mesa_glinterop: make GL interop version field bidirectional

This allows clear and easy communication between the two.

Caller: Requesting information (struct vN)
Callee: I know how to deal with older version (vN-1) only. Here is your
data and the version I support.
Caller: Older version ? Sure I'll cap all access to the fields provided
by the older version (vN-1)

Signed-off-by: Emil Velikov <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>
Tested-by: Tom Stellard <[email protected]>

2 files changed, 20 insertions, 5 deletions

diff --git a/include/GL/internal/dri_interface.h b/include/GL/internal/dri_interface.h
index 4008658dcef..f80233b82b6 100644
--- a/include/GL/internal/dri_interface.h
+++ b/include/GL/internal/dri_interface.h
@@ -414,7 +414,7 @@ struct __DRI2interopExtensionRec {
 
    /** Same as MesaGLInterop*ExportObject. */
    int (*export_object)(__DRIcontext *ctx,
-                        const mesa_glinterop_export_in *in,
+                        mesa_glinterop_export_in *in,
                         mesa_glinterop_export_out *out);
 };
 
diff --git a/include/GL/mesa_glinterop.h b/include/GL/mesa_glinterop.h
index 0a22b9be321..b805d63d3e1 100644
--- a/include/GL/mesa_glinterop.h
+++ b/include/GL/mesa_glinterop.h
@@ -94,6 +94,11 @@ enum {
  */
 typedef struct _mesa_glinterop_device_info {
    /* The caller should set this to the version of the struct they support */
+   /* The callee will overwrite it if it supports a lower version.
+    *
+    * The caller should check the value and access up-to the version supported
+    * by the the callee.
+    */
    /* NOTE: Do not use the MESA_GLINTEROP_DEVICE_INFO_VERSION macro */
    uint32_t version;
 
@@ -117,6 +122,11 @@ typedef struct _mesa_glinterop_device_info {
  */
 typedef struct _mesa_glinterop_export_in {
    /* The caller should set this to the version of the struct they support */
+   /* The callee will overwrite it if it supports a lower version.
+    *
+    * The caller should check the value and access up-to the version supported
+    * by the the callee.
+    */
    /* NOTE: Do not use the MESA_GLINTEROP_EXPORT_IN_VERSION macro */
    uint32_t version;
 
@@ -177,6 +187,11 @@ typedef struct _mesa_glinterop_export_in {
  */
 typedef struct _mesa_glinterop_export_out {
    /* The caller should set this to the version of the struct they support */
+   /* The callee will overwrite it if it supports a lower version.
+    *
+    * The caller should check the value and access up-to the version supported
+    * by the the callee.
+    */
    /* NOTE: Do not use the MESA_GLINTEROP_EXPORT_OUT_VERSION macro */
    uint32_t version;
 
@@ -257,7 +272,7 @@ MesaGLInteropEGLQueryDeviceInfo(EGLDisplay dpy, EGLContext context,
  */
 int
 MesaGLInteropGLXExportObject(Display *dpy, GLXContext context,
-                             const mesa_glinterop_export_in *in,
+                             mesa_glinterop_export_in *in,
                              mesa_glinterop_export_out *out);
 
 
@@ -267,7 +282,7 @@ MesaGLInteropGLXExportObject(Display *dpy, GLXContext context,
  */
 int
 MesaGLInteropEGLExportObject(EGLDisplay dpy, EGLContext context,
-                             const mesa_glinterop_export_in *in,
+                             mesa_glinterop_export_in *in,
                              mesa_glinterop_export_out *out);
 
 
@@ -276,10 +291,10 @@ typedef int (PFNMESAGLINTEROPGLXQUERYDEVICEINFOPROC)(Display *dpy, GLXContext co
 typedef int (PFNMESAGLINTEROPEGLQUERYDEVICEINFOPROC)(EGLDisplay dpy, EGLContext context,
                                                      mesa_glinterop_device_info *out);
 typedef int (PFNMESAGLINTEROPGLXEXPORTOBJECTPROC)(Display *dpy, GLXContext context,
-                                                  const mesa_glinterop_export_in *in,
+                                                  mesa_glinterop_export_in *in,
                                                   mesa_glinterop_export_out *out);
 typedef int (PFNMESAGLINTEROPEGLEXPORTOBJECTPROC)(EGLDisplay dpy, EGLContext context,
-                                                  const mesa_glinterop_export_in *in,
+                                                  mesa_glinterop_export_in *in,
                                                   mesa_glinterop_export_out *out);
 
 #ifdef __cplusplus