[Mesa-dev] [PATCH 1/2] mesa: Keep a computed value for dual source blend func with each buffer.

[Ian Romanick]

On 05/18/2012 08:00 PM, Eric Anholt wrote:
> The i965 driver needed this as well for hardware setup, so instead of
> duplicating the logic, just save it off.

This patch is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

I'll have to take your word for it on the other one. :)

> ---
>   src/mesa/main/blend.c   |   20 ++++++++++++++++++++
>   src/mesa/main/context.c |   24 +++++++-----------------
>   src/mesa/main/mtypes.h  |    5 +++++
>   3 files changed, 32 insertions(+), 17 deletions(-)
>
> diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
> index bc446ed..5bc40a0 100644
> --- a/src/mesa/main/blend.c
> +++ b/src/mesa/main/blend.c
> @@ -166,6 +166,24 @@ _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
>      _mesa_BlendFuncSeparateEXT(sfactor, dfactor, sfactor, dfactor);
>   }
>
> +static GLboolean
> +blend_factor_is_dual_src(GLenum factor)
> +{
> +   return (factor == GL_SRC1_COLOR ||
> +	   factor == GL_SRC1_ALPHA ||
> +	   factor == GL_ONE_MINUS_SRC1_COLOR ||
> +	   factor == GL_ONE_MINUS_SRC1_ALPHA);
> +}
> +
> +static void
> +update_uses_dual_src(struct gl_context *ctx, int buf)
> +{
> +   ctx->Color.Blend[buf]._UsesDualSrc =
> +      (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
> +       blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
> +       blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
> +       blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
> +}
>
>   /**
>    * Set the separate blend source/dest factors for all draw buffers.
> @@ -220,6 +238,7 @@ _mesa_BlendFuncSeparateEXT( GLenum sfactorRGB, GLenum dfactorRGB,
>         ctx->Color.Blend[buf].DstRGB = dfactorRGB;
>         ctx->Color.Blend[buf].SrcA = sfactorA;
>         ctx->Color.Blend[buf].DstA = dfactorA;
> +      update_uses_dual_src(ctx, buf);
>      }
>      ctx->Color._BlendFuncPerBuffer = GL_FALSE;
>
> @@ -282,6 +301,7 @@ _mesa_BlendFuncSeparatei(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
>      ctx->Color.Blend[buf].DstRGB = dfactorRGB;
>      ctx->Color.Blend[buf].SrcA = sfactorA;
>      ctx->Color.Blend[buf].DstA = dfactorA;
> +   update_uses_dual_src(ctx, buf);
>      ctx->Color._BlendFuncPerBuffer = GL_TRUE;
>
>      if (ctx->Driver.BlendFuncSeparatei) {
> diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
> index bafd250..2753f56 100644
> --- a/src/mesa/main/context.c
> +++ b/src/mesa/main/context.c
> @@ -1700,13 +1700,6 @@ _mesa_set_mvp_with_dp4( struct gl_context *ctx,
>      ctx->mvp_with_dp4 = flag;
>   }
>
> -static GLboolean
> -blend_factor_is_dual_src(GLenum factor)
> -{
> -   return factor == GL_SRC1_COLOR || factor == GL_SRC1_ALPHA ||
> -      factor == GL_ONE_MINUS_SRC1_COLOR || factor == GL_ONE_MINUS_SRC1_ALPHA;
> -}
> -
>   /*
>    * ARB_blend_func_extended - ERRORS section
>    * "The error INVALID_OPERATION is generated by Begin or any procedure that
> @@ -1719,16 +1712,13 @@ static GLboolean
>   _mesa_check_blend_func_error(struct gl_context *ctx)
>   {
>      GLuint i;
> -   for (i = 0; i<  ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
> -      if (blend_factor_is_dual_src(ctx->Color.Blend[i].SrcRGB) ||
> -          blend_factor_is_dual_src(ctx->Color.Blend[i].DstRGB) ||
> -          blend_factor_is_dual_src(ctx->Color.Blend[i].SrcA) ||
> -          blend_factor_is_dual_src(ctx->Color.Blend[i].DstA)) {
> -         if (i>= ctx->Const.MaxDualSourceDrawBuffers) {
> -            _mesa_error(ctx, GL_INVALID_OPERATION,
> -                        "dual source blend on illegal attachment");
> -            return GL_FALSE;
> -         }
> +   for (i = ctx->Const.MaxDualSourceDrawBuffers;
> +	i<  ctx->DrawBuffer->_NumColorDrawBuffers;
> +	i++) {
> +      if (ctx->Color.Blend[i]._UsesDualSrc) {
> +	 _mesa_error(ctx, GL_INVALID_OPERATION,
> +		     "dual source blend on illegal attachment");
> +	 return GL_FALSE;
>         }
>      }
>      return GL_TRUE;
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index c306ac6..b63eac6 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -755,6 +755,11 @@ struct gl_colorbuffer_attrib
>         GLenum DstA;               /**<  Alpha blend dest term */
>         GLenum EquationRGB;        /**<  GL_ADD, GL_SUBTRACT, etc. */
>         GLenum EquationA;          /**<  GL_ADD, GL_SUBTRACT, etc. */
> +      /**
> +       * Set if any blend factor uses SRC1.  Computed at the time blend factors
> +       * get set.
> +       */
> +      GLboolean _UsesDualSrc;
>      } Blend[MAX_DRAW_BUFFERS];
>      /** Are the blend func terms currently different for each buffer/target? */
>      GLboolean _BlendFuncPerBuffer;