t_vb_texgen.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  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
 * BRIAN PAUL 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.
 *
 * Authors:
 *    Brian Paul
 *    Keith Whitwell <[e-mail]>
 */

/*
 * Regarding GL_NV_texgen_reflection:
 *
 * Portions of this software may use or implement intellectual
 * property owned and licensed by NVIDIA Corporation. NVIDIA disclaims
 * any and all warranties with respect to such intellectual property,
 * including any use thereof or modifications thereto.
 */

#include "glheader.h"
#include "colormac.h"
#include "context.h"
#include "macros.h"
#include "imports.h"
#include "mtypes.h"

#include "math/m_xform.h"

#include "t_context.h"
#include "t_pipeline.h"


/***********************************************************************
 * Automatic texture coordinate generation (texgen) code.
 */


struct texgen_stage_data;

typedef void (*texgen_func)( GLcontext *ctx,
			     struct texgen_stage_data *store,
			     GLuint unit);


struct texgen_stage_data {

   /* Per-texunit derived state.
    */
   GLuint TexgenSize[MAX_TEXTURE_COORD_UNITS];
   texgen_func TexgenFunc[MAX_TEXTURE_COORD_UNITS];

   /* Temporary values used in texgen.
    */
   GLfloat (*tmp_f)[3];
   GLfloat *tmp_m;

   /* Buffered outputs of the stage.
    */
   GLvector4f texcoord[MAX_TEXTURE_COORD_UNITS];
};


#define TEXGEN_STAGE_DATA(stage) ((struct texgen_stage_data *)stage->privatePtr)



static GLuint all_bits[5] = {
   0,
   VEC_SIZE_1,
   VEC_SIZE_2,
   VEC_SIZE_3,
   VEC_SIZE_4,
};

#define VEC_SIZE_FLAGS (VEC_SIZE_1|VEC_SIZE_2|VEC_SIZE_3|VEC_SIZE_4)

#define TEXGEN_NEED_M            (TEXGEN_SPHERE_MAP)
#define TEXGEN_NEED_F            (TEXGEN_SPHERE_MAP        | \
				  TEXGEN_REFLECTION_MAP_NV)



static void build_m3( GLfloat f[][3], GLfloat m[],
		      const GLvector4f *normal,
		      const GLvector4f *eye )
{
   GLuint stride = eye->stride;
   GLfloat *coord = (GLfloat *)eye->start;
   GLuint count = eye->count;
   const GLfloat *norm = normal->start;
   GLuint i;

   for (i=0;i<count;i++,STRIDE_F(coord,stride),STRIDE_F(norm,normal->stride)) {
      GLfloat u[3], two_nu, fx, fy, fz;
      COPY_3V( u, coord );
      NORMALIZE_3FV( u );
      two_nu = 2.0F * DOT3(norm,u);
      fx = f[i][0] = u[0] - norm[0] * two_nu;
      fy = f[i][1] = u[1] - norm[1] * two_nu;
      fz = f[i][2] = u[2] - norm[2] * two_nu;
      m[i] = fx * fx + fy * fy + (fz + 1.0F) * (fz + 1.0F);
      if (m[i] != 0.0F) {
	 m[i] = 0.5F * _mesa_inv_sqrtf(m[i]);
      }
   }
}



static void build_m2( GLfloat f[][3], GLfloat m[],
		      const GLvector4f *normal,
		      const GLvector4f *eye )
{
   GLuint stride = eye->stride;
   GLfloat *coord = eye->start;
   GLuint count = eye->count;

   GLfloat *norm = normal->start;
   GLuint i;

   for (i=0;i<count;i++,STRIDE_F(coord,stride),STRIDE_F(norm,normal->stride)) {
      GLfloat u[3], two_nu, fx, fy, fz;
      COPY_2V( u, coord );
      u[2] = 0;
      NORMALIZE_3FV( u );
      two_nu = 2.0F * DOT3(norm,u);
      fx = f[i][0] = u[0] - norm[0] * two_nu;
      fy = f[i][1] = u[1] - norm[1] * two_nu;
      fz = f[i][2] = u[2] - norm[2] * two_nu;
      m[i] = fx * fx + fy * fy + (fz + 1.0F) * (fz + 1.0F);
      if (m[i] != 0.0F) {
	 m[i] = 0.5F * _mesa_inv_sqrtf(m[i]);
      }
   }
}



typedef void (*build_m_func)( GLfloat f[][3],
			      GLfloat m[],
			      const GLvector4f *normal,
			      const GLvector4f *eye );


static build_m_func build_m_tab[5] = {
   NULL,
   NULL,
   build_m2,
   build_m3,
   build_m3
};


