import json import struct import pyglet from pyglet.gl import GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_FLOAT from pyglet.gl import GL_UNSIGNED_INT, GL_ELEMENT_ARRAY_BUFFER, GL_ARRAY_BUFFER, GL_TRIANGLES from .. import Model, Material, MaterialGroup from . import ModelDecodeException, ModelDecoder # pyglet.graphics types _pyglet_types = { GL_BYTE: 'b', GL_UNSIGNED_BYTE: 'B', GL_SHORT: 's', GL_UNSIGNED_SHORT: 'S', GL_UNSIGNED_INT: 'I', GL_FLOAT: 'f', } # struct module types _struct_types = { GL_BYTE: 'b', GL_UNSIGNED_BYTE: 'B', GL_SHORT: 'h', GL_UNSIGNED_SHORT: 'H', GL_UNSIGNED_INT: 'I', GL_FLOAT: 'f', } # OpenGL type sizes _component_sizes = { GL_BYTE: 1, GL_UNSIGNED_BYTE: 1, GL_SHORT: 2, GL_UNSIGNED_SHORT: 2, GL_UNSIGNED_INT: 4, GL_FLOAT: 4 } _accessor_type_sizes = { "SCALAR": 1, "VEC2": 2, "VEC3": 3, "VEC4": 4, "MAT2": 4, "MAT3": 9, "MAT4": 16 } _targets = { GL_ELEMENT_ARRAY_BUFFER: "element_array", GL_ARRAY_BUFFER: "array", } # GLTF to pyglet shorthand types: _attributes = { 'POSITION': 'v', 'NORMAL': 'n', 'TANGENT': None, 'TEXCOORD_0': '0t', 'TEXCOORD_1': '1t', 'COLOR_0': 'c', 'JOINTS_0': None, 'WEIGHTS_0': None } class Buffer: # TODO: support GLB format # TODO: support data uris def __init__(self, length, uri): self._length = length self._uri = uri def read(self, offset, length): file = pyglet.resource.file(self._uri, 'rb') file.seek(offset) data = file.read(length) file.close() return data class BufferView: def __init__(self, buffer, offset, length, target, stride): self.buffer = buffer self.offset = offset self.length = length self.target = target self.stride = stride class Accessor: # TODO: support sparse accessors def __init__(self, buffer_view, offset, comp_type, count, maximum, minimum, accessor_type, sparse): self.buffer_view = buffer_view self.offset = offset self.component_type = comp_type self.count = count self.maximum = maximum self.minimum = minimum self.type = accessor_type self.sparse = sparse self.size = _component_sizes[comp_type] * _accessor_type_sizes[accessor_type] def read(self): offset = self.offset + self.buffer_view.offset length = self.size * self.count stride = self.buffer_view.stride or 1 # TODO: handle stride data = self.buffer_view.buffer.read(offset, length) return data def parse_gltf_file(file, filename, batch): if file is None: file = pyglet.resource.file(filename, 'r') elif file.mode != 'r': file.close() file = pyglet.resource.file(filename, 'r') try: data = json.load(file) except json.JSONDecodeError: raise ModelDecodeException('Json error. Does not appear to be a valid glTF file.') finally: file.close() if 'asset' not in data: raise ModelDecodeException('Not a valid glTF file. Asset property not found.') else: if float(data['asset']['version']) < 2.0: raise ModelDecodeException('Only glTF 2.0+ models are supported') buffers = dict() buffer_views = dict() accessors = dict() materials = dict() for i, item in enumerate(data.get('buffers', [])): buffers[i] = Buffer(item['byteLength'], item['uri']) for i, item in enumerate(data.get('bufferViews', [])): buffer_index = item['buffer'] buffer = buffers[buffer_index] offset = item.get('byteOffset', 0) length = item.get('byteLength') target = item.get('target') stride = item.get('byteStride', 1) buffer_views[i] = BufferView(buffer, offset, length, target, stride) for i, item in enumerate(data.get('accessors', [])): buf_view_index = item.get('bufferView') buf_view = buffer_views[buf_view_index] offset = item.get('byteOffset', 0) comp_type = item.get('componentType') count = item.get('count') maxi = item.get('max') mini = item.get('min') acc_type = item.get('type') sparse = item.get('sparse', None) accessors[i] = Accessor(buf_view, offset, comp_type, count, maxi, mini, acc_type, sparse) vertex_lists = [] for mesh_data in data.get('meshes'): for primitive in mesh_data.get('primitives', []): indices = None attribute_list = [] count = 0 for attribute_type, i in primitive['attributes'].items(): accessor = accessors[i] attrib = _attributes[attribute_type] if not attrib: # TODO: Add support for these attribute types to pyglet continue attrib_size = _accessor_type_sizes[accessor.type] pyglet_type = _pyglet_types[accessor.component_type] pyglet_fmt = "{0}{1}{2}".format(attrib, attrib_size, pyglet_type) count = accessor.count struct_fmt = str(count * attrib_size) + _struct_types[accessor.component_type] array = struct.unpack('<' + struct_fmt, accessor.read()) attribute_list.append((pyglet_fmt, array)) if 'indices' in primitive: indices_index = primitive.get('indices') accessor = accessors[indices_index] attrib_size = _accessor_type_sizes[accessor.type] fmt = str(accessor.count * attrib_size) + _struct_types[accessor.component_type] indices = struct.unpack('<' + fmt, accessor.read()) # if 'material' in primitive: # material_index = primitive.get('material') # color = materials[material_index] # attribute_list.append(('c4f', color * count)) diffuse = [1.0, 1.0, 1.0] ambient = [1.0, 1.0, 1.0] specular = [1.0, 1.0, 1.0] emission = [0.0, 0.0, 0.0] shininess = 100.0 opacity = 1.0 material = Material("Default", diffuse, ambient, specular, emission, shininess, opacity) group = MaterialGroup(material=material) if indices: vlist = batch.add_indexed(count, GL_TRIANGLES, group, indices, *attribute_list) else: vlist = batch.add(count, GL_TRIANGLES, group, *attribute_list) vertex_lists.append(vlist) return vertex_lists ################################################### # Decoder definitions start here: ################################################### class GLTFModelDecoder(ModelDecoder): def get_file_extensions(self): return ['.gltf'] def decode(self, file, filename, batch): if not batch: batch = pyglet.graphics.Batch() vertex_lists = parse_gltf_file(file=file, filename=filename, batch=batch) textures = {} return Model(vertex_lists, textures, batch=batch) def get_decoders(): return [GLTFModelDecoder()] def get_encoders(): return []