Re: FLI type error
"Paul Werkowski (as pw at snoopy dot qozzy dot com)" <[email protected]>
| Newsgroups | gmane.lisp.lispworks.general |
|---|---|
| Message-ID | <[email protected]> |
No, *default-character-element-type* is BASE-CHAR. On 3/7/2026 2:04 PM, David McClain wrote: > Web search shows GLCHAR is 8-bit char (ASCII ?). We had 30+ years of stability and simplicity once EBCDIC gave way to ASCII. > > But my recent experience with the Rust world shows that simplicity is no longer relevant. Very possibly you are using Wide Lisp chars instead of BASE-CHAR? > > > >> On Mar 7, 2026, at 11:24, Paul Werkowski (as pw at snoopy dot qozzy dot com) <[email protected]> wrote: >> >> Well, GLCHAR is lisp :char. I see that the FLI manual has things like convert-to-foreign-type etc. I shall poke around in there for awhile. >> >> Thanks for the suggestion, >> PW >> >> On 3/7/2026 12:43 PM, David McClain wrote: >>> No… I now see. >>> >>> It appears that Lisp cannot automatically convert your Lisp string to the required C type (:POINTER OPENGL:GLCHAR). There has always been a sometimes conversion ability to allow Lisp strings to become C strings. But your required type is not a “C String” kind of pointer. >>> >>> Yes, even though it probably really is a C string type, I have no idea whether OPENGL:GLCHAR is a 8-bit ASCII char, or a Unicode wide char, etc. So probably no implicit LW conversions would apply. >>> >>> IOW… you probably now have to provide your own explicit conversions. >>> >>> - DM >>> >>>> On Mar 7, 2026, at 10:37, David McClain <[email protected]> wrote: >>>> >>>>> Both of these get a runtime error >>>>> "aPos" (and "triangleColor") cannot be converted to foreign type >>>>> (:POINTER OPENGL:GLCHAR). >>>>> >>>> Offhand… did the OpenGL API change since 10 years ago? Perhaps now expects an array of char, or a string pointer? >>>> >>>> >>>> >>>>> On Mar 7, 2026, at 09:59, Paul Werkowski (as pw at snoopy dot qozzy dot com) <[email protected]> wrote: >>>>> >>>>> I'm looking at some code from 5-10 years ago, experimenting with OPENGL, that uses the LW example code to setup the interface. The icosahedron example works fine so no issue there. >>>>> >>>>> Here are two fragments from my code. >>>>> >>>>> (let ((pos-attr (gl-get-attrib-location shader-pgm "aPos")) >>>>> >>>>> (let((unicolor (gl-get-uniform-location >>>>> shader-pgm "triangleColor"))) >>>>> >>>>> Both of these get a runtime error >>>>> "aPos" (and "triangleColor") cannot be converted to foreign type >>>>> (:POINTER OPENGL:GLCHAR). >>>>> >>>>> GLCHAR is defined in opengl/types.lisp as >>>>> >>>>> (fli:define-c-typedef (glchar (:foreign-name "GLchar")) >>>>> :char) >>>>> >>>>> Same issue with both LWW 8.1.2 64 bit and 7.1.2 32 bit. >>>>> >>>>> This all used to work. What could be wrong??? >>>>> >>>>> Puzzled again, >>>>> Paul >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Lisp Hug - the mailing list for LispWorks users >>>>> [email protected] >>>>> http://www.lispworks.com/support/lisp-hug.html >> _______________________________________________ >> Lisp Hug - the mailing list for LispWorks users >> [email protected] >> http://www.lispworks.com/support/lisp-hug.html _______________________________________________ Lisp Hug - the mailing list for LispWorks users [email protected] http://www.lispworks.com/support/lisp-hug.html