[Mesa-dev] [PATCH 08/38] main: Refactor get_texture_for_framebuffer.

[Fredrik Höglund]

On Wednesday 04 March 2015, Laura Ekstrand wrote:
> This moves a few blocks around so that the control flow is more obvious.  If
> the texture is 0, just return true at the beginning of the function.
> Likewise, if the texObj is NULL, return true at the beginning of the funciton
> as well.
> ---
>  src/mesa/main/fbobject.c | 43 +++++++++++++++++++++----------------------
>  1 file changed, 21 insertions(+), 22 deletions(-)
> 
> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
> index 143c6b4..f86e1a0 100644
> --- a/src/mesa/main/fbobject.c
> +++ b/src/mesa/main/fbobject.c
> @@ -2437,17 +2437,34 @@ get_texture_for_framebuffer(struct gl_context *ctx,
>                              struct gl_texture_object **texObj)
>  {
>     GLenum maxLevelsTarget;
> +   GLboolean err = GL_TRUE;
>  
>     *texObj = NULL; /* This will get returned if texture = 0. */
>  
>     /* The textarget, level, and zoffset parameters are only validated if
>      * texture is non-zero.
>      */
> -   if (texture) {
> -      GLboolean err = GL_TRUE;
> +   if (!texture)
> +      return true;
> +
> +   *texObj = _mesa_lookup_texture(ctx, texture);
> +   if (!texObj) {

One more thing: this line is NULL-checking the wrong pointer.
It should be checking *texObj.

> +      /* Can't render to a non-existant texture object.
> +       *
> +       * The OpenGL 4.5 core spec (02.02.2015) in Section 9.2 Binding and
> +       * Managing Framebuffer Objects specifies a different error
> +       * depending upon the calling function (PDF pages 325-328).
> +       * *FramebufferTexture (where *layered = GL_TRUE) throws invalid
> +       * value, while the other commands throw invalid operation (where
> +       * *layered = GL_FALSE).
> +       */
> +      GLenum no_texobj_err = *layered ? GL_INVALID_VALUE :
> +                             GL_INVALID_OPERATION;
> +      _mesa_error(ctx, no_texobj_err,
> +                  "%s(non-generated texture %u)", caller, texture);
> +      return false;
> +   }
>  
> -      *texObj = _mesa_lookup_texture(ctx, texture);
> -      if (*texObj != NULL) {
>           if (textarget == 0) {
>              if (*layered) {
>                 /* We're being called by gl*FramebufferTexture() and textarget
> @@ -2496,23 +2513,6 @@ get_texture_for_framebuffer(struct gl_context *ctx,
>                  ? !_mesa_is_cube_face(textarget)
>                  : ((*texObj)->Target != textarget);
>           }
> -      }
> -      else {
> -         /* Can't render to a non-existant texture object.
> -          *
> -          * The OpenGL 4.5 core spec (02.02.2015) in Section 9.2 Binding and
> -          * Managing Framebuffer Objects specifies a different error
> -          * depending upon the calling function (PDF pages 325-328).
> -          * *FramebufferTexture (where *layered = GL_TRUE) throws invalid
> -          * value, while the other commands throw invalid operation (where
> -          * *layered = GL_FALSE).
> -          */
> -         GLenum no_texobj_err = *layered ? GL_INVALID_VALUE :
> -                                GL_INVALID_OPERATION;
> -         _mesa_error(ctx, no_texobj_err,
> -                     "%s(non-generated texture %u)", caller, texture);
> -         return false;
> -      }
>  
>        if (err) {
>           _mesa_error(ctx, GL_INVALID_OPERATION,
> @@ -2546,7 +2546,6 @@ get_texture_for_framebuffer(struct gl_context *ctx,
>                       "%s(invalid level %d)", caller, level);
>           return false;
>        }
> -   }
>  
>     return true;
>  }
>