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Diffstat (limited to 'PhysX_3.4/Source/GeomUtils/src/convex/GuCubeIndex.h')
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diff --git a/PhysX_3.4/Source/GeomUtils/src/convex/GuCubeIndex.h b/PhysX_3.4/Source/GeomUtils/src/convex/GuCubeIndex.h new file mode 100644 index 00000000..dad4f7d2 --- /dev/null +++ b/PhysX_3.4/Source/GeomUtils/src/convex/GuCubeIndex.h @@ -0,0 +1,155 @@ +// This code contains NVIDIA Confidential Information and is disclosed to you +// under a form of NVIDIA software license agreement provided separately to you. +// +// Notice +// NVIDIA Corporation and its licensors retain all intellectual property and +// proprietary rights in and to this software and related documentation and +// any modifications thereto. Any use, reproduction, disclosure, or +// distribution of this software and related documentation without an express +// license agreement from NVIDIA Corporation is strictly prohibited. +// +// ALL NVIDIA DESIGN SPECIFICATIONS, CODE ARE PROVIDED "AS IS.". NVIDIA MAKES +// NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO +// THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT, +// MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE. +// +// Information and code furnished is believed to be accurate and reliable. +// However, NVIDIA Corporation assumes no responsibility for the consequences of use of such +// information or for any infringement of patents or other rights of third parties that may +// result from its use. No license is granted by implication or otherwise under any patent +// or patent rights of NVIDIA Corporation. Details are subject to change without notice. +// This code supersedes and replaces all information previously supplied. +// NVIDIA Corporation products are not authorized for use as critical +// components in life support devices or systems without express written approval of +// NVIDIA Corporation. +// +// Copyright (c) 2008-2016 NVIDIA Corporation. All rights reserved. +// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved. +// Copyright (c) 2001-2004 NovodeX AG. All rights reserved. + +#ifndef GU_CUBE_INDEX_H +#define GU_CUBE_INDEX_H + +#include "foundation/PxVec3.h" +#include "CmPhysXCommon.h" +#include "PsFPU.h" + +namespace physx +{ + + enum CubeIndex + { + CUBE_RIGHT, + CUBE_LEFT, + CUBE_TOP, + CUBE_BOTTOM, + CUBE_FRONT, + CUBE_BACK, + + CUBE_FORCE_DWORD = 0x7fffffff + }; + + /* + It's pretty straightforwards in concept (though the execution in hardware is + a bit crufty and complex). You use a 3D texture coord to look up a texel in + a cube map. First you find which of the axis has the largest value (i.e. + X,Y,Z), and then the sign of that axis decides which face you are going to + use. Which is why the faces are called +X, -X, +Y, -Y, +Z, -Z - after their + principle axis. Then you scale the vector so that the largest value is +/-1. + Then use the other two as 2D coords to look up your texel (with a 0.5 scale + & offset). + + For example, vector (0.4, -0.2, -0.5). Largest value is the Z axis, and it's + -ve, so we're reading from the -Z map. Scale so that this Z axis is +/-1, + and you get the vector (0.8, -0.4, -1.0). So now use the other two values to + look up your texel. So we look up texel (0.8, -0.4). The scale & offset move + the -1->+1 range into the usual 0->1 UV range, so we actually look up texel + (0.9, 0.3). The filtering is extremely complex, especially where three maps + meet, but that's a hardware problem :-) + */ + + /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + /** + * Cubemap lookup function. + * + * To transform returned uvs into mapping coordinates : + * u += 1.0f; u *= 0.5f; + * v += 1.0f; v *= 0.5f; + * + * \fn CubemapLookup(const PxVec3& direction, float& u, float& v) + * \param direction [in] a direction vector + * \param u [out] impact coordinate on the unit cube, in [-1,1] + * \param v [out] impact coordinate on the unit cube, in [-1,1] + * \return cubemap texture index + */ + /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + PX_INLINE CubeIndex CubemapLookup(const PxVec3& direction, float& u, float& v); + + PX_INLINE PxU32 ComputeCubemapOffset(const PxVec3& dir, PxU32 subdiv) + { + float u,v; + const CubeIndex CI = CubemapLookup(dir, u, v); + + // Remap to [0, subdiv[ + const float Coeff = 0.5f * float(subdiv-1); + u += 1.0f; u *= Coeff; + v += 1.0f; v *= Coeff; + + // Compute offset + return PxU32(CI)*(subdiv*subdiv) + PxU32(u)*subdiv + PxU32(v); + } + + + PX_INLINE PxU32 ComputeCubemapNearestOffset(const PxVec3& dir, PxU32 subdiv) + { + float u,v; + const CubeIndex CI = CubemapLookup(dir, u, v); + + // Remap to [0, subdiv] + const float Coeff = 0.5f * float(subdiv-1); + u += 1.0f; u *= Coeff; + v += 1.0f; v *= Coeff; + + // Compute offset + return PxU32(CI)*(subdiv*subdiv) + PxU32(u + 0.5f)*subdiv + PxU32(v + 0.5f); + } + + + PX_INLINE CubeIndex CubemapLookup(const PxVec3& direction, float& u, float& v) + { + const PxU32* binary = reinterpret_cast<const PxU32*>(&direction.x); + + const PxU32 absPx = binary[0] & ~PX_SIGN_BITMASK; + const PxU32 absNy = binary[1] & ~PX_SIGN_BITMASK; + const PxU32 absNz = binary[2] & ~PX_SIGN_BITMASK; + + PxU32 Index1 = 0; //x biggest axis + PxU32 Index2 = 1; + PxU32 Index3 = 2; + if( (absNy > absPx) & (absNy > absNz)) + { + //y biggest + Index2 = 2; + Index3 = 0; + Index1 = 1; + } + else if(absNz > absPx) + { + //z biggest + Index2 = 0; + Index3 = 1; + Index1 = 2; + } + + const PxF32* data = &direction.x; + const float Coeff = 1.0f / fabsf(data[Index1]); + u = data[Index2] * Coeff; + v = data[Index3] * Coeff; + + const PxU32 Sign = binary[Index1]>>31; + return CubeIndex(Sign|(Index1+Index1)); + } + +} + +#endif |