scripts/shader-cpp.sh

   1 #!/bin/sh
   2
   3 case "$0" in
   4         */*)
   5                 cd "${0%/*}"
   6                 ;;
   7 esac
   8
   9 . ./shader-parser.subr
  10 set -e
  11
  12 err()
  13 {
  14         echo >&2 "(EE) $*"
  15         exit 1
  16 }
  17
  18 LF="
  19 "
  20 TAB="   "
  21
  22 parse_shader_pre()
  23 {
  24         shadertext=
  25         shaderconds=
  26 }
  27 parse_conditional()
  28 {
  29         shaderconds="$shaderconds$LF$*"
  30 }
  31 parse_shader_line()
  32 {
  33         case "$1" in
  34                 '#if')
  35                         parse_conditional $2 $3
  36                         ;;
  37         esac
  38         shadertext="$shadertext$LF$TAB$*"
  39 }
  40 parse_shaderstage_pre()
  41 {
  42         shadertext="$shadertext$LF$TAB{"
  43 }
  44 parse_shaderstage_line()
  45 {
  46         case "$1" in
  47                 '#if')
  48                         parse_conditional $2 $3
  49                         ;;
  50         esac
  51         shadertext="$shadertext$LF$TAB$TAB$*"
  52 }
  53 parse_shaderstage_post()
  54 {
  55         shadertext="$shadertext$LF$TAB}"
  56 }
  57 # note: the conds are what is FALSE, not TRUE
  58 shaderkill()
  59 {
  60         parseALLtheconds=$conds
  61         while :; do
  62                 case "$parseALLtheconds" in
  63                         '')
  64                                 break
  65                                 ;;
  66                         *$LF*)
  67                                 thiscond=${parseALLtheconds%%$LF*}
  68                                 parseALLtheconds=${parseALLtheconds#*$LF}
  69                                 ;;
  70                         *)
  71                                 thiscond=$parseALLtheconds
  72                                 parseALLtheconds=
  73                                 ;;
  74                 esac
  75                 [ -n "$thiscond" ] || continue
  76                 echo "$TAB""dpshaderkillifcvar $thiscond"
  77         done
  78 }
  79 preprocess()
  80 {
  81         echo "$shadertext" | {
  82                 condstack=
  83                 while IFS= read -r L; do
  84                         [ -n "$L" ] || continue
  85                         set -- $L
  86                         k=$1
  87                         shift
  88                         case "$k" in
  89                                 '#if')
  90                                         case "$LF$conds$LF" in
  91                                                 *"$LF$*$LF"*)
  92                                                         condstack=0$condstack
  93                                                         ;;
  94                                                 *)
  95                                                         condstack=1$condstack
  96                                                         ;;
  97                                         esac
  98                                         ;;
  99                                 '#else')
 100                                         if [ -z "$condstack" ]; then
 101                                                 err "unmatched #else"
 102                                         fi
 103                                         case "$condstack" in
 104                                                 0*)
 105                                                         condstack=1${condstack#0}
 106                                                         ;;
 107                                                 1*)
 108                                                         condstack=0${condstack#1}
 109                                                         ;;
 110                                         esac
 111                                         ;;
 112                                 '#endif')
 113                                         if [ -z "$condstack" ]; then
 114                                                 err "unmatched #endif"
 115                                         fi
 116                                         condstack=${condstack#?}
 117                                         ;;
 118                                 *)
 119                                         case "$condstack" in
 120                                                 *0*)
 121                                                         ;;
 122                                                 *)
 123                                                         echo "${L% }"
 124                                                         ;;
 125                                         esac
 126                                         ;;
 127                         esac
 128                 done
 129                 if [ -n "$condstack" ]; then
 130                         err "unmatched #if"
 131                 fi
 132         }
 133 }
 134 conditionalize()
 135 {
 136         case "$1" in
 137                 '')
 138                         # no conditions
 139                         echo "$parsing_shader"
 140                         echo "{"
 141                         shaderkill
 142                         preprocess
 143                         echo "}"
 144                         return
 145                         ;;
 146                 *$LF*)
 147                         # many conditions
 148                         firstcond="${1%%$LF*}"
 149                         restcond="${1#*$LF}"
 150                         ;;
 151                 *)
 152                         firstcond=$1
 153                         restcond=
 154                         ;;
 155         esac
 156         (
 157                 conds="$conds$LF$firstcond"
 158                 conditionalize "$restcond"
 159         )
 160         (
 161                 set -- $firstcond
 162                 case "$2" in
 163                         '==') op='!=' ;;
 164                         '!=') op='==' ;;
 165                         '>') op='<=' ;;
 166                         '<') op='>=' ;;
 167                         '>=') op='<' ;;
 168                         '<=') op='>' ;;
 169                 esac
 170                 set -- "$1" "$op" "$3"
 171                 conds="$conds$LF$*"
 172                 conditionalize "$restcond"
 173         )
 174 }
 175 parse_shader_post()
 176 {
 177         allconds=`echo "$shaderconds" | sort -u | grep . || true`
 178         conds=
 179         conditionalize "$allconds"
 180 }
 181
 182 parse_shaders "$@"