void
gegl_matrix3_invert (GeglMatrix3 *matrix)
{
GeglMatrix3 copy;
gdouble coeff;
gegl_matrix3_copy_into (©, matrix);
coeff = 1 / gegl_matrix3_determinant (matrix);
matrix->coeff [0][0] = (copy.coeff [1][1] * copy.coeff [2][2] -
copy.coeff [1][2] * copy.coeff [2][1]) * coeff;
matrix->coeff [1][0] = (copy.coeff [1][2] * copy.coeff [2][0] -
copy.coeff [1][0] * copy.coeff [2][2]) * coeff;
matrix->coeff [2][0] = (copy.coeff [1][0] * copy.coeff [2][1] -
copy.coeff [1][1] * copy.coeff [2][0]) * coeff;
matrix->coeff [0][1] = (copy.coeff [0][2] * copy.coeff [2][1] -
copy.coeff [0][1] * copy.coeff [2][2]) * coeff;
matrix->coeff [1][1] = (copy.coeff [0][0] * copy.coeff [2][2] -
copy.coeff [0][2] * copy.coeff [2][0]) * coeff;
matrix->coeff [2][1] = (copy.coeff [0][1] * copy.coeff [2][0] -
copy.coeff [0][0] * copy.coeff [2][1]) * coeff;
matrix->coeff [0][2] = (copy.coeff [0][1] * copy.coeff [1][2] -
copy.coeff [0][2] * copy.coeff [1][1]) * coeff;
matrix->coeff [1][2] = (copy.coeff [0][2] * copy.coeff [1][0] -
copy.coeff [0][0] * copy.coeff [1][2]) * coeff;
matrix->coeff [2][2] = (copy.coeff [0][0] * copy.coeff [1][1] -
copy.coeff [0][1] * copy.coeff [1][0]) * coeff;
}
gboolean
gegl_matrix3_is_translate (GeglMatrix3 *matrix)
{
GeglMatrix3 copy;
gegl_matrix3_copy_into (©, matrix);
copy.coeff [0][2] = copy.coeff [1][2] = 0.;
return gegl_matrix3_is_identity (©);
}
static gboolean
gegl_affine_matrix3_allow_fast_reflect_y (GeglMatrix3 *matrix)
{
GeglMatrix3 copy;
if (! GEGL_FLOAT_EQUAL (matrix->coeff[0][0], -1.0))
return FALSE;
gegl_matrix3_copy_into (©, matrix);
copy.coeff[0][0] = 1.;
return gegl_affine_matrix3_allow_fast_translate (©);
}
void
gegl_matrix3_multiply (GeglMatrix3 *left,
GeglMatrix3 *right,
GeglMatrix3 *product)
{
GeglMatrix3 temp;
gint i;
for (i = 0; i < 3; i++)
{
temp.coeff [i][0] = left->coeff [i][0] * right->coeff [0][0]
+ left->coeff [i][1] * right->coeff [1][0]
+ left->coeff [i][2] * right->coeff [2][0];
temp.coeff [i][1] = left->coeff [i][0] * right->coeff [0][1]
+ left->coeff [i][1] * right->coeff [1][1]
+ left->coeff [i][2] * right->coeff [2][1];
temp.coeff [i][2] = left->coeff [i][0] * right->coeff [0][2]
+ left->coeff [i][1] * right->coeff [1][2]
+ left->coeff [i][2] * right->coeff [2][2];
}
gegl_matrix3_copy_into (product, &temp);
}
static void
affine_generic (GeglBuffer *dest,
GeglBuffer *src,
GeglMatrix3 *matrix,
GeglSampler *sampler)
{
GeglBufferIterator *i;
const GeglRectangle *dest_extent;
gint x, y;
gfloat * restrict dest_buf,
*dest_ptr;
GeglMatrix3 inverse;
GeglMatrix2 inverse_jacobian;
gdouble u_start,
v_start,
u_float,
v_float;
Babl *format;
gint dest_pixels;
format = babl_format ("RaGaBaA float");
/* XXX: fast paths as existing in files in the same dir as affine.c
* should probably be hooked in here, and bailing out before using
* the generic code.
*/
g_object_get (dest, "pixels", &dest_pixels, NULL);
dest_extent = gegl_buffer_get_extent (dest);
i = gegl_buffer_iterator_new (dest, dest_extent, format, GEGL_BUFFER_WRITE);
while (gegl_buffer_iterator_next (i))
{
GeglRectangle *roi = &i->roi[0];
dest_buf = (gfloat *)i->data[0];
gegl_matrix3_copy_into (&inverse, matrix);
gegl_matrix3_invert (&inverse);
inverse_jacobian.coeff[0][0] = inverse.coeff[0][0];
inverse_jacobian.coeff[0][1] = inverse.coeff[0][1];
inverse_jacobian.coeff[1][0] = inverse.coeff[1][0];
inverse_jacobian.coeff[1][1] = inverse.coeff[1][1];
/* set inverse_jacobian for samplers that support it */
u_start = inverse.coeff[0][0] * roi->x + inverse.coeff[0][1]
* roi->y + inverse.coeff[0][2];
v_start = inverse.coeff[1][0] * roi->x + inverse.coeff[1][1]
* roi->y + inverse.coeff[1][2];
/* correct rounding on e.g. negative scaling (is this sound?) */
if (inverse.coeff [0][0] < 0.) u_start -= .001;
if (inverse.coeff [1][1] < 0.) v_start -= .001;
for (dest_ptr = dest_buf, y = roi->height; y--;)
{
u_float = u_start;
v_float = v_start;
for (x = roi->width; x--;)
{
gegl_sampler_get (sampler, u_float, v_float, &inverse_jacobian, dest_ptr);
dest_ptr+=4;
u_float += inverse.coeff [0][0];
v_float += inverse.coeff [1][0];
}
u_start += inverse.coeff [0][1];
v_start += inverse.coeff [1][1];
}
}
}