Finish implementing Canvas Background mode

7 files changed, 77 insertions, 38 deletions

diff --git a/servers/rendering/renderer_rd/effects/copy_effects.cpp b/servers/rendering/renderer_rd/effects/copy_effects.cpp
index 0ab21bc4ef..a05db8c563 100644
--- a/servers/rendering/renderer_rd/effects/copy_effects.cpp
+++ b/servers/rendering/renderer_rd/effects/copy_effects.cpp
@@ -510,16 +510,18 @@ void CopyEffects::copy_to_atlas_fb(RID p_source_rd_texture, RID p_dest_framebuff
 
 	memset(&copy_to_fb.push_constant, 0, sizeof(CopyToFbPushConstant));
 
-	copy_to_fb.push_constant.use_section = true;
+	copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_USE_SECTION;
 	copy_to_fb.push_constant.section[0] = p_uv_rect.position.x;
 	copy_to_fb.push_constant.section[1] = p_uv_rect.position.y;
 	copy_to_fb.push_constant.section[2] = p_uv_rect.size.x;
 	copy_to_fb.push_constant.section[3] = p_uv_rect.size.y;
 
 	if (p_flip_y) {
-		copy_to_fb.push_constant.flip_y = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_FLIP_Y;
 	}
 
+	copy_to_fb.push_constant.luminance_multiplier = 1.0;
+
 	// setup our uniforms
 	RID default_sampler = material_storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
 
@@ -537,28 +539,35 @@ void CopyEffects::copy_to_atlas_fb(RID p_source_rd_texture, RID p_dest_framebuff
 	RD::get_singleton()->draw_list_draw(draw_list, true);
 }
 
-void CopyEffects::copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y, bool p_force_luminance, bool p_alpha_to_zero, bool p_srgb, RID p_secondary, bool p_multiview, bool p_alpha_to_one) {
+void CopyEffects::copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y, bool p_force_luminance, bool p_alpha_to_zero, bool p_srgb, RID p_secondary, bool p_multiview, bool p_alpha_to_one, bool p_linear) {
 	UniformSetCacheRD *uniform_set_cache = UniformSetCacheRD::get_singleton();
 	ERR_FAIL_NULL(uniform_set_cache);
 	MaterialStorage *material_storage = MaterialStorage::get_singleton();
 	ERR_FAIL_NULL(material_storage);
 
 	memset(&copy_to_fb.push_constant, 0, sizeof(CopyToFbPushConstant));
+	copy_to_fb.push_constant.luminance_multiplier = 1.0;
 
 	if (p_flip_y) {
-		copy_to_fb.push_constant.flip_y = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_FLIP_Y;
 	}
 	if (p_force_luminance) {
-		copy_to_fb.push_constant.force_luminance = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_FORCE_LUMINANCE;
 	}
 	if (p_alpha_to_zero) {
-		copy_to_fb.push_constant.alpha_to_zero = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_ALPHA_TO_ZERO;
 	}
 	if (p_srgb) {
-		copy_to_fb.push_constant.srgb = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_SRGB;
 	}
 	if (p_alpha_to_one) {
-		copy_to_fb.push_constant.alpha_to_one = true;
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_ALPHA_TO_ONE;
+	}
+	if (p_linear) {
+		// Used for copying to a linear buffer. In the mobile renderer we divide the contents of the linear buffer
+		// to allow for a wider effective range.
+		copy_to_fb.push_constant.flags |= COPY_TO_FB_FLAG_LINEAR;
+		copy_to_fb.push_constant.luminance_multiplier = prefer_raster_effects ? 2.0 : 1.0;
 	}
 
 	// setup our uniforms
diff --git a/servers/rendering/renderer_rd/effects/copy_effects.h b/servers/rendering/renderer_rd/effects/copy_effects.h
index cda4f70730..83f7a51a36 100644
--- a/servers/rendering/renderer_rd/effects/copy_effects.h
+++ b/servers/rendering/renderer_rd/effects/copy_effects.h
@@ -181,16 +181,21 @@ private:
 		COPY_TO_FB_MAX,
 	};
 
+	enum CopyToFBFlags {
+		COPY_TO_FB_FLAG_FLIP_Y = (1 << 0),
+		COPY_TO_FB_FLAG_USE_SECTION = (1 << 1),
+		COPY_TO_FB_FLAG_FORCE_LUMINANCE = (1 << 2),
+		COPY_TO_FB_FLAG_ALPHA_TO_ZERO = (1 << 3),
+		COPY_TO_FB_FLAG_SRGB = (1 << 4),
+		COPY_TO_FB_FLAG_ALPHA_TO_ONE = (1 << 5),
+		COPY_TO_FB_FLAG_LINEAR = (1 << 6),
+	};
+
 	struct CopyToFbPushConstant {
 		float section[4];
 		float pixel_size[2];
-		uint32_t flip_y;
-		uint32_t use_section;
-
-		uint32_t force_luminance;
-		uint32_t alpha_to_zero;
-		uint32_t srgb;
-		uint32_t alpha_to_one;
+		float luminance_multiplier;
+		uint32_t flags;
 
