[Mesa-dev] [PATCH 066/101] mesa: add draw_buffers_error() helper

Timothy Arceri tarceri at itsqueeze.com
Wed Jul 26 02:10:24 UTC 2017


On 22/07/17 03:40, Samuel Pitoiset wrote:
> And make draw_buffers() always inline.
> 
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>   src/mesa/main/buffers.c | 223 ++++++++++++++++++++++++++----------------------
>   1 file changed, 119 insertions(+), 104 deletions(-)
> 
> diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
> index 9a049e94c7..a2a1a3a741 100644
> --- a/src/mesa/main/buffers.c
> +++ b/src/mesa/main/buffers.c
> @@ -389,9 +389,9 @@ _mesa_NamedFramebufferDrawBuffer(GLuint framebuffer, GLenum buf)
>    *                 that is considered special and allowed as far as n is one
>    *                 since 4.5.
>    */
> -static void
> -draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
> -             GLsizei n, const GLenum *buffers, const char *caller)
> +static ALWAYS_INLINE void
> +draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb, GLsizei n,
> +             const GLenum *buffers, const char *caller, bool no_error)
>   {
>      GLuint output;
>      GLbitfield usedBufferMask, supportedMask;
> @@ -399,22 +399,24 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
>   
>      FLUSH_VERTICES(ctx, 0);
>   
> -   /* Turns out n==0 is a valid input that should not produce an error.
> -    * The remaining code below correctly handles the n==0 case.
> -    *
> -    * From the OpenGL 3.0 specification, page 258:
> -    * "An INVALID_VALUE error is generated if n is greater than
> -    *  MAX_DRAW_BUFFERS."
> -    */
> -   if (n < 0) {
> -      _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", caller);
> -      return;
> -   }
> +   if (!no_error) {
> +      /* Turns out n==0 is a valid input that should not produce an error.
> +       * The remaining code below correctly handles the n==0 case.
> +       *
> +       * From the OpenGL 3.0 specification, page 258:
> +       * "An INVALID_VALUE error is generated if n is greater than
> +       *  MAX_DRAW_BUFFERS."
> +       */
> +      if (n < 0) {
> +         _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", caller);
> +         return;
> +      }
>   
> -   if (n > (GLsizei) ctx->Const.MaxDrawBuffers) {
> -      _mesa_error(ctx, GL_INVALID_VALUE,
> -                  "%s(n > maximum number of draw buffers)", caller);
> -      return;
> +      if (n > (GLsizei) ctx->Const.MaxDrawBuffers) {
> +         _mesa_error(ctx, GL_INVALID_VALUE,
> +                     "%s(n > maximum number of draw buffers)", caller);
> +         return;
> +      }
>      }
>   
>      supportedMask = supported_buffer_bitmask(ctx, fb);

You seem to have missed an error check here.

    /* From the ES 3.0 specification, page 180:
     * "If the GL is bound to the default framebuffer, then n must be 1
     *  and the constant must be BACK or NONE."
     * (same restriction applies with GL_EXT_draw_buffers specification)
     */
    if (ctx->API == API_OPENGLES2 && _mesa_is_winsys_fbo(fb) &&
        (n != 1 || (buffers[0] != GL_NONE && buffers[0] != GL_BACK))) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "%s(invalid buffers)", 
caller);
       return;
    }

This should be moved into the new if block above.

With that fixed this patch is:

