Initial commit

obja.py

@@ -0,0 +1,243 @@
+#!/usr/bin/env python3
+
+import sys
+
+"""
+obja parser for python.
+"""
+
+class Vertex:
+    """
+    The class that holds the x, y, and z coordinates of a vertex.
+    """
+    def __init__(self, array):
+        """
+        Initializes a vertex from an array of string representing floats.
+        """
+        self.set(array)
+
+    def set(self, array):
+        """
+        Sets a vertex from an array of string representing floats.
+        """
+        self.x = float(array[0])
+        self.y = float(array[1])
+        self.z = float(array[2])
+
+    def translate(self, array):
+        """
+        Translates a vertex from an array of string representing floats.
+        """
+        self.x += float(array[0])
+        self.y += float(array[1])
+        self.z += float(array[2])
+
+class Face:
+    """
+    The class that holds a, b, and c, the indices of the vertices of the face.
+    """
+    def __init__(self, array):
+        """
+        Initializes a face from an array of strings representing vertex indices (starting at 1)
+        """
+        self.set(array)
+        self.visible = True
+
+    def set(self, array):
+        """
+        Sets a face from an array of strings representing vertex indices (starting at 1)
+        """
+        self.a = int(array[0]) - 1
+        self.b = int(array[1]) - 1
+        self.c = int(array[2]) - 1
+
+    def test(self, vertices, line = "unknown"):
+        """
+        Tests if a face references only vertices that exist when the face is declared.
+        """
+        if self.a >= len(vertices):
+            raise VertexError(self.a + 1, line)
+        if self.b >= len(vertices):
+            raise VertexError(self.b + 1, line)
+        if self.c >= len(vertices):
+            raise VertexError(self.c + 1, line)
+
+class VertexError(Exception):
+    """
+    An operation references a vertex that does not exist.
+    """
+    def __init__(self, index, line):
+        """
+        Creates the error from index of the referenced vertex and the line where the error occured.
+        """
+        self.line = line
+        self.index = index
+        super().__init__()
+
+    def __str__(self):
+        """
+        Pretty prints the error.
+        """
+        return f'There is no vertex {self.index} (line {self.line})'
+
+class FaceError(Exception):
+    """
+    An operation references a face that does not exist.
+    """
+    def __init__(self, index, line):
+        """
+        Creates the error from index of the referenced face and the line where the error occured.
+        """
+        self.line = line
+        self.index = index
+        super().__init__()
+
+    def __str__(self):
+        """
+        Pretty prints the error.
+        """
+        return f'There is no face {self.index} (line {self.line})'
+
+class FaceVertexError(Exception):
+    """
+    An operation references a face vertex that does not exist.
+    """
+    def __init__(self, index, line):
+        """
+        Creates the error from index of the referenced face vertex and the line where the error occured.
+        """
+        self.line = line
+        self.index = index
+        super().__init__()
+
+    def __str__(self):
+        """
+        Pretty prints the error.
+        """
+        return f'Face has no vertex {self.index} (line {self.line})'
+
+class UnknownInstruction(Exception):
+    """
+    An instruction is unknown.
+    """
+    def __init__(self, instruction, line):
+        """
+        Creates the error from instruction and the line where the error occured.
+        """
+        self.line = line
+        self.instruction = instruction
+        super().__init__()
+
+    def __str__(self):
+        """
+        Pretty prints the error.
+        """
+        return f'Instruction {self.instruction} unknown (line {self.line})'
+
+class Parser:
+    """
+    The OBJA parser.
+    """
+    def __init__(self):
+        """
+        Intializes an empty parser.
+        """
+        self.vertices = []
+        self.faces = []
+        self.line = 0
+
+    def get_vertex(self, string):
+        """
+        Gets a vertex from a string representing the index of the vertex, starting at 1.
+        """
+        index = int(string) - 1
+        if index >= len(self.vertices):
+            raise FaceError(index + 1, self.line)
+        return self.vertices[index]
+
+    def get_face(self, string):
+        """
+        Gets a face from a string representing the index of the face, starting at 1.
+        """
+        index = int(string) - 1
+        if index >= len(self.faces):
+            raise FaceError(index + 1, self.line)
+        return self.faces[index]
+
+    def parse_line(self, line):
+        """
+        Parses a line of obja file.
+        """
+        self.line += 1
+
+        split = line.split()
+
+        if len(split) == 0:
+            return
+
+        if split[0] == "v":
+            self.vertices.append(Vertex(split[1:]))
+
+        elif split[0] == "ev":
+            self.get_vertex(split[1]).set(split[2:])
+
+        elif split[0] == "tv":
+            self.get_vertex(split[1]).translate(split[2:])
+
+        elif split[0] == "f":
+            face = Face(split[1:])
+            face.test(self.vertices, self.line)
+            self.faces.append(face)
+
+        elif split[0] == "ts":
+            for i in range(1, len(split) - 2):
+                if i % 2 == 1:
+                    face = Face([split[i], split[i + 1], split[i + 2]])
+                else:
+                    face = Face([split[i], split[i + 2], split[i + 1]])
+                face.test(self.vertices, self.line)
+                self.faces.append(face)
+
+        elif split[0] == "tf":
+            for i in range(1, len(split) - 2):
+                face = Face(split[i:i+3])
+                face.test(self.vertices, self.line)
+                self.faces.append(face)
+
+        elif split[0] == "ef":
+            self.get_face(split[1]).set(split[2:])
+
+        elif split[0] == "efv":
+            face = self.get_face(split[1])
+            vertex = int(split[2])
+            new_index = int(split[3]) - 1
+            if vertex == 1:
+                face.a = new_index
+            elif vertex == 2:
+                face.b = new_index
+            elif vertex == 3:
+                face.c = new_index
+            else:
+                raise FaceVertexError(vertex, self.line)
+
+        elif split[0] == "df":
+            self.get_face(split[1]).visible = False
+
+        elif split[0] == "#":
+            return
+
+        else:
+            raise UnknownInstruction(split[0], self.line)
+
+def main():
+    if len(sys.argv) == 1:
+        print("obja needs a path to an obja file")
+        return
+
+    parser = Parser()
+    with open(sys.argv[1], "r") as file:
+        for line in file.readlines():
+            parser.parse_line(line)
+
+if __name__ == "__main__":
+    main()