 		float set_color[4];
 	};
@@ -322,7 +327,7 @@ public:
 	void copy_cubemap_to_panorama(RID p_source_cube, RID p_dest_panorama, const Size2i &p_panorama_size, float p_lod, bool p_is_array);
 	void copy_depth_to_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false);
 	void copy_depth_to_rect_and_linearize(RID p_source_rd_texture, RID p_dest_texture, const Rect2i &p_rect, bool p_flip_y, float p_z_near, float p_z_far);
-	void copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false, bool p_force_luminance = false, bool p_alpha_to_zero = false, bool p_srgb = false, RID p_secondary = RID(), bool p_multiview = false, bool alpha_to_one = false);
+	void copy_to_fb_rect(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2i &p_rect, bool p_flip_y = false, bool p_force_luminance = false, bool p_alpha_to_zero = false, bool p_srgb = false, RID p_secondary = RID(), bool p_multiview = false, bool alpha_to_one = false, bool p_linear = false);
 	void copy_to_atlas_fb(RID p_source_rd_texture, RID p_dest_framebuffer, const Rect2 &p_uv_rect, RD::DrawListID p_draw_list, bool p_flip_y = false, bool p_panorama = false);
 	void copy_raster(RID p_source_texture, RID p_dest_framebuffer);
 
diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
index 2d1d0e0951..41fceac7c2 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
@@ -1765,6 +1765,10 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 				draw_sky = true;
 			} break;
 			case RS::ENV_BG_CANVAS: {
+				if (rb.is_valid()) {
+					RID texture = RendererRD::TextureStorage::get_singleton()->render_target_get_rd_texture(rb->get_render_target());
+					copy_effects->copy_to_fb_rect(texture, color_only_framebuffer, Rect2i(), false, false, false, false, RID(), false, false, true);
+				}
 				keep_color = true;
 			} break;
 			case RS::ENV_BG_KEEP: {
diff --git a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
index 558aba62e1..2506f4578b 100644
--- a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
+++ b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
@@ -796,6 +796,11 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 				draw_sky = true;
 			} break;
 			case RS::ENV_BG_CANVAS: {
+				if (rb.is_valid()) {
+					RID dest_framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_ONE_PASS);
+					RID texture = RendererRD::TextureStorage::get_singleton()->render_target_get_rd_texture(rb->get_render_target());
+					copy_effects->copy_to_fb_rect(texture, dest_framebuffer, Rect2i(), false, false, false, false, RID(), false, false, true);
+				}
 				keep_color = true;
 			} break;
 			case RS::ENV_BG_KEEP: {
diff --git a/servers/rendering/renderer_rd/shaders/effects/copy_to_fb.glsl b/servers/rendering/renderer_rd/shaders/effects/copy_to_fb.glsl
index 4d4e983b7f..46bb99794d 100644
--- a/servers/rendering/renderer_rd/shaders/effects/copy_to_fb.glsl
+++ b/servers/rendering/renderer_rd/shaders/effects/copy_to_fb.glsl
@@ -13,6 +13,14 @@
 #endif // has_VK_KHR_multiview
 #endif //MULTIVIEW
 
+#define FLAG_FLIP_Y (1 << 0)
+#define FLAG_USE_SECTION (1 << 1)
+#define FLAG_FORCE_LUMINANCE (1 << 2)
+#define FLAG_ALPHA_TO_ZERO (1 << 3)
+#define FLAG_SRGB (1 << 4)
+#define FLAG_ALPHA_TO_ONE (1 << 5)
+#define FLAG_LINEAR (1 << 6)
+
 #ifdef MULTIVIEW
 layout(location = 0) out vec3 uv_interp;
 #else
@@ -22,13 +30,8 @@ layout(location = 0) out vec2 uv_interp;
 layout(push_constant, std430) uniform Params {
 	vec4 section;
 	vec2 pixel_size;
-	bool flip_y;
-	bool use_section;
-
-	bool force_luminance;
-	bool alpha_to_zero;
-	bool srgb;
-	bool alpha_to_one;
+	float luminance_multiplier;
+	uint flags;
 
 	vec4 color;
 }
@@ -41,13 +44,13 @@ void main() {
 	uv_interp.z = ViewIndex;
 #endif
 	vec2 vpos = uv_interp.xy;
-	if (params.use_section) {
+	if (bool(params.flags & FLAG_USE_SECTION)) {
 		vpos = params.section.xy + vpos * params.section.zw;
 	}
 
 	gl_Position = vec4(vpos * 2.0 - 1.0, 0.0, 1.0);
 
