Replaced a lot of trig calls with lookup tables for common prim types in an attempt to improve meshing speed.

Added a new between points interpolation method to improve accuracy of profile cuts in triangle and square profile prims.

1 files changed, 202 insertions, 43 deletions

diff --git a/OpenSim/Region/Physics/Meshing/PrimMesher.cs b/OpenSim/Region/Physics/Meshing/PrimMesher.cs
index e15804e..86bdabc 100644
--- a/OpenSim/Region/Physics/Meshing/PrimMesher.cs
+++ b/OpenSim/Region/Physics/Meshing/PrimMesher.cs
@@ -79,10 +79,137 @@ namespace OpenSim.Region.Physics.Meshing
         }
     }
 
+    //internal float angles3[][] = [
+    //[0.0f, 1.0f, 0.0f],
+    //[0.33333333333333331f, -0.49999999999999978f, 0.86602540378443871f],
+    //[0.66666666666666663f, -0.50000000000000044f, -0.86602540378443837f],
+    //[1.0f, 1.0f, -2.4492127076447545e-016f]];
+    /*
+angles3 = [
+        [0.0, 1.0, 0.0],
+        [0.33333333333333331, -0.49999999999999978, 0.86602540378443871],
+        [0.66666666666666663, -0.50000000000000044, -0.86602540378443837],
+        [1.0, 1.0, -2.4492127076447545e-016]]
+        
+angles4 = [
+        [0.0, 1.0, 0.0],
+        [0.25, 0.0, 1.0],
+        [0.5, -1.0, 0.0],
+        [0.75, 0.0, -1.0],
+        [1.0, 1.0, 0.0]]
+
+angles24 = [
+        [0.0, 0.5, 0.0],
+        [0.041666666666666664, 0.48296291314453416, 0.12940952255126037],
+        [0.083333333333333329, 0.43301270189221935, 0.25],
+        [0.125, 0.35355339059327379, 0.35355339059327373],
+        [0.16666666666666666, 0.25, 0.4330127018922193],
+        [0.20833333333333331, 0.12940952255126048, 0.4829629131445341],
+        [0.25, 0.0, 0.5],
+        [0.29166666666666663, -0.12940952255126031, 0.48296291314453416],
+        [0.33333333333333331, -0.25, 0.43301270189221935],
+        [0.375, -0.35355339059327373, 0.35355339059327379],
+        [0.41666666666666663, -0.43301270189221924, 0.25],
+        [0.45833333333333331, -0.4829629131445341, 0.12940952255126051],
+        [0.5, -0.5, 0.0],
+        [0.54166666666666663, -0.48296291314453421, -0.12940952255126018],
+        [0.58333333333333326, -0.43301270189221941, -0.25],
+        [0.62499999999999989, -0.35355339059327395, -0.35355339059327356],
+        [0.66666666666666663, -0.25, -0.43301270189221919],
+        [0.70833333333333326, -0.12940952255126076, -0.48296291314453405],
+        [0.75, 0.0, -0.5],
+        [0.79166666666666663, 0.12940952255126015, -0.48296291314453421],
+        [0.83333333333333326, 0.25, -0.43301270189221952],
+        [0.875, 0.35355339059327368, -0.35355339059327384],
+        [0.91666666666666663, 0.43301270189221919, -0.25],
+        [0.95833333333333326, 0.48296291314453405, -0.12940952255126079],
+        [1.0, 0.5, 0.0]]
+        
+angles24 = [
+        [0.0, 1.0, 0.0],
+        [0.041666666666666664, 0.96592582628906831, 0.25881904510252074],
+        [0.083333333333333329, 0.86602540378443871, 0.5],
+        [0.125, 0.70710678118654757, 0.70710678118654746],
+        [0.16666666666666667, 0.5, 0.8660254037844386],
+        [0.20833333333333331, 0.25881904510252096, 0.9659258262890682],
+        [0.25, 6.1230317691118863e-017, 1.0],
+        [0.29166666666666663, -0.25881904510252063, 0.96592582628906831],
+        [0.33333333333333333, -0.5, 0.86602540378443871],
+        [0.375, -0.70710678118654746, 0.70710678118654757],
+        [0.41666666666666663, -0.86602540378443849, 0.5],
+        [0.45833333333333331, -0.9659258262890682, 0.25881904510252102],
+        [0.5, -1.0, 1.2246063538223773e-016],
+        [0.54166666666666663, -0.96592582628906842, -0.25881904510252035],
+        [0.58333333333333326, -0.86602540378443882, -0.5],
+        [0.62499999999999989, -0.70710678118654791, -0.70710678118654713],
+        [0.66666666666666667, -0.5, -0.86602540378443837],
+        [0.70833333333333326, -0.25881904510252152, -0.96592582628906809],
+        [0.75, -1.8369095307335659e-016, -1.0],
+        [0.79166666666666663, 0.2588190451025203, -0.96592582628906842],
+        [0.83333333333333326, 0.5, -0.86602540378443904],
+        [0.875, 0.70710678118654735, -0.70710678118654768],
+        [0.91666666666666663, 0.86602540378443837, -0.5],
+        [0.95833333333333326, 0.96592582628906809, -0.25881904510252157],
+        [1.0, 1.0, -2.4492127076447545e-016]]
+
+     */
+
     internal class AngleList
     {
         private float iX, iY; // intersection point
 
