Fix unsupported sampler filter used for voxel GI

doc/classes/RenderingDevice.xml

@@ -452,6 +452,14 @@
 			<description>
 			</description>
 		</method>
+		<method name="sampler_is_format_supported_for_filter" qualifiers="const">
+			<return type="bool" />
+			<param index="0" name="format" type="int" enum="RenderingDevice.DataFormat" />
+			<param index="1" name="sampler_filter" type="int" enum="RenderingDevice.SamplerFilter" />
+			<description>
+				Returns [code]true[/code] if implementation supports using a texture of [param format] with the given [param sampler_filter].
+			</description>
+		</method>
 		<method name="screen_get_framebuffer_format" qualifiers="const">
 			<return type="int" />
 			<description>

drivers/vulkan/rendering_device_vulkan.cpp

@@ -4305,6 +4305,18 @@ RID RenderingDeviceVulkan::sampler_create(const SamplerState &p_state) {
 	return id;
 }
 
+bool RenderingDeviceVulkan::sampler_is_format_supported_for_filter(DataFormat p_format, SamplerFilter p_sampler_filter) const {
+	ERR_FAIL_INDEX_V(p_format, DATA_FORMAT_MAX, false);
+
+	_THREAD_SAFE_METHOD_
+
+	// Validate that this image is supported for the intended filtering.
+	VkFormatProperties properties;
+	vkGetPhysicalDeviceFormatProperties(context->get_physical_device(), vulkan_formats[p_format], &properties);
+
+	return p_sampler_filter == RD::SAMPLER_FILTER_NEAREST || (p_sampler_filter == RD::SAMPLER_FILTER_LINEAR && (properties.optimalTilingFeatures & VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT));
+}
+
 /**********************/
 /**** VERTEX ARRAY ****/
 /**********************/

drivers/vulkan/rendering_device_vulkan.h

@@ -1084,6 +1084,7 @@ public:
 	/*****************/
 
 	virtual RID sampler_create(const SamplerState &p_state);
+	virtual bool sampler_is_format_supported_for_filter(DataFormat p_format, SamplerFilter p_sampler_filter) const;
 
 	/**********************/
 	/**** VERTEX ARRAY ****/

servers/rendering/renderer_rd/environment/gi.cpp

@@ -3493,6 +3493,9 @@ void GI::init(SkyRD *p_sky) {
 		if (RendererSceneRenderRD::get_singleton()->is_vrs_supported()) {
 			defines += "\n#define USE_VRS\n";
 		}
+		if (!RD::get_singleton()->sampler_is_format_supported_for_filter(RD::DATA_FORMAT_R8G8_UINT, RD::SAMPLER_FILTER_LINEAR)) {
+			defines += "\n#define SAMPLE_VOXEL_GI_NEAREST\n";
+		}
 
 		Vector<String> gi_modes;
 
@@ -3931,7 +3934,6 @@ void GI::process_gi(Ref<RenderSceneBuffersRD> p_render_buffers, const RID *p_nor
 				u.append_id(material_storage->sampler_rd_get_default(RS::CANVAS_ITEM_TEXTURE_FILTER_LINEAR_WITH_MIPMAPS, RS::CANVAS_ITEM_TEXTURE_REPEAT_DISABLED));
 				uniforms.push_back(u);
 			}
-
 			{
 				RD::Uniform u;
 				u.uniform_type = RD::UNIFORM_TYPE_IMAGE;

servers/rendering/renderer_rd/shaders/environment/gi.glsl

@@ -4,6 +4,10 @@
 
 #VERSION_DEFINES
 
+#ifdef SAMPLE_VOXEL_GI_NEAREST
+#extension GL_EXT_samplerless_texture_functions : enable
+#endif
+
 layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
 
 #define M_PI 3.141592
@@ -625,7 +629,11 @@ void process_gi(ivec2 pos, vec3 vertex, inout vec4 ambient_light, inout vec4 ref
 
 #ifdef USE_VOXEL_GI_INSTANCES
 		{
+#ifdef SAMPLE_VOXEL_GI_NEAREST
+			uvec2 voxel_gi_tex = texelFetch(voxel_gi_buffer, pos, 0).rg;
+#else
 			uvec2 voxel_gi_tex = texelFetch(usampler2D(voxel_gi_buffer, linear_sampler), pos, 0).rg;
+#endif
 			roughness *= roughness;
 			//find arbitrary tangent and bitangent, then build a matrix
 			vec3 v0 = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);

servers/rendering/rendering_device.cpp

@@ -723,6 +723,7 @@ void RenderingDevice::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("framebuffer_is_valid", "framebuffer"), &RenderingDevice::framebuffer_is_valid);
 
 	ClassDB::bind_method(D_METHOD("sampler_create", "state"), &RenderingDevice::_sampler_create);
+	ClassDB::bind_method(D_METHOD("sampler_is_format_supported_for_filter", "format", "sampler_filter"), &RenderingDevice::sampler_is_format_supported_for_filter);
 
 	ClassDB::bind_method(D_METHOD("vertex_buffer_create", "size_bytes", "data", "use_as_storage"), &RenderingDevice::vertex_buffer_create, DEFVAL(Vector<uint8_t>()), DEFVAL(false));
 	ClassDB::bind_method(D_METHOD("vertex_format_create", "vertex_descriptions"), &RenderingDevice::_vertex_format_create);

servers/rendering/rendering_device.h

@@ -653,6 +653,7 @@ public:
 	};
 
 	virtual RID sampler_create(const SamplerState &p_state) = 0;
+	virtual bool sampler_is_format_supported_for_filter(DataFormat p_format, SamplerFilter p_sampler_filter) const = 0;
 
 	/**********************/
 	/**** VERTEX ARRAY ****/