From b663d6bc6f4de9439107fc6444e436d14e21ee79 Mon Sep 17 00:00:00 2001
From: Francisco Jerez <currojerez@riseup.net>
Date: Sat, 31 Jan 2015 17:00:19 +0200
Subject: mesa: Initialize image units to default state on context creation.

This is the required initial image unit state according to "Table 23.45. Image
State (state per image unit)" of the OpenGL 4.3 specification.

Reviewed-by: Matt Turner <mattst88@gmail.com>
---
 src/mesa/main/context.c     |  2 ++
 src/mesa/main/shaderimage.c | 13 +++++++++++++
 src/mesa/main/shaderimage.h |  6 ++++++
 3 files changed, 21 insertions(+)

(limited to 'src')

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 4aaf8b1af57..0a192de8c0a 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -118,6 +118,7 @@
 #include "scissor.h"
 #include "shared.h"
 #include "shaderobj.h"
+#include "shaderimage.h"
 #include "util/simple_list.h"
 #include "state.h"
 #include "stencil.h"
@@ -821,6 +822,7 @@ init_attrib_groups(struct gl_context *ctx)
    _mesa_init_feedback( ctx );
    _mesa_init_fog( ctx );
    _mesa_init_hint( ctx );
+   _mesa_init_image_units( ctx );
    _mesa_init_line( ctx );
    _mesa_init_lighting( ctx );
    _mesa_init_matrix( ctx );
diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
index 8caff2f2660..efe439c6dfd 100644
--- a/src/mesa/main/shaderimage.c
+++ b/src/mesa/main/shaderimage.c
@@ -331,6 +331,19 @@ get_image_format_class(mesa_format format)
    }
 }
 
+void
+_mesa_init_image_units(struct gl_context *ctx)
+{
+   unsigned i;
+
+   for (i = 0; i < ARRAY_SIZE(ctx->ImageUnits); ++i) {
+      struct gl_image_unit *u = &ctx->ImageUnits[i];
+      u->Access = GL_READ_ONLY;
+      u->Format = GL_R8;
+      u->_ActualFormat = _mesa_get_shader_image_format(u->Format);
+   }
+}
+
 static GLboolean
 validate_image_unit(struct gl_context *ctx, struct gl_image_unit *u)
 {
diff --git a/src/mesa/main/shaderimage.h b/src/mesa/main/shaderimage.h
index 1c7d1e0e894..33d8a1eff55 100644
--- a/src/mesa/main/shaderimage.h
+++ b/src/mesa/main/shaderimage.h
@@ -42,6 +42,12 @@ struct gl_context;
 mesa_format
 _mesa_get_shader_image_format(GLenum format);
 
+/**
+ * Initialize a context's shader image units to the default state.
+ */
+void
+_mesa_init_image_units(struct gl_context *ctx);
+
 /**
  * Recalculate the \c _Valid flag of a context's shader image units.
  *
-- 
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