/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "brush_primit.h"
#include "globaldefs.h"

#include "debugging/debugging.h"

#include "itexdef.h"
#include "itextures.h"

#include <algorithm>

#include "stringio.h"
#include "texturelib.h"
#include "math/matrix.h"
#include "math/plane.h"
#include "math/aabb.h"

#include "winding.h"
#include "preferences.h"


/*!
   \brief Construct a transform from XYZ space to ST space (3d to 2d).
   This will be one of three axis-aligned spaces, depending on the surface normal.
   NOTE: could also be done by swapping values.
 */
void Normal_GetTransform(const Vector3 &normal, Matrix4 &transform)
{
    switch (projectionaxis_for_normal(normal)) {
        case eProjectionAxisZ:
            transform[0] = 1;
            transform[1] = 0;
            transform[2] = 0;

            transform[4] = 0;
            transform[5] = 1;
            transform[6] = 0;

            transform[8] = 0;
            transform[9] = 0;
            transform[10] = 1;
            break;
        case eProjectionAxisY:
            transform[0] = 1;
            transform[1] = 0;
            transform[2] = 0;

            transform[4] = 0;
            transform[5] = 0;
            transform[6] = -1;

            transform[8] = 0;
            transform[9] = 1;
            transform[10] = 0;
            break;
        case eProjectionAxisX:
            transform[0] = 0;
            transform[1] = 0;
            transform[2] = 1;

            transform[4] = 1;
            transform[5] = 0;
            transform[6] = 0;

            transform[8] = 0;
            transform[9] = 1;
            transform[10] = 0;
            break;
    }
    transform[3] = transform[7] = transform[11] = transform[12] = transform[13] = transform[14] = 0;
    transform[15] = 1;
}

/*!
   \brief Construct a transform in ST space from the texdef.
   Transforms constructed from quake's texdef format are (-shift)*(1/scale)*(-rotate) with x translation sign flipped.
   This would really make more sense if it was inverseof(shift*rotate*scale).. oh well.
 */
inline void Texdef_toTransform(const texdef_t &texdef, float width, float height, Matrix4 &transform)
{
    double inverse_scale[2];

    // transform to texdef shift/scale/rotate
    inverse_scale[0] = 1 / (texdef.scale[0] * width);
    inverse_scale[1] = 1 / (texdef.scale[1] * -height);
    transform[12] = texdef.shift[0] / width;
    transform[13] = -texdef.shift[1] / -height;
    double c = cos(degrees_to_radians(-texdef.rotate));
    double s = sin(degrees_to_radians(-texdef.rotate));
    transform[0] = static_cast<float>( c * inverse_scale[0] );
    transform[1] = static_cast<float>( s * inverse_scale[1] );
    transform[4] = static_cast<float>( -s * inverse_scale[0] );
    transform[5] = static_cast<float>( c * inverse_scale[1] );
    transform[2] = transform[3] = transform[6] = transform[7] = transform[8] = transform[9] = transform[11] = transform[14] = 0;
    transform[10] = transform[15] = 1;
}

inline void BPTexdef_toTransform(const brushprimit_texdef_t &bp_texdef, Matrix4 &transform)
{
    transform = g_matrix4_identity;
    transform.xx() = bp_texdef.coords[0][0];
    transform.yx() = bp_texdef.coords[0][1];
    transform.tx() = bp_texdef.coords[0][2];
    transform.xy() = bp_texdef.coords[1][0];
    transform.yy() = bp_texdef.coords[1][1];
    transform.ty() = bp_texdef.coords[1][2];
}

inline void Texdef_toTransform(const TextureProjection &projection, float width, float height, Matrix4 &transform)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_toTransform(projection.m_brushprimit_texdef, transform);
    } else {
        Texdef_toTransform(projection.m_texdef, width, height, transform);
    }
}

// handles degenerate cases, just in case library atan2 doesn't
inline double arctangent_yx(double y, double x)
{
    if (fabs(x) > 1.0E-6) {
        return atan2(y, x);
    } else if (y > 0) {
        return c_half_pi;
    } else {
        return -c_half_pi;
    }
}

inline void Texdef_fromTransform(texdef_t &texdef, float width, float height, const Matrix4 &transform)
{
    texdef.scale[0] = static_cast<float>((1.0 / vector2_length(Vector2(transform[0], transform[4]))) / width );
    texdef.scale[1] = static_cast<float>((1.0 / vector2_length(Vector2(transform[1], transform[5]))) / height );

    texdef.rotate = static_cast<float>( -radians_to_degrees(arctangent_yx(-transform[4], transform[0])));

    if (texdef.rotate == -180.0f) {
        texdef.rotate = 180.0f;
    }

    texdef.shift[0] = transform[12] * width;
    texdef.shift[1] = transform[13] * height;

    // If the 2d cross-product of the x and y axes is positive, one of the axes has a negative scale.
    if (vector2_cross(Vector2(transform[0], transform[4]), Vector2(transform[1], transform[5])) > 0) {
        if (texdef.rotate >= 180.0f) {
            texdef.rotate -= 180.0f;
            texdef.scale[0] = -texdef.scale[0];
        } else {
            texdef.scale[1] = -texdef.scale[1];
        }
    }
    //globalOutputStream() << "fromTransform: " << texdef.shift[0] << " " << texdef.shift[1] << " " << texdef.scale[0] << " " << texdef.scale[1] << " " << texdef.rotate << "\n";
}

inline void BPTexdef_fromTransform(brushprimit_texdef_t &bp_texdef, const Matrix4 &transform)
{
    bp_texdef.coords[0][0] = transform.xx();
    bp_texdef.coords[0][1] = transform.yx();
    bp_texdef.coords[0][2] = transform.tx();
    bp_texdef.coords[1][0] = transform.xy();
    bp_texdef.coords[1][1] = transform.yy();
    bp_texdef.coords[1][2] = transform.ty();
}

inline void Texdef_fromTransform(TextureProjection &projection, float width, float height, const Matrix4 &transform)
{
    ASSERT_MESSAGE((transform[0] != 0 || transform[4] != 0)
                   && (transform[1] != 0 || transform[5] != 0), "invalid texture matrix");

    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_fromTransform(projection.m_brushprimit_texdef, transform);
    } else {
        Texdef_fromTransform(projection.m_texdef, width, height, transform);
    }
}

inline void Texdef_normalise(texdef_t &texdef, float width, float height)
{
    // it may be useful to also normalise the rotation here, if this function is used elsewhere.
    texdef.shift[0] = float_mod(texdef.shift[0], width);
    texdef.shift[1] = float_mod(texdef.shift[1], height);
    //globalOutputStream() << "normalise: " << texdef.shift[0] << " " << texdef.shift[1] << " " << texdef.scale[0] << " " << texdef.scale[1] << " " << texdef.rotate << "\n";
}

inline void BPTexdef_normalise(brushprimit_texdef_t &bp_texdef, float width, float height)
{
    bp_texdef.coords[0][2] = float_mod(bp_texdef.coords[0][2], width);
    bp_texdef.coords[1][2] = float_mod(bp_texdef.coords[1][2], height);
}

