1#include "EffectsWebGPU.h"
3#include "GraphicsDeviceWebGPU.h"
5#include "Foundation/Logging/Logger.h"
15 bool starts_with(std::string::const_iterator begin, std::string::const_iterator end,
const char* s, std::string::const_iterator& next) {
16 std::string::const_iterator it = begin;
18 while (it != end && *s !=
'\0') {
32 void eat_white(std::string::const_iterator& it, std::string::const_iterator end) {
33 while (it != end && std::isspace(*it)) {
38 WGPUTextureViewDimension extractViewDimention(std::string::const_iterator& type_it, std::string::const_iterator end) {
39 WGPUTextureViewDimension tvd = WGPUTextureViewDimension_Undefined;
40 if (starts_with(type_it, end,
"2d_array", type_it)) {
41 tvd = WGPUTextureViewDimension_2DArray;
43 else if (starts_with(type_it, end,
"2d", type_it)) {
44 tvd = WGPUTextureViewDimension_2D;
46 else if (starts_with(type_it, end,
"cube", type_it)) {
47 tvd = WGPUTextureViewDimension_Cube;
49 else if (starts_with(type_it, end,
"1d", type_it)) {
50 tvd = WGPUTextureViewDimension_1D;
52 else if (starts_with(type_it, end,
"cube_array", type_it)) {
53 tvd = WGPUTextureViewDimension_CubeArray;
55 else if (starts_with(type_it, end,
"3d", type_it)) {
56 tvd = WGPUTextureViewDimension_3D;
61 WGPUTextureFormat extractTextureFormat(std::string::const_iterator& type_it, std::string::const_iterator end) {
62 WGPUTextureFormat tf = WGPUTextureFormat_Undefined;
63 if (starts_with(type_it, end,
"rgba8unorm", type_it)) {
64 tf = WGPUTextureFormat_RGBA8Unorm;
66 else if (starts_with(type_it, end,
"rgba8snorm", type_it)) {
67 tf = WGPUTextureFormat_RGBA8Snorm;
69 else if (starts_with(type_it, end,
"rgba8uint", type_it)) {
70 tf = WGPUTextureFormat_RGBA8Uint;
72 else if (starts_with(type_it, end,
"rgba8sint", type_it)) {
73 tf = WGPUTextureFormat_RGBA8Sint;
75 else if (starts_with(type_it, end,
"rgba16uint", type_it)) {
76 tf = WGPUTextureFormat_RGBA16Uint;
78 else if (starts_with(type_it, end,
"rgba16sint", type_it)) {
79 tf = WGPUTextureFormat_RGBA16Sint;
81 else if (starts_with(type_it, end,
"rgba16float", type_it)) {
82 tf = WGPUTextureFormat_RGBA16Float;
84 else if (starts_with(type_it, end,
"r32uint", type_it)) {
85 tf = WGPUTextureFormat_R32Uint;
87 else if (starts_with(type_it, end,
"r32sint", type_it)) {
88 tf = WGPUTextureFormat_R32Sint;
90 else if (starts_with(type_it, end,
"r32float", type_it)) {
91 tf = WGPUTextureFormat_R32Float;
93 else if (starts_with(type_it, end,
"rg32uint", type_it)) {
94 tf = WGPUTextureFormat_RG32Uint;
96 else if (starts_with(type_it, end,
"rg32sint", type_it)) {
97 tf = WGPUTextureFormat_RG32Sint;
99 else if (starts_with(type_it, end,
"rg32float", type_it)) {
100 tf = WGPUTextureFormat_RG32Float;
102 else if (starts_with(type_it, end,
"rgba32uint", type_it)) {
103 tf = WGPUTextureFormat_RGBA32Uint;
105 else if (starts_with(type_it, end,
"rgba32sint", type_it)) {
106 tf = WGPUTextureFormat_RGBA32Sint;
108 else if (starts_with(type_it, end,
"rgba32float", type_it)) {
109 tf = WGPUTextureFormat_RGBA32Float;
111 else if (starts_with(type_it, end,
"bgra8unorm", type_it)) {
112 tf = WGPUTextureFormat_BGRA8Unorm;
117 WGPUStorageTextureAccess extractStorageTextureAccess(std::string::const_iterator& type_it, std::string::const_iterator end) {
118 WGPUStorageTextureAccess sta = WGPUStorageTextureAccess_Undefined;
119 if (starts_with(type_it, end,
"read", type_it)) {
120 sta = WGPUStorageTextureAccess_ReadOnly;
122 else if (starts_with(type_it, end,
"write", type_it)) {
123 sta = WGPUStorageTextureAccess_WriteOnly;
125 else if (starts_with(type_it, end,
"readwrite", type_it)) {
126 sta = WGPUStorageTextureAccess_ReadWrite;
131 std::vector<Cogs::WebGPUConstantBufferBinding> extractConstantBindingLayout(std::string shaderSource, WGPUShaderStage usage) {
