error loading object file when "usemtl" references an undefined material

SConstruct

@@ -1,6 +1,6 @@
 
 # vim:filetype=python
 
-env = Environment(LIBS = ['GL'])
+env = Environment(LIBS = ['GL'], CXXFLAGS = ['-Wall', '-DGL_GLEXT_PROTOTYPES'])
 
 env.Program('driver', Glob('*.cc'))

WFObj.cc

@@ -1,6 +1,4 @@
 
-#define GL_GLEXT_PROTOTYPES
-
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -8,7 +6,6 @@
 #include <ctype.h>      /* isspace() */
 #include <string.h>     /* strlen() */
 #include <stdlib.h>     /* atoi */
-#include <GL/gl.h>
 
 #include <vector>
 #include <string>
@@ -100,14 +97,8 @@ static void checkGLErrorLine(const char * function, int line)
 
 /****** WFObj functions ******/
 
-WFObj::WFObj(loadfile_t lf, loadtexture_t lt)
+WFObj::WFObj()
 {
-    m_loadfile = lf;
-    m_loadtexture = lt;
-    if (m_loadfile == NULL)
-    {
-        m_loadfile = loadfile;
-    }
     if (m_valid)
     {
         glDeleteBuffers(1, &m_data_vbo);
@@ -123,18 +114,24 @@ WFObj::~WFObj()
 
 void WFObj::clear()
 {
-    for (int i = 0; i < sizeof(m_vertices)/sizeof(m_vertices[0]); i++)
+    for (size_t i = 0; i < sizeof(m_vertices)/sizeof(m_vertices[0]); i++)
         m_vertices[i].clear();
     m_faces.clear();
-    m_face_indices.clear();
     m_materials.clear();
     m_valid = false;
     m_path = "";
     m_current_material_name = "";
 }
 
-bool WFObj::load(const char *fname)
+bool WFObj::load(const char *fname, loadfile_t lf, loadtexture_t lt)
 {
+    m_loadfile = lf;
+    m_loadtexture = lt;
+    if (m_loadfile == NULL)
+    {
+        m_loadfile = loadfile;
+    }
+
     clear();
 
     Buffer buff;
@@ -217,7 +214,10 @@ void WFObj::processInputLine(const std::string & input)
     else if (type == "f")
     {
         if (m_faces.find(m_current_material_name) == m_faces.end())
+        {
             m_faces[m_current_material_name] = vector<Face>();
+            m_num_materials = m_faces.size();
+        }
         vector<Face> faces = readFaces(tokens);
         for (vector<Face>::iterator it = faces.begin(); it != faces.end(); it++)
             m_faces[m_current_material_name].push_back(*it);
@@ -339,7 +339,7 @@ WFObj::VertexRef WFObj::readVertexRef(const std::string ref)
 void WFObj::loadMaterial(const std::string & name)
 {
     Buffer buff;
-    string path = (name[0] != '/') ? basePath(m_path) + name : name;
+    string path = resolvePath(name);
     if (!m_loadfile(path.c_str(), buff))
     {
         cerr << "WFObj: error: couldn't open material file '" << path << "'"
@@ -370,7 +370,7 @@ void WFObj::loadMaterial(const std::string & name)
         else if (tokens[0] == "Ns")
         {
             m_materials[mat_name].shininess = atof(tokens[1].c_str());
-            m_materials[mat_name].flags |= Material::MAT_SHININESS;
+            m_materials[mat_name].flags |= Material::SHININESS_BIT;
         }
         else if (tokens[0] == "Ka")
         {
@@ -380,7 +380,7 @@ void WFObj::loadMaterial(const std::string & name)
                     m_materials[mat_name].ambient[i] =
                         atof(tokens[i + 1].c_str());
                 m_materials[mat_name].ambient[3] = 1.0;
-                m_materials[mat_name].flags |= Material::MAT_AMBIENT;
+                m_materials[mat_name].flags |= Material::AMBIENT_BIT;
             }
             else
                 cerr << "WFObj: error: 'Ka' material directive requires"
@@ -394,7 +394,7 @@ void WFObj::loadMaterial(const std::string & name)
                     m_materials[mat_name].diffuse[i] =
                         atof(tokens[i + 1].c_str());
                 m_materials[mat_name].diffuse[3] = 1.0;
-                m_materials[mat_name].flags |= Material::MAT_DIFFUSE;
+                m_materials[mat_name].flags |= Material::DIFFUSE_BIT;
             }
             else
                 cerr << "WFObj: error: 'Kd' material directive requires"
@@ -408,7 +408,7 @@ void WFObj::loadMaterial(const std::string & name)
                     m_materials[mat_name].specular[i] =
                         atof(tokens[i + 1].c_str());
                 m_materials[mat_name].specular[3] = 1.0;
-                m_materials[mat_name].flags |= Material::MAT_SPECULAR;
+                m_materials[mat_name].flags |= Material::SPECULAR_BIT;
             }
             else
                 cerr << "WFObj: error: 'Ks' material directive requires"
@@ -418,9 +418,15 @@ void WFObj::loadMaterial(const std::string & name)
         {
             /* ignore these parameters */
         }
+        else if (tokens[0] == "map_Kd")
+        {
+            m_materials[mat_name].texture = loadTexture(resolvePath(tokens[1]));
+            if (m_materials[mat_name].texture != 0)
+                m_materials[mat_name].flags |= Material::TEXTURE_BIT;
+        }
         else
         {
-            cerr << "WFObj: error: unrecognized material directive: '"
+            cerr << "WFObj: warning: unrecognized material directive: '"
                 << tokens[0] << "'" << endl;
         }
     }
@@ -456,6 +462,12 @@ bool WFObj::buildVBO()
             it != m_faces.end();
             it++)
     {
+        if (m_materials.find(it->first) == m_materials.end())
+        {
+            cerr << "Material '" << it->first << "' referenced in '"
+                << m_path << "' is not defined." << endl;
+            return false;
+        }
         for (vector<Face>::iterator fit = it->second.begin();
                 fit != it->second.end();
                 fit++)
@@ -529,7 +541,8 @@ bool WFObj::buildVBO()
                 vid++;
             }
         }
-        m_face_indices[it->first] = make_pair(first, vid - first);
+        m_materials[it->first].first_vertex = first;
+        m_materials[it->first].num_vertices = vid - first;
     }
     glGenBuffers(1, &m_data_vbo);
     glGenBuffers(1, &m_index_vbo);
@@ -545,52 +558,26 @@ bool WFObj::buildVBO()
     return true;
 }
 