/// \brief Normalise \p projection for a given texture \p width and \p height.
///
/// All texture-projection translation (shift) values are congruent modulo the dimensions of the texture.
/// This function normalises shift values to the smallest positive congruent values.
void Texdef_normalise(TextureProjection &projection, float width, float height)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_normalise(projection.m_brushprimit_texdef, width, height);
    } else {
        Texdef_normalise(projection.m_texdef, width, height);
    }
}

void ComputeAxisBase(const Vector3 &normal, Vector3 &texS, Vector3 &texT);

inline void DebugAxisBase(const Vector3 &normal)
{
    Vector3 x, y;
    ComputeAxisBase(normal, x, y);
    globalOutputStream() << "BP debug: " << x << y << normal << "\n";
}

void Texdef_basisForNormal(const TextureProjection &projection, const Vector3 &normal, Matrix4 &basis)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        basis = g_matrix4_identity;
        ComputeAxisBase(normal, vector4_to_vector3(basis.x()), vector4_to_vector3(basis.y()));
        vector4_to_vector3(basis.z()) = normal;
        matrix4_transpose(basis);
        //DebugAxisBase(normal);
    } else if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_HALFLIFE) {
        basis = g_matrix4_identity;
        vector4_to_vector3(basis.x()) = projection.m_basis_s;
        vector4_to_vector3(basis.y()) = vector3_negated(projection.m_basis_t);
        vector4_to_vector3(basis.z()) = vector3_normalised(
                vector3_cross(vector4_to_vector3(basis.x()), vector4_to_vector3(basis.y())));
        matrix4_multiply_by_matrix4(basis, matrix4_rotation_for_z_degrees(-projection.m_texdef.rotate));
        //globalOutputStream() << "debug: " << projection.m_basis_s << projection.m_basis_t << normal << "\n";
        matrix4_transpose(basis);
    } else {
        Normal_GetTransform(normal, basis);
    }
}

void
Texdef_EmitTextureCoordinates(const TextureProjection &projection, std::size_t width, std::size_t height, Winding &w,
                              const Vector3 &normal, const Matrix4 &localToWorld)
{
    if (w.numpoints < 3) {
        return;
    }
    //globalOutputStream() << "normal: " << normal << "\n";

    Matrix4 local2tex;
    Texdef_toTransform(projection, (float) width, (float) height, local2tex);
    //globalOutputStream() << "texdef: " << static_cast<const Vector3&>(local2tex.x()) << static_cast<const Vector3&>(local2tex.y()) << "\n";

#if 0
    {
        TextureProjection tmp;
        Texdef_fromTransform( tmp, (float)width, (float)height, local2tex );
        Matrix4 tmpTransform;
        Texdef_toTransform( tmp, (float)width, (float)height, tmpTransform );
        ASSERT_MESSAGE( matrix4_equal_epsilon( local2tex, tmpTransform, 0.0001f ), "bleh" );
    }
#endif

    {
        Matrix4 xyz2st;
        // we don't care if it's not normalised...
        Texdef_basisForNormal(projection, matrix4_transformed_direction(localToWorld, normal), xyz2st);
        //globalOutputStream() << "basis: " << static_cast<const Vector3&>(xyz2st.x()) << static_cast<const Vector3&>(xyz2st.y()) << static_cast<const Vector3&>(xyz2st.z()) << "\n";
        matrix4_multiply_by_matrix4(local2tex, xyz2st);
    }

    Vector3 tangent(vector3_normalised(vector4_to_vector3(matrix4_transposed(local2tex).x())));
    Vector3 bitangent(vector3_normalised(vector4_to_vector3(matrix4_transposed(local2tex).y())));

    matrix4_multiply_by_matrix4(local2tex, localToWorld);

    for (Winding::iterator i = w.begin(); i != w.end(); ++i) {
        Vector3 texcoord = matrix4_transformed_point(local2tex, (*i).vertex);
        (*i).texcoord[0] = texcoord[0];
        (*i).texcoord[1] = texcoord[1];

        (*i).tangent = tangent;
        (*i).bitangent = bitangent;
    }
}

/*!
   \brief Provides the axis-base of the texture ST space for this normal,
   as they had been transformed to world XYZ space.
 */
void TextureAxisFromNormal(const Vector3 &normal, Vector3 &s, Vector3 &t)
{
    switch (projectionaxis_for_normal(normal)) {
        case eProjectionAxisZ:
            s[0] = 1;
            s[1] = 0;
            s[2] = 0;

            t[0] = 0;
            t[1] = -1;
            t[2] = 0;

            break;
        case eProjectionAxisY:
            s[0] = 1;
            s[1] = 0;
            s[2] = 0;

            t[0] = 0;
            t[1] = 0;
            t[2] = -1;

            break;
        case eProjectionAxisX:
            s[0] = 0;
            s[1] = 1;
            s[2] = 0;

            t[0] = 0;
            t[1] = 0;
            t[2] = -1;

            break;
    }
}

void Texdef_Assign(texdef_t &td, const texdef_t &other)
{
    td = other;
}

void Texdef_Shift(texdef_t &td, float s, float t)
{
    td.shift[0] += s;
    td.shift[1] += t;
}

void Texdef_Scale(texdef_t &td, float s, float t)
{
    td.scale[0] += s;
    td.scale[1] += t;
}

void Texdef_Rotate(texdef_t &td, float angle)
{
    td.rotate += angle;
    td.rotate = static_cast<float>( float_to_integer(td.rotate) % 360 );
}

// NOTE: added these from Ritual's Q3Radiant
void ClearBounds(Vector3 &mins, Vector3 &maxs)
{
    mins[0] = mins[1] = mins[2] = 99999;
    maxs[0] = maxs[1] = maxs[2] = -99999;
}

void AddPointToBounds(const Vector3 &v, Vector3 &mins, Vector3 &maxs)
{
    int i;
    float val;

    for (i = 0; i < 3; i++) {
        val = v[i];
        if (val < mins[i]) {
            mins[i] = val;
        }
        if (val > maxs[i]) {
            maxs[i] = val;
        }
    }
}

template<typename Element>
inline BasicVector3<Element> vector3_inverse(const BasicVector3<Element> &self)
{
    return BasicVector3<Element>(
            Element(1.0 / self.x()),
            Element(1.0 / self.y()),
            Element(1.0 / self.z())
    );
}

// low level functions .. put in mathlib?
#define BPMatCopy(a, b) {b[0][0] = a[0][0]; b[0][1] = a[0][1]; b[0][2] = a[0][2]; b[1][0] = a[1][0]; b[1][1] = a[1][1]; b[1][2] = a[1][2]; }
// apply a scale transformation to the BP matrix
#define BPMatScale(m, sS, sT) {m[0][0] *= sS; m[1][0] *= sS; m[0][1] *= sT; m[1][1] *= sT; }
// apply a translation transformation to a BP matrix
#define BPMatTranslate(m, s, t) {m[0][2] += m[0][0] * s + m[0][1] * t; m[1][2] += m[1][0] * s + m[1][1] * t; }

// 2D homogeneous matrix product C = A*B
void BPMatMul(float A[2][3], float B[2][3], float C[2][3]);

// apply a rotation (degrees)
void BPMatRotate(float A[2][3], float theta);

#if GDEF_DEBUG

void BPMatDump(float A[2][3]);

#endif

#if GDEF_DEBUG
//#define DBG_BP
#endif


bp_globals_t g_bp_globals;
float g_texdef_default_scale;

// compute a determinant using Sarrus rule
//++timo "inline" this with a macro
// NOTE : the three vectors are understood as columns of the matrix
inline float SarrusDet(const Vector3 &a, const Vector3 &b, const Vector3 &c)
{
    return a[0] * b[1] * c[2] + b[0] * c[1] * a[2] + c[0] * a[1] * b[2]
           - c[0] * b[1] * a[2] - a[1] * b[0] * c[2] - a[0] * b[2] * c[1];
}

