From 07fc765d2bdb16a5b4e4025d6c734e1fd13aa423 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Alexis=20Laferri=C3=A8re?= <alexis.laf@xymus.net>
Date: Sat, 19 Dec 2015 10:36:07 -0500
Subject: [PATCH] lib/gamnit: intro new services and refine `StringProcessor`
 to read model files
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Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
---
 lib/gamnit/model_parsers/model_parser_base.nit |  181 ++++++++++++++++++++++++
 1 file changed, 181 insertions(+)
 create mode 100644 lib/gamnit/model_parsers/model_parser_base.nit

diff --git a/lib/gamnit/model_parsers/model_parser_base.nit b/lib/gamnit/model_parsers/model_parser_base.nit
new file mode 100644
index 0000000..de0fa21
--- /dev/null
+++ b/lib/gamnit/model_parsers/model_parser_base.nit
@@ -0,0 +1,181 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Services to parse models from a text description
+module model_parser_base
+
+import parser_base
+
+# Vector of 3 values, either `x, y, z`, `u, v, z` or `r, g, b`
+class Vec3
+
+	# X value
+	var x = 0.0 is writable
+
+	# Y value
+	var y = 0.0 is writable
+
+	# Z value
+	var z = 0.0 is writable
+
+	# U value (redirection as `x`)
+	fun u: Float do return x
+
+	# Set U value (redirection for `x=`)
+	fun u=(value: Float) do x = value
+
+	# V value (redirection as `y`)
+	fun v: Float do return y
+
+	# Set V value (redirection for `y=`)
+	fun v=(value: Float) do y = value
+
+	# R value
+	fun r: Float do return x
+
+	# Set R value (redirection for `x=`)
+	fun r=(value: Float) do x = value
+
+	# G value
+	fun g: Float do return y
+
+	# Set G value (redirection for `y=`)
+	fun g=(value: Float) do y = value
+
+	# B value
+	fun b: Float do return z
+
+	# Set B value (redirection for `z=`)
+	fun b=(value: Float) do z = value
+
+	# Return all values into a new `Array[Float]`
+	fun to_a: Array[Float] do return [x, y, z]
+
+	redef fun to_s do return "<{class_name} {x} {y} {z}>"
+end
+
+# Vector of 4 values, either `x, y, z, w`, `u, v, z, w` or `r, g, b, a`
+class Vec4
+	super Vec3
+
+	# W value
+	var w = 1.0 is writable
+
+	# A value (redirection to `z`)
+	fun a: Float do return z
+
+	# Set A value (redirection for `z=`)
+	fun a=(value: Float) do z = value
+
+	# Return all values into a new `Array[Float]`
+	redef fun to_a do return [x, y, z, w]
+
+	redef fun to_s do return "<{class_name} {x} {y} {z} {w}>"
+end
+
+redef class StringProcessor
+	# Read a single token after skipping preceding whitespaces
+	#
+	# Returns an empty string when at `eof`
+	protected fun read_token: String
+	do
+		while not eof and src[pos].is_whitespace and src[pos] != '\n' do
+			pos += 1
+		end
+
+		var start = pos
+		ignore_until_whitespace_or_comment
+		var ending = pos
+		var str = src.substring(start, ending-start)
+		return str
+	end
+
+	# Read 3 or 4 numbers and return them as a `Vec4`
+	#
+	# If there is no fourth value, `Vec4::w` is set to 1.0.
+	protected fun read_vec4: Vec4
+	do
+		var vec = new Vec4
+		vec.x = read_number
+		vec.y = read_number
+		vec.z = read_number
+
+		var wstr = read_token
+		if wstr.length > 0 then
+			vec.w = if wstr.is_numeric then wstr.to_f else 0.0
+		else
+			vec.w = 1.0
+		end
+
+		return vec
+	end
+
+	# Read 2 or 3 numbers and return them as a `Vec3`
+	#
+	# If there is no third value, `Vec3::z` is set to 0.0.
+	protected fun read_vec3: Vec3
+	do
+		var vec = new Vec3
+		vec.x = read_number
+		vec.y = read_number # Make optional
+
+		var wstr = read_token
+		if wstr.length > 0 then
+			vec.z = if wstr.is_numeric then wstr.to_f else 0.0
+		else
+			vec.z = 0.0
+		end
+
+		return vec
+	end
+
+	# Advance `pos` until a whitespace or `#` is encountered
+	protected fun ignore_until_whitespace_or_comment: Int
+	do
+		while src.length > pos and not src[pos].is_whitespace and src[pos] != '#' do
+			pos += 1
+		end
+		return pos
+	end
+
+	# Read a token and parse it as a `Float`
+	protected fun read_number: Float
+	do
+		var str = read_token
+		return if str.is_numeric then str.to_f else 0.0
+	end
+
+	# Advance `pos` until the next end of line or a `#`
+	protected fun read_until_eol_or_comment: String
+	do
+		ignore_whitespaces
+		var start = pos
+		while not eof and src[pos] != '#' and src[pos] != '\n' do
+			pos += 1
+		end
+		var ending = pos
+		var str = src.substring(start, ending-start)
+		return str.trim
+	end
+
+	# Advance `pos` to skip the next end of line
+	protected fun skip_eol
+	do
+		while not eof do
+			var c = src.chars[pos]
+			pos += 1
+			if c == '\n' then break
+		end
+	end
+end
-- 
1.7.9.5