-void WFObj::draw()
+void WFObj::bindBuffers()
 {
-    if (!m_valid)
-        return;
     glBindBuffer(GL_ARRAY_BUFFER, m_data_vbo);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_index_vbo);
-    glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
-    glEnableClientState(GL_VERTEX_ARRAY);
-    glEnableClientState(GL_NORMAL_ARRAY);
-    size_t stride = sizeof(GLfloat) * m_n_floats_per_vref;
-    glVertexPointer(3, GL_FLOAT, stride, NULL);
-    glNormalPointer(GL_FLOAT, stride, (GLvoid *) (sizeof(GLfloat) * 3));
-    if (m_do_textures)
-    {
-        glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-        glTexCoordPointer(2, GL_FLOAT, stride,
-                (GLvoid *) (sizeof(GLfloat) * 6));
-    }
-    for (map<string, vector<Face> >::iterator it = m_faces.begin();
-            it != m_faces.end();
-            it++)
-    {
-        glPushAttrib(GL_LIGHTING_BIT);
-        renderMaterial(m_materials[it->first]);
-        glDrawElements(GL_TRIANGLES, m_face_indices[it->first].second,
-                GL_UNSIGNED_SHORT,
-                (GLvoid *) (sizeof(GLshort) * m_face_indices[it->first].first));
-        glPopAttrib();
-    }
-    glPopClientAttrib();
 }
 
-void WFObj::renderMaterial(const WFObj::Material & m)
+GLuint WFObj::loadTexture(const std::string & path)
 {
-    if (m.flags & Material::MAT_SHININESS)
-        glMaterialf(GL_FRONT, GL_SHININESS, m.shininess);
-    if (m.flags & Material::MAT_AMBIENT)
-        glMaterialfv(GL_FRONT, GL_AMBIENT, &m.ambient[0]);
-    if (m.flags & Material::MAT_DIFFUSE)
-        glMaterialfv(GL_FRONT, GL_DIFFUSE, &m.diffuse[0]);
-    if (m.flags & Material::MAT_SPECULAR)
-        glMaterialfv(GL_FRONT, GL_SPECULAR, &m.specular[0]);
-    if (m.flags & Material::MAT_TEXTURE)
-    {
-        cerr << "WFObj: error: textured materials not implemented yet" << endl;
-    }
+    if (m_loadtexture == NULL)
+        return 0;
+    if (m_textures.find(path) != m_textures.end())
+        return m_textures[path];
+    GLuint id = m_loadtexture(path.c_str());
+    m_textures[path] = id;
+    return id;
+}
+
+string WFObj::resolvePath(const string & name)
+{
+    return (name[0] != '/') ? basePath(m_path) + name : name;
 }
 