132 std::vector<Cogs::WebGPUConstantBufferBinding> result;
133 std::istringstream iss(shaderSource);
134 std::string expr = R
"(^\s*@group\(([0-9]+)\) @binding\(([0-9]+)\)\s+var(<uniform>)?\s+([^\s]+)[\s]*:\s?(.*)\s?;)";
135 std::regex regex_expression(expr);
137 for (std::string line; std::getline(iss, line); )
140 if (std::regex_search(line, match, regex_expression))
142 size_t group = std::stoi(match.str(1));
143 unsigned int loc = std::stoi(match.str(2));
144 bool isUniform = match.str(3) ==
"<uniform>";
145 std::string name = match.str(4);
146 std::string type = match.str(5);
148 std::string::const_iterator type_it = type.begin();
152 bool alreadyInserted =
false;
153 for (
auto& e : result) {
154 if (e.group == group && e.bg_ent.binding == loc) {
155 e.bg_ent.visibility |= usage;
156 alreadyInserted =
true;
160 if (alreadyInserted) {
163 WGPUBindGroupLayoutEntry bg_ent = {};
164 bg_ent.binding =
static_cast<uint32_t
>(loc);
165 bg_ent.visibility = (WGPUShaderStage)usage;
168 bg_ent.buffer.type = WGPUBufferBindingType_Uniform;
171 else if (starts_with(type_it, type.end(),
"texture_storage_", type_it)) {
172 bg_ent.storageTexture.viewDimension = extractViewDimention(type_it, type.end());
173 eat_white(type_it, type.end());
174 if (!starts_with(type_it, type.end(),
"<", type_it)) {
175 LOG_DEBUG(logger,
"Texture type %s not yet supported", type.c_str());
177 bg_ent.storageTexture.format = extractTextureFormat(type_it, type.end());
178 eat_white(type_it, type.end());
179 if (!starts_with(type_it, type.end(),
",", type_it)) {
180 LOG_DEBUG(logger,
"Texture type %s not yet supported", type.c_str());
182 eat_white(type_it, type.end());
183 bg_ent.storageTexture.access = extractStorageTextureAccess(type_it, type.end());
184 eat_white(type_it, type.end());
185 if (!starts_with(type_it, type.end(),
">", type_it)) {
186 LOG_DEBUG(logger,
"Texture type %s not yet supported", type.c_str());
189 else if (starts_with(type_it, type.end(),
"texture_", type_it)) {
190 bool isDepth =
false;
193 bg_ent.texture.sampleType = WGPUTextureSampleType_Float;
194 bg_ent.texture.viewDimension = WGPUTextureViewDimension_2D;
195 bg_ent.texture.multisampled = 0;
196 if (starts_with(type_it, type.end(),
"depth_", type_it)) {
199 if (starts_with(type_it, type.end(),
"multisampled_", type_it)) {
200 bg_ent.texture.multisampled = 1;
203 bg_ent.texture.viewDimension = extractViewDimention(type_it, type.end());
204 eat_white(type_it, type.end());
206 bg_ent.texture.sampleType = WGPUTextureSampleType_Depth;
207 }
else if (starts_with(type_it, type.end(),
"<f32>", type_it)) {
209 bg_ent.texture.sampleType = WGPUTextureSampleType_UnfilterableFloat;
211 bg_ent.texture.sampleType = WGPUTextureSampleType_Float;
214 else if (starts_with(type_it, type.end(),
"<i32>", type_it)) {
215 bg_ent.texture.sampleType = WGPUTextureSampleType_Sint;
217 else if (starts_with(type_it, type.end(),
"<u32>", type_it)) {
218 bg_ent.texture.sampleType = WGPUTextureSampleType_Uint;
221 LOG_DEBUG(logger,
"Texture type %s not yet supported", type.c_str());
224 else if (type ==
"sampler") {
226 bg_ent.sampler.type = WGPUSamplerBindingType_Filtering;
228 else if (type ==
"sampler_comparison") {
230 bg_ent.sampler.type = WGPUSamplerBindingType_Comparison;
233 LOG_DEBUG(logger,
"Unknown uniform type%s", type.c_str());
237 result.push_back(binding);
243 const char* semanticNames[]
255 WGPUVertexFormat format =
static_cast<WGPUVertexFormat
>(0);
258 case Cogs::hash(
"f32"): format = WGPUVertexFormat::WGPUVertexFormat_Float32;
break;
259 case Cogs::hash(
"vec2f"): format = WGPUVertexFormat::WGPUVertexFormat_Float32x2;
break;
260 case Cogs::hash(
