ora_set_stdcmap_approx( &vis_info, &cmap_info, &capx_info );

    /* Create the window, giving it a gray background. */
    bkgd_color.red = bkgd_color.green = bkgd_color.blue = 0x5555;
    bkgd_color.flags = DoRed | DoGreen | DoBlue;
    window = ora_create_window( dpy, &vis_info, &cmap_info, WIN_GEOM,
			        &bkgd_color );
    
    if ( IMMED_MODE_SPT( pexinfo ) ) {
	renderer = ora_setup_renderer( dpy, window, &capx_info,
				       &rattrs );
    } else {
	fprintf( stderr, "No immediate mode.\n" );
	exit(1);
    }

    /* Set the view. */
    set_view( dpy, rattrs.view_table );
    
    /* Read and respond to X events. */
    XSelectInput( dpy, window, ExposureMask | ButtonPressMask );
    while ( !done ) {
	XNextEvent( dpy, &event );
	switch ( event.type ) {
	case Expose:
	    /* Flush remaining Expose events, then redraw. */
	    while ( XCheckTypedWindowEvent( dpy, window,
					    Expose, &event ) )
		; /* empty statement */
	    redraw( dpy, window, renderer );
	    break;
	case ButtonPress:
	    done = 1;
	    break;
	}
    }

    XCloseDisplay( dpy );
    return 0;
}