void gst_gl_set_affine_transformation_meta_from_ndc
(GstVideoAffineTransformationMeta * meta, const gfloat * matrix)
{
float tmp[16];
g_return_if_fail (meta != NULL);
/* change of basis multiplications */
gst_gl_multiply_matrix4 (from_ndc_matrix, matrix, tmp);
gst_gl_multiply_matrix4 (tmp, to_ndc_matrix, meta->matrix);
}
void
gst_gl_get_affine_transformation_meta_as_ndc (GstVideoAffineTransformationMeta *
meta, gfloat * matrix)
{
if (!meta) {
int i;
for (i = 0; i < 16; i++) {
matrix[i] = identity_matrix[i];
}
} else {
gfloat tmp[16] = { 0.0f };
gst_gl_multiply_matrix4 (from_ndc_matrix, meta->matrix, tmp);
gst_gl_multiply_matrix4 (tmp, to_ndc_matrix, matrix);
}
}
/*
* gst_gl_get_affine_transformation_meta_as_ndc:
* @meta: (nullable): a #GstVideoAffineTransformationMeta
* @matrix: (out): result of the 4x4 matrix
*
* Retrieves the stored 4x4 affine transformation matrix stored in @meta in
* NDC coordinates. if @meta is NULL, an identity matrix is returned.
*
* NDC is a left-handed coordinate sytem
* - x - [-1, 1] - +ve X moves right
* - y - [-1, 1] - +ve Y moves up
* - z - [-1, 1] - +ve Z moves into
*/
void
gst_gl_get_affine_transformation_meta_as_ndc (GstVideoAffineTransformationMeta *
meta, gfloat * matrix)
{
if (!meta) {
int i;
for (i = 0; i < 16; i++) {
matrix[i] = identity_matrix[i];
}
} else {
float tmp[16];
/* change of basis multiplications */
gst_gl_multiply_matrix4 (to_ndc_matrix, meta->matrix, tmp);
gst_gl_multiply_matrix4 (tmp, from_ndc_matrix, matrix);
}
}