#include "objreader.h"

T3DObjReader::T3DObjReader(T3DModel &model) {
	m_model = model;
}

T3DObjReader::parseLine(QString line) {
	line = line.trimmed();
	if (line.isEmpty() || line.at(0) == '#')
		return;

	QStringList params = line.split(' ', QString::SkipEmptyParts);
	QString cmd = params[0];

	if (cmd == "v") {
		float x, y, z;
		x = params[1].toFloat();
		y = params[2].toFloat();
		z = params[3].toFloat();
		known_vertices.append(Vec(x, y, z));
	}

	if (cmd == "vt") {
		float x, y;
		x = params[1].toFloat();
		y = params[2].toFloat();
		known_texcoords.append(Vec2(x, y));
	}

	if (cmd == "vn") {
		float x, y, z;
		x = params[1].toFloat();
		y = params[2].toFloat();
		z = params[3].toFloat();
		known_normals.append(Vec(x, y, z));
	}

	if (cmd == "f") {
		int vtxCount = params.count() - 1;
		if (vtxCount < 3 || vtxCount > 4)
			return;

		int vtxID[4], tcID[4], nrmID[4];

		for (int i = 0; i < vtxCount; i++) {
			QString face = params[i+1];
			QStringList ids = face.split('/');
			vtxID[i] = ids[0].isEmpty() ? 0 : ids[0].toInt();
			tcID[i] = ids[1].isEmpty() ? 0 : ids[1].toInt();
			nrmID[i] = ids[2].isEmpty() ? 0 : ids[2].toInt();
		}

		if (vtxCount == 3) {
			Triangle tri;
			for (int i = 0; i < 3; i++) {
				tri.vertex[i] = known_vertices[vtxID[i]];
				tri.texcoord[i] = known_texcoords[tcID[i]];
				tri.normal[i] = known_normals[nrmID[i]];
			}
			m_currentMesh->triangles.append(tri);
		}

		if (vtxCount == 4) {
			Quad q;
			for (int i = 0; i < 4; i++) {
				q.vertex[i] = known_vertices[vtxID[i]];
				q.texcoord[i] = known_texcoords[tcID[i]];
				q.normal[i] = known_normals[nrmID[i]];
			}
			m_currentMesh->quads.append(q);
		}
	}

	if (cmd == "usemtl") {
		// treat this as "new shape"
		m_currentMesh = new T3DMesh();
		m_model->meshes.append(m_currentMesh);
		m_currentMesh->material = materials[params[1]];
	}
}