
/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * New (3.1) transformation code written by Keith Whitwell.
 */

/* Functions to tranform a vector of normals.  This includes applying
 * the transformation matrix, rescaling and normalization.
 */

/*
 * mat - the 4x4 transformation matrix
 * scale - uniform scale factor of the transformation matrix (not always used)
 * in - the source vector of normals
 * lengths - length of each incoming normal (may be NULL) (a display list
 *           optimization)
 * dest - the destination vector of normals
 */
static void _XFORMAPI
TAG(transform_normalize_normals)( const GLmatrix *mat,
                                  GLfloat scale,
                                  const GLvector4f *in,
                                  const GLfloat *lengths,
                                  GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   const GLfloat *m = mat->inv;
   GLfloat m0 = m[0],  m4 = m[4],  m8 = m[8];
   GLfloat m1 = m[1],  m5 = m[5],  m9 = m[9];
   GLfloat m2 = m[2],  m6 = m[6],  m10 = m[10];
   GLuint i;

   if (!lengths) {
      STRIDE_LOOP {
	 GLfloat tx, ty, tz;
	 {
	    const GLfloat ux = from[0],  uy = from[1],  uz = from[2];
	    tx = ux * m0 + uy * m1 + uz * m2;
	    ty = ux * m4 + uy * m5 + uz * m6;
	    tz = ux * m8 + uy * m9 + uz * m10;
	 }
	 {
	    GLdouble len = tx*tx + ty*ty + tz*tz;
	    if (len > 1e-20) {
	       GLfloat scale = INV_SQRTF(len);
	       out[i][0] = tx * scale;
	       out[i][1] = ty * scale;
	       out[i][2] = tz * scale;
	    }
	    else {
	       out[i][0] = out[i][1] = out[i][2] = 0;
	    }
	 }
      }
   }
   else {
      if (scale != 1.0) {
	 m0 *= scale,  m4 *= scale,  m8 *= scale;
	 m1 *= scale,  m5 *= scale,  m9 *= scale;
	 m2 *= scale,  m6 *= scale,  m10 *= scale;
      }

      STRIDE_LOOP {
	 GLfloat tx, ty, tz;
	 {
	    const GLfloat ux = from[0],  uy = from[1],  uz = from[2];
	    tx = ux * m0 + uy * m1 + uz * m2;
	    ty = ux * m4 + uy * m5 + uz * m6;
	    tz = ux * m8 + uy * m9 + uz * m10;
	 }
	 {
	    GLfloat len = lengths[i];
	    out[i][0] = tx * len;
	    out[i][1] = ty * len;
	    out[i][2] = tz * len;
	 }
      }
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(transform_normalize_normals_no_rot)( const GLmatrix *mat,
                                         GLfloat scale,
                                         const GLvector4f *in,
                                         const GLfloat *lengths,
                                         GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   const GLfloat *m = mat->inv;
   GLfloat m0 = m[0];
   GLfloat m5 = m[5];
   GLfloat m10 = m[10];
   GLuint i;

   if (!lengths) {
      STRIDE_LOOP {
	 GLfloat tx, ty, tz;
	 {
	    const GLfloat ux = from[0],  uy = from[1],  uz = from[2];
	    tx = ux * m0                    ;
	    ty =           uy * m5          ;
	    tz =                     uz * m10;
	 }
	 {
	    GLdouble len = tx*tx + ty*ty + tz*tz;
	    if (len > 1e-20) {
	       GLfloat scale = INV_SQRTF(len);
	       out[i][0] = tx * scale;
	       out[i][1] = ty * scale;
	       out[i][2] = tz * scale;
	    }
	    else {
	       out[i][0] = out[i][1] = out[i][2] = 0;
	    }
	 }
      }
   }
   else {
      m0 *= scale;
      m5 *= scale;
      m10 *= scale;

      STRIDE_LOOP {
	 GLfloat tx, ty, tz;
	 {
	    const GLfloat ux = from[0],  uy = from[1],  uz = from[2];
	    tx = ux * m0                    ;
	    ty =           uy * m5          ;
	    tz =                     uz * m10;
	 }
	 {
	    GLfloat len = lengths[i];
	    out[i][0] = tx * len;
	    out[i][1] = ty * len;
	    out[i][2] = tz * len;
	 }
      }
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(transform_rescale_normals_no_rot)( const GLmatrix *mat,
                                       GLfloat scale,
                                       const GLvector4f *in,
                                       const GLfloat *lengths,
                                       GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   const GLfloat *m = mat->inv;
   const GLfloat m0 = scale*m[0];
   const GLfloat m5 = scale*m[5];
   const GLfloat m10 = scale*m[10];
   GLuint i;

   (void) lengths;

