bool matrix_3x3_square_to_quad(const float dx0, const float dy0,
const float dx1, const float dy1,
const float dx3, const float dy3,
const float dx2, const float dy2,
math_matrix_3x3 *mat)
{
float ax = dx0 - dx1 + dx2 - dx3;
float ay = dy0 - dy1 + dy2 - dy3;
if (float_is_zero(ax) && float_is_zero(ay))
{
/* affine case */
matrix_3x3_inits(mat,
dx1 - dx0, dy1 - dy0, 0,
dx2 - dx1, dy2 - dy1, 0,
dx0, dy0, 1);
}
else
{
float a, b, c, d, e, f, g, h;
float ax1 = dx1 - dx2;
float ax2 = dx3 - dx2;
float ay1 = dy1 - dy2;
float ay2 = dy3 - dy2;
/* determinants */
float gtop = ax * ay2 - ax2 * ay;
float htop = ax1 * ay - ax * ay1;
float bottom = ax1 * ay2 - ax2 * ay1;
if (!bottom)
return false;
g = gtop / bottom;
h = htop / bottom;
a = dx1 - dx0 + g * dx1;
b = dx3 - dx0 + h * dx3;
c = dx0;
d = dy1 - dy0 + g * dy1;
e = dy3 - dy0 + h * dy3;
f = dy0;
matrix_3x3_inits(mat,
a, d, g,
b, e, h,
c, f, 1.f);
}
return true;
}
bool matrix_3x3_invert(math_matrix_3x3 *mat)
{
float det = matrix_3x3_determinant(mat);
if (float_is_zero(det))
return false;
matrix_3x3_adjoint(mat);
matrix_3x3_divide_scalar(mat, det);
return true;
}
node_t* node_optimize2(node_t*n, bool*again)
{
int t,num;
switch(node_get_opcode(n)) {
case opcode_node_block:
for(t=0;t<n->num_children;t++) {
if(n->child[t]->type == &node_nop) {
node_remove_child(n, t--);
}
}
break;
case opcode_node_in:
/* convert
a in [x]
to
a == x
*/
if(node_is_array(n->child[1]) &&
n->child[1]->value.a->size == 1) {
node_t*new_node = node_new(&node_equals, n->parent);
node_t*constant = node_new_with_args(&node_constant, n->child[1]->value.a->entries[0]);
node_append_child(new_node, n->child[0]);
node_append_child(new_node, constant);
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_mul:
/* convert
a * 1.0
or
1.0 * a
to
a
*/
if(n->child[1]->type == &node_float &&
float_is_one(n->child[1]->value.f)) {
node_t*new_node = n->child[0];
node_destroy(n->child[1]);
node_destroy_self(n);
return new_node;
}
if(n->child[0]->type == &node_float &&
float_is_one(n->child[0]->value.f)) {
node_t*new_node = n->child[1];
node_destroy(n->child[0]);
node_destroy_self(n);
return new_node;
}
/* convert
a * 0.0
or
0.0 * a
to
0.0
*/
if(n->child[0]->type == &node_float &&
float_is_zero(n->child[0]->value.f)) {
node_t*new_node = n->child[0];
node_destroy(n->child[1]);
node_destroy_self(n);
return new_node;
}
if(n->child[1]->type == &node_float &&
float_is_zero(n->child[1]->value.f)) {
node_t*new_node = n->child[1];
node_destroy(n->child[0]);
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_sub:
/* convert
a - 0.0
to
a
*/
if(n->child[1]->type == &node_float &&
float_is_zero(n->child[1]->value.f)) {
node_t*new_node = n->child[0];
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_div:
/* convert
a / 1.0
to
a
*/
if(n->child[1]->type == &node_float &&
float_is_one(n->child[1]->value.f)) {
node_t*new_node = n->child[0];
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_add:
/* convert
a + 0.0
to
a
*/
num = 0;
for(t=0;t<n->num_children;t++) {
node_set_child(n, num, n->child[t]);
if(n->child[t]->type != &node_float ||
!float_is_zero(n->child[t]->value.f)) {
num++;
}
}
if(!num) {
node_set_child(n, num++, node_new_with_args(&node_float, 0.0));
}
n->num_children = num;
if(num==1) {
node_t*new_node = n->child[0];
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_if:
/* convert
if
c
then
a
else
a
to
a
*/
if(node_equals_node(n->child[1], n->child[2])) {
node_t*new_node = n->child[1];
node_destroy_self(n);
return new_node;
}
break;
case opcode_node_setlocal:
/* convert
setlocal i
getlocal i
to
nop
*/
if(n->child[0]->type == &node_getlocal) {
if(n->child[0]->value.i == n->value.i) {
node_t*new_node = node_new(&node_nop, n->parent);
node_destroy(n);
*again = true;
return new_node;
}
}
break;
}
for(t=0;t<n->num_children;t++) {
node_set_child(n, t, node_optimize2(n->child[t], again));
}
return n;
}