// in many case we know three points A,B,C in two axis base B1 and B2
// and we want the matrix M so that A(B1) = T * A(B2)
// NOTE: 2D homogeneous space stuff
// NOTE: we don't do any check to see if there's a solution or we have a particular case .. need to make sure before calling
// NOTE: the third coord of the A,B,C point is ignored
// NOTE: see the commented out section to fill M and D
//++timo TODO: update the other members to use this when possible
void MatrixForPoints(Vector3 M[3], Vector3 D[2], brushprimit_texdef_t *T)
{
//	Vector3 M[3]; // columns of the matrix .. easier that way (the indexing is not standard! it's column-line .. later computations are easier that way)
    float det;
//	Vector3 D[2];
    M[2][0] = 1.0f;
    M[2][1] = 1.0f;
    M[2][2] = 1.0f;
#if 0
    // fill the data vectors
    M[0][0] = A2[0]; M[0][1] = B2[0]; M[0][2] = C2[0];
    M[1][0] = A2[1]; M[1][1] = B2[1]; M[1][2] = C2[1];
    M[2][0] = 1.0f; M[2][1] = 1.0f; M[2][2] = 1.0f;
    D[0][0] = A1[0];
    D[0][1] = B1[0];
    D[0][2] = C1[0];
    D[1][0] = A1[1];
    D[1][1] = B1[1];
    D[1][2] = C1[1];
#endif
    // solve
    det = SarrusDet(M[0], M[1], M[2]);
    T->coords[0][0] = SarrusDet(D[0], M[1], M[2]) / det;
    T->coords[0][1] = SarrusDet(M[0], D[0], M[2]) / det;
    T->coords[0][2] = SarrusDet(M[0], M[1], D[0]) / det;
    T->coords[1][0] = SarrusDet(D[1], M[1], M[2]) / det;
    T->coords[1][1] = SarrusDet(M[0], D[1], M[2]) / det;
    T->coords[1][2] = SarrusDet(M[0], M[1], D[1]) / det;
}

//++timo replace everywhere texX by texS etc. ( ----> and in q3map !)
// NOTE : ComputeAxisBase here and in q3map code must always BE THE SAME !
// WARNING : special case behaviour of atan2(y,x) <-> atan(y/x) might not be the same everywhere when x == 0
// rotation by (0,RotY,RotZ) assigns X to normal
void ComputeAxisBase(const Vector3 &normal, Vector3 &texS, Vector3 &texT)
{
#if 1
    const Vector3 up(0, 0, 1);
    const Vector3 down(0, 0, -1);

    if (vector3_equal_epsilon(normal, up, float(1e-6))) {
        texS = Vector3(0, 1, 0);
        texT = Vector3(1, 0, 0);
    } else if (vector3_equal_epsilon(normal, down, float(1e-6))) {
        texS = Vector3(0, 1, 0);
        texT = Vector3(-1, 0, 0);
    } else {
        texS = vector3_normalised(vector3_cross(normal, up));
        texT = vector3_normalised(vector3_cross(normal, texS));
        vector3_negate(texS);
    }

#else
    float RotY,RotZ;
    // do some cleaning
    /*
       if (fabs(normal[0])<1e-6)
          normal[0]=0.0f;
       if (fabs(normal[1])<1e-6)
          normal[1]=0.0f;
       if (fabs(normal[2])<1e-6)
          normal[2]=0.0f;
     */
    RotY = -atan2( normal[2],sqrt( normal[1] * normal[1] + normal[0] * normal[0] ) );
    RotZ = atan2( normal[1],normal[0] );
    // rotate (0,1,0) and (0,0,1) to compute texS and texT
    texS[0] = -sin( RotZ );
    texS[1] = cos( RotZ );
    texS[2] = 0;
    // the texT vector is along -Z ( T texture coorinates axis )
    texT[0] = -sin( RotY ) * cos( RotZ );
    texT[1] = -sin( RotY ) * sin( RotZ );
    texT[2] = -cos( RotY );
#endif
}

#if 0 // texdef conversion
void FaceToBrushPrimitFace( face_t *f ){
    Vector3 texX,texY;
    Vector3 proj;
    // ST of (0,0) (1,0) (0,1)
    float ST[3][5]; // [ point index ] [ xyz ST ]
    //++timo not used as long as brushprimit_texdef and texdef are static
/*	f->brushprimit_texdef.contents=f->texdef.contents;
    f->brushprimit_texdef.flags=f->texdef.flags;
    f->brushprimit_texdef.value=f->texdef.value;
    strcpy(f->brushprimit_texdef.name,f->texdef.name); */
#ifdef DBG_BP
    if ( f->plane.normal[0] == 0.0f && f->plane.normal[1] == 0.0f && f->plane.normal[2] == 0.0f ) {
        globalOutputStream() << "Warning : f->plane.normal is (0,0,0) in FaceToBrushPrimitFace\n";
    }
    // check d_texture
    if ( !f->d_texture ) {
        globalOutputStream() << "Warning : f.d_texture is 0 in FaceToBrushPrimitFace\n";
        return;
    }
#endif
    // compute axis base
    ComputeAxisBase( f->plane.normal,texX,texY );
    // compute projection vector
    VectorCopy( f->plane.normal,proj );
    VectorScale( proj,f->plane.dist,proj );
    // (0,0) in plane axis base is (0,0,0) in world coordinates + projection on the affine plane
    // (1,0) in plane axis base is texX in world coordinates + projection on the affine plane
    // (0,1) in plane axis base is texY in world coordinates + projection on the affine plane
    // use old texture code to compute the ST coords of these points
    VectorCopy( proj,ST[0] );
    EmitTextureCoordinates( ST[0], f->pShader->getTexture(), f );
    VectorCopy( texX,ST[1] );
    VectorAdd( ST[1],proj,ST[1] );
    EmitTextureCoordinates( ST[1], f->pShader->getTexture(), f );
    VectorCopy( texY,ST[2] );
    VectorAdd( ST[2],proj,ST[2] );
    EmitTextureCoordinates( ST[2], f->pShader->getTexture(), f );
    // compute texture matrix
    f->brushprimit_texdef.coords[0][2] = ST[0][3];
    f->brushprimit_texdef.coords[1][2] = ST[0][4];
    f->brushprimit_texdef.coords[0][0] = ST[1][3] - f->brushprimit_texdef.coords[0][2];
    f->brushprimit_texdef.coords[1][0] = ST[1][4] - f->brushprimit_texdef.coords[1][2];
    f->brushprimit_texdef.coords[0][1] = ST[2][3] - f->brushprimit_texdef.coords[0][2];
    f->brushprimit_texdef.coords[1][1] = ST[2][4] - f->brushprimit_texdef.coords[1][2];
}

