Scale color output in the mobile renderer to provide HDR support

3 files changed, 12 insertions, 3 deletions

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 2064d9c5c5..926d599c84 100644
--- a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
+++ b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp
@@ -271,6 +271,12 @@ bool RenderForwardMobile::free(RID p_rid) {
 
 /* Render functions */
 
+float RenderForwardMobile::_render_buffers_get_luminance_multiplier() {
+	// On mobile renderer we need to multiply source colors by 2 due to using a UNORM buffer
+	// and multiplying by the output color during 3D rendering by 0.5
+	return 2.0;
+}
+
 RD::DataFormat RenderForwardMobile::_render_buffers_get_color_format() {
 	// Using 32bit buffers enables AFBC on mobile devices which should have a definite performance improvement (MALI G710 and newer support this on 64bit RTs)
 	return RD::DATA_FORMAT_A2B10G10R10_UNORM_PACK32;
@@ -631,7 +637,7 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 
 			RID sky_rid = env->sky;
 			if (sky_rid.is_valid()) {
-				sky.update(env, projection, p_render_data->cam_transform, time);
+				sky.update(env, projection, p_render_data->cam_transform, time, _render_buffers_get_luminance_multiplier());
 				radiance_texture = sky.sky_get_radiance_texture_rd(sky_rid);
 			} else {
 				// do not try to draw sky if invalid
@@ -750,9 +756,9 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 				CameraMatrix correction;
 				correction.set_depth_correction(true);
 				CameraMatrix projection = correction * p_render_data->cam_projection;
-				sky.draw(draw_list, env, framebuffer, 1, &projection, p_render_data->cam_transform, time);
+				sky.draw(draw_list, env, framebuffer, 1, &projection, p_render_data->cam_transform, time, _render_buffers_get_luminance_multiplier());
 			} else {
-				sky.draw(draw_list, env, framebuffer, p_render_data->view_count, p_render_data->view_projection, p_render_data->cam_transform, time);
+				sky.draw(draw_list, env, framebuffer, p_render_data->view_count, p_render_data->view_projection, p_render_data->cam_transform, time, _render_buffers_get_luminance_multiplier());
 			}
 
 			RD::get_singleton()->draw_command_end_label(); // Draw Sky Subpass
diff --git a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
index 764d8e80df..38f80c5347 100644
--- a/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
+++ b/servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h
@@ -202,6 +202,7 @@ protected:
 		}
 	};
 
+	virtual float _render_buffers_get_luminance_multiplier() override;
 	virtual RD::DataFormat _render_buffers_get_color_format() override;
 	virtual bool _render_buffers_can_be_storage() override;
 
diff --git a/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp b/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
index 735014a2ec..f4c2c51b35 100644
--- a/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
+++ b/servers/rendering/renderer_rd/forward_mobile/scene_shader_forward_mobile.cpp
@@ -665,6 +665,8 @@ void SceneShaderForwardMobile::init(RendererStorageRD *p_storage, const String p
 		actions.global_buffer_array_variable = "global_variables.data";
 		actions.instance_uniform_index_variable = "draw_call.instance_uniforms_ofs";
 
+		actions.apply_luminance_multiplier = true; // apply luminance multiplier to screen texture
+
 		compiler.initialize(actions);
 	}