[Mesa-dev] [PATCH 1/4] meta: Pause/resume an active occlusion query over any meta operation

[Ian Romanick]

On 12/17/2012 02:24 PM, Carl Worth wrote:
> This avoids the occlusion query erroneously accumulating results during the
> meta operation.
>
> This fixes the following es3conform tests:
>
> 	occlusion_query_draw_occluded.test
>   	occlusion_query_clear
> 	occlusion_query_custom_framebuffer
> 	occlusion_query_stencil_test
> 	occlusion_query_discarded_fragments
> ---
>   src/mesa/drivers/common/meta.c |   21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
> index f95d207..e66476c 100644
> --- a/src/mesa/drivers/common/meta.c
> +++ b/src/mesa/drivers/common/meta.c
> @@ -54,6 +54,7 @@
>   #include "main/pixel.h"
>   #include "main/pbo.h"
>   #include "main/polygon.h"
> +#include "main/queryobj.h"
>   #include "main/readpix.h"
>   #include "main/scissor.h"
>   #include "main/shaderapi.h"
> @@ -89,6 +90,9 @@ struct save_state
>   {
>      GLbitfield SavedState;  /**< bitmask of MESA_META_* flags */
>
> +   /** MESA_META_CLEAR (and others?) */
> +   struct gl_query_object *CurrentOcclusionObject;
> +
>      /** MESA_META_ALPHA_TEST */
>      GLboolean AlphaEnabled;
>      GLenum AlphaFunc;
> @@ -479,6 +483,13 @@ _mesa_meta_begin(struct gl_context *ctx, GLbitfield state)
>      if (save->TransformFeedbackNeedsResume)
>         _mesa_PauseTransformFeedback();
>
> +   /* After saving the current occlusion object, call EndQuery so that no
> +    * occlusion querying will be active during the meta-operation.
> +    */
> +   save->CurrentOcclusionObject = ctx->Query.CurrentOcclusionObject;
> +   if (save->CurrentOcclusionObject)
> +      _mesa_EndQuery(save->CurrentOcclusionObject->Target);
> +

I think we need a flag to select this behavior.  There are some meta ops 
that *do* generate fragments (e.g., _mesa_meta_DrawPixels), and this 
will prevent them from being counted.

>      if (state & MESA_META_ALPHA_TEST) {
>         save->AlphaEnabled = ctx->Color.AlphaEnabled;
>         save->AlphaFunc = ctx->Color.AlphaFunc;
> @@ -807,6 +818,16 @@ _mesa_meta_end(struct gl_context *ctx)
>      struct save_state *save = &ctx->Meta->Save[ctx->Meta->SaveStackDepth - 1];
>      const GLbitfield state = save->SavedState;
>
> +   /* After starting a new occlusion query, initialize the results to the
> +    * values saved previously. The driver will then continue to increment
> +    * these values.
> +    */
> +   if (save->CurrentOcclusionObject) {
> +      _mesa_BeginQuery(save->CurrentOcclusionObject->Target,
> +                       save->CurrentOcclusionObject->Id);
> +      ctx->Query.CurrentOcclusionObject->Result = save->CurrentOcclusionObject->Result;
> +   }
> +
>      if (state & MESA_META_ALPHA_TEST) {
>         if (ctx->Color.AlphaEnabled != save->AlphaEnabled)
>            _mesa_set_enable(ctx, GL_ALPHA_TEST, save->AlphaEnabled);
>