commit 4c568a672d21e5ec0c2417dc7b982c54285bc543
Author: Leszek Koltunski <leszek@koltunski.pl>
Date:   Thu Nov 11 16:22:32 2021 +0100

    Float vertices - scratchbook

diff --git a/src/main/java/org/distorted/library/main/QuatHelper.java b/src/main/java/org/distorted/library/main/QuatHelper.java
index 8a305ac..07b66af 100644
--- a/src/main/java/org/distorted/library/main/QuatHelper.java
+++ b/src/main/java/org/distorted/library/main/QuatHelper.java
@@ -48,6 +48,77 @@ public class QuatHelper
     return new Static4D(tx,ty,tz,tw);
     }
 
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// return quat1*(rx,ry,rz,rw)
+
+  public static Static4D quatMultiply( Static4D quat1, float rx, float ry, float rz, float rw )
+    {
+    float qx = quat1.get0();
+    float qy = quat1.get1();
+    float qz = quat1.get2();
+    float qw = quat1.get3();
+
+    float tx = rw*qx - rz*qy + ry*qz + rx*qw;
+    float ty = rw*qy + rz*qx + ry*qw - rx*qz;
+    float tz = rw*qz + rz*qw - ry*qx + rx*qy;
+    float tw = rw*qw - rz*qz - ry*qy - rx*qx;
+
+    return new Static4D(tx,ty,tz,tw);
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// return (qx,qy,qz,qw)*quat2
+
+  public static Static4D quatMultiply( float qx, float qy, float qz, float qw, Static4D quat2 )
+    {
+    float rx = quat2.get0();
+    float ry = quat2.get1();
+    float rz = quat2.get2();
+    float rw = quat2.get3();
+
+    float tx = rw*qx - rz*qy + ry*qz + rx*qw;
+    float ty = rw*qy + rz*qx + ry*qw - rx*qz;
+    float tz = rw*qz + rz*qw - ry*qx + rx*qy;
+    float tw = rw*qw - rz*qz - ry*qy - rx*qx;
+
+    return new Static4D(tx,ty,tz,tw);
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// return (qx,qy,qz,qw)*(rx,ry,rz,rw)
+
+  public static Static4D quatMultiply( float qx, float qy, float qz, float qw, float rx, float ry, float rz, float rw )
+    {
+    float tx = rw*qx - rz*qy + ry*qz + rx*qw;
+    float ty = rw*qy + rz*qx + ry*qw - rx*qz;
+    float tz = rw*qz + rz*qw - ry*qx + rx*qy;
+    float tw = rw*qw - rz*qz - ry*qy - rx*qx;
+
+    return new Static4D(tx,ty,tz,tw);
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// ret = (qx,qy,qz,qw)*(rx,ry,rz,rw)
+
+  public static void quatMultiply( float[] ret, float qx, float qy, float qz, float qw, float rx, float ry, float rz, float rw )
+    {
+    ret[0] = rw*qx - rz*qy + ry*qz + rx*qw;
+    ret[1] = rw*qy + rz*qx + ry*qw - rx*qz;
+    ret[2] = rw*qz + rz*qw - ry*qx + rx*qy;
+    ret[3] = rw*qw - rz*qz - ry*qy - rx*qx;
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// ret = (qx,qy,qz,qw)*(rx,ry,rz,rw)
+
+  public static void quatMultiply( float[] ret, float[] q, float[] r )
+    {
+    ret[0] = r[3]*q[0] - r[2]*q[1] + r[1]*q[2] + r[0]*q[3];
+    ret[1] = r[3]*q[1] + r[2]*q[0] + r[1]*q[3] - r[0]*q[2];
+    ret[2] = r[3]*q[2] + r[2]*q[3] - r[1]*q[0] + r[0]*q[1];
+    ret[3] = r[3]*q[3] - r[2]*q[2] - r[1]*q[1] - r[0]*q[0];
+    }
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // rotate 'vector' by quat  ( i.e. return quat*vector*(quat^-1) )
 
@@ -58,10 +129,44 @@ public class QuatHelper
     float qz = quat.get2();
     float qw = quat.get3();
 
-    Static4D quatInverted= new Static4D(-qx,-qy,-qz,qw);
-    Static4D tmp = quatMultiply(quat,vector);
+    Static4D tmp = quatMultiply(qx,qy,qz,qw,vector);
+
+    return quatMultiply(tmp,-qx,-qy,-qz,qw);
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// rotate (x1,x2,x3,x4) by quat  ( i.e. return quat*vector*(quat^-1) )
+
+  public static Static4D rotateVectorByQuat(float x, float y, float z, float w, Static4D quat)
+    {
+    float qx = quat.get0();
+    float qy = quat.get1();
+    float qz = quat.get2();
+    float qw = quat.get3();
+
+    Static4D tmp = quatMultiply(qx,qy,qz,qw,x,y,z,w);
+
+    return quatMultiply(tmp,-qx,-qy,-qz,qw);
+    }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// rotate vec by quat ( i.e. return quat*vector*(quat^-1) )
+
+  public static void rotateVectorByQuat(float[] output, float[] vec, float[] quat)
+    {
+    float[] tmp = new float[4];
+
+    quatMultiply(tmp,quat,vec);
+
+    quat[0] = -quat[0];
+    quat[1] = -quat[1];
+    quat[2] = -quat[2];
+
+    quatMultiply(output,tmp,quat);
 
-    return quatMultiply(tmp,quatInverted);
+    quat[0] = -quat[0];
+    quat[1] = -quat[1];
+    quat[2] = -quat[2];
     }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
@@ -74,8 +179,7 @@ public class QuatHelper
     float qz = quat.get2();
     float qw = quat.get3();
 
-    Static4D quatInverted= new Static4D(-qx,-qy,-qz,qw);
-    Static4D tmp = quatMultiply(quatInverted,vector);
+    Static4D tmp = quatMultiply(-qx,-qy,-qz,qw,vector);
 
     return quatMultiply(tmp,quat);
     }