OpenXR: Fix ViewportTextures not displaying correct texture (Compatibility)

(cherry picked from commit a38256c19e823d11aa9f2acae8e796fac384fc84)

drivers/gles3/storage/texture_storage.cpp

@@ -789,7 +789,7 @@ void TextureStorage::texture_free(RID p_texture) {
 
 	texture_atlas_remove_texture(p_texture);
 
-	for (int i = 0; i < t->proxies.size(); i++) {
+	for (uint32_t i = 0; i < t->proxies.size(); i++) {
 		Texture *p = texture_owner.get_or_null(t->proxies[i]);
 		ERR_CONTINUE(!p);
 		p->proxy_to = RID();
@@ -1064,6 +1064,27 @@ void TextureStorage::texture_proxy_update(RID p_texture, RID p_proxy_to) {
 	proxy_to->proxies.push_back(p_texture);
 }
 
+void TextureStorage::texture_remap_proxies(RID p_from_texture, RID p_to_texture) {
+	Texture *from_tex = texture_owner.get_or_null(p_from_texture);
+	ERR_FAIL_NULL(from_tex);
+	ERR_FAIL_COND(from_tex->is_proxy);
+	Texture *to_tex = texture_owner.get_or_null(p_to_texture);
+	ERR_FAIL_NULL(to_tex);
+	ERR_FAIL_COND(to_tex->is_proxy);
+
+	if (from_tex == to_tex) {
+		return;
+	}
+
+	// Make a local copy, we're about to change the content of the original.
+	thread_local LocalVector<RID> proxies = from_tex->proxies;
+
+	// Now change them to our new texture.
+	for (RID &proxy : proxies) {
+		texture_proxy_update(proxy, p_to_texture);
+	}
+}
+
 void TextureStorage::texture_2d_placeholder_initialize(RID p_texture) {
 	texture_2d_initialize(p_texture, texture_2d_placeholder);
 }
@@ -2553,6 +2574,9 @@ void TextureStorage::render_target_set_override(RID p_render_target, RID p_color
 	ERR_FAIL_NULL(rt);
 	ERR_FAIL_COND(rt->direct_to_screen);
 
+	// Remember what our current color output is.
+	RID was_color_texture = render_target_get_texture(p_render_target);
+
 	rt->overridden.velocity = p_velocity_texture;
 
 	if (rt->overridden.color == p_color_texture && rt->overridden.depth == p_depth_texture) {
@@ -2560,6 +2584,11 @@ void TextureStorage::render_target_set_override(RID p_render_target, RID p_color
 	}
 
 	if (p_color_texture.is_null() && p_depth_texture.is_null()) {
+		// Set this back to our default textures.
+		if (was_color_texture.is_valid()) {
+			texture_remap_proxies(was_color_texture, rt->texture);
+		}
+
 		_clear_render_target(rt);
 		_update_render_target(rt);
 		return;
@@ -2574,6 +2603,12 @@ void TextureStorage::render_target_set_override(RID p_render_target, RID p_color
 	rt->overridden.depth_has_stencil = p_depth_texture.is_null();
 	rt->overridden.is_overridden = true;
 
+	// Update to our new color output.
+	RID new_color_texture = render_target_get_texture(p_render_target);
+	if (was_color_texture.is_valid() && new_color_texture.is_valid()) {
+		texture_remap_proxies(was_color_texture, new_color_texture);
+	}
+
 	uint32_t hash_key = hash_murmur3_one_64(p_color_texture.get_id());
 	hash_key = hash_murmur3_one_64(p_depth_texture.get_id(), hash_key);
 	hash_key = hash_fmix32(hash_key);

drivers/gles3/storage/texture_storage.h

@@ -151,7 +151,7 @@ struct Texture {
 	bool is_render_target = false;
 
 	RID proxy_to;
-	Vector<RID> proxies;
+	LocalVector<RID> proxies;
 
 	String path;
 	int width = 0;
@@ -525,6 +525,7 @@ public:
 	virtual void texture_3d_update(RID p_texture, const Vector<Ref<Image>> &p_data) override;
 	virtual void texture_external_update(RID p_texture, int p_width, int p_height, uint64_t p_external_buffer) override;
 	virtual void texture_proxy_update(RID p_proxy, RID p_base) override;
+	void texture_remap_proxies(RID p_from_texture, RID p_to_texture);
 
 	Ref<Image> texture_2d_placeholder;
 	Vector<Ref<Image>> texture_2d_array_placeholder;