wined3d: Introduce a helper to retrieve the texture target in…

dlls/wined3d/context.c

@@ -454,17 +454,11 @@ static inline void context_set_fbo_key_for_render_target(const struct wined3d_co
             key->rb_namespace |= 1 << idx;
             return;
         }
-
-        key->objects[idx].target = surface->texture_target;
-        key->objects[idx].level = surface->texture_level;
-        key->objects[idx].layer = surface->texture_layer;
-    }
-    else
-    {
-        key->objects[idx].target = texture->target;
-        key->objects[idx].level = sub_resource_idx % texture->level_count;
-        key->objects[idx].layer = sub_resource_idx / texture->level_count;
     }
+    key->objects[idx].target = wined3d_texture_get_sub_resource_target(texture, sub_resource_idx);
+    key->objects[idx].level = sub_resource_idx % texture->level_count;
+    key->objects[idx].layer = sub_resource_idx / texture->level_count;
+
     if (render_target->layer_count != 1)
         key->objects[idx].layer = WINED3D_ALL_LAYERS;
 

dlls/wined3d/wined3d_private.h

@@ -3179,6 +3179,23 @@ static inline struct wined3d_texture *texture_from_resource(struct wined3d_resou
     return CONTAINING_RECORD(resource, struct wined3d_texture, resource);
 }
 
+static inline GLenum wined3d_texture_get_sub_resource_target(const struct wined3d_texture *texture,
+        unsigned int sub_resource_idx)
+{
+    static const GLenum cube_targets[] =
+    {
+        GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
+        GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
+        GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
+        GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
+        GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
+        GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB,
+    };
+
+    return texture->resource.usage & WINED3DUSAGE_LEGACY_CUBEMAP
+            ? cube_targets[sub_resource_idx / texture->level_count] : texture->target;
+}
+
 static inline struct gl_texture *wined3d_texture_get_gl_texture(struct wined3d_texture *texture,
         BOOL srgb)
 {