Add HDR output support to Vulkan on macOS.

drivers/apple_embedded/display_server_apple_embedded.mm

@@ -837,6 +837,7 @@ _FORCE_INLINE_ int _convert_utf32_offset_to_utf16(const String &p_existing_text,
 
 	float reference_luminance = _calculate_current_reference_luminance();
 	rendering_context->window_set_hdr_output_reference_luminance(DisplayServerEnums::MAIN_WINDOW_ID, reference_luminance);
+	rendering_context->window_set_hdr_output_linear_luminance_scale(DisplayServerEnums::MAIN_WINDOW_ID, reference_luminance);
 
 	float max_luminance = _screen_potential_edr_headroom() * hardware_reference_luminance_nits;
 	rendering_context->window_set_hdr_output_max_luminance(DisplayServerEnums::MAIN_WINDOW_ID, max_luminance);

drivers/metal/rendering_context_driver_metal.cpp

@@ -461,11 +461,13 @@ float RenderingContextDriverMetal::surface_get_hdr_output_max_luminance(SurfaceI
 }
 
 void RenderingContextDriverMetal::surface_set_hdr_output_linear_luminance_scale(SurfaceID p_surface, float p_linear_luminance_scale) {
+	Surface *surface = (Surface *)(p_surface);
+	surface->hdr_linear_luminance_scale = p_linear_luminance_scale;
 }
 
 float RenderingContextDriverMetal::surface_get_hdr_output_linear_luminance_scale(SurfaceID p_surface) const {
 	Surface *surface = (Surface *)(p_surface);
-	return surface->hdr_reference_luminance;
+	return surface->hdr_linear_luminance_scale;
 }
 
 float RenderingContextDriverMetal::surface_get_hdr_output_max_value(SurfaceID p_surface) const {

drivers/metal/rendering_context_driver_metal.h

@@ -98,6 +98,8 @@ class API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0)) RenderingContextDriverMe
 		// to be a more pleasant player-facing value.
 		float hdr_reference_luminance = 200.0f;
 		float hdr_max_luminance = 1000.0f;
+		// linear_luminance_scale must always equal hdr_reference_luminance on Apple platforms.
+		float hdr_linear_luminance_scale = 200.0f;
 		bool needs_resize = false;
 		bool hdr_output = false;
 

drivers/vulkan/rendering_device_driver_vulkan.cpp

@@ -7332,8 +7332,8 @@ bool RenderingDeviceDriverVulkan::has_feature(Features p_feature) {
 			// involving integrated GPU hardware do not function correctly
 			// with HDR output.
 			return false;
-#elif defined(MACOS_ENABLED) || defined(APPLE_EMBEDDED_ENABLED)
-			// HDR support has not yet been thoroughly tested and validated for Apple platforms.
+#elif defined(APPLE_EMBEDDED_ENABLED)
+			// HDR output with Vulkan currently does not function correctly on iOS. (Tested on iPhone 13 Pro, iOS 26.3.1(a))
 			return false;
 #else
 			return context_driver->is_colorspace_supported();

platform/macos/display_server_macos_base.mm

@@ -569,6 +569,7 @@
 	float current_ref_luminance = rendering_context->window_get_hdr_output_reference_luminance(p_window);
 	if (!Math::is_equal_approx(current_ref_luminance, new_reference_luminance)) {
 		rendering_context->window_set_hdr_output_reference_luminance(p_window, new_reference_luminance);
+		rendering_context->window_set_hdr_output_linear_luminance_scale(p_window, new_reference_luminance);
 		hdr_state_changed = true;
 	}