[waffle] [PATCH 2/3] egl: retrieve the libEGL function pointers at wegl_platform_init()

[Jordan Justen]

On Tue, Aug 26, 2014 at 10:47 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> Which will be used in our next step, to make libEGL free waffle.
> Paving the way of waffle to have little to-no dependencies.
>
> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> ---
>  src/waffle/egl/wegl_platform.c | 70 ++++++++++++++++++++++++++++++++++++++++--
>  src/waffle/egl/wegl_platform.h | 36 ++++++++++++++++++++++
>  2 files changed, 104 insertions(+), 2 deletions(-)
>
> diff --git a/src/waffle/egl/wegl_platform.c b/src/waffle/egl/wegl_platform.c
> index b67e8d2..5766adb 100644
> --- a/src/waffle/egl/wegl_platform.c
> +++ b/src/waffle/egl/wegl_platform.c
> @@ -23,14 +23,32 @@
>  // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
>  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
>
> +#include <dlfcn.h>
> +
> +#include "wcore_error.h"
>  #include "wegl_platform.h"
>
> +// XXX: Use the actual SONAME for linux ?
> +// Should we treat Android the same way as linux ?
> +static const char *libEGL_filename = "libEGL.so";

I think we should use libEGL.so.1 to specify the library ABI version.
(But, waffle only does this on libGL.)

BTW, I tested with gbm and x11_egl. It would be good to test Wayland
and Android too.

>  bool
>  wegl_platform_teardown(struct wegl_platform *self)
>  {
> -    bool ok;
> +    bool ok = true;
> +    int error = 0;
>
> -    ok = wcore_platform_teardown(&self->wcore);
> +    if (self->eglHandle) {
> +        error = dlclose(self->eglHandle);
> +        if (error) {
> +            ok = false;
> +            wcore_errorf(WAFFLE_ERROR_UNKNOWN,
>
> +                         "dlclose(\"%s\") failed: %s",
> +                         libEGL_filename, dlerror());
> +        }
> +    }
> +
> +    ok &= wcore_platform_teardown(&self->wcore);
>      return ok;
>  }
>  bool
> @@ -39,6 +57,54 @@ wegl_platform_init(struct wegl_platform *self)
>      bool ok;
>
>      ok = wcore_platform_init(&self->wcore);
> +    if (!ok)
> +        goto error;
> +
> +    self->eglHandle = dlopen(libEGL_filename, RTLD_LAZY | RTLD_LOCAL);
> +    if (!self->eglHandle) {
> +        wcore_errorf(WAFFLE_ERROR_UNKNOWN,

Chad, would WAFFLE_ERROR_FATAL be appropriate here (and below)?

-Jordan

> +                     "dlopen(\"%s\") failed: %s",
> +                     libEGL_filename, dlerror());
> +        goto error;
> +    }
> +
> +#define RETREIVE_EGL_SYMBOL(function)                                  \
> +    self->function = dlsym(self->eglHandle, #function);                \
> +    if (!self->function) {                                             \
> +        wcore_errorf(WAFFLE_ERROR_UNKNOWN,                             \
> +                     "dlsym(\"%s\", \"" #function "\") failed: %s",    \
> +                     libEGL_filename, dlerror());                      \
> +        goto error;                                                    \
> +    }
> +
> +    RETREIVE_EGL_SYMBOL(eglMakeCurrent);
> +    RETREIVE_EGL_SYMBOL(eglGetProcAddress);
> +
> +    // display
> +    RETREIVE_EGL_SYMBOL(eglGetDisplay);
> +    RETREIVE_EGL_SYMBOL(eglInitialize);
> +    RETREIVE_EGL_SYMBOL(eglQueryString);
> +    RETREIVE_EGL_SYMBOL(eglGetError);
> +    RETREIVE_EGL_SYMBOL(eglTerminate);
> +
> +    // config
> +    RETREIVE_EGL_SYMBOL(eglChooseConfig);
> +
> +    // context
> +    RETREIVE_EGL_SYMBOL(eglBindAPI);
> +    RETREIVE_EGL_SYMBOL(eglCreateContext);
> +    RETREIVE_EGL_SYMBOL(eglDestroyContext);
> +
> +    // window
> +    RETREIVE_EGL_SYMBOL(eglGetConfigAttrib);
> +    RETREIVE_EGL_SYMBOL(eglCreateWindowSurface);
> +    RETREIVE_EGL_SYMBOL(eglDestroySurface);
> +    RETREIVE_EGL_SYMBOL(eglSwapBuffers);
> +
> +#undef RETREIVE_EGL_SYMBOL
>
> +error:
> +    // On failure the caller of wegl_platform_init will trigger it's own
> +    // destruction which will execute wegl_platform_teardown.
>      return ok;
>  }
> diff --git a/src/waffle/egl/wegl_platform.h b/src/waffle/egl/wegl_platform.h
> index 43108dc..645c3f8 100644
> --- a/src/waffle/egl/wegl_platform.h
> +++ b/src/waffle/egl/wegl_platform.h
> @@ -25,6 +25,8 @@
>
>  #pragma once
>
> +#include <EGL/egl.h>
> +
>  #include "wcore_platform.h"
>  #include "wcore_util.h"
>
> @@ -32,6 +34,40 @@ struct wegl_platform {
>      struct wcore_platform wcore;
>
>      // EGL function pointers
> +    void *eglHandle;
> +
> +    EGLBoolean (*eglMakeCurrent)(EGLDisplay dpy, EGLSurface draw,
> +                                 EGLSurface read, EGLContext ctx);
> +    __eglMustCastToProperFunctionPointerType
> +       (*eglGetProcAddress)(const char *procname);
> +
> +    // display
> +    EGLDisplay (*eglGetDisplay)(EGLNativeDisplayType display_id);
> +    EGLBoolean (*eglInitialize)(EGLDisplay dpy, EGLint *major, EGLint *minor);
> +    const char * (*eglQueryString)(EGLDisplay dpy, EGLint name);
> +    EGLint (*eglGetError)(void);
> +    EGLBoolean (*eglTerminate)(EGLDisplay dpy);
> +
> +    // config
> +    EGLBoolean (*eglChooseConfig)(EGLDisplay dpy, const EGLint *attrib_list,
> +                                  EGLConfig *configs, EGLint config_size,
> +                                  EGLint *num_config);
> +
> +    // context
> +    EGLBoolean (*eglBindAPI)(EGLenum api);
> +    EGLContext (*eglCreateContext)(EGLDisplay dpy, EGLConfig config,
> +                                   EGLContext share_context,
> +                                   const EGLint *attrib_list);
> +    EGLBoolean (*eglDestroyContext)(EGLDisplay dpy, EGLContext ctx);
> +
> +    // window
> +    EGLBoolean (*eglGetConfigAttrib)(EGLDisplay dpy, EGLConfig config,
> +                                     EGLint attribute, EGLint *value);
> +    EGLSurface (*eglCreateWindowSurface)(EGLDisplay dpy, EGLConfig config,
> +                                         EGLNativeWindowType win,
> +                                         const EGLint *attrib_list);
> +    EGLBoolean (*eglDestroySurface)(EGLDisplay dpy, EGLSurface surface);
> +    EGLBoolean (*eglSwapBuffers)(EGLDisplay dpy, EGLSurface surface);
>  };
>
>  DEFINE_CONTAINER_CAST_FUNC(wegl_platform,
> --
> 2.0.2
>
> _______________________________________________
> waffle mailing list
> waffle at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/waffle