[Performous-commit] Tapio Vierros : 3d object class and simple Wavefront Obj file format parser .

[Tapio V. <aa...@us...>]

Module: performous
Branch: master
Commit: 4beb4de2a8d4a3b95c8d15f7e206601e46bbe1f4

Author: Tapio Vierros <tap...@gm...>
Date:   Mon Nov  9 23:03:04 2009 +0200

3d object class and simple Wavefront Obj file format parser.

---

 game/3dobject.cc |  121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 game/3dobject.hh |   53 +++++++++++++++++++++++
 2 files changed, 174 insertions(+), 0 deletions(-)

diff --git a/game/3dobject.cc b/game/3dobject.cc
new file mode 100644
index 0000000..1bac829
--- /dev/null
+++ b/game/3dobject.cc
@@ -0,0 +1,121 @@
+#include "3dobject.hh"
+#include "surface.hh"
+#include "glutil.hh"
+
+#include <vector>
+#include <map>
+#include <iostream>
+#include <sstream>
+#include <fstream>
+#include <stdexcept>
+#include <string>
+#include <cmath>
+
+
+// TODO: use display lists for drawing?
+// TODO: test & fix faces that doesn't have texcoords in the file
+// TODO: group handling for loader
+
+
+namespace {
+	/// Returns a word (delimited by delim) in a string st at position pos (1-based)
+	std::string getWord(std::string& st, size_t pos, char delim) {
+		std::istringstream iss(st);
+		std::string ret;
+		for (size_t i = 1; i <= pos; i++)
+			getline(iss, ret, delim);
+		return ret;
+	}
+}
+
+
+void Object3d::loadWavefrontObj(std::string filepath, float scale) {
+	std::string row;
+	std::ifstream file(filepath.c_str());
+	if (!file.is_open()) throw std::runtime_error("Couldn't open object file "+filepath);
+	m_vertices.clear();
+	m_faces.clear();
+	m_texcoords.clear();
+	while (!file.eof()) {
+		getline(file, row);
+		std::istringstream srow(row);
+		float x,y,z;
+		std::string tempst;
+		if (row.substr(0,2) == "v ") { 				// Vertices
+			srow >> tempst >> x >> y >> z;
+			m_vertices.push_back(Vertex(x*scale,y*scale,z*scale));
+		} else if (row.substr(0,2) == "vt") { 		// Texture Coordinates
+			srow >> tempst >> x >> y;
+			m_texcoords.push_back(TexCoord(x,y));
+		} else if (row.substr(0,2) == "vn") { 		// Normals
+			srow >> tempst >> x >> y >> z;
+			double sum = std::abs(x)+std::abs(y)+std::abs(z);
+			if (sum == 0) throw std::runtime_error("Object "+filepath+" has invalid normal(s).");
+			x /= sum; y /= sum; z /= sum;
+			m_normals.push_back(Vertex(x,y,z));
+		} else if (row.substr(0,2) == "f ") {		// Faces
+			Face f;
+			srow >> tempst;
+			int v_id;
+			// Parse face point's coordinate references
+			while (!srow.eof()) {
+				srow >> tempst;
+				for (size_t i = 1; i <= 3; i++) {
+					std::string st_id(getWord(tempst,i,'/'));
+					if (!st_id.empty()) {
+						std::istringstream conv_int(st_id);
+						conv_int >> v_id;
+						switch (i) {
+							// Vertex indices are 1-based in the file
+							case 1: f.vertices.push_back(v_id-1); break;
+							case 2: f.texcoords.push_back(v_id-1); break;
+							case 3: f.normals.push_back(v_id-1); break;
+						}
+					}
+				}
+			}
+			// Face must have equal number of v, vt, vn or none of a kind
+			if (f.vertices.size() > 0
+			  && (f.texcoords.empty() || (f.texcoords.size() == f.vertices.size()))
+			  && (f.normals.empty()   || (f.normals.size() == f.vertices.size()))) {
+				m_faces.push_back(f);
+			} else {
+				throw std::runtime_error("Object "+filepath+" has invalid face(s).");
+			}
+		}
+	}
+}
+
+
+void Object3d::draw(float x, float y, float z) const {
+	//UseTexture tex(*m_texture);
+	std::vector<Face>::const_iterator it;
+	// Iterate through faces
+	for (it = m_faces.begin(); it != m_faces.end(); it++) {
+		// Select a suitable primitive
+		GLenum polyType = GL_POLYGON;
+		switch (it->vertices.size()) {
+			case 3: polyType = GL_TRIANGLES; break;
+			case 4: polyType = GL_QUADS; break;
+		}
+		glutil::Begin block(polyType);
+		// Iterate through face's points
+		std::vector<int>::const_iterator it2;
+		for (size_t i = 0; i < it->vertices.size(); i++) {
+			// Texture coordinates
+			if (!it->texcoords.empty()) 
+			  glTexCoord2f(m_texcoords[it->texcoords[i]].s, m_texcoords[it->texcoords[i]].t);
+			// Normals
+			if (!it->normals.empty())
+			  glNormal3f(
+				m_normals[it->normals[i]].x, 
+				m_normals[it->normals[i]].y, 
+				m_normals[it->normals[i]].z);
+			// Vertices
+			glVertex3f(
+			  m_vertices[it->vertices[i]].x+x, 
+			  m_vertices[it->vertices[i]].y+y, 
+			  m_vertices[it->vertices[i]].z+z);
+		}
+	}
+}
diff --git a/game/3dobject.hh b/game/3dobject.hh
new file mode 100644
index 0000000..9baef99
--- /dev/null
+++ b/game/3dobject.hh
@@ -0,0 +1,53 @@
+#pragma once
+
+#include <vector>
+#include <map>
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+#include "surface.hh"
+#include "glutil.hh"
+
+// TODO: Exception handling
+// TODO: Texture loading
+
+struct Vertex {
+	Vertex(float x = 0, float y = 0, float z = 0): x(x), y(y), z(z) {}
+	float x;
+	float y;	
+	float z;
+};
+
+struct TexCoord {
+	TexCoord(float s = 0, float t = 0): s(s), t(t) {}
+	float s;
+	float t;
+};
+
+struct Face {
+	std::vector<int> vertices;
+	std::vector<int> texcoords;
+	std::vector<int> normals;
+};
+
+
+class Object3d {
+  private:
+	std::vector<Vertex> m_vertices;
+	std::vector<TexCoord> m_texcoords;
+	std::vector<Vertex> m_normals;
+	std::vector<Face> m_faces;
+	//boost::scoped_ptr<Texture> m_texture;	
+	/// load a Wavefront .obj 3d object file
+	void loadWavefrontObj(std::string filepath, float scale = 1.0);
+  public:
+	/// constructors
+	Object3d();
+	Object3d(std::string filepath, float scale = 1.0) {
+		//m_texture.reset(new Texture("button.svg"));
+		loadWavefrontObj(filepath, scale);
+	}
+	/// draws the object
+	void draw(float x = 0, float y = 0, float z = 0) const;
+};