diff options
Diffstat (limited to 'intern/cycles/scene/curves.cpp')
-rw-r--r-- | intern/cycles/scene/curves.cpp | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/intern/cycles/scene/curves.cpp b/intern/cycles/scene/curves.cpp new file mode 100644 index 00000000000..6e45905d367 --- /dev/null +++ b/intern/cycles/scene/curves.cpp @@ -0,0 +1,79 @@ +/* + * 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. + */ + +#include "scene/curves.h" +#include "device/device.h" +#include "scene/mesh.h" +#include "scene/object.h" +#include "scene/scene.h" + +#include "util/util_foreach.h" +#include "util/util_map.h" +#include "util/util_progress.h" +#include "util/util_vector.h" + +CCL_NAMESPACE_BEGIN + +/* Curve functions */ + +void curvebounds(float *lower, float *upper, float3 *p, int dim) +{ + float *p0 = &p[0].x; + float *p1 = &p[1].x; + float *p2 = &p[2].x; + float *p3 = &p[3].x; + + /* Catmull-Rom weights. */ + float curve_coef[4]; + curve_coef[0] = p1[dim]; + curve_coef[1] = 0.5f * (-p0[dim] + p2[dim]); + curve_coef[2] = 0.5f * (2 * p0[dim] - 5 * p1[dim] + 4 * p2[dim] - p3[dim]); + curve_coef[3] = 0.5f * (-p0[dim] + 3 * p1[dim] - 3 * p2[dim] + p3[dim]); + + float discroot = curve_coef[2] * curve_coef[2] - 3 * curve_coef[3] * curve_coef[1]; + float ta = -1.0f; + float tb = -1.0f; + + if (discroot >= 0) { + discroot = sqrtf(discroot); + ta = (-curve_coef[2] - discroot) / (3 * curve_coef[3]); + tb = (-curve_coef[2] + discroot) / (3 * curve_coef[3]); + ta = (ta > 1.0f || ta < 0.0f) ? -1.0f : ta; + tb = (tb > 1.0f || tb < 0.0f) ? -1.0f : tb; + } + + *upper = max(p1[dim], p2[dim]); + *lower = min(p1[dim], p2[dim]); + + float exa = p1[dim]; + float exb = p2[dim]; + + if (ta >= 0.0f) { + float t2 = ta * ta; + float t3 = t2 * ta; + exa = curve_coef[3] * t3 + curve_coef[2] * t2 + curve_coef[1] * ta + curve_coef[0]; + } + if (tb >= 0.0f) { + float t2 = tb * tb; + float t3 = t2 * tb; + exb = curve_coef[3] * t3 + curve_coef[2] * t2 + curve_coef[1] * tb + curve_coef[0]; + } + + *upper = max(*upper, max(exa, exb)); + *lower = min(*lower, min(exa, exb)); +} + +CCL_NAMESPACE_END |