diff options
Diffstat (limited to 'source/blender/blenkernel/mikktspace.h')
| -rw-r--r-- | source/blender/blenkernel/mikktspace.h | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/source/blender/blenkernel/mikktspace.h b/source/blender/blenkernel/mikktspace.h deleted file mode 100644 index 7775667b527..00000000000 --- a/source/blender/blenkernel/mikktspace.h +++ /dev/null @@ -1,143 +0,0 @@ -/** - * Copyright (C) 2011 by Morten S. Mikkelsen - * - * This software is provided 'as-is', without any express or implied - * warranty. In no event will the authors be held liable for any damages - * arising from the use of this software. - * - * Permission is granted to anyone to use this software for any purpose, - * including commercial applications, and to alter it and redistribute it - * freely, subject to the following restrictions: - * - * 1. The origin of this software must not be misrepresented; you must not - * claim that you wrote the original software. If you use this software - * in a product, an acknowledgment in the product documentation would be - * appreciated but is not required. - * 2. Altered source versions must be plainly marked as such, and must not be - * misrepresented as being the original software. - * 3. This notice may not be removed or altered from any source distribution. - */ - -#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 -{ - SMikkTSpaceInterface * m_pInterface; // initialized with callback functions - void * m_pUserData; // pointer to client side mesh data etc. (passed as the first parameter with every interface call) -}; - -// these are both thread safe! -tbool genTangSpaceDefault(const SMikkTSpaceContext * pContext); // Default (recommended) fAngularThreshold is 180 degrees (which means threshold disabled) -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 |