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authorsanine <sanine.not@pm.me>2022-04-16 11:55:09 -0500
committersanine <sanine.not@pm.me>2022-04-16 11:55:09 -0500
commitdb81b925d776103326128bf629cbdda576a223e7 (patch)
tree58bea8155c686733310009f6bed7363f91fbeb9d /libs/assimp/code/Common/assbin_chunks.h
parent55860037b14fb3893ba21cf2654c83d349cc1082 (diff)
move 3rd-party librarys into libs/ and add built-in honeysuckle
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+#ifndef INCLUDED_ASSBIN_CHUNKS_H
+#define INCLUDED_ASSBIN_CHUNKS_H
+
+#define ASSBIN_VERSION_MAJOR 1
+#define ASSBIN_VERSION_MINOR 0
+
+/**
+@page assfile .ASS File formats
+
+@section over Overview
+Assimp provides its own interchange format, which is intended to applications which need
+to serialize 3D-models and to reload them quickly. Assimp's file formats are designed to
+be read by Assimp itself. They encode additional information needed by Assimp to optimize
+its postprocessing pipeline. If you once apply specific steps to a scene, then save it
+and reread it from an ASS format using the same post processing settings, they won't
+be executed again.
+
+The format comes in two flavours: XML and binary - both of them hold a complete dump of
+the 'aiScene' data structure returned by the APIs. The focus for the binary format
+(<tt>.assbin</tt>) is fast loading. Optional deflate compression helps reduce file size. The XML
+flavour, <tt>.assxml</tt> or simply .xml, is just a plain-to-xml conversion of aiScene.
+
+ASSBIN is Assimp's binary interchange format. assimp_cmd (<tt>&lt;root&gt;/tools/assimp_cmd</tt>) is able to
+write it and the core library provides a loader for it.
+
+@section assxml XML File format
+
+The format is pretty much self-explanatory due to its similarity to the in-memory aiScene structure.
+With few exceptions, C structures are wrapped in XML elements.
+
+The DTD for ASSXML can be found in <tt>&lt;root&gt;/doc/AssXML_Scheme.xml</tt>. Or have look
+at the output files generated by assimp_cmd.
+
+@section assbin Binary file format
+
+The ASSBIN file format is composed of chunks to represent the hierarchical aiScene data structure.
+This makes the format extensible and allows backward-compatibility with future data structure
+versions. The <tt>&lt;root&gt;/code/assbin_chunks.h</tt> header contains some magic constants
+for use by stand-alone ASSBIN loaders. Also, Assimp's own file writer can be found
+in <tt>&lt;root&gt;/tools/assimp_cmd/WriteDump.cpp</tt> (yes, the 'b' is no typo ...).
+
+@verbatim
+
+-------------------------------------------------------------------------------
+1. File structure:
+-------------------------------------------------------------------------------
+
+----------------------
+| Header (512 bytes) |
+----------------------
+| Variable chunks |
+----------------------
+
+-------------------------------------------------------------------------------
+2. Definitions:
+-------------------------------------------------------------------------------
+
+integer is four bytes wide, stored in little-endian byte order.
+short is two bytes wide, stored in little-endian byte order.
+byte is a single byte.
+string is an integer n followed by n UTF-8 characters, not terminated by zero
+float is an IEEE 754 single-precision floating-point value
+double is an IEEE 754 double-precision floating-point value
+t[n] is an array of n elements of type t
+
+-------------------------------------------------------------------------------
+2. Header:
+-------------------------------------------------------------------------------
+
+byte[44] Magic identification string for ASSBIN files.
+ 'ASSIMP.binary'
+
+integer Major version of the Assimp library which wrote the file
+integer Minor version of the Assimp library which wrote the file
+ match these against ASSBIN_VERSION_MAJOR and ASSBIN_VERSION_MINOR
+
+integer SVN revision of the Assimp library (intended for our internal
+ debugging - if you write Ass files from your own APPs, set this value to 0.
+integer Assimp compile flags
+
+short 0 for normal files, 1 for shortened dumps for regression tests
+ these should have the file extension assbin.regress
+
+short 1 if the data after the header is compressed with the DEFLATE algorithm,
+ 0 for uncompressed files.