   STRIDE_LOOP {
      GLfloat ux = from[0],  uy = from[1],  uz = from[2];
      out[i][0] = ux * m0;
      out[i][1] =           uy * m5;
      out[i][2] =                     uz * m10;
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(transform_rescale_normals)( const GLmatrix *mat,
                                GLfloat scale,
                                const GLvector4f *in,
                                const GLfloat *lengths,
                                GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   /* Since we are unlikely to have < 3 vertices in the buffer,
    * it makes sense to pre-multiply by scale.
    */
   const GLfloat *m = mat->inv;
   const GLfloat m0 = scale*m[0],  m4 = scale*m[4],  m8 = scale*m[8];
   const GLfloat m1 = scale*m[1],  m5 = scale*m[5],  m9 = scale*m[9];
   const GLfloat m2 = scale*m[2],  m6 = scale*m[6],  m10 = scale*m[10];
   GLuint i;

   (void) lengths;

   STRIDE_LOOP {
      GLfloat ux = from[0],  uy = from[1],  uz = from[2];
      out[i][0] = ux * m0 + uy * m1 + uz * m2;
      out[i][1] = ux * m4 + uy * m5 + uz * m6;
      out[i][2] = ux * m8 + uy * m9 + uz * m10;
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(transform_normals_no_rot)( const GLmatrix *mat,
			       GLfloat scale,
			       const GLvector4f *in,
			       const GLfloat *lengths,
			       GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   const GLfloat *m = mat->inv;
   const GLfloat m0 = m[0];
   const GLfloat m5 = m[5];
   const GLfloat m10 = m[10];
   GLuint i;

   (void) scale;
   (void) lengths;

   STRIDE_LOOP {
      GLfloat ux = from[0],  uy = from[1],  uz = from[2];
      out[i][0] = ux * m0;
      out[i][1] =           uy * m5;
      out[i][2] =                     uz * m10;
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(transform_normals)( const GLmatrix *mat,
                        GLfloat scale,
                        const GLvector4f *in,
                        const GLfloat *lengths,
                        GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   const GLfloat *m = mat->inv;
   const GLfloat m0 = m[0],  m4 = m[4],  m8 = m[8];
   const GLfloat m1 = m[1],  m5 = m[5],  m9 = m[9];
   const GLfloat m2 = m[2],  m6 = m[6],  m10 = m[10];
   GLuint i;

   (void) scale;
   (void) lengths;

   STRIDE_LOOP {
      GLfloat ux = from[0],  uy = from[1],  uz = from[2];
      out[i][0] = ux * m0 + uy * m1 + uz * m2;
      out[i][1] = ux * m4 + uy * m5 + uz * m6;
      out[i][2] = ux * m8 + uy * m9 + uz * m10;
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(normalize_normals)( const GLmatrix *mat,
                        GLfloat scale,
                        const GLvector4f *in,
                        const GLfloat *lengths,
                        GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   GLuint i;

   (void) mat;
   (void) scale;

   if (lengths) {
      STRIDE_LOOP {
	 const GLfloat x = from[0], y = from[1], z = from[2];
	 GLfloat invlen = lengths[i];
	 out[i][0] = x * invlen;
	 out[i][1] = y * invlen;
	 out[i][2] = z * invlen;
      }
   }
   else {
      STRIDE_LOOP {
	 const GLfloat x = from[0], y = from[1], z = from[2];
	 GLdouble len = x * x + y * y + z * z;
	 if (len > 1e-50) {
	    len = INV_SQRTF(len);
	    out[i][0] = (GLfloat)(x * len);
	    out[i][1] = (GLfloat)(y * len);
	    out[i][2] = (GLfloat)(z * len);
	 }
	 else {
	    out[i][0] = x;
	    out[i][1] = y;
	    out[i][2] = z;
	 }
      }
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(rescale_normals)( const GLmatrix *mat,
                      GLfloat scale,
                      const GLvector4f *in,
                      const GLfloat *lengths,
                      GLvector4f *dest )
{
   GLfloat (*out)[4] = (GLfloat (*)[4])dest->start;
   const GLfloat *from = in->start;
   const GLuint stride = in->stride;
   const GLuint count = in->count;
   GLuint i;

   (void) mat;
   (void) lengths;

   STRIDE_LOOP {
      SCALE_SCALAR_3V( out[i], scale, from );
   }
   dest->count = in->count;
}


static void _XFORMAPI
TAG(init_c_norm_transform)( void )
{
   _mesa_normal_tab[NORM_TRANSFORM_NO_ROT] =
      TAG(transform_normals_no_rot);

   _mesa_normal_tab[NORM_TRANSFORM_NO_ROT | NORM_RESCALE] =
      TAG(transform_rescale_normals_no_rot);

   _mesa_normal_tab[NORM_TRANSFORM_NO_ROT | NORM_NORMALIZE] =
      TAG(transform_normalize_normals_no_rot);

   _mesa_normal_tab[NORM_TRANSFORM] =
      TAG(transform_normals);

   _mesa_normal_tab[NORM_TRANSFORM | NORM_RESCALE] =
      TAG(transform_rescale_normals);

   _mesa_normal_tab[NORM_TRANSFORM | NORM_NORMALIZE] =
      TAG(transform_normalize_normals);

   _mesa_normal_tab[NORM_RESCALE] =
      TAG(rescale_normals);

   _mesa_normal_tab[NORM_NORMALIZE] =
      TAG(normalize_normals);
}
