diff options
Diffstat (limited to 'intern/mikktspace/mikktspace.h')
| -rw-r--r-- | intern/mikktspace/mikktspace.h | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/intern/mikktspace/mikktspace.h b/intern/mikktspace/mikktspace.h deleted file mode 100644 index 30c0584c2fb..00000000000 --- a/intern/mikktspace/mikktspace.h +++ /dev/null @@ -1,152 +0,0 @@ -/* SPDX-License-Identifier: Zlib - * Copyright 2011 by Morten S. Mikkelsen. */ - -/** \file - * \ingroup mikktspace - */ - -#ifndef __MIKKTSPACE_H__ -#define __MIKKTSPACE_H__ - -#ifdef __cplusplus -extern "C" { -#endif - -/* Author: Morten S. Mikkelsen - * Version: 1.0 - * - * The files mikktspace.h and mikktspace.c are designed to be - * stand-alone files and it is important that they are kept this way. - * Not having dependencies on structures/classes/libraries specific - * to the program, in which they are used, allows them to be copied - * and used as is into any tool, program or plugin. - * The code is designed to consistently generate the same - * tangent spaces, for a given mesh, in any tool in which it is used. - * This is done by performing an internal welding step and subsequently an order-independent - * evaluation of tangent space for meshes consisting of triangles and quads. - * This means faces can be received in any order and the same is true for - * the order of vertices of each face. The generated result will not be affected - * by such reordering. Additionally, whether degenerate (vertices or texture coordinates) - * primitives are present or not will not affect the generated results either. - * Once tangent space calculation is done the vertices of degenerate primitives will simply - * inherit tangent space from neighboring non degenerate primitives. - * The analysis behind this implementation can be found in my master's thesis - * which is available for download --> http://image.diku.dk/projects/media/morten.mikkelsen.08.pdf - * Note that though the tangent spaces at the vertices are generated in an order-independent way, - * by this implementation, the interpolated tangent space is still affected by which diagonal is - * chosen to split each quad. A sensible solution is to have your tools pipeline always - * split quads by the shortest diagonal. This choice is order-independent and works with mirroring. - * If these have the same length then compare the diagonals defined by the texture coordinates. - * XNormal which is a tool for baking normal maps allows you to write your own tangent space plugin - * and also quad triangulator plugin. - */ - -typedef int tbool; -typedef struct SMikkTSpaceContext SMikkTSpaceContext; - -typedef struct { - // Returns the number of faces (triangles/quads) on the mesh to be processed. - int (*m_getNumFaces)(const SMikkTSpaceContext *pContext); - - // Returns the number of vertices on face number iFace - // iFace is a number in the range {0, 1, ..., getNumFaces()-1} - int (*m_getNumVerticesOfFace)(const SMikkTSpaceContext *pContext, const int iFace); - - // returns the position/normal/texcoord of the referenced face of vertex number iVert. - // iVert is in the range {0,1,2} for triangles and {0,1,2,3} for quads. - void (*m_getPosition)(const SMikkTSpaceContext *pContext, - float fvPosOut[], - const int iFace, - const int iVert); - void (*m_getNormal)(const SMikkTSpaceContext *pContext, - float fvNormOut[], - const int iFace, - const int iVert); - void (*m_getTexCoord)(const SMikkTSpaceContext *pContext, - float fvTexcOut[], - const int iFace, - const int iVert); - - // either (or both) of the two setTSpace callbacks can be set. - // The call-back m_setTSpaceBasic() is sufficient for basic normal mapping. - - // This function is used to return the tangent and fSign to the application. - // fvTangent is a unit length vector. - // For normal maps it is sufficient to use the following simplified version of the bitangent - // which is generated at pixel/vertex level. - // bitangent = fSign * cross(vN, tangent); - // Note that the results are returned unindexed. It is possible to generate a new index list - // But averaging/overwriting tangent spaces by using an already existing index list WILL produce - // INCRORRECT results. - // DO NOT! use an already existing index list. - void (*m_setTSpaceBasic)(const SMikkTSpaceContext *pContext, - const float fvTangent[], - const float fSign, - const int iFace, - const int iVert); - - // This function is used to return tangent space results to the application. - // fvTangent and fvBiTangent are unit length vectors and fMagS and fMagT are their - // true magnitudes which can be used for relief mapping effects. - // fvBiTangent is the "real" bitangent and thus may not be perpendicular to fvTangent. - // However, both are perpendicular to the vertex normal. - // For normal maps it is sufficient to use the following simplified version of the bitangent - // which is generated at pixel/vertex level. - // fSign = bIsOrientationPreserving ? 1.0f : (-1.0f); - // bitangent = fSign * cross(vN, tangent); - // Note that the results are returned unindexed. It is possible to generate a new index list - // But averaging/overwriting tangent spaces by using an already existing index list WILL produce - // INCRORRECT results. DO NOT! use an already existing index list. - void (*m_setTSpace)(const SMikkTSpaceContext *pContext, - const float fvTangent[], - const float fvBiTangent[], - const float fMagS, - const float fMagT, - const tbool bIsOrientationPreserving, - const int iFace, - const int iVert); -} SMikkTSpaceInterface; - -struct SMikkTSpaceContext { - // initialized with callback functions - SMikkTSpaceInterface *m_pInterface; - // pointer to client side mesh data etc. - // (passed as the first parameter with every interface call) - void *m_pUserData; -}; - -// these are both thread safe! -// Default (recommended) fAngularThreshold is 180 degrees (which means threshold disabled) -tbool genTangSpaceDefault(const SMikkTSpaceContext *pContext); -tbool genTangSpace(const SMikkTSpaceContext *pContext, const float fAngularThreshold); - -// To avoid visual errors (distortions/unwanted hard edges in lighting), when using sampled normal -// maps, the normal map sampler must use the exact inverse of the pixel shader transformation. -// The most efficient transformation we can possibly do in the pixel shader is achieved by using, -// directly, the "unnormalized" interpolated tangent, bitangent and vertex normal: vT, vB and vN. -// pixel shader (fast transform out) -// vNout = normalize( vNt.x * vT + vNt.y * vB + vNt.z * vN ); -// where vNt is the tangent space normal. The normal map sampler must likewise use the -// interpolated and "unnormalized" tangent, bitangent and vertex normal to be compliant with the -// pixel shader. sampler does (exact inverse of pixel shader): -// float3 row0 = cross(vB, vN); -// float3 row1 = cross(vN, vT); -// float3 row2 = cross(vT, vB); -// float fSign = dot(vT, row0)<0 ? -1 : 1; -// vNt = normalize( fSign * float3(dot(vNout,row0), dot(vNout,row1), dot(vNout,row2)) ); -// where vNout is the sampled normal in some chosen 3D space. -// -// Should you choose to reconstruct the bitangent in the pixel shader instead -// of the vertex shader, as explained earlier, then be sure to do this in the normal map sampler -// also. Finally, beware of quad triangulations. If the normal map sampler doesn't use the same -// triangulation of quads as your renderer then problems will occur since the interpolated tangent -// spaces will differ eventhough the vertex level tangent spaces match. This can be solved either -// by triangulating before sampling/exporting or by using the order-independent choice of diagonal -// for splitting quads suggested earlier. However, this must be used both by the sampler and your -// tools/rendering pipeline. - -#ifdef __cplusplus -} -#endif - -#endif |