[Mesa-dev] [PATCH] vbo: signal _NEW_ARRAY when transitioning between glBegin/End, glDrawArrays

[Marek Olšák]

Hi Brian,

Is there a reason to set _NEW_ARRAY when transitioning between
DrawArrays and DrawElements?

Marek

On Wed, Dec 21, 2011 at 1:58 AM, Brian Paul <brianp at vmware.com> wrote:
> This fixes a regression seen with the isosurf demo when switching between
> glBegin/End and glDrawArrays (do it several times).  The problem was the
> driver wasn't getting _NEW_ARRAY when the arrays were subtly changed:
> (vertex3f, normal3f) vs. (normal3f, vertex3f).
>
> This patch fixes that by signaling _NEW_ARRAY whenever we transition
> between glBegin/End and glDrawArrays mode.
>
> The patch also fixes up the initialization of the map_vp_none[] array
> to stop putting strange values in the last five elements of the array.
> ---
>  src/mesa/vbo/vbo_context.c    |   11 ++++-------
>  src/mesa/vbo/vbo_exec.h       |   33 +++++++++++++++++++++++++++++++++
>  src/mesa/vbo/vbo_exec_api.c   |    2 ++
>  src/mesa/vbo/vbo_exec_array.c |    4 ++++
>  4 files changed, 43 insertions(+), 7 deletions(-)
>
> diff --git a/src/mesa/vbo/vbo_context.c b/src/mesa/vbo/vbo_context.c
> index b2e6bbc..d83f2fd 100644
> --- a/src/mesa/vbo/vbo_context.c
> +++ b/src/mesa/vbo/vbo_context.c
> @@ -176,17 +176,14 @@ GLboolean _vbo_CreateContext( struct gl_context *ctx )
>    {
>       GLuint i;
>
> -      /* When no vertex program, pull in the material attributes in
> -       * the generic range.
> -       */
> -      for (i = 0; i < VERT_ATTRIB_FF_MAX; i++)
> +      /* identity mapping */
> +      for (i = 0; i < Elements(vbo->map_vp_none); i++)
>         vbo->map_vp_none[i] = i;
> +      /* map material attribs to generic slots */
>       for (i = 0; i < NR_MAT_ATTRIBS; i++)
>         vbo->map_vp_none[VERT_ATTRIB_GENERIC(i)]
>             = VBO_ATTRIB_MAT_FRONT_AMBIENT + i;
> -      for (i = NR_MAT_ATTRIBS; i < VERT_ATTRIB_GENERIC_MAX; i++)
> -        vbo->map_vp_none[VERT_ATTRIB_GENERIC(i)] = i;
> -
> +
>       for (i = 0; i < Elements(vbo->map_vp_arb); i++)
>         vbo->map_vp_arb[i] = i;
>    }
> diff --git a/src/mesa/vbo/vbo_exec.h b/src/mesa/vbo/vbo_exec.h
> index cfed8e8..339461d 100644
> --- a/src/mesa/vbo/vbo_exec.h
> +++ b/src/mesa/vbo/vbo_exec.h
> @@ -78,12 +78,23 @@ struct vbo_exec_copied_vtx {
>  };
>
>
> +enum draw_method
> +{
> +   DRAW_NONE,
> +   DRAW_BEGIN_END,
> +   DRAW_ELEMENTS,
> +   DRAW_ARRAYS
> +};
> +
> +
>  struct vbo_exec_context
>  {
>    struct gl_context *ctx;
>    GLvertexformat vtxfmt;
>    GLvertexformat vtxfmt_noop;
>
> +   enum draw_method last_draw_method;
> +
>    struct {
>       struct gl_buffer_object *bufferobj;
>
> @@ -164,6 +175,28 @@ void vbo_exec_array_destroy( struct vbo_exec_context *exec );
>  void vbo_exec_vtx_init( struct vbo_exec_context *exec );
>  void vbo_exec_vtx_destroy( struct vbo_exec_context *exec );
>
> +
> +/**
> + * This is called by glBegin, glDrawArrays and glDrawElements (and
> + * variations of those calls).  When we transition from immediate mode
> + * drawing to array drawing we need to invalidate the array state.
> + *
> + * glBegin/End builds vertex arrays.  Those arrays may look identical
> + * to glDrawArrays arrays except that the position of the elements may
> + * be different.  For example, arrays of (position3v, normal3f) vs. arrays
> + * of (normal3f, position3f).  So we need to make sure we notify drivers
> + * that arrays may be changing.
> + */
> +static inline void
> +vbo_draw_method(struct vbo_exec_context *exec, enum draw_method method)
> +{
> +   if (exec->last_draw_method != method) {
> +      exec->ctx->NewState |= _NEW_ARRAY;
> +      exec->last_draw_method = method;
> +   }
> +}
> +
> +
>  #if FEATURE_beginend
>
>  void vbo_exec_vtx_flush( struct vbo_exec_context *exec, GLboolean unmap );
> diff --git a/src/mesa/vbo/vbo_exec_api.c b/src/mesa/vbo/vbo_exec_api.c
> index 4be0169..cb5f9ae 100644
> --- a/src/mesa/vbo/vbo_exec_api.c
> +++ b/src/mesa/vbo/vbo_exec_api.c
> @@ -701,6 +701,8 @@ static void GLAPIENTRY vbo_exec_Begin( GLenum mode )
>          return;
>       }
>
> +      vbo_draw_method(exec, DRAW_BEGIN_END);
> +
>       if (ctx->Driver.PrepareExecBegin)
>         ctx->Driver.PrepareExecBegin(ctx);
>
> diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
> index a6e41e9..e84c0f3 100644
> --- a/src/mesa/vbo/vbo_exec_array.c
> +++ b/src/mesa/vbo/vbo_exec_array.c
> @@ -558,6 +558,8 @@ vbo_draw_arrays(struct gl_context *ctx, GLenum mode, GLint start,
>
>    vbo_bind_arrays(ctx);
>
> +   vbo_draw_method(exec, DRAW_ARRAYS);
> +
>    /* Again... because we may have changed the bitmask of per-vertex varying
>     * attributes.  If we regenerate the fixed-function vertex program now
>     * we may be able to prune down the number of vertex attributes which we
> @@ -773,6 +775,8 @@ vbo_validated_drawrangeelements(struct gl_context *ctx, GLenum mode,
>
>    vbo_bind_arrays( ctx );
>
> +   vbo_draw_method(exec, DRAW_ELEMENTS);
> +
>    /* check for dirty state again */
>    if (ctx->NewState)
>       _mesa_update_state( ctx );
> --
> 1.7.3.4
>
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