/*
This file is part of Magnum .
Copyright © 2010 , 2011 , 2012 , 2013 , 2014 , 2015
Vladimír Vondruš < mosra @ centrum . cz >
Permission is hereby granted , free of charge , to any person obtaining a
copy of this software and associated documentation files ( the " Software " ) ,
to deal in the Software without restriction , including without limitation
the rights to use , copy , modify , merge , publish , distribute , sublicense ,
and / or sell copies of the Software , and to permit persons to whom the
Software is furnished to do so , subject to the following conditions :
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software .
THE SOFTWARE IS PROVIDED " AS IS " , WITHOUT WARRANTY OF ANY KIND , EXPRESS OR
IMPLIED , INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY ,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT . IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM , DAMAGES OR OTHER
LIABILITY , WHETHER IN AN ACTION OF CONTRACT , TORT OR OTHERWISE , ARISING
FROM , OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE .
*/
# include "GenerateFlatNormals.h"
# include "Magnum/Math/Vector3.h"
# include "Magnum/MeshTools/Duplicate.h"
# include "Magnum/MeshTools/RemoveDuplicates.h"
namespace Magnum { namespace MeshTools {
std : : tuple < std : : vector < UnsignedInt > , std : : vector < Vector3 > > generateFlatNormals ( const std : : vector < UnsignedInt > & indices , const std : : vector < Vector3 > & positions ) {
CORRADE_ASSERT ( ! ( indices . size ( ) % 3 ) , " MeshTools::generateFlatNormals(): index count is not divisible by 3! " , ( std : : tuple < std : : vector < UnsignedInt > , std : : vector < Vector3 > > ( ) ) ) ;
/* Create normal for every triangle (assuming counterclockwise winding) */
std : : vector < UnsignedInt > normalIndices ;
normalIndices . reserve ( indices . size ( ) ) ;
std : : vector < Vector3 > normals ;
normals . reserve ( indices . size ( ) / 3 ) ;
for ( std : : size_t i = 0 ; i ! = indices . size ( ) ; i + = 3 ) {
Math: made dot(), angle(), *lerp() and cross() free functions.
It is often annoying to write e.g. this, especially in generic code:
T dot = Math::Vector<size, T>::dot(a, b);
When this is more than enough and the compiler can infer the rest from
the context:
T dot = Math::dot(a, b);
There are more downsides and confusing cases (you can call
Math::Vector<3, T>::dot(), Math::Vector3<T>::dot() and Color3::dot() and
it is still the same function), so I made these as free functions in
Math namespace. You can now also abuse ADL for the calls, but I would
advise against that for better readability:
T d = dot(a, b); // dot?! what on earth is dot? and what is a?
The only downside found when porting is that you need to specify the
type somehow when having both parameters as initializer lists:
T d = dot({2.0f, -1.5f}, {1.0f, 2.5f}); // error
T d = dot(Complex{2.0f, -1.5f}, {1.0f, 2.5f}); // okay
But that's probably reasonable (and it's also highly corner case,
the functions were used this way only in tests).
The original static member functions are of course still present, but
marked as deprecated and will be removed at some point in future.
11 years ago
const Vector3 normal = Math : : cross ( positions [ indices [ i + 2 ] ] - positions [ indices [ i + 1 ] ] ,
positions [ indices [ i ] ] - positions [ indices [ i + 1 ] ] ) . normalized ( ) ;
/* Use the same normal for all three vertices of the face */
normalIndices . push_back ( normals . size ( ) ) ;
normalIndices . push_back ( normals . size ( ) ) ;
normalIndices . push_back ( normals . size ( ) ) ;
normals . push_back ( normal ) ;
}
/* Remove duplicate normals and return */
normalIndices = MeshTools : : duplicate ( normalIndices , MeshTools : : removeDuplicates ( normals ) ) ;
return std : : make_tuple ( std : : move ( normalIndices ) , std : : move ( normals ) ) ;
}
} }
