From 615ba115632c602d2a77535c1d52024f827a0ace Mon Sep 17 00:00:00 2001
From: =?utf8?q?Nicolai=20H=C3=A4hnle?= <nicolai.haehnle@amd.com>
Date: Wed, 8 Jun 2016 13:22:52 +0200
Subject: [PATCH] st/mesa: add readpix_cache structure
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Reviewed-by: Marek Olšák <marek.olsak@amd.com>
---
 src/mesa/state_tracker/st_cb_readpixels.c |  8 ++++++++
 src/mesa/state_tracker/st_context.c       |  3 +++
 src/mesa/state_tracker/st_context.h       | 11 +++++++++++
 3 files changed, 22 insertions(+)

diff --git a/src/mesa/state_tracker/st_cb_readpixels.c b/src/mesa/state_tracker/st_cb_readpixels.c
index ef575baca9d..a501b7b3ee4 100644
--- a/src/mesa/state_tracker/st_cb_readpixels.c
+++ b/src/mesa/state_tracker/st_cb_readpixels.c
@@ -218,6 +218,14 @@ fail:
    return success;
 }
 
+/* Invalidate the readpixels cache to ensure we don't read stale data.
+ */
+void st_invalidate_readpix_cache(struct st_context *st)
+{
+   pipe_resource_reference(&st->readpix_cache.src, NULL);
+   pipe_resource_reference(&st->readpix_cache.cache, NULL);
+}
+
 /**
  * Create a staging texture and blit the requested region to it.
  */
diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 308094a43ac..472121581eb 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -184,6 +184,9 @@ st_destroy_context_priv(struct st_context *st)
    free(st->drawpix_cache.image);
    pipe_resource_reference(&st->drawpix_cache.texture, NULL);
 
+   /* free glReadPixels cache data */
+   st_invalidate_readpix_cache(st);
+
    cso_destroy_context(st->cso_context);
    free( st );
 }
diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index e3bee60d4d7..cc25e06111e 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -228,6 +228,16 @@ struct st_context
       struct pipe_resource *texture;
    } drawpix_cache;
 
+   /** for glReadPixels */
+   struct {
+      struct pipe_resource *src;
+      struct pipe_resource *cache;
+      enum pipe_format dst_format;
+      unsigned level;
+      unsigned layer;
+      unsigned hits;
+   } readpix_cache;
+
    /** for glClear */
    struct {
       struct pipe_rasterizer_state raster;
@@ -306,6 +316,7 @@ extern void st_init_driver_functions(struct pipe_screen *screen,
 
 void st_invalidate_state(struct gl_context * ctx, GLbitfield new_state);
 
+void st_invalidate_readpix_cache(struct st_context *st);
 
 
 #define Y_0_TOP 1
-- 
2.30.2