RayTracing Code

/** 3DGPL *************************************************\ * () * * Interpreting ascii data description, constructing a * * data structure in memory, atempting to do correct * * alignment for items in the structs. * * * * Defines: * * D_data Getting a specified export. * * * * Internals: * * DI_char Next char of the source; * * DI_token Next token of the stream; * * DI_type Interpreting type; * * DI_var Interpreting var list; * * DI_length Length of type in bytes. * * * * (c) 1995-98 Sergei Savchenko, (savs@cs.mcgill.ca) * \**********************************************************/ #include "RayTracing.h" /* HW_error */ #include "data.h" /* self definition */ #include <stdio.h> /* FILE etc. */ #include <string.h> /* cmpstr etc. */ #include <stdlib.h> /* malloc etc. */ #define D_MAX_TOKEN_LENGTH 100 /* token taken from the source */ #define D_NAME_LENGTH 32 /* names gotta be this long */ #define D_BUFFER_LENGTH 256 /* chars being read */ enum D_token_type /* enumerates all tokens */ { D_EOF, /* end of file */ D_NAME, /* starting from the letter */ D_NUMBER, /* starting from a number */ D_NUMBERF, /* starting from a float number */ D_BASE_INT, /* base types */ D_BASE_FLOAT, D_BASE_SHORT, D_BASE_BYTE, D_BASE_PTR, /* typeless pointer */ D_DEREF, /* dereferencing symbol */ D_OPEN_SQ, /* describes an array */ D_CLOSE_SQ, D_OPEN_CURL, /* describes a structure */ D_CLOSE_CURL, D_OPEN_RAW, /* describes a raw data array */ D_CLOSE_RAW, D_STATE_TYPE, /* statements */ D_STATE_VAR, /* "name" */ D_STATE_EXPORT }; struct D_token /* describes a token */ { char d_description[D_MAX_TOKEN_LENGTH]; /* actual text of a token */ enum D_token_type d_type; /* enumeration of this token */ }; struct D_token D_tokens[]= /* what is in the grammer */ { {"int" ,D_BASE_INT}, /* base types */ {"float" ,D_BASE_FLOAT}, {"short" ,D_BASE_SHORT}, {"byte" ,D_BASE_BYTE}, {"ptr" ,D_BASE_PTR}, {"@" ,D_DEREF}, /* dereferencing symbol */ {"[" ,D_OPEN_SQ}, /* array */ {"]" ,D_CLOSE_SQ}, {"{" ,D_OPEN_CURL}, /* structure */ {"}" ,D_CLOSE_CURL}, {"<" ,D_OPEN_RAW}, /* raw array */ {">" ,D_CLOSE_RAW}, {"type" ,D_STATE_TYPE}, /* statements */ {"var" ,D_STATE_VAR}, {"export",D_STATE_EXPORT}, {"" ,(D_token_type)0} /* tagging the last one */ }; char D_terminators[]=" \n\r@[]{}<>\xff"; /* expression terminators */ char D_filters[]=" \n\r"; /* characters which are ignored */ int D_current; /* char being read */ int D_last; /* how many chars are there */ int D_line; /* number of lines read */ char *D_buffer; /* the chars being read */ FILE *D_file; /* handle to the input */ char D_fname[D_NAME_LENGTH]; /* name of the current file */ struct D_int_alignment_struct { char d_char; int d_int; } D_int_check; struct D_float_alignment_struct { char d_char; float d_float; } D_float_check; struct D_short_alignment_struct { char d_char; short d_short; } D_short_check; struct D_ptr_alignment_struct { char d_char; char *d_ptr; } D_ptr_check; int D_int_alignment; /* alignment type for int */ int D_float_alignment; /* alignment type for int */ int D_short_alignment; /* alignment type for int */ int D_ptr_alignment; /* gotta be same as int but... */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * *\ * Stream of chars from the script file. * * * * RETURNS: Next character from the script stream. * * -------- * \* * * * * * * * * * * * * * * * * * * * * * * * * * * * */ char DI_char(void) { if(D_current<D_last) /* as long as have something */ { return(D_buffer[D_current++]); /* current char */ } else { if((D_last=fread(D_buffer,sizeof(char),D_BUFFER_LENGTH,D_file))==0) return('\xff'); /* end of the source */ D_current=0; /* starting from the first one */ return(D_buffer[D_current++]); } } /* * * * * * * * * * * * * * * * * * * * * * * * * * * * *\ * Tokenizer. token is defined as a text between * * a filter ( ignored ) and a terminator. token might * * be a terminator. * * * * RETURNS: Type of the current token. * * -------- * * SETS: D_token_text,D_token_number for some kinds of * * ----- tokens, D_line would have number of \n read. * \* * * * * * * * * * * * * * * * * * * * * * * * * * * * */ char D_token_text[D_MAX_TOKEN_LENGTH]; /* set after DI_token */ int D_token_number; float D_token_numberf; /* * * * * * * * * * * * * * * * * * * * * * * * * * * * */ enum D_token_type DI_token(void) { int i,lng=0; /* empty yet */ char c; for(;;) /* ignore preceding filters */ { c=DI_char(); if(c=='\xff') /* end of input strem */ { D_token_text[lng]=0; /* no text associated here */ return(D_EOF); /* end of the source */ } for(i=0;D_filters[i]!=0;i++) if(c==D_filters[i]) break; /* yes, filter current symbol */ if(D_filters[i]==0) { D_current--; /* process further */ break; /* nope, none of filters */ } if(D_filters[i]=='\n') D_line++; /* counter of lines read */ } for(;;) /* copy until the terminator */ { c=DI_char(); for(i=0;D_terminators[i]!=0;i++) if(c==D_terminators[i]) break; /* yes, terminate on this one */ if(D_terminators[i]==0) /* not a terminator */ { D_token_text[lng++]=c; /* char in the token */ } else /* yes a terminator */ { D_token_text[lng]=0; /* end of line */ D_current--; /* process a terminator further */ break; /* finished composing a token */ } } if(lng==0) /* checking tokens/terminators */ { for(