add support for while() loops again ugly syntax while(condition, statements) but very simple implementation

Originally committed as revision 6814 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-10-27 22:35:55 +00:00
parent 835954e3a4
commit 45ee0e3282
1 changed files with 8 additions and 1 deletions

View File

@ -133,7 +133,7 @@ struct ff_expr_s {
e_squish, e_gauss, e_ld,
e_mod, e_max, e_min, e_eq, e_gt, e_gte,
e_pow, e_mul, e_div, e_add,
e_last, e_st,
e_last, e_st, e_while,
} type;
double value; // is sign in other types
union {
@ -155,6 +155,12 @@ static double eval_expr(Parser * p, AVEvalExpr * e) {
case e_squish: return 1/(1+exp(4*eval_expr(p, e->param[0])));
case e_gauss: { double d = eval_expr(p, e->param[0]); return exp(-d*d/2)/sqrt(2*M_PI); }
case e_ld: return e->value * p->var[clip(eval_expr(p, e->param[0]), 0, VARS-1)];
case e_while: {
double d;
while(eval_expr(p, e->param[0]))
d=eval_expr(p, e->param[1]);
return d;
}
default: {
double d = eval_expr(p, e->param[0]);
double d2 = eval_expr(p, e->param[1]);
@ -266,6 +272,7 @@ static AVEvalExpr * parse_primary(Parser *p) {
else if( strmatch(next, "lt" ) ) { AVEvalExpr * tmp = d->param[1]; d->param[1] = d->param[0]; d->param[0] = tmp; d->type = e_gte; }
else if( strmatch(next, "ld" ) ) d->type = e_ld;
else if( strmatch(next, "st" ) ) d->type = e_st;
else if( strmatch(next, "while" ) ) d->type = e_while;
else {
for(i=0; p->func1_name && p->func1_name[i]; i++){
if(strmatch(next, p->func1_name[i])){