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);
@@ -123,7 +114,7 @@ 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_materials.clear();
@@ -132,8 +123,15 @@ void WFObj::clear()
     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;
@@ -341,7 +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 << "'"
@@ -420,9 +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;
         }
     }
@@ -458,6 +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++)
@@ -554,6 +564,22 @@ void WFObj::bindBuffers()
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_index_vbo);
 }
 
+GLuint WFObj::loadTexture(const std::string & path)
+{
+    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
 {
     if (vertex != other.vertex)

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;
@@ -43,7 +48,7 @@ public:
             GLfloat ambient[4];
             GLfloat diffuse[4];
             GLfloat specular[4];
-            std::string texture;
+            GLuint texture;
             int flags;
             int first_vertex;
             int num_vertices;
@@ -55,11 +60,11 @@ public:
     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; }
     size_t getStride() { return sizeof(GLfloat) * m_n_floats_per_vref; }
@@ -87,9 +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;
     };
 
@@ -110,6 +115,8 @@ protected:
     std::string getLine(const Buffer & buff, size_t idx, size_t *update_idx);
     void loadMaterial(const std::string & name);
     bool buildVBO();
+    GLuint loadTexture(const std::string & path);
+    std::string resolvePath(const std::string & name);
 
     /* variables */
     std::vector<Vertex> m_vertices[VERTEX_TYPES];
@@ -125,6 +132,7 @@ protected:
     bool m_do_textures;
     size_t m_n_floats_per_vref;
     size_t m_num_materials;
+    std::map<std::string, GLuint> m_textures;
 };
 
 #endif