+ For compressed files, the first integer after the header is
+ always the uncompressed data size
+
+byte[256] Zero-terminated source file name, UTF-8
+byte[128] Zero-terminated command line parameters passed to assimp_cmd, UTF-8
+
+byte[64] Reserved for future use
+---> Total length: 512 bytes
+
+-------------------------------------------------------------------------------
+3. Chunks:
+-------------------------------------------------------------------------------
+
+integer Magic chunk ID (ASSBIN_CHUNK_XXX)
+integer Chunk data length, in bytes
+ (unknown chunks are possible, a good reader skips over them)
+ (chunk-data-length does not include the first two integers)
+
+byte[n] chunk-data-length bytes of data, depending on the chunk type
+
+Chunks can contain nested chunks. Nested chunks are ALWAYS at the end of the chunk,
+their size is included in chunk-data-length.
+
+The chunk layout for all ASSIMP data structures is derived from their C declarations.
+The general 'rule' to get from Assimp headers to the serialized layout is:
+
+ 1. POD members (i.e. aiMesh::mPrimitiveTypes, aiMesh::mNumVertices),
+ in order of declaration.
+
+ 2. Array-members (aiMesh::mFaces, aiMesh::mVertices, aiBone::mWeights),
+ in order of declaration.
+
+ 2. Object array members (i.e aiMesh::mBones, aiScene::mMeshes) are stored in
+ subchunks directly following the data written in 1.) and 2.)
+
+
+ Of course, there are some exceptions to this general order:
+
+[[aiScene]]
+
+ - The root node holding the scene structure is naturally stored in
+ a ASSBIN_CHUNK_AINODE subchunk following 1.) and 2.) (which is
+ empty for aiScene).
+
+[[aiMesh]]
+
+ - mTextureCoords and mNumUVComponents are serialized as follows:
+
+ [number of used uv channels times]
+ integer mNumUVComponents[n]
+ float mTextureCoords[n][3]
+
+ -> more than AI_MAX_TEXCOORD_CHANNELS can be stored. This allows Assimp
+ builds with different settings for AI_MAX_TEXCOORD_CHANNELS to exchange
+ data.
+ -> the on-disk format always uses 3 floats to write UV coordinates.
+ If mNumUVComponents[0] is 1, the corresponding mTextureCoords array
+ consists of 3 floats.
+
+ - The array member block of aiMesh is prefixed with an integer that specifies
+ the kinds of vertex components actually present in the mesh. This is a
+ bitwise combination of the ASSBIN_MESH_HAS_xxx constants.
+
+[[aiFace]]
+
+ - mNumIndices is stored as short
+ - mIndices are written as short, if aiMesh::mNumVertices<65536
+
+[[aiNode]]
+
+ - mParent is omitted
+
+[[aiLight]]
+
+ - mAttenuationXXX not written if aiLight::mType == aiLightSource_DIRECTIONAL
+ - mAngleXXX not written if aiLight::mType != aiLightSource_SPOT
+
+[[aiMaterial]]
+
+ - mNumAllocated is omitted, for obvious reasons :-)
+
+
+ @endverbatim*/
+
+
+#define ASSBIN_HEADER_LENGTH 512
+
+// these are the magic chunk identifiers for the binary ASS file format
+#define ASSBIN_CHUNK_AICAMERA 0x1234
+#define ASSBIN_CHUNK_AILIGHT 0x1235
+#define ASSBIN_CHUNK_AITEXTURE 0x1236
+#define ASSBIN_CHUNK_AIMESH 0x1237
+#define ASSBIN_CHUNK_AINODEANIM 0x1238
+#define ASSBIN_CHUNK_AISCENE 0x1239
+#define ASSBIN_CHUNK_AIBONE 0x123a
+#define ASSBIN_CHUNK_AIANIMATION 0x123b
+#define ASSBIN_CHUNK_AINODE 0x123c
+#define ASSBIN_CHUNK_AIMATERIAL 0x123d
+#define ASSBIN_CHUNK_AIMATERIALPROPERTY 0x123e
+
+#define ASSBIN_MESH_HAS_POSITIONS 0x1
+#define ASSBIN_MESH_HAS_NORMALS 0x2
+#define ASSBIN_MESH_HAS_TANGENTS_AND_BITANGENTS 0x4
+#define ASSBIN_MESH_HAS_TEXCOORD_BASE 0x100
+#define ASSBIN_MESH_HAS_COLOR_BASE 0x10000
+
+#define ASSBIN_MESH_HAS_TEXCOORD(n) (ASSBIN_MESH_HAS_TEXCOORD_BASE << n)
+#define ASSBIN_MESH_HAS_COLOR(n) (ASSBIN_MESH_HAS_COLOR_BASE << n)
+
+
+#endif // INCLUDED_ASSBIN_CHUNKS_H