 bool WFObj::VertexRef::operator<(const VertexRef & other) const

WFObj.h

@@ -2,7 +2,12 @@
 #ifndef WFOBJ_H
 #define WFOBJ_H
 
+#ifdef GL_INCLUDE_FILE
+#include GL_INCLUDE_FILE
+#else
 #include <GL/gl.h>
+#endif
+
 #include <vector>
 #include <string>
 #include <map>
@@ -14,7 +19,7 @@ public:
     class Buffer
     {
         public:
-            Buffer() : m_alloc(false) {}
+            Buffer() : m_alloc(false) {data = NULL; length = 0;}
             ~Buffer() { if (m_alloc) delete data; }
             uint8_t *data;
             size_t length;
@@ -28,20 +33,48 @@ public:
             bool m_alloc;
     };
 
+    class Material
+    {
+        public:
+            enum {
+                SHININESS_BIT   = 0x01,
+                AMBIENT_BIT     = 0x02,
+                DIFFUSE_BIT     = 0x04,
+                SPECULAR_BIT    = 0x08,
+                TEXTURE_BIT     = 0x10
+            };
+            Material() : flags(0) {}
+            GLfloat shininess;
+            GLfloat ambient[4];
+            GLfloat diffuse[4];
+            GLfloat specular[4];
+            GLuint texture;
+            int flags;
+            int first_vertex;
+            int num_vertices;
+    };
+
     typedef bool (*loadfile_t)(const char *fname, Buffer & buff);
     typedef GLuint (*loadtexture_t)(const char *fname);
 
     enum { VERTEX, VERTEX_TEXTURE, VERTEX_NORMAL, VERTEX_TYPES };
 
     /* constructors */
-    WFObj(loadfile_t lf = NULL, loadtexture_t lt = NULL);
+    WFObj();
     ~WFObj();
 
     /* methods */
-    bool load(const char *fname);
+    bool load(const char *fname, loadfile_t lf = NULL, loadtexture_t lt = NULL);
     bool load(const Buffer &buff);
     const float * const getAABB() { return m_aabb; }
-    void draw();
+    size_t getStride() { return sizeof(GLfloat) * m_n_floats_per_vref; }
+    size_t getVertexOffset() { return 0; }
+    size_t getNormalOffset() { return 3 * sizeof(GLfloat); }
+    size_t getTextureCoordOffset() { return 6 * sizeof(GLfloat); }
+    void bindBuffers();
+    size_t getNumMaterials() { return m_num_materials; }
+    std::map<std::string, Material> & getMaterials() { return m_materials; }
+    bool doTextures() { return m_do_textures; }
 
 protected:
     /* types */
@@ -59,9 +92,9 @@ protected:
     {
         public:
             VertexRef() : vertex(0), texture(0), normal(0) {}
-            int vertex;
-            int texture;
-            int normal;
+            size_t vertex;
+            size_t texture;
+            size_t normal;
             bool operator<(const VertexRef & other) const;
     };
 
@@ -71,25 +104,6 @@ protected:
             VertexRef vertices[3];
     };
 
-    class Material
-    {
-        public:
-            enum {
-                MAT_SHININESS = 0x01,
-                MAT_AMBIENT = 0x02,
-                MAT_DIFFUSE = 0x04,
-                MAT_SPECULAR = 0x08,
-                MAT_TEXTURE = 0x10
-            };
-            Material() : flags(0) {}
-            GLfloat shininess;
-            GLfloat ambient[4];
-            GLfloat diffuse[4];
-            GLfloat specular[4];
-            std::string texture;
-            int flags;
-    };
-
     /* methods */
     void clear();
     void processInputLine(const std::string & input);
@@ -101,12 +115,12 @@ protected:
     std::string getLine(const Buffer & buff, size_t idx, size_t *update_idx);
     void loadMaterial(const std::string & name);
     bool buildVBO();
-    void renderMaterial(const Material & m);
+    GLuint loadTexture(const std::string & path);
+    std::string resolvePath(const std::string & name);
 
     /* variables */
     std::vector<Vertex> m_vertices[VERTEX_TYPES];
     std::map< std::string, std::vector< Face > > m_faces;
-    std::map< std::string, std::pair<int, int> > m_face_indices;
     std::map< std::string, Material > m_materials;
     float m_aabb[6];
     std::string m_path;
@@ -117,6 +131,8 @@ protected:
     GLuint m_data_vbo, m_index_vbo;
     bool m_do_textures;
     size_t m_n_floats_per_vref;
+    size_t m_num_materials;
+    std::map<std::string, GLuint> m_textures;
 };
 
 #endif