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

> @@ -435,65 +437,67 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
>      for (output = 0; output < n; output++) {
>         destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
>   
> -      /* From the OpenGL 3.0 specification, page 258:
> -       * "Each buffer listed in bufs must be one of the values from tables
> -       *  4.5 or 4.6.  Otherwise, an INVALID_ENUM error is generated.
> -       */
> -      if (destMask[output] == BAD_MASK) {
> -         _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
> -                     caller, _mesa_enum_to_string(buffers[output]));
> -         return;
> -      }
> -
> -      /* From the OpenGL 4.5 specification, page 493 (page 515 of the PDF)
> -       * "An INVALID_ENUM error is generated if any value in bufs is FRONT,
> -       *  LEFT, RIGHT, or FRONT_AND_BACK . This restriction applies to both
> -       *  the default framebuffer and framebuffer objects, and exists because
> -       *  these constants may themselves refer to multiple buffers, as shown
> -       *  in table 17.4."
> -       *
> -       * And on page 492 (page 514 of the PDF):
> -       * "If the default framebuffer is affected, then each of the constants
> -       *  must be one of the values listed in table 17.6 or the special value
> -       *  BACK. When BACK is used, n must be 1 and color values are written
> -       *  into the left buffer for single-buffered contexts, or into the back
> -       *  left buffer for double-buffered contexts."
> -       *
> -       * Note "special value BACK". GL_BACK also refers to multiple buffers,
> -       * but it is consider a special case here. This is a change on 4.5. For
> -       * OpenGL 4.x we check that behaviour. For any previous version we keep
> -       * considering it wrong (as INVALID_ENUM).
> -       */
> -      if (_mesa_bitcount(destMask[output]) > 1) {
> -         if (_mesa_is_winsys_fbo(fb) && ctx->Version >= 40 &&
> -             buffers[output] == GL_BACK) {
> -            if (n != 1) {
> -               _mesa_error(ctx, GL_INVALID_OPERATION, "%s(with GL_BACK n must be 1)",
> -                           caller);
> -               return;
> -            }
> -         } else {
> +      if (!no_error) {
> +         /* From the OpenGL 3.0 specification, page 258:
> +          * "Each buffer listed in bufs must be one of the values from tables
> +          *  4.5 or 4.6.  Otherwise, an INVALID_ENUM error is generated.
> +          */
> +         if (destMask[output] == BAD_MASK) {
>               _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
>                           caller, _mesa_enum_to_string(buffers[output]));
>               return;
>            }
> -      }
>   
> -      /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0
> -       * specification says:
> -       *
> -       *     "If the GL is bound to a draw framebuffer object, the ith buffer
> -       *     listed in bufs must be COLOR_ATTACHMENTi or NONE . Specifying a
> -       *     buffer out of order, BACK , or COLOR_ATTACHMENTm where m is greater
> -       *     than or equal to the value of MAX_- COLOR_ATTACHMENTS , will
> -       *     generate the error INVALID_OPERATION .
> -       */
> -      if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(fb) &&
> -          buffers[output] != GL_NONE &&
> -          (buffers[output] < GL_COLOR_ATTACHMENT0 ||
> -           buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) {
> -         _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)");
> -         return;
> +         /* From the OpenGL 4.5 specification, page 493 (page 515 of the PDF)
> +          * "An INVALID_ENUM error is generated if any value in bufs is FRONT,
> +          * LEFT, RIGHT, or FRONT_AND_BACK . This restriction applies to both
> +          * the default framebuffer and framebuffer objects, and exists because
> +          * these constants may themselves refer to multiple buffers, as shown
> +          * in table 17.4."
> +          *
> +          * And on page 492 (page 514 of the PDF):
> +          * "If the default framebuffer is affected, then each of the constants
> +          * must be one of the values listed in table 17.6 or the special value
> +          * BACK. When BACK is used, n must be 1 and color values are written
> +          * into the left buffer for single-buffered contexts, or into the back
> +          * left buffer for double-buffered contexts."
> +          *
> +          * Note "special value BACK". GL_BACK also refers to multiple buffers,
> +          * but it is consider a special case here. This is a change on 4.5.
> +          * For OpenGL 4.x we check that behaviour. For any previous version we
> +          * keep considering it wrong (as INVALID_ENUM).
> +          */
> +         if (_mesa_bitcount(destMask[output]) > 1) {
> +            if (_mesa_is_winsys_fbo(fb) && ctx->Version >= 40 &&
> +                buffers[output] == GL_BACK) {
> +               if (n != 1) {
> +                  _mesa_error(ctx, GL_INVALID_OPERATION, "%s(with GL_BACK n must be 1)",
> +                              caller);
> +                  return;
> +               }
> +            } else {
> +               _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
> +                           caller, _mesa_enum_to_string(buffers[output]));
> +               return;
> +            }
> +         }
> +
> +         /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0
> +          * specification says:
> +          *
> +          *     "If the GL is bound to a draw framebuffer object, the ith
> +          *     buffer listed in bufs must be COLOR_ATTACHMENTi or NONE .
