[Mesa-dev] [PATCH 1/3] mesa: add explicit enable for EXT_float_blend, and error condition

[Tapani Pälli]

Patches 1 and 3 are
Reviewed-by: Tapani Pälli <tapani.palli at intel.com>

On 2/13/19 5:40 AM, Ilia Mirkin wrote:
> If EXT_float_blend is not supported, error out on blending of FP32
> attachments in an ES2 context.
> 
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>   src/mesa/main/draw_validate.c    | 19 +++++++++++++++++++
>   src/mesa/main/extensions_table.h |  2 +-
>   src/mesa/main/fbobject.c         |  4 ++++
>   src/mesa/main/mtypes.h           |  2 ++
>   4 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/src/mesa/main/draw_validate.c b/src/mesa/main/draw_validate.c
> index b715a27f8b7..779cd1c12c7 100644
> --- a/src/mesa/main/draw_validate.c
> +++ b/src/mesa/main/draw_validate.c
> @@ -304,6 +304,25 @@ check_valid_to_render(struct gl_context *ctx, const char *function)
>                        "%s(tess ctrl shader is missing)", function);
>            return false;
>         }
> +
> +      /* From GL_EXT_color_buffer_float:
> +       *
> +       *     "Blending applies only if the color buffer has a fixed-point or
> +       *     or floating-point format. If the color buffer has an integer
> +       *     format, proceed to the next operation.  Furthermore, an
> +       *     INVALID_OPERATION error is generated by DrawArrays and the other
> +       *     drawing commands defined in section 2.8.3 (10.5 in ES 3.1) if
> +       *     blending is enabled (see below) and any draw buffer has 32-bit
> +       *     floating-point format components."
> +       *
> +       * However GL_EXT_float_blend removes this text.
> +       */
> +      if (!ctx->Extensions.EXT_float_blend &&
> +          (ctx->DrawBuffer->_FP32Buffers & ctx->Color.BlendEnabled)) {
> +         _mesa_error(ctx, GL_INVALID_OPERATION,
> +                     "%s(32-bit float output + blending)", function);
> +         return false;
> +      }
>         break;
>   
>      case API_OPENGL_CORE:
> diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h
> index 0d6bb452ffa..b0492fed698 100644
> --- a/src/mesa/main/extensions_table.h
> +++ b/src/mesa/main/extensions_table.h
> @@ -226,7 +226,7 @@ EXT(EXT_draw_buffers_indexed                , ARB_draw_buffers_blend
>   EXT(EXT_draw_elements_base_vertex           , ARB_draw_elements_base_vertex          ,  x ,  x ,  x , ES2, 2014)
>   EXT(EXT_draw_instanced                      , ARB_draw_instanced                     , GLL, GLC,  x ,  x , 2006)
>   EXT(EXT_draw_range_elements                 , dummy_true                             , GLL,  x ,  x ,  x , 1997)
> -EXT(EXT_float_blend                         , dummy_true                             ,  x ,  x ,  x ,  30, 2015)
> +EXT(EXT_float_blend                         , EXT_float_blend                        ,  x ,  x ,  x ,  30, 2015)
>   EXT(EXT_fog_coord                           , dummy_true                             , GLL,  x ,  x ,  x , 1999)
>   EXT(EXT_frag_depth                          , dummy_true                             ,  x ,  x ,  x , ES2, 2010)
>   EXT(EXT_framebuffer_blit                    , dummy_true                             , GLL, GLC,  x ,  x , 2005)
> diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
> index 87c33be7854..21e3496593c 100644
> --- a/src/mesa/main/fbobject.c
> +++ b/src/mesa/main/fbobject.c
> @@ -1004,6 +1004,7 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
>      fb->_HasAttachments = true;
>      fb->_IntegerBuffers = 0;
>      fb->_RGBBuffers = 0;
> +   fb->_FP32Buffers = 0;
>   
>      /* Start at -2 to more easily loop over all attachment points.
>       *  -2: depth buffer
> @@ -1153,6 +1154,9 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
>            if (f == GL_RGB)
>               fb->_RGBBuffers |= (1 << i);
>   
> +         if (type == GL_FLOAT && _mesa_get_format_max_bits(attFormat) > 16)
> +            fb->_FP32Buffers |= (1 << i);
> +
>            fb->_AllColorBuffersFixedPoint =
>               fb->_AllColorBuffersFixedPoint &&
>               (type == GL_UNSIGNED_NORMALIZED || type == GL_SIGNED_NORMALIZED);
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index dda96cd2f19..ca00de7dc63 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -3506,6 +3506,7 @@ struct gl_framebuffer
>   
>      GLbitfield _IntegerBuffers;  /**< Which color buffers are integer valued */
>      GLbitfield _RGBBuffers;  /**< Which color buffers have baseformat == RGB */
> +   GLbitfield _FP32Buffers; /**< Which color buffers are FP32 */
>   
>      /* ARB_color_buffer_float */
>      GLboolean _AllColorBuffersFixedPoint; /* no integer, no float */
> @@ -4248,6 +4249,7 @@ struct gl_extensions
>      GLboolean EXT_depth_bounds_test;
>      GLboolean EXT_disjoint_timer_query;
>      GLboolean EXT_draw_buffers2;
> +   GLboolean EXT_float_blend;
>      GLboolean EXT_framebuffer_multisample;
>      GLboolean EXT_framebuffer_multisample_blit_scaled;
>      GLboolean EXT_framebuffer_sRGB;
>