// compute texture coordinates for the winding points
void EmitBrushPrimitTextureCoordinates( face_t * f, Winding * w ){
    Vector3 texX,texY;
    float x,y;
    // compute axis base
    ComputeAxisBase( f->plane.normal,texX,texY );
    // in case the texcoords matrix is empty, build a default one
    // same behaviour as if scale[0]==0 && scale[1]==0 in old code
    if ( f->brushprimit_texdef.coords[0][0] == 0 && f->brushprimit_texdef.coords[1][0] == 0 && f->brushprimit_texdef.coords[0][1] == 0 && f->brushprimit_texdef.coords[1][1] == 0 ) {
        f->brushprimit_texdef.coords[0][0] = 1.0f;
        f->brushprimit_texdef.coords[1][1] = 1.0f;
        ConvertTexMatWithQTexture( &f->brushprimit_texdef, 0, &f->brushprimit_texdef, f->pShader->getTexture() );
    }
    int i;
    for ( i = 0 ; i < w.numpoints ; i++ )
    {
        x = vector3_dot( w.point_at( i ),texX );
        y = vector3_dot( w.point_at( i ),texY );
#if 0
#ifdef DBG_BP
        if ( g_bp_globals.bNeedConvert ) {
            // check we compute the same ST as the traditional texture computation used before
            float S = f->brushprimit_texdef.coords[0][0] * x + f->brushprimit_texdef.coords[0][1] * y + f->brushprimit_texdef.coords[0][2];
            float T = f->brushprimit_texdef.coords[1][0] * x + f->brushprimit_texdef.coords[1][1] * y + f->brushprimit_texdef.coords[1][2];
            if ( fabs( S - w.point_at( i )[3] ) > 1e-2 || fabs( T - w.point_at( i )[4] ) > 1e-2 ) {
                if ( fabs( S - w.point_at( i )[3] ) > 1e-4 || fabs( T - w.point_at( i )[4] ) > 1e-4 ) {
                    globalOutputStream() << "Warning : precision loss in brush -> brush primitive texture computation\n";
                }
                else{
                    globalOutputStream() << "Warning : brush -> brush primitive texture computation bug detected\n";
                }
            }
        }
#endif
#endif
        w.point_at( i )[3] = f->brushprimit_texdef.coords[0][0] * x + f->brushprimit_texdef.coords[0][1] * y + f->brushprimit_texdef.coords[0][2];
        w.point_at( i )[4] = f->brushprimit_texdef.coords[1][0] * x + f->brushprimit_texdef.coords[1][1] * y + f->brushprimit_texdef.coords[1][2];
    }
}
#endif

typedef float texmat_t[2][3];

void TexMat_Scale(texmat_t texmat, float s, float t)
{
    texmat[0][0] *= s;
    texmat[0][1] *= s;
    texmat[0][2] *= s;
    texmat[1][0] *= t;
    texmat[1][1] *= t;
    texmat[1][2] *= t;
}

void TexMat_Assign(texmat_t texmat, const texmat_t other)
{
    texmat[0][0] = other[0][0];
    texmat[0][1] = other[0][1];
    texmat[0][2] = other[0][2];
    texmat[1][0] = other[1][0];
    texmat[1][1] = other[1][1];
    texmat[1][2] = other[1][2];
}

void ConvertTexMatWithDimensions(const texmat_t texmat1, std::size_t w1, std::size_t h1,
                                 texmat_t texmat2, std::size_t w2, std::size_t h2)
{
    TexMat_Assign(texmat2, texmat1);
    TexMat_Scale(texmat2, static_cast<float>( w1 ) / static_cast<float>( w2 ),
                 static_cast<float>( h1 ) / static_cast<float>( h2 ));
}

#if 0
// convert a texture matrix between two qtexture_t
// if 0 for qtexture_t, basic 2x2 texture is assumed ( straight mapping between s/t coordinates and geometric coordinates )
void ConvertTexMatWithQTexture( const float texMat1[2][3], const qtexture_t *qtex1, float texMat2[2][3], const qtexture_t *qtex2 ){
    ConvertTexMatWithDimensions( texMat1, ( qtex1 ) ? qtex1->width : 2, ( qtex1 ) ? qtex1->height : 2,
                                 texMat2, ( qtex2 ) ? qtex2->width : 2, ( qtex2 ) ? qtex2->height : 2 );
}

void ConvertTexMatWithQTexture( const brushprimit_texdef_t *texMat1, const qtexture_t *qtex1, brushprimit_texdef_t *texMat2, const qtexture_t *qtex2 ){
    ConvertTexMatWithQTexture( texMat1->coords, qtex1, texMat2->coords, qtex2 );
}
#endif

// compute a fake shift scale rot representation from the texture matrix
// these shift scale rot values are to be understood in the local axis base
// Note: this code looks similar to Texdef_fromTransform, but the algorithm is slightly different.

void TexMatToFakeTexCoords(const brushprimit_texdef_t &bp_texdef, texdef_t &texdef)
{
    texdef.scale[0] = static_cast<float>( 1.0 /
                                          vector2_length(Vector2(bp_texdef.coords[0][0], bp_texdef.coords[1][0])));
    texdef.scale[1] = static_cast<float>( 1.0 /
                                          vector2_length(Vector2(bp_texdef.coords[0][1], bp_texdef.coords[1][1])));

    texdef.rotate = -static_cast<float>( radians_to_degrees(
            arctangent_yx(bp_texdef.coords[1][0], bp_texdef.coords[0][0])));

    texdef.shift[0] = -bp_texdef.coords[0][2];
    texdef.shift[1] = bp_texdef.coords[1][2];

    // determine whether or not an axis is flipped using a 2d cross-product
    double cross = vector2_cross(Vector2(bp_texdef.coords[0][0], bp_texdef.coords[0][1]),
                                 Vector2(bp_texdef.coords[1][0], bp_texdef.coords[1][1]));
    if (cross < 0) {
        // This is a bit of a compromise when using BPs--since we don't know *which* axis was flipped,
        // we pick one (rather arbitrarily) using the following convention: If the X-axis is between
        // 0 and 180, we assume it's the Y-axis that flipped, otherwise we assume it's the X-axis and
        // subtract out 180 degrees to compensate.
        if (texdef.rotate >= 180.0f) {
            texdef.rotate -= 180.0f;
            texdef.scale[0] = -texdef.scale[0];
        } else {
            texdef.scale[1] = -texdef.scale[1];
        }
    }
}

// compute back the texture matrix from fake shift scale rot
void FakeTexCoordsToTexMat(const texdef_t &texdef, brushprimit_texdef_t &bp_texdef)
{
    double r = degrees_to_radians(-texdef.rotate);
    double c = cos(r);
    double s = sin(r);
    double x = 1.0f / texdef.scale[0];
    double y = 1.0f / texdef.scale[1];
    bp_texdef.coords[0][0] = static_cast<float>( x * c );
    bp_texdef.coords[1][0] = static_cast<float>( x * s );
    bp_texdef.coords[0][1] = static_cast<float>( y * -s );
    bp_texdef.coords[1][1] = static_cast<float>( y * c );
    bp_texdef.coords[0][2] = -texdef.shift[0];
    bp_texdef.coords[1][2] = texdef.shift[1];
}