"vec3f"): format = WGPUVertexFormat::WGPUVertexFormat_Float32x3;
break;
261 case Cogs::hash(
"vec4f"): format = WGPUVertexFormat::WGPUVertexFormat_Float32x4;
break;
262 case Cogs::hash(
"i32"): format = WGPUVertexFormat::WGPUVertexFormat_Sint32;
break;
263 case Cogs::hash(
"vec2i"): format = WGPUVertexFormat::WGPUVertexFormat_Sint32x2;
break;
264 case Cogs::hash(
"vec3i"): format = WGPUVertexFormat::WGPUVertexFormat_Sint32x3;
break;
265 case Cogs::hash(
"vec4i"): format = WGPUVertexFormat::WGPUVertexFormat_Sint32x4;
break;
266 case Cogs::hash(
"u32"): format = WGPUVertexFormat::WGPUVertexFormat_Uint32;
break;
267 case Cogs::hash(
"vec2u"): format = WGPUVertexFormat::WGPUVertexFormat_Uint32x2;
break;
268 case Cogs::hash(
"vec3u"): format = WGPUVertexFormat::WGPUVertexFormat_Uint32x3;
break;
269 case Cogs::hash(
"vec4u"): format = WGPUVertexFormat::WGPUVertexFormat_Uint32x4;
break;
271 LOG_ERROR(logger,
"Unsupported vertex attribute type %s", std::string(s).c_str());
305 std::istringstream iss(shaderSource);
306 std::string expr = R
"(\s*const ([^\s^0-9]+)([0-9]+)_LOC\s*=\s*([0-9]+))";
307 std::regex regex_expression(expr);
309 for (std::string line; std::getline(iss, line); )
312 if (std::regex_search(line, match, regex_expression))
314 std::string semanticName = match.str(1);
315 uint8_t slot =
static_cast<uint8_t
>(std::stoi(match.str(2)));
316 uint8_t loc =
static_cast<uint8_t
>(std::stoi(match.str(3)));
317 for (uint8_t i = 0; i < std::size(semanticNames); i++) {
318 if (strcmp(semanticName.c_str(), semanticNames[i]) == 0) {
330 iss.seekg(0, std::ios::beg);
331 std::string expr_location = R
"(@location\(\s*([^\s\)\d]+)([\d]+)_LOC\s*\)\s*([^\s:]+)\s*:\s*([\da-zA-Z]+)[,\s\n])";
332 std::regex regex_location(expr_location);
333 for (std::string line; std::getline(iss, line); )
336 if (std::regex_search(line, match, regex_location))
338 std::string semanticName = match.str(1);
339 uint8_t slot =
static_cast<uint8_t
>(std::stoi(match.str(2)));
340 std::string name = match.str(3);
341 std::string type = match.str(4);
342 uint8_t semantic = std::numeric_limits<uint8_t>::max();
343 for (uint8_t i = 0; i < std::size(semanticNames); i++) {
344 if (strcmp(semanticName.c_str(), semanticNames[i]) == 0) {
349 if (semantic == std::numeric_limits<uint8_t>::max()) {
350 LOG_DEBUG(logger,
"unknown semantic name for vertex attribute %s", semanticName.c_str());
353 for (
size_t i = 0; i < nAttribs; i++) {
354 if (bindings[i].semantic == semantic && bindings[i].slot == slot) {
366 size_t i = (binding.group << 16) + (binding.bg_ent.binding + 1 );
370 void dumpSource(
const std::string& source,
int firstLine = 1,
int lastLine = std::numeric_limits<int>::max())
372 const char* start = source.data();
373 const char* curr = start;
376 while ((*curr !=
'\0') && (line <= lastLine)) {
377 const char* p = curr;
378 while ((*p !=
'\0') && (*p !=
'\n') && (*p !=
'\r')) { p++; }
380 if (firstLine <= line) {
381 LOG_DEBUG(logger,
"%3d: %s", line, std::string(curr, p - curr).c_str());
387 if (*curr !=
'\0') { curr++; };
388 if ((*curr !=
'\0') && (*curr != *p) && ((*curr ==
'\n') || (*curr ==
'\r'))) { curr++; }
392 void printShaderError(
struct WGPUCompilationInfo
const* compilationInfo,
const std::string* source =
nullptr)
394 for (
size_t i = 0; i < compilationInfo->messageCount; i++) {
395 const WGPUCompilationMessage& message = compilationInfo->messages[i];
397 dumpSource(*source, ((
int)message.lineNum) - 3, ((
int)message.lineNum));
400 std::string category_str;
401 switch (message.type) {
402 case WGPUCompilationMessageType::WGPUCompilationMessageType_Info:
403 category = Cogs::Logging::Category::Info;
404 category_str =
"Info";
406 case WGPUCompilationMessageType::WGPUCompilationMessageType_Error:
