[qfcc] Implement wedge products for 3d VGA

That was pretty easy, but necessary for trying out barycentric
coordinates in geometric algebra :)
This commit is contained in:
Bill Currie 2023-09-07 21:40:17 +09:00
parent 5c32077c2a
commit 6096edb1ca

View file

@ -1147,6 +1147,44 @@ static pga_func pga2_wedge_funcs[4][4] = {
}, },
}; };
static void
vga2_x_y_z_wedge_x_y_w (expr_t **c, expr_t *a, expr_t *b, algebra_t *alg)
{
c[2] = cross_expr (algebra_mvec_type (alg, 0x04), a, b);
}
static void
vga2_x_y_w_wedge_yz_zx_xy (expr_t **c, expr_t *a, expr_t *b, algebra_t *alg)
{
c[3] = dot_expr (algebra_mvec_type (alg, 0x08), a, b);
}
static void
vga2_yz_zx_xy_wedge_x_y_w (expr_t **c, expr_t *a, expr_t *b, algebra_t *alg)
{
c[3] = dot_expr (algebra_mvec_type (alg, 0x08), a, b);
}
static pga_func vga3_wedge_funcs[4][4] = {
[0] = {
[0] = scale_component,
[1] = scale_component,
[2] = scale_component,
[3] = scale_component,
},
[1] = {
[0] = scale_component,
[1] = vga2_x_y_z_wedge_x_y_w,
[2] = vga2_x_y_w_wedge_yz_zx_xy,
},
[2] = {
[0] = scale_component,
[1] = vga2_yz_zx_xy_wedge_x_y_w,
},
[3] = {
},
};
static void static void
component_wedge (expr_t **c, expr_t *a, expr_t *b, algebra_t *algebra) component_wedge (expr_t **c, expr_t *a, expr_t *b, algebra_t *algebra)
{ {
@ -1166,6 +1204,12 @@ component_wedge (expr_t **c, expr_t *a, expr_t *b, algebra_t *algebra)
if (pga2_wedge_funcs[ga][gb]) { if (pga2_wedge_funcs[ga][gb]) {
pga2_wedge_funcs[ga][gb] (c, a, b, algebra); pga2_wedge_funcs[ga][gb] (c, a, b, algebra);
} }
} else if (p == 3 && m == 0 && z == 0) {
int ga = get_group (get_type (a), algebra);
int gb = get_group (get_type (b), algebra);
if (vga3_wedge_funcs[ga][gb]) {
vga3_wedge_funcs[ga][gb] (c, a, b, algebra);
}
} else { } else {
internal_error (a, "not implemented"); internal_error (a, "not implemented");
} }