On Tue, 12 Nov 2002, Pierre-Alain Joye wrote:
> 1. php syntax
> After a short discussion on #php, I choose to implement a generic
> function:
> bool imagefilter(resssource img, int filtertype [,arg1,argn,...]);
> where
> int filtertype are predefined constant (IMAGE_FILTER_BRIGHTNESS,
> IMAGE_FILTER_EDGEDETECT,...)
>
> and argN depends on the used filter.
>
> Is this syntax sounds good to you ?
It does to me.
>
>
> 2. The implementation
> It was clear that a generic imagefilter function is easier to use than N
> different functions (inside php). So here I went. But I did not find a
> cool way to do it. One goal of that is to make as easy as possible to
> add filters (in ext/gd/gd.c).
>
> Currently I do:
>
> 3701 if (ZEND_NUM_ARGS()<2 || ZEND_NUM_ARGS()>5 ||
> 3702 zend_get_parameters_array_ex(ZEND_NUM_ARGS(), args) ==
> FAILURE) 3703 ZEND_WRONG_PARAM_COUNT();
> 3704
> 3705 FILTERTYPE = args[1];
> 3706
> 3707 convert_to_long_ex(FILTERTYPE);
> 3708 filtertype = Z_LVAL_PP(FILTERTYPE);
>
> ....
> 3716 switch (filtertype) {
> 3717 case IMAGE_FILTER_NEGATE:
> 3718 if (ZEND_NUM_ARGS()>2) {
> 3719 ZEND_WRONG_PARAM_COUNT();
> 3720 }
> 3721 if (gdImageNegate(im_src)==1) {
> 3722 RETURN_TRUE;
> 3723 }
> 3724 break;
> ....
>
> I do not like the switch, I prefer to see something like an array of
> the available filters, an array of function pointers to which we pass
> the php arguments(INTERNAL_FUNCTION_PARAM_PASSTHRU). It will be easier
> to add new filters.
>
> I try to do it but I ve failed. the problem is I need to call a function
> passing to it all php args and allowing it to return
> errors/warnings/notices to the user. This function does not have to be
> available from php.
>
> I hope I was clear enough :-)
>
> any comments, ideas ?
You can do something like this:
#define FILTER_NONE 0
#define FILTER_NEGATE 1
#define FILTER_BLUR 2
#define FILTER_MAX 2
typedef image_filter {
void (function*)(INTERNAL_FUNCTION_PARAMETERS);
} image_filter;
image_filter filters[] = {
{ image_filter_none },
{ image_filter_negate },
{ image_filter_blur }
};
PHP_FUNCTION(image_filter_none)
{
/* do stuff */
}
and then have:
filters[filter_type]->function(INTERNAL_FUNCTION_PARAMETERS);
which can return errors and stuff just like a normal functon can do.
regards,
Derick
PS.: This is from mind, might not work :-)
Derick
>
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Derick Rethans http://derickrethans.nl/
JDI Media Solutions
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