test.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+return_code=0
+
+for file in tests/*.obja; do
+    echo -n "Testing $file... "
+    ./obja.py $file > /dev/null 2>&1
+
+    if [ $? -eq 0 ]; then
+        echo -e '\033[32mSUCCESS\033[0m'
+    else
+        echo -e '\033[31mFAILURE\033[0m'
+        return_code=1
+    fi
+done
+
+# objb files should fail
+for file in tests/*.objb; do
+    echo -n "Testing $file... "
+    ./obja.py $file > /dev/null 2>&1
+
+    if [ $? -eq 0 ]; then
+        echo -e '\033[31mFAILURE\033[0m'
+        return_code=1
+    else
+        echo -e '\033[32mSUCCESS\033[0m'
+    fi
+done
+
+exit $return_code

tests/1.obja

@@ -0,0 +1,4 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+f 1 2 3

tests/1.objb

@@ -0,0 +1,4 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+f 1 2 4

tests/2.obja

@@ -0,0 +1,2 @@
+v 0.0 0.0 0.0
+ev 1 1.0 1.0 1.0

tests/2.objb

@@ -0,0 +1,2 @@
+v 0.0 0.0 0.0
+ev 2 1.0 1.0 1.0

tests/3.obja

@@ -0,0 +1,2 @@
+v 1.0 2.0 3.0
+tv 1 1.0 1.0 1.0

tests/3.objb

@@ -0,0 +1,2 @@
+v 1.0 2.0 3.0
+tv 2 1.0 1.0 1.0

tests/4.obja

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+ef 1 1 2 4

tests/4.objb

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+ef 2 1 2 3

tests/5.obja

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+efv 1 3 4

tests/5.objb

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+efv 2 3 4

tests/6.obja

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+df 1

tests/6.objb

@@ -0,0 +1,6 @@
+v 0.0 0.0 0.0
+v 1.0 0.0 0.0
+v 1.0 1.0 0.0
+v 1.0 1.0 1.0
+f 1 2 3
+df 2

tests/7.obja

@@ -0,0 +1,6 @@
+v -1.0 0.0 0.0
+v -0.5 1.0 0.0
+v 0.0 0.0 0.0
+v 0.5 1.0 0.0
+v 1.0 0.0 0.0
+ts 1 2 3 4 5

tests/7.objb

@@ -0,0 +1,6 @@
+v -1.0 0.0 0.0
+v -0.5 1.0 0.0
+v 0.0 0.0 0.0
+v 0.5 1.0 0.0
+v 1.0 0.0 0.0
+ts 1 2 3 4 6

tests/8.obja

@@ -0,0 +1,7 @@
+v 0.0 0.0 0.0
+v -1.0 0.0 0.0
+v -0.707 0.707 0.0
+v 0.0 1.0 0.0
+v 0.707 0.707 0.0
+v 1.0 0.0 0.0
+tf 1 2 3 4 5 6

tests/8.objb

@@ -0,0 +1,7 @@
+v 0.0 0.0 0.0
+v -1.0 0.0 0.0
+v -0.707 0.707 0.0
+v 0.0 1.0 0.0
+v 0.707 0.707 0.0
+v 1.0 0.0 0.0
+tf 1 2 3 4 5 7