Public API Reference

csgfx/shaderexp.h

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/*
    Copyright (C) 2003 by Andrew Topp <[email protected]>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#ifndef __CS_GFX_SHADEREXP_H__
#define __CS_GFX_SHADEREXP_H__

#include "csextern.h"

#include "csutil/strhash.h"
#include "csutil/array.h"
#include "csutil/leakguard.h"
#include "csgeom/vector4.h"
#include "ivideo/shader/shader.h"

struct iObjectRegistry;
class csShaderVariable;
struct iShaderVariableContext;
struct iStringSet;
struct iDocumentNode;
struct cons;

class CS_CRYSTALSPACE_EXPORT csShaderExpression 
{
public:
  CS_LEAKGUARD_DECLARE (csShaderExpression);

  struct oper_arg 
  { 
    uint8 type;
    
    union 
    {
      float num;
      csStringID var;
      
      // Illegal outside of a cons cell
      int oper;
      cons * cell;

      // Special internal values
      int acc;
    };
    
    csVector4 vec4;
  };

  struct oper 
  {
    uint8 opcode, acc;
    oper_arg arg1, arg2;
  };

  typedef csArray<oper> oper_array;
  typedef csArray<oper_arg> arg_array;

private:
  iObjectRegistry * obj_reg;
  csRef<iShaderVarStack> stacks;
  csRef<iStringSet> strset;
  oper_array opcodes;
  int accstack_max;
  arg_array accstack;

  bool parse_xml(cons *, iDocumentNode *);
  bool parse_xml_atom(oper_arg &, csStringID, const char *, const char *);
  bool parse_sexp(cons *, iDocumentNode *);
  bool parse_sexp_form(const char *& text, cons *);
  bool parse_sexp_atom(const char *& text, cons *);
  bool parse_num_atom(const char *& text, oper_arg &);

  bool compile_cons(const cons *, int & acc_top);
  bool compile_make_vector(const cons *, int & acc_top, int acc);

  bool eval_const(cons *&);

  bool eval_oper(int oper, oper_arg arg1, oper_arg arg2, oper_arg & output);
  bool eval_oper(int oper, oper_arg arg1, oper_arg & output);
  bool eval_oper(int oper, oper_arg & output);

  bool eval_add(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_sub(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_mul(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_div(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  
  bool eval_elt1(const oper_arg & arg1, oper_arg & output) const;
  bool eval_elt2(const oper_arg & arg1, oper_arg & output) const;
  bool eval_elt3(const oper_arg & arg1, oper_arg & output) const;
  bool eval_elt4(const oper_arg & arg1, oper_arg & output) const;

  bool eval_sin(const oper_arg & arg1, oper_arg & output) const;
  bool eval_cos(const oper_arg & arg1, oper_arg & output) const;
  bool eval_tan(const oper_arg & arg1, oper_arg & output) const;

  bool eval_arcsin(const oper_arg & arg1, oper_arg & output) const;
  bool eval_arccos(const oper_arg & arg1, oper_arg & output) const;
  bool eval_arctan(const oper_arg & arg1, oper_arg & output) const;

  bool eval_dot(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_cross(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_vec_len(const oper_arg & arg1, oper_arg & output) const;
  bool eval_normal(const oper_arg & arg1, oper_arg & output) const;
  bool eval_floor(const oper_arg & arg1, oper_arg & output) const;

  bool eval_pow(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_min(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_max(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;

  bool eval_time(oper_arg & output) const;
  bool eval_frame(oper_arg & output) const;

  bool eval_selt12(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_selt34(const oper_arg & arg1, const oper_arg & arg2,
        oper_arg & output) const;
  bool eval_load(const oper_arg & arg1, oper_arg & output) const;

  bool eval_variable(csShaderVariable *, oper_arg & out);
  bool eval_argument(const oper_arg &, csShaderVariable *);

  void destruct_cons(cons *) const;
  void print_cons(const cons *) const;
  void print_ops(const oper_array &) const;
  void print_result(const oper_arg &) const;

  /*inline*/static const char * GetTypeName (csStringID id)/* const*/;
  /*{
    return xmltypes.Request(id);
  }*/
  static const char* GetOperName (csStringID id);
  static csStringID GetCommonTokenOp (const char* token);
  static csStringID GetXmlTokenOp (const char* token);
  static csStringID GetSexpTokenOp (const char* token);
  static csStringID GetXmlType (const char* token);

  csShaderVariable* ResolveVar (csStringID name);

  mutable csString errorMsg;
  void ParseError (const char* message, ...) const;
  void EvalError (const char* message, ...) const;
public:
  csShaderExpression(iObjectRegistry *);
  ~csShaderExpression();

  bool Parse(iDocumentNode *);

  bool Evaluate(csShaderVariable *, csShaderVarStack& stacks);
  bool Evaluate(csShaderVariable *, iShaderVarStack* stacks);

  const char* GetError() const { return errorMsg; }
};

#endif

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