> +          *     Specifying a buffer out of order, BACK , or COLOR_ATTACHMENTm
> +          *     where m is greater than or equal to the value of MAX_-
> +          *     COLOR_ATTACHMENTS , will generate the error INVALID_OPERATION .
> +          */
> +         if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(fb) &&
> +             buffers[output] != GL_NONE &&
> +             (buffers[output] < GL_COLOR_ATTACHMENT0 ||
> +              buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) {
> +            _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)");
> +            return;
> +         }
>         }
>   
>         if (buffers[output] == GL_NONE) {
> @@ -508,7 +512,7 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
>             *     or equal to the value of MAX_COLOR_ATTACHMENTS, then the error
>             *     INVALID_OPERATION results."
>             */
> -         if (_mesa_is_user_fbo(fb) && buffers[output] >=
> +         if (!no_error && _mesa_is_user_fbo(fb) && buffers[output] >=
>                GL_COLOR_ATTACHMENT0 + ctx->Const.MaxDrawBuffers) {
>               _mesa_error(ctx, GL_INVALID_OPERATION,
>                           "%s(buffers[%d] >= maximum number of draw buffers)",
> @@ -527,37 +531,40 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
>             *  INVALID_OPERATION results."
>             */
>            destMask[output] &= supportedMask;
> -         if (destMask[output] == 0) {
> -            _mesa_error(ctx, GL_INVALID_OPERATION,
> -                        "%s(unsupported buffer %s)",
> -                        caller, _mesa_enum_to_string(buffers[output]));
> -            return;
> -         }
> +         if (!no_error) {
> +            if (destMask[output] == 0) {
> +               _mesa_error(ctx, GL_INVALID_OPERATION,
> +                           "%s(unsupported buffer %s)",
> +                           caller, _mesa_enum_to_string(buffers[output]));
> +               return;
> +            }
>   
> -         /* ES 3.0 is even more restrictive.  From the ES 3.0 spec, page 180:
> -          * "If the GL is bound to a framebuffer object, the ith buffer listed
> -          *  in bufs must be COLOR_ATTACHMENTi or NONE. [...] INVALID_OPERATION."
> -          * (same restriction applies with GL_EXT_draw_buffers specification)
> -          */
> -         if (ctx->API == API_OPENGLES2 && _mesa_is_user_fbo(fb) &&
> -             buffers[output] != GL_NONE &&
> -             buffers[output] != GL_COLOR_ATTACHMENT0 + output) {
> -            _mesa_error(ctx, GL_INVALID_OPERATION,
> -                        "%s(unsupported buffer %s)",
> -                        caller, _mesa_enum_to_string(buffers[output]));
> -            return;
> -         }
> +            /* ES 3.0 is even more restrictive.  From the ES 3.0 spec, page 180:
> +             * "If the GL is bound to a framebuffer object, the ith buffer
> +             * listed in bufs must be COLOR_ATTACHMENTi or NONE. [...]
> +             * INVALID_OPERATION." (same restriction applies with
> +             * GL_EXT_draw_buffers specification)
> +             */
> +            if (ctx->API == API_OPENGLES2 && _mesa_is_user_fbo(fb) &&
> +                buffers[output] != GL_NONE &&
> +                buffers[output] != GL_COLOR_ATTACHMENT0 + output) {
> +               _mesa_error(ctx, GL_INVALID_OPERATION,
> +                           "%s(unsupported buffer %s)",
> +                           caller, _mesa_enum_to_string(buffers[output]));
> +               return;
> +            }
>   
> -         /* From the OpenGL 3.0 specification, page 258:
> -          * "Except for NONE, a buffer may not appear more than once in the
> -          *  array pointed to by bufs.  Specifying a buffer more then once will
> -          *  result in the error INVALID_OPERATION."
> -          */
> -         if (destMask[output] & usedBufferMask) {
> -            _mesa_error(ctx, GL_INVALID_OPERATION,
> -                        "%s(duplicated buffer %s)",
> -                        caller, _mesa_enum_to_string(buffers[output]));
> -            return;
> +            /* From the OpenGL 3.0 specification, page 258:
> +             * "Except for NONE, a buffer may not appear more than once in the
> +             * array pointed to by bufs.  Specifying a buffer more then once
> +             * will result in the error INVALID_OPERATION."
> +             */
> +            if (destMask[output] & usedBufferMask) {
> +               _mesa_error(ctx, GL_INVALID_OPERATION,
> +                           "%s(duplicated buffer %s)",
> +                           caller, _mesa_enum_to_string(buffers[output]));
> +               return;
> +            }
>            }
>   
>            /* update bitmask */
> @@ -583,11 +590,19 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
>   }
>   
>   
> +static void
> +draw_buffers_error(struct gl_context *ctx, struct gl_framebuffer *fb, GLsizei n,
> +                   const GLenum *buffers, const char *caller)
> +{
> +   draw_buffers(ctx, fb, n, buffers, caller, false);
> +}
> +
> +
>   void GLAPIENTRY
>   _mesa_DrawBuffers(GLsizei n, const GLenum *buffers)
>   {
>      GET_CURRENT_CONTEXT(ctx);
> -   draw_buffers(ctx, ctx->DrawBuffer, n, buffers, "glDrawBuffers");
> +   draw_buffers_error(ctx, ctx->DrawBuffer, n, buffers, "glDrawBuffers");
>   }
>   
>   
> @@ -607,7 +622,7 @@ _mesa_NamedFramebufferDrawBuffers(GLuint framebuffer, GLsizei n,
>      else
>         fb = ctx->WinSysDrawBuffer;
>   
> -   draw_buffers(ctx, fb, n, bufs, "glNamedFramebufferDrawBuffers");
> +   draw_buffers_error(ctx, fb, n, bufs, "glNamedFramebufferDrawBuffers");
>   }
>   
>   
> 


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