blender/intern/cycles/subd/subd_patch.cpp
Brecht Van Lommel 731ffd3cd4 Cycles: remove approximate subdivision surface with gregory patches code.
It was never fully implemented and will be replaced by OpenSubdiv. Only linear
subdivision remains now. Also includes some refactoring in the split/dice code,
adding a SubdParams struct to pass around parameters more easily.
2013-11-28 02:11:42 +01:00

124 lines
2.7 KiB
C++

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
/* Parts adapted from code in the public domain in NVidia Mesh Tools. */
#include "mesh.h"
#include "subd_patch.h"
#include "util_math.h"
#include "util_types.h"
CCL_NAMESPACE_BEGIN
/* De Casteljau Evaluation */
static void decasteljau_cubic(float3 *P, float3 *dt, float t, const float3 cp[4])
{
float3 d0 = cp[0] + t*(cp[1] - cp[0]);
float3 d1 = cp[1] + t*(cp[2] - cp[1]);
float3 d2 = cp[2] + t*(cp[3] - cp[2]);
d0 += t*(d1 - d0);
d1 += t*(d2 - d1);
*P = d0 + t*(d1 - d0);
if(dt) *dt = d1 - d0;
}
static void decasteljau_bicubic(float3 *P, float3 *du, float3 *dv, const float3 cp[16], float u, float v)
{
float3 ucp[4], utn[4];
/* interpolate over u */
decasteljau_cubic(ucp+0, utn+0, u, cp);
decasteljau_cubic(ucp+1, utn+1, u, cp+4);
decasteljau_cubic(ucp+2, utn+2, u, cp+8);
decasteljau_cubic(ucp+3, utn+3, u, cp+12);
/* interpolate over v */
decasteljau_cubic(P, dv, v, ucp);
if(du) decasteljau_cubic(du, NULL, v, utn);
}
/* Linear Quad Patch */
void LinearQuadPatch::eval(float3 *P, float3 *dPdu, float3 *dPdv, float u, float v)
{
float3 d0 = interp(hull[0], hull[1], u);
float3 d1 = interp(hull[2], hull[3], u);
*P = interp(d0, d1, v);
if(dPdu && dPdv) {
*dPdu = interp(hull[1] - hull[0], hull[3] - hull[2], v);
*dPdv = interp(hull[2] - hull[0], hull[3] - hull[1], u);
}
}
BoundBox LinearQuadPatch::bound()
{
BoundBox bbox = BoundBox::empty;
for(int i = 0; i < 4; i++)
bbox.grow(hull[i]);
return bbox;
}
/* Linear Triangle Patch */
void LinearTrianglePatch::eval(float3 *P, float3 *dPdu, float3 *dPdv, float u, float v)
{
*P = u*hull[0] + v*hull[1] + (1.0f - u - v)*hull[2];
if(dPdu && dPdv) {
*dPdu = hull[0] - hull[2];
*dPdv = hull[1] - hull[2];
}
}
BoundBox LinearTrianglePatch::bound()
{
BoundBox bbox = BoundBox::empty;
for(int i = 0; i < 3; i++)
bbox.grow(hull[i]);
return bbox;
}
/* Bicubic Patch */
void BicubicPatch::eval(float3 *P, float3 *dPdu, float3 *dPdv, float u, float v)
{
decasteljau_bicubic(P, dPdu, dPdv, hull, u, v);
}
BoundBox BicubicPatch::bound()
{
BoundBox bbox = BoundBox::empty;
for(int i = 0; i < 16; i++)
bbox.grow(hull[i]);
return bbox;
}
CCL_NAMESPACE_END