[Mesa-dev] [PATCH 7/8] mesa: Initialize image units to default state on context creation.

[Francisco Jerez]

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.
---
 src/mesa/main/context.c     |  2 ++
 src/mesa/main/shaderimage.c | 13 +++++++++++++
 src/mesa/main/shaderimage.h |  6 ++++++
 3 files changed, 21 insertions(+)

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 63d30a2..11f3c13 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"
@@ -820,6 +821,7 @@ 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 8caff2f..3189500 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 < Elements(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 1c7d1e0..33d8a1e 100644
--- a/src/mesa/main/shaderimage.h
+++ b/src/mesa/main/shaderimage.h
@@ -43,6 +43,12 @@ 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.
  *
  * To be called when the state of any texture bound to an image unit
-- 
2.1.3