Files
Webcam/include/engine/core/geometry_tangent.cpp

111 lines
3.1 KiB
C++

/* -----------------------------------------------------------------------------
GSFramework
Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
----------------------------------------------------------------------------- */
#include "core/geometry.h"
#include "log/log.h"
using namespace GS::Core;
//------------------------------------------------------------------------------
bool Geometry::ComputePolygonTangent(uint uv_index, bool force)
{
if (!pol.GetCount() || !vtx.GetCount())
return false;
if (!force && (pol_tangent.GetCount() == pol.GetCount()))
return true;
if (!ComputePolygonNormal())
return false;
if ((uv_index >= __UV_PER_GEOMETRY__) || !uv[uv_index])
return false;
// Allocate polygon tangents.
if (!pol_tangent.Allocate(pol.GetCount()))
__ERR__(__LOG_W__ << "Geometry::ComputePolygonTangent() failed to allocate buffer!\n", false)
Array <uint> pol_index;
ComputePolygonIndex(pol_index);
for (uint c = 0; c < pol.GetCount(); c++)
if (pol[c].vtx_count > 2)
{
// Compute tangent frame for this polygon.
Vector4 side_0 = vtx[pol[c].binding[0]] - vtx[pol[c].binding[1]],
side_1 = vtx[pol[c].binding[2]] - vtx[pol[c].binding[1]];
float delta_U_0 = uv[uv_index][pol_index[c] + 0].x - uv[uv_index][pol_index[c] + 1].x,
delta_U_1 = uv[uv_index][pol_index[c] + 2].x - uv[uv_index][pol_index[c] + 1].x,
delta_V_0 = uv[uv_index][pol_index[c] + 0].y - uv[uv_index][pol_index[c] + 1].y,
delta_V_1 = uv[uv_index][pol_index[c] + 2].y - uv[uv_index][pol_index[c] + 1].y;
Vector4 T = (side_0 * delta_V_1 - side_1 * delta_V_0).Normalized().Reversed(),
B = (side_0 * delta_U_1 - side_1 * delta_U_0).Normalized();
if (T.Cross(B).Dot(pol_normal[c]) < 0)
{
T.Reverse();
B.Reverse();
}
pol_tangent[c].B = B;
pol_tangent[c].T = T;
}
return true;
}
bool Geometry::ComputeVertexTangent(bool rev_t, bool rev_b, bool force)
{
if (!pol.GetCount() || !vtx.GetCount())
return false;
if (!force && (vtx_tangent.GetCount() == binding.GetCount()))
return true;
if (!ComputeVertexNormal() || !ComputePolygonTangent())
return false;
Array <VertexToPolygon> vtx_to_pol;
ComputeVertexToPolygon(vtx_to_pol);
// Allocate full blown edge normal array.
if (vtx_tangent.Allocate(binding.GetCount()))
for (uint cp = 0, ttp = 0; cp < pol.GetCount(); ++cp)
for (uint cv = 0; cv < pol[cp].vtx_count; ++cv)
{
uint gv = pol[cp].binding[cv];
Vector4 T(0, 0, 0), B(0, 0, 0);
for (uint cg = 0; cg < vtx_to_pol[gv].pol_count; cg++)
{
Vector4 _T = pol_tangent[vtx_to_pol[gv].pol_index[cg]].T,
_B = pol_tangent[vtx_to_pol[gv].pol_index[cg]].B;
if (pol_tangent[cp].T.Dot(_T) < 0.f)
_T = _T.Reversed();
if (pol_tangent[cp].B.Dot(_B) < 0.f)
_B = _B.Reversed();
T += _T;
B += _B;
}
T -= vtx_normal[ttp] * vtx_normal[ttp].Dot(T);
T = T.Normalized();
B = vtx_normal[ttp].Cross(T);
vtx_tangent[ttp].T = rev_t ? T.Reversed() : T;
vtx_tangent[ttp].B = rev_b ? B.Reversed() : B;
++ttp;
}
return true;
}
//------------------------------------------------------------------------------