Initialize default values for viewports in rendering server.

Example with TAA: by default it is `false` in project settings and in
the Viewport node. When the scene tree is created, Viewport.set_use_taa()
is called with the value from ProjectSettings. But because the default
values are already the same, RenderingServer isn't called.
The Viewport struct in the RenderingServer does not initialize this field,
so TAA gets randomly enabled when the game starts with default settings.

servers/rendering/renderer_viewport.h

@@ -48,33 +48,34 @@ public:
 		RID self;
 		RID parent;
 
-		bool use_xr; /* use xr interface to override camera positioning and projection matrices and control output */
+		// use xr interface to override camera positioning and projection matrices and control output
+		bool use_xr = false;
 
 		Size2i internal_size;
 		Size2i size;
 		RID camera;
 		RID scenario;
 
-		RS::ViewportScaling3DMode scaling_3d_mode;
+		RS::ViewportScaling3DMode scaling_3d_mode = RenderingServer::VIEWPORT_SCALING_3D_MODE_BILINEAR;
 		float scaling_3d_scale = 1.0;
 		float fsr_sharpness = 0.2f;
 		float fsr_mipmap_bias = 0.0f;
-		bool fsr_enabled;
-		RS::ViewportUpdateMode update_mode;
+		bool fsr_enabled = false;
+		RS::ViewportUpdateMode update_mode = RenderingServer::VIEWPORT_UPDATE_WHEN_VISIBLE;
 		RID render_target;
 		RID render_target_texture;
 		RID render_buffers;
 
-		RS::ViewportMSAA msaa;
-		RS::ViewportScreenSpaceAA screen_space_aa;
-		bool use_taa;
-		bool use_debanding;
+		RS::ViewportMSAA msaa = RenderingServer::VIEWPORT_MSAA_DISABLED;
+		RS::ViewportScreenSpaceAA screen_space_aa = RenderingServer::VIEWPORT_SCREEN_SPACE_AA_DISABLED;
+		bool use_taa = false;
+		bool use_debanding = false;
 
 		RendererSceneRender::CameraData prev_camera_data;
 		uint64_t prev_camera_data_frame = 0;
 
-		bool use_occlusion_culling;
-		bool occlusion_buffer_dirty;
+		bool use_occlusion_culling = false;
+		bool occlusion_buffer_dirty = false;
 
 		DisplayServer::WindowID viewport_to_screen;
 		Rect2 viewport_to_screen_rect;
@@ -83,10 +84,10 @@ public:
 		bool disable_2d = false;
 		bool disable_environment = false;
 		bool disable_3d = false;
-		bool measure_render_time;
+		bool measure_render_time = false;
 
-		bool snap_2d_transforms_to_pixel;
-		bool snap_2d_vertices_to_pixel;
+		bool snap_2d_transforms_to_pixel = false;
+		bool snap_2d_vertices_to_pixel = false;
 
 		uint64_t time_cpu_begin;
 		uint64_t time_cpu_end;
@@ -95,23 +96,23 @@ public:
 		uint64_t time_gpu_end;
 
 		RID shadow_atlas;
-		int shadow_atlas_size;
+		int shadow_atlas_size = 2048;
 		bool shadow_atlas_16_bits = true;
 
-		bool sdf_active;
+		bool sdf_active = false;
 
 		float mesh_lod_threshold = 1.0;
 
 		uint64_t last_pass = 0;
 
-		RS::ViewportDebugDraw debug_draw;
+		RS::ViewportDebugDraw debug_draw = RenderingServer::VIEWPORT_DEBUG_DRAW_DISABLED;
 
-		RS::ViewportClearMode clear_mode;
+		RS::ViewportClearMode clear_mode = RenderingServer::VIEWPORT_CLEAR_ALWAYS;
 
 		RS::CanvasItemTextureFilter texture_filter = RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR;
 		RS::CanvasItemTextureRepeat texture_repeat = RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED;
 
-		bool transparent_bg;
+		bool transparent_bg = false;
 
 		struct CanvasKey {
 			int64_t stacking;