#if 0 // texture locking (brush primit)
// used for texture locking
// will move the texture according to a geometric vector
void ShiftTextureGeometric_BrushPrimit( face_t *f, Vector3& delta ){
    Vector3 texS,texT;
    float tx,ty;
    Vector3 M[3]; // columns of the matrix .. easier that way
    float det;
    Vector3 D[2];
    // compute plane axis base ( doesn't change with translation )
    ComputeAxisBase( f->plane.normal, texS, texT );
    // compute translation vector in plane axis base
    tx = vector3_dot( delta, texS );
    ty = vector3_dot( delta, texT );
    // fill the data vectors
    M[0][0] = tx; M[0][1] = 1.0f + tx; M[0][2] = tx;
    M[1][0] = ty; M[1][1] = ty; M[1][2] = 1.0f + ty;
    M[2][0] = 1.0f; M[2][1] = 1.0f; M[2][2] = 1.0f;
    D[0][0] = f->brushprimit_texdef.coords[0][2];
    D[0][1] = f->brushprimit_texdef.coords[0][0] + f->brushprimit_texdef.coords[0][2];
    D[0][2] = f->brushprimit_texdef.coords[0][1] + f->brushprimit_texdef.coords[0][2];
    D[1][0] = f->brushprimit_texdef.coords[1][2];
    D[1][1] = f->brushprimit_texdef.coords[1][0] + f->brushprimit_texdef.coords[1][2];
    D[1][2] = f->brushprimit_texdef.coords[1][1] + f->brushprimit_texdef.coords[1][2];
    // solve
    det = SarrusDet( M[0], M[1], M[2] );
    f->brushprimit_texdef.coords[0][0] = SarrusDet( D[0], M[1], M[2] ) / det;
    f->brushprimit_texdef.coords[0][1] = SarrusDet( M[0], D[0], M[2] ) / det;
    f->brushprimit_texdef.coords[0][2] = SarrusDet( M[0], M[1], D[0] ) / det;
    f->brushprimit_texdef.coords[1][0] = SarrusDet( D[1], M[1], M[2] ) / det;
    f->brushprimit_texdef.coords[1][1] = SarrusDet( M[0], D[1], M[2] ) / det;
    f->brushprimit_texdef.coords[1][2] = SarrusDet( M[0], M[1], D[1] ) / det;
}

// shift a texture (texture adjustments) along it's current texture axes
// x and y are geometric values, which we must compute as ST increments
// this depends on the texture size and the pixel/texel ratio
void ShiftTextureRelative_BrushPrimit( face_t *f, float x, float y ){
    float s,t;
    // as a ratio against texture size
    // the scale of the texture is not relevant here (we work directly on a transformation from the base vectors)
    s = ( x * 2.0 ) / (float)f->pShader->getTexture().width;
    t = ( y * 2.0 ) / (float)f->pShader->getTexture().height;
    f->brushprimit_texdef.coords[0][2] -= s;
    f->brushprimit_texdef.coords[1][2] -= t;
}
#endif

// TTimo: FIXME: I don't like that, it feels broken
//   (and it's likely that it's not used anymore)
// best fitted 2D vector is x.X+y.Y
void ComputeBest2DVector(Vector3 &v, Vector3 &X, Vector3 &Y, int &x, int &y)
{
    double sx, sy;
    sx = vector3_dot(v, X);
    sy = vector3_dot(v, Y);
    if (fabs(sy) > fabs(sx)) {
        x = 0;
        if (sy > 0.0) {
            y = 1;
        } else {
            y = -1;
        }
    } else {
        y = 0;
        if (sx > 0.0) {
            x = 1;
        } else {
            x = -1;
        }
    }
}


#if 0 // texdef conversion
void BrushPrimitFaceToFace( face_t *face ){
    // we have parsed brush primitives and need conversion back to standard format
    // NOTE: converting back is a quick hack, there's some information lost and we can't do anything about it
    // FIXME: if we normalize the texture matrix to a standard 2x2 size, we end up with wrong scaling
    // I tried various tweaks, no luck .. seems shifting is lost
    brushprimit_texdef_t aux;
    ConvertTexMatWithQTexture( &face->brushprimit_texdef, face->pShader->getTexture(), &aux, 0 );
    TexMatToFakeTexCoords( aux.coords, face->texdef.shift, &face->texdef.rotate, face->texdef.scale );
    face->texdef.scale[0] /= 2.0;
    face->texdef.scale[1] /= 2.0;
}
#endif


#if 0 // texture locking (brush primit)
// TEXTURE LOCKING -----------------------------------------------------------------------------------------------------
// (Relevant to the editor only?)

// internally used for texture locking on rotation and flipping
// the general algorithm is the same for both lockings, it's only the geometric transformation part that changes
// so I wanted to keep it in a single function
// if there are more linear transformations that need the locking, going to a C++ or code pointer solution would be best
// (but right now I want to keep brush_primit.cpp striclty C)

bool txlock_bRotation;

// rotation locking params
int txl_nAxis;
float txl_fDeg;
Vector3 txl_vOrigin;

// flip locking params
Vector3 txl_matrix[3];
Vector3 txl_origin;

void TextureLockTransformation_BrushPrimit( face_t *f ){
    Vector3 Orig,texS,texT;      // axis base of initial plane
    // used by transformation algo
    Vector3 temp; int j;
    Vector3 vRotate;                        // rotation vector

    Vector3 rOrig,rvecS,rvecT;   // geometric transformation of (0,0) (1,0) (0,1) { initial plane axis base }
    Vector3 rNormal,rtexS,rtexT; // axis base for the transformed plane
    Vector3 lOrig,lvecS,lvecT;  // [2] are not used ( but usefull for debugging )
    Vector3 M[3];
    float det;
    Vector3 D[2];

    // compute plane axis base
    ComputeAxisBase( f->plane.normal, texS, texT );
    VectorSet( Orig, 0.0f, 0.0f, 0.0f );

    // compute coordinates of (0,0) (1,0) (0,1) ( expressed in initial plane axis base ) after transformation
    // (0,0) (1,0) (0,1) ( expressed in initial plane axis base ) <-> (0,0,0) texS texT ( expressed world axis base )
    // input: Orig, texS, texT (and the global locking params)
    // ouput: rOrig, rvecS, rvecT, rNormal
    if ( txlock_bRotation ) {
        // rotation vector
        VectorSet( vRotate, 0.0f, 0.0f, 0.0f );
        vRotate[txl_nAxis] = txl_fDeg;
        VectorRotateOrigin( Orig, vRotate, txl_vOrigin, rOrig );
        VectorRotateOrigin( texS, vRotate, txl_vOrigin, rvecS );
        VectorRotateOrigin( texT, vRotate, txl_vOrigin, rvecT );
        // compute normal of plane after rotation
        VectorRotate( f->plane.normal, vRotate, rNormal );
    }
    else
    {
        for ( j = 0 ; j < 3 ; j++ )
            rOrig[j] = vector3_dot( vector3_subtracted( Orig, txl_origin ), txl_matrix[j] ) + txl_origin[j];
        for ( j = 0 ; j < 3 ; j++ )
            rvecS[j] = vector3_dot( vector3_subtracted( texS, txl_origin ), txl_matrix[j] ) + txl_origin[j];
        for ( j = 0 ; j < 3 ; j++ )
            rvecT[j] = vector3_dot( vector3_subtracted( texT, txl_origin ), txl_matrix[j] ) + txl_origin[j];
        // we also need the axis base of the target plane, apply the transformation matrix to the normal too..
        for ( j = 0 ; j < 3 ; j++ )
            rNormal[j] = vector3_dot( f->plane.normal, txl_matrix[j] );
    }

