lib/gamnit/model_parsers/mtl.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Services to parse .mtl material files
  16 module mtl
  17
  18 import model_parser_base
  19
  20 # Parser of `.mtl` files
  21 #
  22 # ~~~
  23 # var mtl_src = """
  24 # # Green material with low reflections
  25 # newmtl GreenMaterial
  26 # Ns 96.078431
  27 # Ka 0.000000 0.000000 0.000000
  28 # Kd 0.027186 0.180434 0.012088
  29 # Ks 0.500000 0.500000 0.500000
  30 # Ni 1.000000
  31 # d 1.000000
  32 # illum 2
  33 # """
  34 #
  35 # var parser = new MtlFileParser(mtl_src)
  36 # var name_to_mtls = parser.parse
  37 # assert name_to_mtls.keys.join == "GreenMaterial"
  38 # ~~~
  39 class MtlFileParser
  40         super StringProcessor
  41
  42         # Read and parse source and return all materials organized by their names
  43         fun parse: Map[String, MtlDef]
  44         do
  45                 var mat_lib = new Map[String, MtlDef]
  46                 var material: nullable MtlDef = null
  47
  48                 while not eof do
  49                         var token = read_token
  50                         if token == "newmtl" then
  51                                 var name = read_until_eol_or_comment
  52                                 material = new MtlDef(name)
  53                                 mat_lib[name] = material
  54                         else if material != null then
  55                                 if token == "Ka" then
  56                                         material.ambient = read_vec3
  57                                 else if token == "Kd" then
  58                                         material.diffuse = read_vec3
  59                                 else if token == "Ks" then
  60                                         material.specular = read_vec3
  61                                 else if token == "d" then
  62                                         material.dissolved = read_number
  63                                 else if token == "Tr" then
  64                                         material.dissolved = 1.0 - read_number
  65                                 else if token == "illum" then
  66                                         material.illumination_model = read_number.to_i
  67                                 else if token == "map_Kd" then
  68                                         material.map_diffuse = read_until_eol_or_comment
  69                                 else if token == "map_Bump" then
  70                                         material.map_bump = read_until_eol_or_comment
  71                                 else if token == "map_Ks" then
  72                                         material.map_specular = read_until_eol_or_comment
  73                                 else if token == "map_Ns" then
  74                                         material.map_exponent = read_until_eol_or_comment
  75
  76                                 # TODO other line type headers
  77                                 else if token == "Ns" then
  78                                 else if token == "Ni" then
  79                                 else if token == "sharpness" then
  80                                 else if token == "bump" then
  81                                 end
  82                         end
  83                         skip_eol
  84                 end
  85
  86                 return mat_lib
  87         end
  88 end
  89
  90 # Material defined in a `.mtl` file
  91 class MtlDef
  92
  93         # Name of this material
  94         var name: String
  95
  96         # Ambient color
  97         var ambient = new Vec3 is lazy
  98
  99         # Diffuse color
 100         var diffuse = new Vec3 is lazy
 101
 102         # Specular color
 103         var specular = new Vec3 is lazy
 104
 105         # Dissolved level, where 1.0 is fully visible
 106         var dissolved = 1.0
 107
 108         # Transparency level, where 1.0 is fully invisible
 109         fun transparency: Float do return 1.0 - dissolved
 110
 111         # Illumination model
 112         var illumination_model = 0
 113
 114         # Diffuse map
 115         var map_diffuse: nullable String = null
 116
 117         # Bump map or normals texture
 118         var map_bump: nullable String = null
 119
 120         # Specular reflectivity map
 121         var map_specular: nullable String = null
 122
 123         # Specular exponent map
 124         var map_exponent: nullable String = null
 125
 126         # Collect non-null maps from `map_diffuse, map_bump, map_specular, map_exponent`
 127         fun maps: Array[String]
 128         do
 129                 return [for m in [map_diffuse, map_bump, map_specular, map_exponent] do if m != null then m]
 130         end
 131 end