/* This is unusual in that we respect the stride of the output vector
 * (f).  This allows us to pass in either a texcoord vector4f, or a
 * temporary vector3f.
 */
static void build_f3( GLfloat *f,
		      GLuint fstride,
		      const GLvector4f *normal,
		      const GLvector4f *eye )
{
   GLuint stride = eye->stride;
   GLfloat *coord = eye->start;
   GLuint count = eye->count;

   GLfloat *norm = normal->start;
   GLuint i;

   for (i=0;i<count;i++) {
      GLfloat u[3], two_nu;
      COPY_3V( u, coord );
      NORMALIZE_3FV( u );
      two_nu = 2.0F * DOT3(norm,u);
      f[0] = u[0] - norm[0] * two_nu;
      f[1] = u[1] - norm[1] * two_nu;
      f[2] = u[2] - norm[2] * two_nu;
      STRIDE_F(coord,stride);
      STRIDE_F(f,fstride);
      STRIDE_F(norm, normal->stride);
   }
}


static void build_f2( GLfloat *f,
		      GLuint fstride,
		      const GLvector4f *normal,
		      const GLvector4f *eye )
{
   GLuint stride = eye->stride;
   GLfloat *coord = eye->start;
   GLuint count = eye->count;
   GLfloat *norm = normal->start;
   GLuint i;

   for (i=0;i<count;i++) {

      GLfloat u[3], two_nu;
      COPY_2V( u, coord );
      u[2] = 0;
      NORMALIZE_3FV( u );
      two_nu = 2.0F * DOT3(norm,u);
      f[0] = u[0] - norm[0] * two_nu;
      f[1] = u[1] - norm[1] * two_nu;
      f[2] = u[2] - norm[2] * two_nu;

      STRIDE_F(coord,stride);
      STRIDE_F(f,fstride);
      STRIDE_F(norm, normal->stride);
   }
}

typedef void (*build_f_func)( GLfloat *f,
			      GLuint fstride,
			      const GLvector4f *normal_vec,
			      const GLvector4f *eye );



/* Just treat 4-vectors as 3-vectors.
 */
static build_f_func build_f_tab[5] = {
   NULL,
   NULL,
   build_f2,
   build_f3,
   build_f3
};



/* Special case texgen functions.
 */
static void texgen_reflection_map_nv( GLcontext *ctx,
				      struct texgen_stage_data *store,
				      GLuint unit )
{
   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
   GLvector4f *in = VB->AttribPtr[VERT_ATTRIB_TEX0 + unit];
   GLvector4f *out = &store->texcoord[unit];

   build_f_tab[VB->EyePtr->size]( out->start,
				  out->stride,
				  VB->AttribPtr[_TNL_ATTRIB_NORMAL],
				  VB->EyePtr );

   out->flags |= (in->flags & VEC_SIZE_FLAGS) | VEC_SIZE_3;
   out->count = VB->Count;
   out->size = MAX2(in->size, 3);
   if (in->size == 4) 
      _mesa_copy_tab[0x8]( out, in );
}



static void texgen_normal_map_nv( GLcontext *ctx,
				  struct texgen_stage_data *store,
				  GLuint unit )
{
   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
   GLvector4f *in = VB->AttribPtr[VERT_ATTRIB_TEX0 + unit];
   GLvector4f *out = &store->texcoord[unit];
   GLvector4f *normal = VB->AttribPtr[_TNL_ATTRIB_NORMAL];
   GLfloat (*texcoord)[4] = (GLfloat (*)[4])out->start;
   GLuint count = VB->Count;
   GLuint i;
   const GLfloat *norm = normal->start;

   for (i=0;i<count;i++, STRIDE_F(norm, normal->stride)) {
      texcoord[i][0] = norm[0];
      texcoord[i][1] = norm[1];
      texcoord[i][2] = norm[2];
   }


   out->flags |= (in->flags & VEC_SIZE_FLAGS) | VEC_SIZE_3;
   out->count = count;
   out->size = MAX2(in->size, 3);
   if (in->size == 4) 
      _mesa_copy_tab[0x8]( out, in );
}


static void texgen_sphere_map( GLcontext *ctx,
			       struct texgen_stage_data *store,
			       GLuint unit )
{
   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;