papercraft/corners.c

/** \file
 * Generate an OpenSCAD with connectors for each face.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <unistd.h>
#include <math.h>
#include <err.h>
#include <assert.h>
#include "v3.h"
#include "stl_3d.h"


static void
make_faces(
	const stl_3d_t * const stl,
	const stl_vertex_t * const v,
	const double thickness,
	const double inset_dist,
	const double hole_dist,
	const double hole_rad
)
{
	int * const face_used = calloc(sizeof(*face_used), stl->num_face);
	const double hole_height = 40;

	// generate all of the coplanar polygons at this vertex
	const stl_vertex_t ** const vertex_list = calloc(sizeof(**vertex_list), stl->num_vertex);

	for (int j = 0 ; j < v->num_face; j++)
	{
		// generate the polygon face for this vertex
		const stl_face_t * const f = v->face[j];
		if (face_used[f - stl->face])
			continue;

		const int start_vertex = v->face_num[j];
		const int vertex_count = stl_trace_face(
			stl,
			f,
			vertex_list,
			face_used,
			start_vertex
		);

		refframe_t ref;
		refframe_init(&ref,
			f->vertex[(start_vertex+0) % 3]->p,
			f->vertex[(start_vertex+1) % 3]->p,
			f->vertex[(start_vertex+2) % 3]->p
		);

		// use the transpose of the rotation matrix,
		// which will rotate from (x,y) to the correct
		// orientation relative to this connector node.
		printf("multmatrix(m=[[%f,%f,%f,0],[%f,%f,%f,0],[%f,%f,%f,0],[0,0,0,1]]) {\n",
			ref.x.p[0],
			ref.y.p[0],
			ref.z.p[0],
			ref.x.p[1],
			ref.y.p[1],
			ref.z.p[1],
			ref.x.p[2],
			ref.y.p[2],
			ref.z.p[2]
		);

		// generate the polygon plane
		printf("translate([0,0,%f]) linear_extrude(height=%f) polygon(points=[\n",
			-thickness/2,
			thickness
		);

		for(int k=0 ; k < vertex_count ; k++)
		{
			double x, y;
			refframe_inset(&ref, inset_dist, &x, &y,
				vertex_list[(k+0) % vertex_count]->p,
				vertex_list[(k+1) % vertex_count]->p,
				vertex_list[(k+2) % vertex_count]->p
			);
			printf("[%f,%f],", x, y);
		}
		printf("\n]);\n");

		// generate the mounting holes
		if (hole_rad)
		{
		for(int k=0 ; k < vertex_count ; k++)
		{
			double x, y;
			refframe_inset(&ref, inset_dist+hole_dist, &x, &y,
				vertex_list[(k+0) % vertex_count]->p,
				vertex_list[(k+1) % vertex_count]->p,
				vertex_list[(k+2) % vertex_count]->p
			);
			printf("translate([%f,%f,0]) cylinder(r=%f,h=%f, center=true, $fs=1);\n",
				x, y,
				hole_rad,
				hole_height
			);
		}
		}

		printf("}\n");
	}

	free(face_used);
	free(vertex_list);
}


int
main(void)
{
	stl_3d_t * const stl = stl_3d_parse(STDIN_FILENO);
	if (!stl)
		return EXIT_FAILURE;
	const double thickness = 3;
	const double inset_dist = 2;
	const double hole_dist = 6;
	const double hole_rad = 3.3/2;
	const double hole_height = 40;

	// for each vertex, find the coplanar triangles
	// \todo: do coplanar bits

	for(int i = 0 ; i < stl->num_vertex ; i++)
	{
		const stl_vertex_t * const v = &stl->vertex[i];
		const v3_t origin = v->p;

		printf("// vertex %d\n"
			"//translate([%f,%f,%f])\n"
			"render() difference()\n"
			"{\n"
			"//sphere(r=%f);\n",
			i, origin.p[0], origin.p[1], origin.p[2], thickness/2);
		
		printf("render() intersection() {\n");
		printf("sphere(r=20);\nunion() {\n");
		make_faces(stl, v, 2*thickness, -thickness/2, 0, 0);
		printf("}\n");
		printf("}\n");

		make_faces(stl, v, thickness, inset_dist, hole_dist, hole_rad);


		printf("}\n");

		break;
		//if (i == 0) break; // only do one right now
	}

	return 0;
}