godot/modules/glslang/register_types.cpp

/**************************************************************************/
/*  register_types.cpp                                                    */
/**************************************************************************/
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#include "register_types.h"

#include "core/config/engine.h"
#include "core/os/os.h"
#include "shader_compile.h"

GODOT_GCC_WARNING_PUSH_AND_IGNORE("-Wshadow")

#include <glslang/Public/ResourceLimits.h>
#include <glslang/Public/ShaderLang.h>
#include <glslang/SPIRV/GlslangToSpv.h>

GODOT_GCC_WARNING_POP

Vector<uint8_t> compile_glslang_shader(RenderingDeviceCommons::ShaderStage p_stage, const String &p_source_code, RenderingDeviceCommons::ShaderLanguageVersion p_language_version, RenderingDeviceCommons::ShaderSpirvVersion p_spirv_version, String *r_error) {
	Vector<uint8_t> ret;
	EShLanguage stages[RenderingDeviceCommons::SHADER_STAGE_MAX] = {
		EShLangVertex,
		EShLangFragment,
		EShLangTessControl,
		EShLangTessEvaluation,
		EShLangCompute
	};

	int ClientInputSemanticsVersion = 100; // maps to, say, #define VULKAN 100

	// The enum values can be converted directly.
	glslang::EShTargetClientVersion ClientVersion = (glslang::EShTargetClientVersion)p_language_version;
	glslang::EShTargetLanguageVersion TargetVersion = (glslang::EShTargetLanguageVersion)p_spirv_version;

	glslang::TShader shader(stages[p_stage]);
	CharString cs = p_source_code.utf8();
	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 (!preamble.empty()) {
		shader.setPreamble(preamble.c_str());
	}

	bool generate_spirv_debug_info = Engine::get_singleton()->is_generate_spirv_debug_info_enabled();
#ifdef D3D12_ENABLED
	if (OS::get_singleton()->get_current_rendering_driver_name() == "d3d12") {
		// SPIRV to DXIL conversion does not support debug info.
		generate_spirv_debug_info = false;
	}
#endif

	EShMessages messages = (EShMessages)(EShMsgSpvRules | EShMsgVulkanRules);
	if (generate_spirv_debug_info) {
		messages = (EShMessages)(messages | EShMsgDebugInfo);
	}
	const int DefaultVersion = 100;

	//parse
	if (!shader.parse(GetDefaultResources(), DefaultVersion, false, messages)) {
		if (r_error) {
			(*r_error) = "Failed parse:\n";
			(*r_error) += shader.getInfoLog();
			(*r_error) += "\n";
			(*r_error) += shader.getInfoDebugLog();
		}
		return ret;
	}

	//link
	glslang::TProgram program;
	program.addShader(&shader);

	if (!program.link(messages)) {
		if (r_error) {
			(*r_error) = "Failed link:\n";
			(*r_error) += program.getInfoLog();
			(*r_error) += "\n";
			(*r_error) += program.getInfoDebugLog();
		}

		return ret;
	}

	std::vector<uint32_t> SpirV;
	spv::SpvBuildLogger logger;
	glslang::SpvOptions spvOptions;

	if (generate_spirv_debug_info) {
		spvOptions.generateDebugInfo = true;
		spvOptions.emitNonSemanticShaderDebugInfo = true;
		spvOptions.emitNonSemanticShaderDebugSource = true;
	}

	glslang::GlslangToSpv(*program.getIntermediate(stages[p_stage]), SpirV, &logger, &spvOptions);

	ret.resize(SpirV.size() * sizeof(uint32_t));
	{
		uint8_t *w = ret.ptrw();
		memcpy(w, &SpirV[0], SpirV.size() * sizeof(uint32_t));
	}

	return ret;
}

void initialize_glslang_module(ModuleInitializationLevel p_level) {
	if (p_level != MODULE_INITIALIZATION_LEVEL_CORE) {
		return;
	}

	// Initialize in case it's not initialized. This is done once per thread
	// and it's safe to call multiple times.
	glslang::InitializeProcess();
}

void uninitialize_glslang_module(ModuleInitializationLevel p_level) {
	if (p_level != MODULE_INITIALIZATION_LEVEL_CORE) {
		return;
	}

	glslang::FinalizeProcess();
}