/* pseudo.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"

#define WIN_GEOM	"500x500+50+50"
#define NUM_REDS	6
#define NUM_GREENS	6
#define NUM_BLUES	6

static Display		*dpy;
static Window		window;
static PEXStructure	struct_id;
static PEXRenderer	renderer;

static void
redraw()
{
    XClearWindow( dpy, window );
    PEXRenderNetwork( dpy, window, renderer, struct_id );
    XFlush( dpy );
}

#define X0	0.3
#define XN	0.7
#define Y0	0.1
#define YN	0.9
	
static void
create_structure( nr, ng, nb )
    int		nr, ng, nb;
{
    int		i, j, k,  num_colors;
    double	y, dy;
    PEXColor	color;
    PEXCoord2D	pts[4];
    
    num_colors = nr * ng * nb;
    dy = (YN - Y0) / num_colors;
    
    /* Create the structure. */
    struct_id = PEXCreateStructure( dpy );
    
    /* Set the interior style to solid. */
    PEXSetInteriorStyle( dpy, struct_id, PEXOCStore,
			PEXInteriorStyleSolid );
    
    /* Create the fill areas, one for each color. */
    y = YN;
    for ( i = 0; i < nr; i++ ) {
	for ( j = 0; j < ng; j++ ) {
	    for ( k = 0; k < nb; k++ ) {
		color.rgb.red = i * 1.0 / (nr - 1);
		color.rgb.green = j * 1.0 / (ng - 1);
		color.rgb.blue = k * 1.0 / (nb - 1);
		PEXSetSurfaceColor( dpy, struct_id, PEXOCStore,
				    PEXColorTypeRGB, &color );
		pts[0].x = pts[1].x = X0;
		pts[2].x = pts[3].x = XN;
		pts[0].y = pts[3].y = y;
		pts[1].y = pts[2].y = y - dy;
		PEXFillArea2D( dpy, struct_id, PEXOCStore,
			      PEXShapeConvex, False, 4, pts );
		y -= dy;
	    }
	}
    }
}

main( argc, argv )
    int		argc;
    char	*argv[];
{
    XEvent			event;
    XVisualInfo			*vis_info, vis_templ;
    XColor			bkgd_color;
    XStandardColormap		cmap_info;
    PEXColorApproxEntry		capx_info;
    PEXExtensionInfo		*pexinfo;
    PEXRendererAttributes	rattrs;
    int				done = 0, num_vis;
    
    /* Open a display and initialize PEX. */
    dpy = ora_init_pex( argv, &pexinfo );
    if ( !dpy ) exit(1);
    
    /* Get an 8-bit PseudoColor visual. */
    vis_templ.screen = DefaultScreen( dpy );
    vis_templ.depth = 8;
    vis_templ.class = PseudoColor;
    vis_info = XGetVisualInfo( dpy,
	VisualScreenMask | VisualDepthMask | VisualClassMask ,
	&vis_templ, &num_vis );
    if ( num_vis == 0 ) {
	fprintf ( stderr, "No 8-bit PseudoColor visual.\n" );
	exit(1);
    }
    
    /* Create a colormap for the visual. */
    if ( !ora_create_pseudo_map( dpy, vis_info,
				 NUM_REDS, NUM_GREENS, NUM_BLUES,
				 &cmap_info, &capx_info ) ) {
	fprintf ( stderr, "Cannot create a colormap\n" );
	exit(1);
    }
    capx_info.dither = PEXOff;

    /* 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 );
    
    /* Create the renderer and the structure. */
    if ( STRUCTURE_SPT( pexinfo ) ) {
	renderer = ora_setup_renderer( dpy, window, &capx_info,
				       &rattrs );
	create_structure( NUM_REDS, NUM_GREENS, NUM_BLUES );
    } else {
	fprintf( stderr, "Structures not supported.\n" );
	exit(1);
    }
    
    /* 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();
	    break;
	case ButtonPress:
	    done = 1;
	    break;
	}
    }

    XCloseDisplay( dpy );
    return 0;
}