-	if (params.flip_y) {
+	if (bool(params.flags & FLAG_FLIP_Y)) {
 		uv_interp.y = 1.0 - uv_interp.y;
 	}
 }
@@ -67,16 +70,19 @@ void main() {
 #endif // has_VK_KHR_multiview
 #endif //MULTIVIEW
 
+#define FLAG_FLIP_Y (1 << 0)
+#define FLAG_USE_SECTION (1 << 1)
+#define FLAG_FORCE_LUMINANCE (1 << 2)
+#define FLAG_ALPHA_TO_ZERO (1 << 3)
+#define FLAG_SRGB (1 << 4)
+#define FLAG_ALPHA_TO_ONE (1 << 5)
+#define FLAG_LINEAR (1 << 6)
+
 layout(push_constant, std430) uniform Params {
 	vec4 section;
 	vec2 pixel_size;
-	bool flip_y;
-	bool use_section;
-
-	bool force_luminance;
-	bool alpha_to_zero;
-	bool srgb;
-	bool alpha_to_one;
+	float luminance_multiplier;
+	uint flags;
 
 	vec4 color;
 }
@@ -110,6 +116,10 @@ vec3 linear_to_srgb(vec3 color) {
 	return mix((vec3(1.0f) + a) * pow(color.rgb, vec3(1.0f / 2.4f)) - a, 12.92f * color.rgb, lessThan(color.rgb, vec3(0.0031308f)));
 }
 
+vec3 srgb_to_linear(vec3 color) {
+	return mix(pow((color.rgb + vec3(0.055)) * (1.0 / (1.0 + 0.055)), vec3(2.4)), color.rgb * (1.0 / 12.92), lessThan(color.rgb, vec3(0.04045)));
+}
+
 void main() {
 #ifdef MODE_SET_COLOR
 	frag_color = params.color;
@@ -165,19 +175,22 @@ void main() {
 #endif /* MODE_TWO_SOURCES */
 #endif /* MULTIVIEW */
 
-	if (params.force_luminance) {
+	if (bool(params.flags & FLAG_FORCE_LUMINANCE)) {
 		color.rgb = vec3(max(max(color.r, color.g), color.b));
 	}
-	if (params.alpha_to_zero) {
+	if (bool(params.flags & FLAG_ALPHA_TO_ZERO)) {
 		color.rgb *= color.a;
 	}
-	if (params.srgb) {
+	if (bool(params.flags & FLAG_SRGB)) {
 		color.rgb = linear_to_srgb(color.rgb);
 	}
-	if (params.alpha_to_one) {
+	if (bool(params.flags & FLAG_ALPHA_TO_ONE)) {
 		color.a = 1.0;
 	}
+	if (bool(params.flags & FLAG_LINEAR)) {
+		color.rgb = srgb_to_linear(color.rgb);
+	}
 
-	frag_color = color;
+	frag_color = color / params.luminance_multiplier;
 #endif // MODE_SET_COLOR
 }
diff --git a/servers/rendering/renderer_scene_cull.cpp b/servers/rendering/renderer_scene_cull.cpp
index 348f6e4695..4ee355ee9f 100644
--- a/servers/rendering/renderer_scene_cull.cpp
+++ b/servers/rendering/renderer_scene_cull.cpp
@@ -3319,7 +3319,7 @@ void RendererSceneCull::render_empty_scene(const Ref<RenderSceneBuffers> &p_rend
 	RendererSceneRender::CameraData camera_data;
 	camera_data.set_camera(Transform3D(), Projection(), true, false);
 
-	scene_render->render_scene(p_render_buffers, &camera_data, &camera_data, PagedArray<RenderGeometryInstance *>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), RID(), RID(), p_shadow_atlas, RID(), scenario->reflection_atlas, RID(), 0, 0, nullptr, 0, nullptr, 0, nullptr);
+	scene_render->render_scene(p_render_buffers, &camera_data, &camera_data, PagedArray<RenderGeometryInstance *>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), PagedArray<RID>(), environment, RID(), p_shadow_atlas, RID(), scenario->reflection_atlas, RID(), 0, 0, nullptr, 0, nullptr, 0, nullptr);
 #endif
 }
 
diff --git a/servers/rendering/renderer_viewport.cpp b/servers/rendering/renderer_viewport.cpp
index 2836889de5..8cec531393 100644
--- a/servers/rendering/renderer_viewport.cpp
+++ b/servers/rendering/renderer_viewport.cpp
@@ -550,6 +550,9 @@ void RendererViewport::_draw_viewport(Viewport *p_viewport) {
 			if (!can_draw_3d) {
 				RSG::scene->render_empty_scene(p_viewport->render_buffers, p_viewport->scenario, p_viewport->shadow_atlas);
 			} else {
+				// There may be an outstanding clear request if a clear was requested, but no 2D elements were drawn.
+				// Clear now otherwise we copy over garbage from the render target.
+				RSG::texture_storage->render_target_do_clear_request(p_viewport->render_target);
 				_draw_3d(p_viewport);
 			}
 		}