+        private Angle[] angles3 = 
+        {
+                new Angle(0.0f, 1.0f, 0.0f),
+                new Angle(0.33333333333333333f, -0.5f, 0.86602540378443871f),
+                new Angle(0.66666666666666667f, -0.5f, -0.86602540378443837f),
+                new Angle(1.0f, 1.0f, 0.0f)
+        };
+
+        private Angle[] angles4 = 
+        {
+            new Angle(0.0f, 1.0f, 0.0f),
+            new Angle(0.25f, 0.0f, 1.0f),
+            new Angle(0.5f, -1.0f, 0.0f),
+            new Angle(0.75f, 0.0f, -1.0f),
+            new Angle(1.0f, 1.0f, 0.0f)
+        };
+
+        private Angle[] angles24 =
+        {
+            new Angle(0.0f, 1.0f, 0.0f),
+                new Angle(0.041666666666666664f, 0.96592582628906831f, 0.25881904510252074f),
+                new Angle(0.083333333333333329f, 0.86602540378443871f, 0.5f),
+                new Angle(0.125f, 0.70710678118654757f, 0.70710678118654746f),
+                new Angle(0.16666666666666667f, 0.5f, 0.8660254037844386f),
+                new Angle(0.20833333333333331f, 0.25881904510252096f, 0.9659258262890682f),
+                new Angle(0.25f, 0.0f, 1.0f),
+                new Angle(0.29166666666666663f, -0.25881904510252063f, 0.96592582628906831f),
+                new Angle(0.33333333333333333f, -0.5f, 0.86602540378443871f),
+                new Angle(0.375f, -0.70710678118654746f, 0.70710678118654757f),
+                new Angle(0.41666666666666663f, -0.86602540378443849f, 0.5f),
+                new Angle(0.45833333333333331f, -0.9659258262890682f, 0.25881904510252102f),
+                new Angle(0.5f, -1.0f, 0.0f),
+                new Angle(0.54166666666666663f, -0.96592582628906842f, -0.25881904510252035f),
+                new Angle(0.58333333333333326f, -0.86602540378443882f, -0.5f),
+                new Angle(0.62499999999999989f, -0.70710678118654791f, -0.70710678118654713f),
+                new Angle(0.66666666666666667f, -0.5f, -0.86602540378443837f),
+                new Angle(0.70833333333333326f, -0.25881904510252152f, -0.96592582628906809f),
+                new Angle(0.75f, 0.0f, -1.0f),
+                new Angle(0.79166666666666663f, 0.2588190451025203f, -0.96592582628906842f),
+                new Angle(0.83333333333333326f, 0.5f, -0.86602540378443904f),
+                new Angle(0.875f, 0.70710678118654735f, -0.70710678118654768f),
+                new Angle(0.91666666666666663f, 0.86602540378443837f, -0.5f),
+                new Angle(0.95833333333333326f, 0.96592582628906809f, -0.25881904510252157f),
+                new Angle(1.0f, 1.0f, 0.0f)
+        };
+
+        private Angle interpolatePoints(float newPoint, Angle p1, Angle p2)
+        {
+            float m = (newPoint - p1.angle) / (p2.angle - p1.angle);
+            return new Angle(newPoint, p1.X + m * (p2.X - p1.X), p1.Y + m * (p2.Y - p1.Y));
+        }
+
         private void intersection(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
         { // ref: http://local.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/
             double denom = (y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1);
@@ -98,64 +225,96 @@ namespace OpenSim.Region.Physics.Meshing
 
         internal List<Angle> angles;
 
-        // this class should have a table of most commonly computed values
-        // instead of all the trig function calls
-        // most common would be for sides = 3, 4, or 24
         internal void makeAngles( int sides, float startAngle, float stopAngle )
         {
             angles = new List<Angle>();
             double twoPi = System.Math.PI * 2.0;
+            float twoPiInv = 1.0f / (float)twoPi;
 
             if (sides < 1)
                 throw new Exception("number of sides not greater than zero");
             if (stopAngle <= startAngle)
                 throw new Exception("stopAngle not greater than startAngle");
 
