glsl_toon.C

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/*****************************************************************
 * glsl_toon.C
 *****************************************************************/
#include "gtex/gl_extensions.H"
#include "glsl_toon.H"

static bool debug = Config::get_var_bool("DEBUG_GLSL_TOON", false);

/**********************************************************************
 * GLSLToonShader:
 *
 *   Does 1D Toon shading in GLSL.
 **********************************************************************/
GLuint          GLSLToonShader::_program = 0;
bool            GLSLToonShader::_did_init = false;
GLint           GLSLToonShader::_tex_loc = -1;
GLSLToonShader* GLSLToonShader::_instance(0);

GLSLToonShader::GLSLToonShader(Patch* p) : GLSLShader(p)
{
   set_tex(GtexUtil::toon_name(
      Config::get_var_str("GLSL_TOON_FILENAME","clear-black.png")
      ));
}

GLSLToonShader* 
GLSLToonShader::get_instance()
{
   if (!_instance) {
      _instance = new GLSLToonShader();
      assert(_instance);
   }
   return _instance;
}

// If this isn't declared static, it never gets called!!!!!!!!!
static void
init_params(TEXTUREglptr& tex)
{
   // set parameters for 1D toon shading
   if (tex) {
      tex->set_wrap_s(GL_CLAMP_TO_EDGE);
      tex->set_wrap_t(GL_CLAMP_TO_EDGE);
      tex->set_mipmap(false);
   }
}

void 
GLSLToonShader::set_tex(Cstr_ptr& filename)
{
   // Set the name of the texture to use
   if (_tex) {
      _tex->set_texture(filename);
   } else {
      set_tex(new TEXTUREgl(filename));
      assert(_tex);
   }
}

void 
GLSLToonShader::set_tex(CTEXTUREglptr& tex)
{
   // set the TEXTUREgl to use:
   init_params(_tex = tex);
}

void
GLSLToonShader::init_textures()
{
   // no-op after the first time:
   if (!load_texture(_tex))
      return;
}

void
GLSLToonShader::activate_textures()
{
   activate_texture(_tex);      // GL_ENABLE_BIT
/*
   if (_tex->wrap_r() == GL_CLAMP_TO_EDGE)
      cerr << "wrap r is correct" << endl;
   else
      cerr << "wrap r is incorrect" << endl;

   if (_tex->wrap_s() == GL_CLAMP_TO_EDGE)
      cerr << "wrap s is correct" << endl;
   else
      cerr << "wrap s is incorrect" << endl;

   if (_tex->wrap_t() == GL_CLAMP_TO_EDGE)
      cerr << "wrap t is correct" << endl;
   else
      cerr << "wrap t is incorrect" << endl;
*/
}

bool 
GLSLToonShader::get_variable_locs()
{
   get_uniform_loc("toon_tex", _tex_loc);

   // other variables here as needed...

   return true;
}

bool
GLSLToonShader::set_uniform_variables() const
{
   // send uniform variable values to the program

   if (_tex) {
      glUniform1i(_tex_loc, _tex->get_tex_unit() - GL_TEXTURE0);
      return true;
   }
   return false;
}

void
GLSLToonShader::draw_start(
   TEXTUREglptr toon_tex,       // the 1D toon texture
   CCOLOR& base_color,          // base color for triangles
   double  base_alpha,          // base alpha for triangles
   bool    do_culling           // enable backface culling
   )
{
   // init program
   get_instance()->init();
 
   // set toon texture on static instance:
   get_instance()->set_tex(toon_tex);

   // set gl state
   glPushAttrib(GL_ENABLE_BIT | GL_CURRENT_BIT);
   if (do_culling) glEnable (GL_CULL_FACE);     // GL_ENABLE_BIT
   else            glDisable(GL_CULL_FACE);
   GL_COL(base_color, base_alpha);              // GL_CURRENT_BIT

   // activate texture
   get_instance()->activate_textures();

   // activate program
   get_instance()->activate_program();

   // set uniform variables
   get_instance()->set_uniform_variables();
}

void
GLSLToonShader::draw_end()
{
   // deactivate program
   get_instance()->deactivate_program();

   // resture gl state
   get_instance()->restore_gl_state();
}

// end of file glsl_toon.C

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