struct st_renderbuffer *acc_strb
= st_renderbuffer(ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
struct st_renderbuffer *color_strb
struct st_renderbuffer *acc_strb
= st_renderbuffer(ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
struct st_renderbuffer *color_strb