    // compute rotated plane axis base
    ComputeAxisBase( rNormal, rtexS, rtexT );
    // compute S/T coordinates of the three points in rotated axis base ( in M matrix )
    lOrig[0] = vector3_dot( rOrig, rtexS );
    lOrig[1] = vector3_dot( rOrig, rtexT );
    lvecS[0] = vector3_dot( rvecS, rtexS );
    lvecS[1] = vector3_dot( rvecS, rtexT );
    lvecT[0] = vector3_dot( rvecT, rtexS );
    lvecT[1] = vector3_dot( rvecT, rtexT );
    M[0][0] = lOrig[0]; M[1][0] = lOrig[1]; M[2][0] = 1.0f;
    M[0][1] = lvecS[0]; M[1][1] = lvecS[1]; M[2][1] = 1.0f;
    M[0][2] = lvecT[0]; M[1][2] = lvecT[1]; M[2][2] = 1.0f;
    // fill data vector
    D[0][0] = f->brushprimit_texdef.coords[0][2];
    D[0][1] = f->brushprimit_texdef.coords[0][0] + f->brushprimit_texdef.coords[0][2];
    D[0][2] = f->brushprimit_texdef.coords[0][1] + f->brushprimit_texdef.coords[0][2];
    D[1][0] = f->brushprimit_texdef.coords[1][2];
    D[1][1] = f->brushprimit_texdef.coords[1][0] + f->brushprimit_texdef.coords[1][2];
    D[1][2] = f->brushprimit_texdef.coords[1][1] + f->brushprimit_texdef.coords[1][2];
    // solve
    det = SarrusDet( M[0], M[1], M[2] );
    f->brushprimit_texdef.coords[0][0] = SarrusDet( D[0], M[1], M[2] ) / det;
    f->brushprimit_texdef.coords[0][1] = SarrusDet( M[0], D[0], M[2] ) / det;
    f->brushprimit_texdef.coords[0][2] = SarrusDet( M[0], M[1], D[0] ) / det;
    f->brushprimit_texdef.coords[1][0] = SarrusDet( D[1], M[1], M[2] ) / det;
    f->brushprimit_texdef.coords[1][1] = SarrusDet( M[0], D[1], M[2] ) / det;
    f->brushprimit_texdef.coords[1][2] = SarrusDet( M[0], M[1], D[1] ) / det;
}

// texture locking
// called before the points on the face are actually rotated
void RotateFaceTexture_BrushPrimit( face_t *f, int nAxis, float fDeg, Vector3& vOrigin ){
    // this is a placeholder to call the general texture locking algorithm
    txlock_bRotation = true;
    txl_nAxis = nAxis;
    txl_fDeg = fDeg;
    VectorCopy( vOrigin, txl_vOrigin );
    TextureLockTransformation_BrushPrimit( f );
}

// compute the new brush primit texture matrix for a transformation matrix and a flip order flag (change plane orientation)
// this matches the select_matrix algo used in select.cpp
// this needs to be called on the face BEFORE any geometric transformation
// it will compute the texture matrix that will represent the same texture on the face after the geometric transformation is done
void ApplyMatrix_BrushPrimit( face_t *f, Vector3 matrix[3], Vector3& origin ){
    // this is a placeholder to call the general texture locking algorithm
    txlock_bRotation = false;
    VectorCopy( matrix[0], txl_matrix[0] );
    VectorCopy( matrix[1], txl_matrix[1] );
    VectorCopy( matrix[2], txl_matrix[2] );
    VectorCopy( origin, txl_origin );
    TextureLockTransformation_BrushPrimit( f );
}
#endif

// don't do C==A!
void BPMatMul(float A[2][3], float B[2][3], float C[2][3])
{
    C[0][0] = A[0][0] * B[0][0] + A[0][1] * B[1][0];
    C[1][0] = A[1][0] * B[0][0] + A[1][1] * B[1][0];
    C[0][1] = A[0][0] * B[0][1] + A[0][1] * B[1][1];
    C[1][1] = A[1][0] * B[0][1] + A[1][1] * B[1][1];
    C[0][2] = A[0][0] * B[0][2] + A[0][1] * B[1][2] + A[0][2];
    C[1][2] = A[1][0] * B[0][2] + A[1][1] * B[1][2] + A[1][2];
}

void BPMatDump(float A[2][3])
{
    globalOutputStream() << "" << A[0][0]
                         << " " << A[0][1]
                         << " " << A[0][2]
                         << "\n" << A[1][0]
                         << " " << A[1][2]
                         << " " << A[1][2]
                         << "\n0 0 1\n";
}

void BPMatRotate(float A[2][3], float theta)
{
    float m[2][3];
    float aux[2][3];
    memset(&m, 0, sizeof(float) * 6);
    m[0][0] = static_cast<float>( cos(degrees_to_radians(theta)));
    m[0][1] = static_cast<float>( -sin(degrees_to_radians(theta)));
    m[1][0] = -m[0][1];
    m[1][1] = m[0][0];
    BPMatMul(A, m, aux);
    BPMatCopy(aux, A);
}

#if 0 // camera-relative texture shift
// get the relative axes of the current texturing
void BrushPrimit_GetRelativeAxes( face_t *f, Vector3& vecS, Vector3& vecT ){
    float vS[2],vT[2];
    // first we compute them as expressed in plane axis base
    // BP matrix has coordinates of plane axis base expressed in geometric axis base
    // so we use the line vectors
    vS[0] = f->brushprimit_texdef.coords[0][0];
    vS[1] = f->brushprimit_texdef.coords[0][1];
    vT[0] = f->brushprimit_texdef.coords[1][0];
    vT[1] = f->brushprimit_texdef.coords[1][1];
    // now compute those vectors in geometric space
    Vector3 texS, texT; // axis base of the plane (geometric)
    ComputeAxisBase( f->plane.normal, texS, texT );
    // vecS[] = vS[0].texS[] + vS[1].texT[]
    // vecT[] = vT[0].texS[] + vT[1].texT[]
    vecS[0] = vS[0] * texS[0] + vS[1] * texT[0];
    vecS[1] = vS[0] * texS[1] + vS[1] * texT[1];
    vecS[2] = vS[0] * texS[2] + vS[1] * texT[2];
    vecT[0] = vT[0] * texS[0] + vT[1] * texT[0];
    vecT[1] = vT[0] * texS[1] + vT[1] * texT[1];
    vecT[2] = vT[0] * texS[2] + vT[1] * texT[2];
}

// brush primitive texture adjustments, use the camera view to map adjustments
// ShiftTextureRelative_BrushPrimit ( s , t ) will shift relative to the texture
void ShiftTextureRelative_Camera( face_t *f, int x, int y ){
    Vector3 vecS, vecT;
    float XY[2]; // the values we are going to send for translation
    float sgn[2]; // +1 or -1
    int axis[2];
    CamWnd* pCam;

    // get the two relative texture axes for the current texturing
    BrushPrimit_GetRelativeAxes( f, vecS, vecT );

    // center point of the face, project it on the camera space
    Vector3 C;
    VectorClear( C );
    int i;
    for ( i = 0; i < f->face_winding->numpoints; i++ )
    {
        VectorAdd( C,f->face_winding->point_at( i ),C );
    }
    VectorScale( C,1.0 / f->face_winding->numpoints,C );

    pCam = g_pParentWnd->GetCamWnd();
    pCam->MatchViewAxes( C, vecS, axis[0], sgn[0] );
    pCam->MatchViewAxes( C, vecT, axis[1], sgn[1] );

    // this happens when the two directions can't be mapped on two different directions on the screen
    // then the move will occur against a single axis
    // (i.e. the user is not positioned well enough to send understandable shift commands)
    // NOTE: in most cases this warning is not very relevant because the user would use one of the two axes
    // for which the solution is easy (the other one being unknown)
    // so this warning could be removed
    if ( axis[0] == axis[1] ) {
        globalOutputStream() << "Warning: degenerate in ShiftTextureRelative_Camera\n";
    }