-            double stepSize = twoPi / sides;
-
-            int startStep = (int) (startAngle / stepSize);
-            double angle = stepSize * startStep;
-            int step = startStep;
-            double stopAngleTest = stopAngle;
-            if (stopAngle < twoPi)
+            if ((sides == 3 || sides == 4 || sides == 24))
             {
-                stopAngleTest = stepSize * ((int)(stopAngle / stepSize) + 1);
-                if (stopAngleTest < stopAngle)
-                    stopAngleTest += stepSize;
-                if (stopAngleTest > twoPi)
-                    stopAngleTest = twoPi;
+                startAngle *= twoPiInv;
+                stopAngle *= twoPiInv;
+
+                Angle[] sourceAngles;
+                if (sides == 3)
+                    sourceAngles = angles3;
+                else if (sides == 4)
+                    sourceAngles = angles4;
+                else sourceAngles = angles24;
+
+                int startAngleIndex = (int)(startAngle * sides);
+                int endAngleIndex = sourceAngles.Length - 1;
+                if (stopAngle < 1.0f)
+                    endAngleIndex = (int)(stopAngle * sides) + 1;
+                if (endAngleIndex == startAngleIndex)
+                    endAngleIndex++;
+
+                for (int angleIndex = startAngleIndex; angleIndex < endAngleIndex + 1; angleIndex++)
+                    angles.Add(sourceAngles[angleIndex]);
+
+                if (startAngle > 0.0f)
+                    angles[0] = interpolatePoints(startAngle, angles[0], angles[1]);
+
+                if (stopAngle < 1.0f)
+                {
+                    int lastAngleIndex = angles.Count - 1;
+                    angles[lastAngleIndex] = interpolatePoints(stopAngle, angles[lastAngleIndex - 1], angles[lastAngleIndex]);
+                }
             }
-
-            while (angle <= stopAngleTest)
+            else
             {
-                Angle newAngle;
-                newAngle.angle = (float) angle;
-                newAngle.X = (float) System.Math.Cos(angle);
-                newAngle.Y = (float) System.Math.Sin(angle);
-                angles.Add(newAngle);
-                step += 1;
-                angle = stepSize * step;
-            }
+                double stepSize = twoPi / sides;
 
-            if (startAngle > angles[0].angle)
-            {
-                Angle newAngle;
-                intersection(angles[0].X, angles[0].Y, angles[1].X, angles[1].Y, 0.0f, 0.0f, (float)Math.Cos(startAngle), (float)Math.Sin(startAngle));
-                newAngle.angle = startAngle;
-                newAngle.X = iX;
-                newAngle.Y = iY;
-                angles[0] = newAngle;
-            }
+                int startStep = (int)(startAngle / stepSize);
+                double angle = stepSize * startStep;
+                int step = startStep;
+                double stopAngleTest = stopAngle;
+                if (stopAngle < twoPi)
+                {
+                    stopAngleTest = stepSize * ((int)(stopAngle / stepSize) + 1);
+                    if (stopAngleTest < stopAngle)
+                        stopAngleTest += stepSize;
+                    if (stopAngleTest > twoPi)
+                        stopAngleTest = twoPi;
+                }
 
-            int index = angles.Count - 1;
-            if (stopAngle < angles[index].angle)
-            {
-                Angle newAngle;
-                intersection(angles[index - 1].X, angles[index - 1].Y, angles[index].X, angles[index].Y, 0.0f, 0.0f, (float)Math.Cos(stopAngle), (float)Math.Sin(stopAngle));
-                newAngle.angle = stopAngle;
-                newAngle.X = iX;
-                newAngle.Y = iY;
-                angles[index] = newAngle;
+                while (angle <= stopAngleTest)
+                {
+                    Angle newAngle;
+                    newAngle.angle = (float)angle;
+                    newAngle.X = (float)System.Math.Cos(angle);
+                    newAngle.Y = (float)System.Math.Sin(angle);
+                    angles.Add(newAngle);
+                    step += 1;
+                    angle = stepSize * step;
+                }
+
+                if (startAngle > angles[0].angle)
+                {
+                    Angle newAngle;
+                    intersection(angles[0].X, angles[0].Y, angles[1].X, angles[1].Y, 0.0f, 0.0f, (float)Math.Cos(startAngle), (float)Math.Sin(startAngle));
+                    newAngle.angle = startAngle;
+                    newAngle.X = iX;
+                    newAngle.Y = iY;
+                    angles[0] = newAngle;
+                }
+
+                int index = angles.Count - 1;
+                if (stopAngle < angles[index].angle)
+                {
+                    Angle newAngle;
+                    intersection(angles[index - 1].X, angles[index - 1].Y, angles[index].X, angles[index].Y, 0.0f, 0.0f, (float)Math.Cos(stopAngle), (float)Math.Sin(stopAngle));
+                    newAngle.angle = stopAngle;
+                    newAngle.X = iX;
+                    newAngle.Y = iY;
+                    angles[index] = newAngle;
+                }
             }
         }
     }