Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/scene/curves.cpp

@@ -0,0 +1,60 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#include "scene/curves.h"
+
+#include "util/math.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Curve functions */
+
+void curvebounds(float *lower, float *upper, float3 *p, const 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 && curve_coef[3] != 0.0f) {
+    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) {
+    const float t2 = ta * ta;
+    const float t3 = t2 * ta;
+    exa = curve_coef[3] * t3 + curve_coef[2] * t2 + curve_coef[1] * ta + curve_coef[0];
+  }
+  if (tb >= 0.0f) {
+    const float t2 = tb * tb;
+    const 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