    // compute the X Y geometric increments
    // those geometric increments will be applied along the texture axes (the ones we computed above)
    XY[0] = 0;
    XY[1] = 0;
    if ( x != 0 ) {
        // moving right/left
        XY[axis[0]] += sgn[0] * x;
    }
    if ( y != 0 ) {
        XY[axis[1]] += sgn[1] * y;
    }
    // we worked out a move along vecS vecT, and we now it's geometric amplitude
    // apply it
    ShiftTextureRelative_BrushPrimit( f, XY[0], XY[1] );
}
#endif


void BPTexdef_Assign(brushprimit_texdef_t &bp_td, const brushprimit_texdef_t &bp_other)
{
    bp_td = bp_other;
}

void BPTexdef_Shift(brushprimit_texdef_t &bp_td, float s, float t)
{
    // shift a texture (texture adjustments) along it's current texture axes
    // x and y are geometric values, which we must compute as ST increments
    // this depends on the texture size and the pixel/texel ratio
    // as a ratio against texture size
    // the scale of the texture is not relevant here (we work directly on a transformation from the base vectors)
    bp_td.coords[0][2] -= s;
    bp_td.coords[1][2] += t;
}

void BPTexdef_Scale(brushprimit_texdef_t &bp_td, float s, float t)
{
    // apply same scale as the spinner button of the surface inspector
    texdef_t texdef;
    // compute fake shift scale rot
    TexMatToFakeTexCoords(bp_td, texdef);
    // update
    texdef.scale[0] += s;
    texdef.scale[1] += t;
    // compute new normalized texture matrix
    FakeTexCoordsToTexMat(texdef, bp_td);
}

void BPTexdef_Rotate(brushprimit_texdef_t &bp_td, float angle)
{
    // apply same scale as the spinner button of the surface inspector
    texdef_t texdef;
    // compute fake shift scale rot
    TexMatToFakeTexCoords(bp_td, texdef);
    // update
    texdef.rotate += angle;
    // compute new normalized texture matrix
    FakeTexCoordsToTexMat(texdef, bp_td);
}

void BPTexdef_Construct(brushprimit_texdef_t &bp_td, std::size_t width, std::size_t height)
{
    bp_td.coords[0][0] = 1.0f;
    bp_td.coords[1][1] = 1.0f;
    ConvertTexMatWithDimensions(bp_td.coords, 2, 2, bp_td.coords, width, height);
}

void Texdef_Assign(TextureProjection &projection, const TextureProjection &other)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_Assign(projection.m_brushprimit_texdef, other.m_brushprimit_texdef);
    } else {
        Texdef_Assign(projection.m_texdef, other.m_texdef);
        if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_HALFLIFE) {
            projection.m_basis_s = other.m_basis_s;
            projection.m_basis_t = other.m_basis_t;
        }
    }
}

void Texdef_Shift(TextureProjection &projection, float s, float t)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_Shift(projection.m_brushprimit_texdef, s, t);
    } else {
        Texdef_Shift(projection.m_texdef, s, t);
    }
}

void Texdef_Scale(TextureProjection &projection, float s, float t)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_Scale(projection.m_brushprimit_texdef, s, t);
    } else {
        Texdef_Scale(projection.m_texdef, s, t);
    }
}

void Texdef_Rotate(TextureProjection &projection, float angle)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        BPTexdef_Rotate(projection.m_brushprimit_texdef, angle);
    } else {
        Texdef_Rotate(projection.m_texdef, angle);
    }
}

void Texdef_FitTexture(TextureProjection &projection, std::size_t width, std::size_t height, const Vector3 &normal,
                       const Winding &w, float s_repeat, float t_repeat)
{
    if (w.numpoints < 3) {
        return;
    }

    Matrix4 st2tex;
    Texdef_toTransform(projection, (float) width, (float) height, st2tex);

    // the current texture transform
    Matrix4 local2tex = st2tex;
    {
        Matrix4 xyz2st;
        Texdef_basisForNormal(projection, normal, xyz2st);
        matrix4_multiply_by_matrix4(local2tex, xyz2st);
    }

    // the bounds of the current texture transform
    AABB bounds;
    for (Winding::const_iterator i = w.begin(); i != w.end(); ++i) {
        Vector3 texcoord = matrix4_transformed_point(local2tex, (*i).vertex);
        aabb_extend_by_point_safe(bounds, texcoord);
    }
    bounds.origin.z() = 0;
    bounds.extents.z() = 1;

    // the bounds of a perfectly fitted texture transform
    AABB perfect(Vector3(s_repeat * 0.5, t_repeat * 0.5, 0), Vector3(s_repeat * 0.5, t_repeat * 0.5, 1));

    // the difference between the current texture transform and the perfectly fitted transform
    Matrix4 matrix(matrix4_translation_for_vec3(bounds.origin - perfect.origin));
    matrix4_pivoted_scale_by_vec3(matrix, bounds.extents / perfect.extents, perfect.origin);
    matrix4_affine_invert(matrix);

    // apply the difference to the current texture transform
    matrix4_premultiply_by_matrix4(st2tex, matrix);

    Texdef_fromTransform(projection, (float) width, (float) height, st2tex);
    Texdef_normalise(projection, (float) width, (float) height);
}

float Texdef_getDefaultTextureScale()
{
    return g_texdef_default_scale;
}

void TexDef_Construct_Default(TextureProjection &projection)
{
    projection.m_texdef.scale[0] = Texdef_getDefaultTextureScale();
    projection.m_texdef.scale[1] = Texdef_getDefaultTextureScale();

    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        FakeTexCoordsToTexMat(projection.m_texdef, projection.m_brushprimit_texdef);
    }
}


void ShiftScaleRotate_fromFace(texdef_t &shiftScaleRotate, const TextureProjection &projection)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        TexMatToFakeTexCoords(projection.m_brushprimit_texdef, shiftScaleRotate);
    } else {
        shiftScaleRotate = projection.m_texdef;
    }
}

void ShiftScaleRotate_toFace(const texdef_t &shiftScaleRotate, TextureProjection &projection)
{
    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_BRUSHPRIMITIVES) {
        // compute texture matrix
        // the matrix returned must be understood as a qtexture_t with width=2 height=2
        FakeTexCoordsToTexMat(shiftScaleRotate, projection.m_brushprimit_texdef);
    } else {
        projection.m_texdef = shiftScaleRotate;
    }
}


inline void print_vector3(const Vector3 &v)
{
    globalOutputStream() << "( " << v.x() << " " << v.y() << " " << v.z() << " )\n";
}

inline void print_3x3(const Matrix4 &m)
{
    globalOutputStream() << "( " << m.xx() << " " << m.xy() << " " << m.xz() << " ) "
                         << "( " << m.yx() << " " << m.yy() << " " << m.yz() << " ) "
                         << "( " << m.zx() << " " << m.zy() << " " << m.zz() << " )\n";
}


inline Matrix4 matrix4_rotation_for_vector3(const Vector3 &x, const Vector3 &y, const Vector3 &z)
{
    return Matrix4(
            x.x(), x.y(), x.z(), 0,
            y.x(), y.y(), y.z(), 0,
            z.x(), z.y(), z.z(), 0,
            0, 0, 0, 1
    );
}

inline Matrix4 matrix4_swap_axes(const Vector3 &from, const Vector3 &to)
{
    if (from.x() != 0 && to.y() != 0) {
        return matrix4_rotation_for_vector3(to, from, g_vector3_axis_z);
    }

    if (from.x() != 0 && to.z() != 0) {
        return matrix4_rotation_for_vector3(to, g_vector3_axis_y, from);
    }

    if (from.y() != 0 && to.z() != 0) {
        return matrix4_rotation_for_vector3(g_vector3_axis_x, to, from);
    }

    if (from.y() != 0 && to.x() != 0) {
        return matrix4_rotation_for_vector3(from, to, g_vector3_axis_z);
    }

    if (from.z() != 0 && to.x() != 0) {
        return matrix4_rotation_for_vector3(from, g_vector3_axis_y, to);
    }

    if (from.z() != 0 && to.y() != 0) {
        return matrix4_rotation_for_vector3(g_vector3_axis_x, from, to);
    }

