Initial commit

Library/PackageCache/com.unity.2d.animation@3.2.6/Runtime/Triangle/Tools/Interpolation.cs

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+namespace UnityEngine.U2D.Animation.TriangleNet
+    .Tools
+{
+    using Animation.TriangleNet.Geometry;
+
+    internal static class Interpolation
+    {
+#if USE_ATTRIBS
+        /// <summary>
+        /// Linear interpolation of vertex attributes.
+        /// </summary>
+        /// <param name="vertex">The interpolation vertex.</param>
+        /// <param name="triangle">The triangle containing the vertex.</param>
+        /// <param name="n">The number of vertex attributes.</param>
+        /// <remarks>
+        /// The vertex is expected to lie inside the triangle.
+        /// </remarks>
+        internal static void InterpolateAttributes(Vertex vertex, ITriangle triangle, int n)
+        {
+            Vertex org = triangle.GetVertex(0);
+            Vertex dest = triangle.GetVertex(1);
+            Vertex apex = triangle.GetVertex(2);
+
+            double xdo, ydo, xao, yao;
+            double denominator;
+            double dx, dy;
+            double xi, eta;
+
+            // Compute the circumcenter of the triangle.
+            xdo = dest.x - org.x;
+            ydo = dest.y - org.y;
+            xao = apex.x - org.x;
+            yao = apex.y - org.y;
+
+            denominator = 0.5 / (xdo * yao - xao * ydo);
+
+            //dx = (yao * dodist - ydo * aodist) * denominator;
+            //dy = (xdo * aodist - xao * dodist) * denominator;
+
+            dx = vertex.x - org.x;
+            dy = vertex.y - org.y;
+
+            // To interpolate vertex attributes for the new vertex, define a
+            // coordinate system with a xi-axis directed from the triangle's
+            // origin to its destination, and an eta-axis, directed from its
+            // origin to its apex.
+            xi = (yao * dx - xao * dy) * (2.0 * denominator);
+            eta = (xdo * dy - ydo * dx) * (2.0 * denominator);
+
+            for (int i = 0; i < n; i++)
+            {
+                // Interpolate the vertex attributes.
+                vertex.attributes[i] = org.attributes[i]
+                    + xi * (dest.attributes[i] - org.attributes[i])
+                    + eta * (apex.attributes[i] - org.attributes[i]);
+            }
+        }
+
+#endif
+
+#if USE_Z
+        /// <summary>
+        /// Linear interpolation of a scalar value.
+        /// </summary>
+        /// <param name="p">The interpolation point.</param>
+        /// <param name="triangle">The triangle containing the point.</param>
+        /// <remarks>
+        /// The point is expected to lie inside the triangle.
+        /// </remarks>
+        internal static void InterpolateZ(Point p, ITriangle triangle)
+        {
+            Vertex org = triangle.GetVertex(0);
+            Vertex dest = triangle.GetVertex(1);
+            Vertex apex = triangle.GetVertex(2);
+
+            double xdo, ydo, xao, yao;
+            double denominator;
+            double dx, dy;
+            double xi, eta;
+
+            // Compute the circumcenter of the triangle.
+            xdo = dest.x - org.x;
+            ydo = dest.y - org.y;
+            xao = apex.x - org.x;
+            yao = apex.y - org.y;
+
+            denominator = 0.5 / (xdo * yao - xao * ydo);
+
+            //dx = (yao * dodist - ydo * aodist) * denominator;
+            //dy = (xdo * aodist - xao * dodist) * denominator;
+
+            dx = p.x - org.x;
+            dy = p.y - org.y;
+
+            // To interpolate z value for the given point inserted, define a
+            // coordinate system with a xi-axis, directed from the triangle's
+            // origin to its destination, and an eta-axis, directed from its
+            // origin to its apex.
+            xi = (yao * dx - xao * dy) * (2.0 * denominator);
+            eta = (xdo * dy - ydo * dx) * (2.0 * denominator);
+
+            p.z = org.z + xi * (dest.z - org.z) + eta * (apex.z - org.z);
+        }
+
+#endif
+    }
+}