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..7863ce6c666
--- /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/foreach.h"
+#include "util/map.h"
+#include "util/progress.h"
+#include "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