    ERROR_MESSAGE("unhandled axis swap case");

    return g_matrix4_identity;
}

inline Matrix4 matrix4_reflection_for_plane(const Plane3 &plane)
{
    return Matrix4(
            static_cast<float>( 1 - (2 * plane.a * plane.a)),
            static_cast<float>( -2 * plane.a * plane.b ),
            static_cast<float>( -2 * plane.a * plane.c ),
            0,
            static_cast<float>( -2 * plane.b * plane.a ),
            static_cast<float>( 1 - (2 * plane.b * plane.b)),
            static_cast<float>( -2 * plane.b * plane.c ),
            0,
            static_cast<float>( -2 * plane.c * plane.a ),
            static_cast<float>( -2 * plane.c * plane.b ),
            static_cast<float>( 1 - (2 * plane.c * plane.c)),
            0,
            static_cast<float>( -2 * plane.d * plane.a ),
            static_cast<float>( -2 * plane.d * plane.b ),
            static_cast<float>( -2 * plane.d * plane.c ),
            1
    );
}

inline Matrix4 matrix4_reflection_for_plane45(const Plane3 &plane, const Vector3 &from, const Vector3 &to)
{
    Vector3 first = from;
    Vector3 second = to;

    if ((vector3_dot(from, plane.normal()) > 0) == (vector3_dot(to, plane.normal()) > 0)) {
        first = vector3_negated(first);
        second = vector3_negated(second);
    }

#if 0
    globalOutputStream() << "normal: ";
    print_vector3( plane.normal() );

    globalOutputStream() << "from: ";
    print_vector3( first );

    globalOutputStream() << "to: ";
    print_vector3( second );
#endif

    Matrix4 swap = matrix4_swap_axes(first, second);

    swap.tx() = -static_cast<float>( -2 * plane.a * plane.d );
    swap.ty() = -static_cast<float>( -2 * plane.b * plane.d );
    swap.tz() = -static_cast<float>( -2 * plane.c * plane.d );

    return swap;
}

void Texdef_transformLocked(TextureProjection &projection, std::size_t width, std::size_t height, const Plane3 &plane,
                            const Matrix4 &identity2transformed)
{
    //globalOutputStream() << "identity2transformed: " << identity2transformed << "\n";

    //globalOutputStream() << "plane.normal(): " << plane.normal() << "\n";

    Vector3 normalTransformed(matrix4_transformed_direction(identity2transformed, plane.normal()));

    //globalOutputStream() << "normalTransformed: " << normalTransformed << "\n";

    // identity: identity space
    // transformed: transformation
    // stIdentity: base st projection space before transformation
    // stTransformed: base st projection space after transformation
    // stOriginal: original texdef space

    // stTransformed2stOriginal = stTransformed -> transformed -> identity -> stIdentity -> stOriginal

    Matrix4 identity2stIdentity;
    Texdef_basisForNormal(projection, plane.normal(), identity2stIdentity);
    //globalOutputStream() << "identity2stIdentity: " << identity2stIdentity << "\n";

    if (g_bp_globals.m_texdefTypeId == TEXDEFTYPEID_HALFLIFE) {
        matrix4_transform_direction(identity2transformed, projection.m_basis_s);
        matrix4_transform_direction(identity2transformed, projection.m_basis_t);
    }

    Matrix4 transformed2stTransformed;
    Texdef_basisForNormal(projection, normalTransformed, transformed2stTransformed);

    Matrix4 stTransformed2identity(
            matrix4_affine_inverse(matrix4_multiplied_by_matrix4(transformed2stTransformed, identity2transformed)));

    Vector3 originalProjectionAxis(vector4_to_vector3(matrix4_affine_inverse(identity2stIdentity).z()));

    Vector3 transformedProjectionAxis(vector4_to_vector3(stTransformed2identity.z()));

    Matrix4 stIdentity2stOriginal;
    Texdef_toTransform(projection, (float) width, (float) height, stIdentity2stOriginal);
    Matrix4 identity2stOriginal(matrix4_multiplied_by_matrix4(stIdentity2stOriginal, identity2stIdentity));

    //globalOutputStream() << "originalProj: " << originalProjectionAxis << "\n";
    //globalOutputStream() << "transformedProj: " << transformedProjectionAxis << "\n";
    double dot = vector3_dot(originalProjectionAxis, transformedProjectionAxis);
    //globalOutputStream() << "dot: " << dot << "\n";
    if (dot == 0) {
        // The projection axis chosen for the transformed normal is at 90 degrees
        // to the transformed projection axis chosen for the original normal.
        // This happens when the projection axis is ambiguous - e.g. for the plane
        // 'X == Y' the projection axis could be either X or Y.
        //globalOutputStream() << "flipped\n";
#if 0
        globalOutputStream() << "projection off by 90\n";
        globalOutputStream() << "normal: ";
        print_vector3( plane.normal() );
        globalOutputStream() << "original projection: ";
        print_vector3( originalProjectionAxis );
        globalOutputStream() << "transformed projection: ";
        print_vector3( transformedProjectionAxis );
#endif

        Matrix4 identityCorrected = matrix4_reflection_for_plane45(plane, originalProjectionAxis,
                                                                   transformedProjectionAxis);

        identity2stOriginal = matrix4_multiplied_by_matrix4(identity2stOriginal, identityCorrected);
    }

    Matrix4 stTransformed2stOriginal = matrix4_multiplied_by_matrix4(identity2stOriginal, stTransformed2identity);

    Texdef_fromTransform(projection, (float) width, (float) height, stTransformed2stOriginal);
    Texdef_normalise(projection, (float) width, (float) height);
}

#if 1

void Q3_to_matrix(const texdef_t &texdef, float width, float height, const Vector3 &normal, Matrix4 &matrix)
{
    Normal_GetTransform(normal, matrix);

    Matrix4 transform;

    Texdef_toTransform(texdef, width, height, transform);

    matrix4_multiply_by_matrix4(matrix, transform);
}

void BP_from_matrix(brushprimit_texdef_t &bp_texdef, const Vector3 &normal, const Matrix4 &transform)
{
    Matrix4 basis;
    basis = g_matrix4_identity;
    ComputeAxisBase(normal, vector4_to_vector3(basis.x()), vector4_to_vector3(basis.y()));
    vector4_to_vector3(basis.z()) = normal;
    matrix4_transpose(basis);
    matrix4_affine_invert(basis);

    Matrix4 basis2texture = matrix4_multiplied_by_matrix4(basis, transform);

    BPTexdef_fromTransform(bp_texdef, basis2texture);
}

void Q3_to_BP(const texdef_t &texdef, float width, float height, const Vector3 &normal, brushprimit_texdef_t &bp_texdef)
{
    Matrix4 matrix;
    Q3_to_matrix(texdef, width, height, normal, matrix);
    BP_from_matrix(bp_texdef, normal, matrix);
}

#endif