Merge pull request #83192 from DarioSamo/fsr2-shader-backbuffer-fix

Add an extra backbuffer color texture that can be used when an upscaler is in use.
godotengine · Oct 20, 2023 · ecc2bd6 · ecc2bd6
2 parents a434062 + 4890e96
commit ecc2bd6
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Showing 3 changed files with 37 additions and 8 deletions.
diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
@@ -2137,6 +2137,12 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 		RD::get_singleton()->draw_list_end();
 	}
 
+	if (rb_data.is_valid() && using_fsr2) {
+		// Make sure the upscaled texture is initialized, but not necessarily filled, before running screen copies
+		// so it properly detect if a dedicated copy texture should be used.
+		rb->ensure_upscaled();
+	}
+
 	if (scene_state.used_screen_texture) {
 		RENDER_TIMESTAMP("Copy Screen Texture");
 
@@ -2200,7 +2206,6 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 
 	if (rb_data.is_valid() && (using_fsr2 || using_taa)) {
 		if (using_fsr2) {
-			rb->ensure_upscaled();
 			rb_data->ensure_fsr2(fsr2_effect);
 
 			RID exposure;

diff --git a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
@@ -260,15 +260,29 @@ void RendererSceneRenderRD::_render_buffers_copy_screen_texture(const RenderData
 
 	RD::get_singleton()->draw_command_begin_label("Copy screen texture");
 
-	rb->allocate_blur_textures();
-
+	StringName texture_name;
 	bool can_use_storage = _render_buffers_can_be_storage();
 	Size2i size = rb->get_internal_size();
 
+	// When upscaling, the blur texture needs to be at the target size for post-processing to work. We prefer to use a
+	// dedicated backbuffer copy texture instead if the blur texture is not an option so shader effects work correctly.
+	Size2i target_size = rb->get_target_size();
+	bool internal_size_matches = (size.width == target_size.width) && (size.height == target_size.height);
+	bool reuse_blur_texture = !rb->has_upscaled_texture() || internal_size_matches;
+	if (reuse_blur_texture) {
+		rb->allocate_blur_textures();
+		texture_name = RB_TEX_BLUR_0;
+	} else {
+		uint32_t usage_bits = RD::TEXTURE_USAGE_SAMPLING_BIT | RD::TEXTURE_USAGE_CAN_COPY_TO_BIT;
+		usage_bits |= can_use_storage ? RD::TEXTURE_USAGE_STORAGE_BIT : RD::TEXTURE_USAGE_COLOR_ATTACHMENT_BIT;
+		rb->create_texture(RB_SCOPE_BUFFERS, RB_TEX_BACK_COLOR, rb->get_base_data_format(), usage_bits);
+		texture_name = RB_TEX_BACK_COLOR;
+	}
+
 	for (uint32_t v = 0; v < rb->get_view_count(); v++) {
 		RID texture = rb->get_internal_texture(v);
-		int mipmaps = int(rb->get_texture_format(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0).mipmaps);
-		RID dest = rb->get_texture_slice(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0, v, 0);
+		int mipmaps = int(rb->get_texture_format(RB_SCOPE_BUFFERS, texture_name).mipmaps);
+		RID dest = rb->get_texture_slice(RB_SCOPE_BUFFERS, texture_name, v, 0);
 
 		if (can_use_storage) {
 			copy_effects->copy_to_rect(texture, dest, Rect2i(0, 0, size.x, size.y));
@@ -279,8 +293,8 @@ void RendererSceneRenderRD::_render_buffers_copy_screen_texture(const RenderData
 
 		for (int i = 1; i < mipmaps; i++) {
 			RID source = dest;
-			dest = rb->get_texture_slice(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0, v, i);
-			Size2i msize = rb->get_texture_slice_size(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0, i);
+			dest = rb->get_texture_slice(RB_SCOPE_BUFFERS, texture_name, v, i);
+			Size2i msize = rb->get_texture_slice_size(RB_SCOPE_BUFFERS, texture_name, i);
 
 			if (can_use_storage) {
 				copy_effects->make_mipmap(source, dest, msize);

diff --git a/servers/rendering/renderer_rd/storage_rd/render_scene_buffers_rd.h b/servers/rendering/renderer_rd/storage_rd/render_scene_buffers_rd.h
@@ -58,6 +58,7 @@
 #define RB_TEX_BLUR_1 SNAME("blur_1")
 #define RB_TEX_HALF_BLUR SNAME("half_blur") // only for raster!
 
+#define RB_TEX_BACK_COLOR SNAME("back_color")
 #define RB_TEX_BACK_DEPTH SNAME("back_depth")
 
 class RenderSceneBuffersRD : public RenderSceneBuffers {
@@ -267,7 +268,16 @@ class RenderSceneBuffersRD : public RenderSceneBuffers {
 	}
 
 	// back buffer (color)
-	RID get_back_buffer_texture() const { return has_texture(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0) ? get_texture(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0) : RID(); } // We (re)use our blur texture here.
+	RID get_back_buffer_texture() const {
+		// Prefer returning the dedicated backbuffer color texture if it was created. Return the reused blur texture otherwise.
+		if (has_texture(RB_SCOPE_BUFFERS, RB_TEX_BACK_COLOR)) {
+			return get_texture(RB_SCOPE_BUFFERS, RB_TEX_BACK_COLOR);
+		} else if (has_texture(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0)) {
+			return get_texture(RB_SCOPE_BUFFERS, RB_TEX_BLUR_0);
+		} else {
+			return RID();
+		}
+	}
 
 	// Upscaled.
 	void ensure_upscaled();