glsl - Light per vertex shader -

i´m trying compile glsl shader looks has wrong, because fails. message error _log gaves me: vertex shader(s) not compiled before gllinkprogram()was called.link failed.

its light per vertex shader:

  vec4 ambient()     {         vec4 ambient = vec4 (0.0);         ambient = gl_frontmaterial.ambient * gl_lightsource[0].ambient;         ambient += (gl_lightmodel.ambient * gl_frontmaterial.ambient);         return ambient;      }      vec4 diffuse(vec3 normal)     {          vec3 diffuse  = gl_lightsource[0].position * normal;          float diff = max(dot(normal,diffuse),0.0);         diffuse = gl_lightsource[0].diffuse * gl_frontmaterial.diffuse * diff;         return diffuse;     }      vec4 specular(vec3 normal)     {         float hv = max(dot(normal, vec3(gl_lightsource[0].halfvector)), 0.0);          float spec = pow(hv, gl_frontmaterial.shininess);          return gl_lightsource[0].specular * gl_frontmaterial.specular * spec;     }      void main()     {          vec3 normal = normalize(gl_normalmatrix * gl_normal);             vec4 ambient = ambient();         vec4 diffuse = diffuse(normal);         vec4 specular = specular(normal);          gl_frontcolor = gl_color*(ambient+difuse)+specular;           gl_position = ftransform();      } 

this shader class:

#include "shader.h" namespace topicos {  #include "shader.h"  shader::shader() {     program = glcreateprogram(); }  shader::~shader() {      gldetachshader(program, vertexshader);     gldetachshader(program, geometryshader);     gldetachshader(program, fragmentshader);      gldeleteshader(vertexshader);     gldeleteshader(geometryshader);     gldeleteshader(fragmentshader);      gldeleteprogram(program); }  void shader::determinarfontes(std::string vertex, std::string geometry, std::string fragment) {      vertexfilename = vertex;     geometryfilename = geometry;     fragmentfilename = fragment; }  void shader::ativarshader() {     gllinkprogram(program);     gluseprogram(program);     programlog(program);     shaderlog(program);      std::cout<<_log;   }  void shader::desativarshader() {      gluseprogram(0); }  void shader::shaderlog(unsigned int obj) {      int infologlength = 0;     int charswritten  = 0;     char *infolog;      glgetshaderiv(obj, gl_info_log_length, &infologlength);      if (infologlength > 0)     {         infolog = new char[infologlength];         glgetshaderinfolog(obj, infologlength, &charswritten, infolog);          std::string str(infolog);          if (!str.empty())         {             _log += "\n" + str;         }         else         {             _log += "done.\n";         }          delete [] infolog;     } }  void shader::programlog(unsigned int obj) {      int infologlength = 0;     int charswritten  = 0;     char *infolog;      glgetprogramiv(obj, gl_info_log_length, &infologlength);      if (infologlength > 0)     {         infolog = new char[infologlength];         glgetprograminfolog(obj, infologlength, &charswritten, infolog);          std::string str(infolog);          if (!str.empty())         {             _log += "\n" + str;         }         else         {             _log += "done.\n";         }          delete [] infolog;     } } std::string shader::loadshader(std::string shaderfile) {      std::string texto = "";      std::ifstream obj;     obj.open(shaderfile.c_str(), std::ifstream::in);     // std::cout << " ..>> " << obj.is_open() << std::endl;      std::string linha;      while(std::getline(obj, linha))     {         texto +=  linha + "\n";     }     obj.close(); //std::cout<<"texto: " << texto<< std::endl;     return texto; } void shader::makevertexshader(const std::string& vertexfilename) {     /**this function creates vertex shader,     compiles , attached program**/     const char *stringconvertidavertex = loadshader(vertexfilename).c_str();     //std::cout<<"vertex shader: " << loadshader(vertexfilename)<<std::endl;     vertexshader = glcreateshader(gl_vertex_shader);     glshadersource(vertexshader, 1, &stringconvertidavertex, null);     glcompileshader(vertexshader);     glattachshader(program, vertexshader); } void shader::makefragmentshader(const std::string& fragmentfilename) {     /**this function creates fragment shader,     compiles , attached program**/     const char *stringconvertidafragment = loadshader(fragmentfilename).c_str();     fragmentshader = glcreateshader(gl_fragment_shader);     glshadersource(fragmentshader, 1, &stringconvertidafragment, null);     glcompileshader(fragmentshader);     glattachshader(program, fragmentshader); } void shader::makegeometryshader(const std::string& geometryfilename) {     /**this function creates fragment shader,     compiles , attached program**/     const char *stringconvertidageometry = loadshader(geometryfilename).c_str();     geometryshader = glcreateshader(gl_geometry_shader);     glshadersource(geometryshader, 1, &stringconvertidageometry, null);     glcompileshader(geometryshader);     glattachshader(program, geometryshader); }  } 

any appreciated.

i think

gl_frontcolor = gl_color*(ambient+difuse)+specular; 

should be

gl_frontcolor = gl_color*(ambient+diffuse)+specular; 

to let driver display these errors don't have find them yourself, (it's in c, i'm not sure host language using)

// checks if compilation of shader successful. // on success, returns gl_true. on failure, prints // error message stderr , returns gl_false.  glint check_shader_compilation_status(gluint shader) {     glchar* info_log;     glint r;     glgetshaderiv(shader, gl_compile_status, &r);     if (r == gl_false)     {         glgetshaderiv(shader, gl_info_log_length, &r);         info_log = malloc(sizeof(glchar) * r);         glgetshaderinfolog(shader, r, null, info_log);         fprintf(stderr, "%s", info_log);         free(info_log);         return gl_false;     }     return gl_true;