Facet Object

Introduction

Example

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <Xint/View3D.h>

static int GetColor(XintColor4 color) {
	do {
		color[0] = drand48();
		color[1] = drand48();
		color[2] = drand48();
		color[3] = 1.0;
	} while((color[0] + color[1] + color[2]) < 1.3);
}
main(int argc, char **argv) {
	XtAppContext	app_context;
	Widget	toplevel;
	Widget	view;
	XintView3DMaterialAttributes	ma;
	int	i, ii, index;
	int	rows, cols;
	int	num_verts;
	float	x, y, z;
	unsigned int	flags;
	unsigned int	bitmask;
	XintVector3	*verts;
	int	num_indices[1];
	int	**indices;
	int	num_facets;
	XintView3DMaterialColor	color;
	XintView3DMaterial	*material;
	XintView3DObject	*cell;
	static String fallback_resources[] = {
		"*title:Cell Demo",
		"cell*background:#cdc0af",
		"cell*foreground:#104e8b",
		NULL
	};
  
	/* Initialize the application */
	toplevel = XtVaAppInitialize(&app_context, "cell", NULL, 0, &argc, 
		argv, fallback_resources, NULL);
  
	/* Create a viewer */
	view = XtVaCreateWidget("Viewer", xintView3DWidgetClass, toplevel,
		XmNwidth, 500, XmNheight, 500,
		XmNtopAttachment, XmATTACH_FORM,
		XmNleftAttachment, XmATTACH_FORM,
		XmNrightAttachment, XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_FORM,
		XmNxUnit, "meters", XmNyUnit, "meters",
		XmNzUnit, "meters", XmNaxisOn, False, NULL);

	/* Manage and realize all widgets */
	XtManageChild(view);
	XtRealizeWidget(toplevel);

	/* Create the cellular surface */
	rows = 31;
	cols = 25;
	verts = (XintVector3 *)malloc(rows * cols * sizeof(XintVector3));
	for(index=0, y=0.0, x=0.0, i=0; i<cols; ++i, x+=10.0) {
		for(z=0.0, ii=0; ii<rows; ++ii, z += (6.0 - (drand48() * 4))) {
		    verts[index][0] = x;
		    verts[index][1] = y;
		    verts[index][2] = z;
		    ++index;
		}
	}
	num_verts = index;
	num_facets = (rows-1) * (cols-1);
	num_indices[0] = num_facets * 4;
	indices = (int **)malloc(1 * sizeof(int *));
	indices[0] = (int *)malloc(num_indices[0] * sizeof(int));
	for(index=0, i=0; i<cols-1); ++i) {
		for(ii=0; ii<rows-1); ++ii) {
		    indices[0][index++] = i*(rows) + ii;
		    indices[0][index++] = i*(rows) + ii + 1;
		    indices[0][index++] = (i+1)*(rows) + ii + 1;
		    indices[0][index++] = (i+1)*(rows) + ii;
		}
	}

	cell = XintView3DCreateFacet("Cells", XintOBJECT_FACET_QUADS, 
			num_verts, verts, NULL, num_facets,
			num_indices, indices, False, NULL,
			NULL);

	/* Cellular material */
	color.multi.num_colors = num_facets;
	color.multi.colors = (XintColor4 *)malloc(num_facets * 
		sizeof(XintColor4));

	for(i=0; i<num_facets; ++i) 
		GetColor(color.multi.colors[i]);
	ma.draw_grid = True;
	flags = XintMA_DRAW_GRID;
	material = XintView3DCreateMaterial("CellMaterial1", 
		XintMATERIAL_MULTI_COLOR, &color,
		flags, &ma);

	/* Add the surface and material */
	XintView3DAddObjectAndMaterial(view, cell, material, NULL);

	XtAppMainLoop(app_context);
}

The following is the output of the program.

Figure 11: Output of example program.

Materials

All materials that can be applied to Mesh Surfaces can also be applied to Facets. The only difference is that the Materials for Mesh Surfaces are applied per vertex, and the Materials applied to Facets are applied per facet.