shader.cpp

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/////////////////////////////////////////////////////////////////////
// 6/6/02       Aaron Lefohn    Scientific Computing and Imaging Institute
// School of Computing          University of Utah
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2.1 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
////////////////////////////////////////////////////////////////////////
//
// Shader.cpp: implementation of the Shader class.
//
/////////////////////////////////////////////////////////////////////

#include <state/shader.h>
#include <texture/multiTex.h>
#include <iostream>
#include <GL/glUtil.h>

using namespace std;
using namespace gutz;

using namespace glift;

//////////////////////////////////////////////////////////////////////
/// Construction/Destruction
//////////////////////////////////////////////////////////////////////

Shader::Shader( GenState* genState )
{
   initMembers( NULL, NULL, genState ? VecStateP(1,genState) : VecStateP() );
}

Shader::Shader( const VecStateP& genAttribs )
{
   initMembers( NULL, NULL, genAttribs );
}

Shader::Shader( Texture* tex, GenState* genState )
{
   initMembers( tex, NULL, genState ? VecStateP(1,genState) : VecStateP() );
}

Shader::Shader( Texture* tex, const VecStateP& genAttribs )
{
   initMembers( tex, NULL, genAttribs);
}

Shader::Shader( Texture* tex, ProgShader* progShader, GenState* genState )
{
   initMembers( tex, progShader, genState ? VecStateP(1,genState) : VecStateP() );
}

Shader::Shader( Texture* tex, ProgShader* progShader, const VecStateP& genAttribs )
{
   initMembers( tex, progShader, genAttribs );
}

Shader::Shader( const Shader& rhs )
{
   initMembers( rhs );
}

Shader& Shader::operator=( const Shader& rhs )
{
   if( &rhs != this ) {
      initMembers( rhs );
   }
   return *this;
}

void Shader::initMembers( Texture* tex, ProgShader* progShader, const VecStateP& genAttribs )
{
   m_texture = tex;
   m_progShader = progShader;
   m_genAttribs  = genAttribs;

   /// - Make sure that the number of textures and number of texture offsets match.
   if( m_progShader || m_texture)  {
      checkTexture();
   }
}

void Shader::initMembers( const Shader& rhs )
{
   initMembers( rhs.m_texture, rhs.m_progShader, rhs.m_genAttribs );
}

void Shader::checkTexture()
{
   /// Ensure that progShader specifies the same number of textures as 'm_texture' contains.
   if( m_progShader && m_texture ) {
      if( m_texture->numTexUnits() != m_progShader->numTexUnits() ) {
         err() << "initMembers(...) Error:\n"
            << "\tShader defines " << m_progShader->numTexUnits() 
            << "\ttexture perturbation(s) but " << m_texture->numTexUnits() << " textures were provided.\n"
            << "\t'EmptyTexture' objects can be used to enable texture\n"
            << "\tunits for their texture coordinates only.\n";
         exit(1);
      }
   }    

   /// Check the number of textures vs. number of texture perturbations.
   MultiTex* multiTex = dynamic_cast<MultiTex*>( m_texture );
   if( m_progShader && !multiTex ) {
      if( m_progShader->numTexUnits() > 1 ) {
         err() << "initMembers(...) Error:\n"
            << "\tShader requires " << m_progShader->numTexUnits() 
            << "\ttexture unit(s) and only 1 texture was provided.\n"
            << "\t'EmptyTexture' objects can be used to enable texture\n"
            << "\tunits for their texture coordinates only.\n";
         exit(1);
      }
   }
}

Shader::~Shader()
{}

/// Generate appropriate texture coordinates, taking into account 
/// multiTexturing, texCoordTransforms, and texture contants
MultiTexCoord* Shader::genTexCoords( const arrayw2f& rawTexCoord, const vec3f& primScale ) const
{
   if( m_texture && rawTexCoord.size()==0 ) {
      err() << "genTexCoords(...) Error:\n"
         << "\tAttempt to create texture coordinates for a primitive that does\n"
         << "\tNOT have texture coordinates enabled.\n"
         << "\tIf texture coordinates are desired, construct primitive with \n"
         << "\ttexture coordinate generation enabled.\n";
      exit(1);
   }

   MultiTexCoord* multiTexCoord = NULL;
   if( m_progShader == NULL ) {
      if( !rawTexCoord.empty() ) {
         multiTexCoord = new MultiTexCoord( this->numTexUnits(), rawTexCoord );
      }
   }
   else {
      /// Note: m_progShader and m_tex are guaranteed (by the Shader Constructor)
      ///       to have the same number of texture units.
      multiTexCoord = m_progShader->genTexCoords( rawTexCoord, primScale );
   }

   /// Perturb the texture coords if subTextures are being used
   if( MultiTex* tex = dynamic_cast<MultiTex*>(m_texture) ) {   
      for(int t=0; t < numTexUnits(); t++) {
         if( SubTex* subtex = dynamic_cast<SubTex*>((*tex)[t]) ) {
            subtex->adjustTexCoord( (*multiTexCoord)[t] );
         }
      }
   }
   else if( m_texture ) { /// Single Texture
      if( SubTex* subtex = dynamic_cast<SubTex*>(m_texture) ) {
         subtex->adjustTexCoord( (*multiTexCoord)[0] );
      }
   }

   return multiTexCoord;
}

void Shader::bindDef()
{
   if( m_texture    ) { m_texture->bind(); }
   if( m_progShader ) { m_progShader->bind(); }

   for(unsigned int i=0; i < m_genAttribs.size(); i++) {
      if( m_genAttribs[i] ) { m_genAttribs[i]->bind(); }
   }
   glErr(estr(),"Shader", "bindDef");
}

void Shader::releaseDef()
{
   for(int i=m_genAttribs.size()-1; i >= 0; i--) {
      if( m_genAttribs[i] ) { m_genAttribs[i]->release(); }
   }
   if( m_progShader ) { m_progShader->release(); }
   if( m_texture    ) { m_texture->release(); }
}

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