As GLSLang seems to be all or nothing, added our own defines

modules/glslang/register_types.cpp

@@ -51,6 +51,7 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 	};
 
 	int ClientInputSemanticsVersion = 100; // maps to, say, #define VULKAN 100
+	bool check_subgroup_support = true; // assume we support subgroups
 
 	glslang::EShTargetClientVersion ClientVersion = glslang::EShTargetVulkan_1_2;
 	glslang::EShTargetLanguageVersion TargetVersion = glslang::EShTargetSpv_1_5;
@@ -60,6 +61,7 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 		if (p_capabilities->version_major == 1 && p_capabilities->version_minor == 0) {
 			ClientVersion = glslang::EShTargetVulkan_1_0;
 			TargetVersion = glslang::EShTargetSpv_1_0;
+			check_subgroup_support = false; // subgroups are not supported in Vulkan 1.0
 		} else if (p_capabilities->version_major == 1 && p_capabilities->version_minor == 1) {
 			ClientVersion = glslang::EShTargetVulkan_1_1;
 			TargetVersion = glslang::EShTargetSpv_1_3;
@@ -77,12 +79,47 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 	glslang::TShader shader(stages[p_stage]);
 	CharString cs = p_source_code.ascii();
 	const char *cs_strings = cs.get_data();
+	std::string preamble = "";
 
 	shader.setStrings(&cs_strings, 1);
 	shader.setEnvInput(glslang::EShSourceGlsl, stages[p_stage], glslang::EShClientVulkan, ClientInputSemanticsVersion);
 	shader.setEnvClient(glslang::EShClientVulkan, ClientVersion);
 	shader.setEnvTarget(glslang::EShTargetSpv, TargetVersion);
 
+	if (check_subgroup_support) {
+		uint32_t stage_bit = 1 << p_stage;
+
+		if ((p_capabilities->subgroup_in_shaders & stage_bit) == stage_bit) {
+			// stage supports subgroups
+			preamble += "#define has_GL_KHR_shader_subgroup_basic 1\n";
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_VOTE_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_vote 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_ARITHMETIC_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_arithmetic 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_BALLOT_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_ballot 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_SHUFFLE_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_shuffle 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_SHUFFLE_RELATIVE_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_shuffle_relative 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_CLUSTERED_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_clustered 1\n";
+			}
+			if (p_capabilities->subgroup_operations & RenderingDevice::SUBGROUP_QUAD_BIT) {
+				preamble += "#define has_GL_KHR_shader_subgroup_quad 1\n";
+			}
+		}
+	}
+
+	if (preamble != "") {
+		shader.setPreamble(preamble.c_str());
+	}
+
 	EShMessages messages = (EShMessages)(EShMsgSpvRules | EShMsgVulkanRules);
 	const int DefaultVersion = 100;
 	std::string pre_processed_code;

servers/rendering/renderer_rd/shaders/cluster_render.glsl

@@ -65,7 +65,7 @@ void main() {
 
 VERSION_DEFINES
 
-#if defined(GL_KHR_shader_subgroup_ballot) && defined(GL_KHR_shader_subgroup_arithmetic) && defined(GL_KHR_shader_subgroup_vote)
+#if defined(has_GL_KHR_shader_subgroup_ballot) && defined(has_GL_KHR_shader_subgroup_arithmetic) && defined(has_GL_KHR_shader_subgroup_vote)
 
 #extension GL_KHR_shader_subgroup_ballot : enable
 #extension GL_KHR_shader_subgroup_arithmetic : enable

servers/rendering/renderer_rd/shaders/scene_forward_clustered_inc.glsl

@@ -3,7 +3,7 @@
 
 #define MAX_GI_PROBES 8
 
-#if defined(GL_KHR_shader_subgroup_ballot) && defined(GL_KHR_shader_subgroup_arithmetic)
+#if defined(has_GL_KHR_shader_subgroup_ballot) && defined(has_GL_KHR_shader_subgroup_arithmetic)
 
 #extension GL_KHR_shader_subgroup_ballot : enable
 #extension GL_KHR_shader_subgroup_arithmetic : enable

servers/rendering/renderer_rd/shaders/volumetric_fog.glsl

@@ -5,10 +5,10 @@
 VERSION_DEFINES
 
 /* Do not use subgroups here, seems there is not much advantage and causes glitches
+#if defined(has_GL_KHR_shader_subgroup_ballot) && defined(has_GL_KHR_shader_subgroup_arithmetic)
 #extension GL_KHR_shader_subgroup_ballot: enable
 #extension GL_KHR_shader_subgroup_arithmetic: enable
 
-#if defined(GL_KHR_shader_subgroup_ballot) && defined(GL_KHR_shader_subgroup_arithmetic)
 #define USE_SUBGROUPS
 #endif
 */