joeylib3d/obj2j3d/main.c

/*
 *  JoeyLib 3D
 *  Copyright (C) 2019 Scott Duensing <scott@kangaroopunch.com>
 *
 *  This software is provided 'as-is', without any express or implied
 *  warranty.  In no event will the authors be held liable for any damages
 *  arising from the use of this software.
 *
 *  Permission is granted to anyone to use this software for any purpose,
 *  including commercial applications, and to alter it and redistribute it
 *  freely, subject to the following restrictions:
 *
 *  1. The origin of this software must not be misrepresented; you must not
 *     claim that you wrote the original software. If you use this software
 *     in a product, an acknowledgment in the product documentation would be
 *     appreciated but is not required.
 *  2. Altered source versions must be plainly marked as such, and must not be
 *     misrepresented as being the original software.
 *  3. This notice may not be removed or altered from any source distribution.
*/


// OBJ format:   http://paulbourke.net/dataformats/obj/


#include <stdio.h>
#include <string.h>

#include "stretchy_buffer.h"

#include "joey.h"
#include "j3d.h"


int main(int argc, char *argv[]) {

	char           *nameIn;
	char           *nameOut;
	jint16          r;
	juint16         x;
	juint16         y;
	char            token[1024];
	char           *c;
	FILE           *f;
	j3CoordinatesT  v;
	j3ObjectT       o;
	j3TriangleT     t;
	j3WorldT        world;

	if (argc < 3) {
		printf("Usage:  %s [infile] [outfile]\n", argv[0]);
		return 1;
	}

	nameIn  = argv[1];
	nameOut = argv[2];

	f = fopen(nameIn, "rt");

	// Did we find the file?
	if (f == NULL) {
		// Nope.
		printf("Unable to open %s\n", nameIn);
		return 1;
	}

	world.objectCount = 0;
	world.objects     = NULL;
	o.vertexCount     = 0;
	o.triangleCount   = 0;
	o.verticies       = NULL;
	o.triangles       = NULL;

	while (true) {

		// Read next token
		r = (jint16)fscanf(f, "%s", token);

		// End of file?
		if (r == EOF) {
			break;
		}

		// Vertex?
		if (strcmp(token, "v" ) == 0) {
			r = (jint16)fscanf(f, "%f %f %f\n", &v.local.x, &v.local.y, &v.local.z);
			sb_push(o.verticies, v);
			o.vertexCount++;
		}

		// Face?
		if (strcmp(token, "f" ) == 0) {
			for (x=0; x<3; x++) {
				// Fetch 'x'th vertex index
				r = (jint16)fscanf(f, "%s", token);
				c = strstr(token, "/");
				if (c) c[0] = 0;
				r = (jint16)atoi(token);
				t.index[x] = (juint16)r - 1;  // obj indicies start at 1
			}
			fscanf(f, "\n");
			sb_push(o.triangles, t);
			o.triangleCount++;
		}
	}

	//***TODO*** support multiple objects - not sure how I want to do this yet
	sb_push(world.objects, o);
	world.objectCount++;

	// Finished reading
	fclose(f);

	printf("Objects:  %d\n", world.objectCount);
	for (x=0; x<world.objectCount; x++) {
		printf("Object %d:\n", x);
		printf("  Verticies:  %d\n", world.objects[x].vertexCount);
		printf("  Triangles:  %d\n", world.objects[x].triangleCount);
	}

	// Create output file
	f = fopen(nameOut, "wb");
	if (f == NULL) {
		// Nope.
		printf("Unable to create %s\n", nameOut);
		return 1;
	}

	// Write header
	fputc('J', f);
	fputc('3', f);
	fputc('D', f);

	// Version
	fputc(0, f);

	// Number of objects in file
	fwrite(&world.objectCount, sizeof(juint16), 1, f);

	// Iterate over objects
	for (x=0; x<world.objectCount; x++) {
		// Number of verticies
		fwrite(&world.objects[x].vertexCount, sizeof(juint16), 1, f);
		// Vertex list
		for (y=0; y<world.objects[x].vertexCount; y++) {
			// Write one at a time in case the struct gets padded
			fwrite(&world.objects[x].verticies[y].local.x, sizeof(float), 1, f);
			fwrite(&world.objects[x].verticies[y].local.y, sizeof(float), 1, f);
			fwrite(&world.objects[x].verticies[y].local.z, sizeof(float), 1, f);
		}
		// Number of triangles
		fwrite(&world.objects[x].triangleCount, sizeof(juint16), 1, f);
		// Triangle list
		for (y=0; y<world.objects[x].triangleCount; y++) {
			// Write one at a time in case the struct gets padded
			fwrite(&world.objects[x].triangles[y].index[0], sizeof(juint16), 1, f);
			fwrite(&world.objects[x].triangles[y].index[1], sizeof(juint16), 1, f);
			fwrite(&world.objects[x].triangles[y].index[2], sizeof(juint16), 1, f);
		}
	}

	// Finished writing
	fclose(f);

	return 0;
}