On Fri, 06 May 2011 05:56:17 -0400, Mike Parker <aldac...@gmail.com> wrote:
Testing out a new binding I knocked up for a C library. One of the
functions takes a struct by value. It looks somewhat like this:
struct S {}
struct Color
{
float r,g,b,a;
}
extern C void function(S* s, Color color, int x, int y, in char*)
draw_text;
Now, there is another function that adjusts color values when making a
color. In C, it is sometimes used like so:
draw_text(s, map_color(255, 0, 0, 0), 0, 0, "Blarg");
When I'm calling draw_text like this on the D side, my text output is
corrupt. I keep getting weird things like ^^P^, but in the appropriate
color. It's consistent, no matter what string I pass, but is different
for each color value. If I call draw_text like this:
auto color = map_color(...);
draw_text(s, color, 0, 0, "Blarg");
It works as expected. Has anyone else seen this, or know of a
workaround? I'm going to dig through bugzilla later on and see if it's
been reported already, but I'm curious if anyone knows of the cause off
hand.
There are two possible causes I can think of, depending on how draw_text
is defined in C.
1. is it truly a function pointer? That is, does the definition look like
void (*draw_text)(S* s, ...), or is it just void draw_text(S* s, ...)?
2. It's possible that the extern C (BTW, I thought it had to be
extern(C)?) is only applying to the symbol name draw_text and not the
function type.
If you answer no to #1, then your problem is your draw_text definition in
D. It should look like this:
extern(C) void draw_text(S * s, Color color, int x, int y, in char *);
If you answer yes to #1, then to check what type the compiler is giving to
draw text, do:
pragma(msg, (typeof(draw_text)).stringof);
This hopefully tells you that it's extern(C), but if not, that is likely
the problem.
If that's not it, I have no idea ;)
-Steve