407 category = Cogs::Logging::Category::Error;
408 category_str =
"Error";
410 case WGPUCompilationMessageType::WGPUCompilationMessageType_Force32:
411 category = Cogs::Logging::Category::Error;
412 category_str =
"Force32";
415 category = Cogs::Logging::Category::Error;
416 category_str =
"Unknown";
423 void compile_callback(WGPUCompilationInfoRequestStatus status,
struct WGPUCompilationInfo
const* compilationInfo,
void* userdata1,
void* )
425 const std::string* source =
reinterpret_cast<std::string*
>(userdata1);
426 if (status != WGPUCompilationInfoRequestStatus_Success || (compilationInfo !=
nullptr && compilationInfo->messageCount != 0))
428 printShaderError(compilationInfo, source);
434 void EffectsWebGPU::initialize(GraphicsDeviceWebGPU *device_in, IBuffers * buffers_in)
436 EffectsCommon::initialize(buffers_in);
437 graphicsDevice = device_in;
446 if (!HandleIsValid(handle))
return;
448 wgpuShaderModuleRelease(effect.vs_module);
449 wgpuShaderModuleRelease(effect.fs_module);
450 this->effects.removeResource(handle);
461 WGPUDevice device = graphicsDevice->device;
464 Utilities::readFile(handler, fileName, csSource);
467 effect.cs_entry =
"main";
468 effect.name = std::string(fileName);
470 std::string cs_source;
471 for(
auto &def : definitions){
472 cs_source +=
"const " + def.first +
" = " + def.second +
";\n";
474 cs_source += csSource.content;
477 LOG_INFO(logger,
"Compiling WebGPU CS:\n%s", cs_source.c_str());
480 WGPUShaderModuleDescriptor descriptor = {};
481 descriptor.label = {fileName.data(), WGPU_STRLEN};
482 WGPUShaderSourceWGSL wgsl_desc = {};
483 wgsl_desc.chain.sType = WGPUSType_ShaderSourceWGSL;
484 wgsl_desc.code = {cs_source.c_str(), WGPU_STRLEN};
485 descriptor.nextInChain = (WGPUChainedStruct*)&wgsl_desc;
487 effect.cs_module = wgpuDeviceCreateShaderModule(device, &descriptor);
490 std::vector<Cogs::WebGPUConstantBufferBinding> bindings = extractConstantBindingLayout(cs_source, WGPUShaderStage_Compute);
491 addConstantBufferBindings(effect, bindings);
493 WGPUCompilationInfoCallbackInfo callbackInfo = {};
494 callbackInfo.nextInChain =
nullptr;
495 callbackInfo.callback = compile_callback;
496 callbackInfo.mode = WGPUCallbackMode_AllowProcessEvents;
497 callbackInfo.userdata1 =
static_cast<void*
>(&cs_source);
499 wgpuShaderModuleGetCompilationInfo(effect.cs_module, callbackInfo);
501 return this->effects.addResource(std::move(effect));
517 bool useSortedDefines =
false;
519 std::sort(unique_definitions.begin(), unique_definitions.end());
520 unique_definitions.erase(std::unique(unique_definitions.begin(), unique_definitions.end()), unique_definitions.end());
521 if (unique_definitions.size() != effect_desc.
definitions.size()) {
522 useSortedDefines =
true;
523 LOG_WARNING(logger,
"Redefinition of precompiler defines not supported in WebGPU backend");
527 assert(!hsSource.origin.size());
528 assert(!dsSource.origin.size());
529 assert(!gsSource.origin.size());
531 WGPUDevice device = graphicsDevice->device;
533 EffectWebGPU effect = {};
534 effect.vs_entry = std::string(vsEntryPoint);
535 effect.fs_entry = std::string(fsEntryPoint);
536 effect.name = std::string(effect_desc.
name);
538 LOG_INFO(logger,
"Compiling WebGPU Effect: %s", effect.name.c_str());
540 std::string definitions_source;
541 for (
auto& def : useSortedDefines ? unique_definitions : effect_desc.
definitions) {
542 definitions_source +=
"const " + def.first +
" = " + def.second +
";\n";
544 std::string vs_source = definitions_source + vsSource.content;
547 LOG_INFO(logger,
"Compiling WebGPU VS:\n%s", vs_source.c_str());
550 WGPUShaderModuleDescriptor descriptor = {};
551 descriptor.label = {effect_desc.
name.
data(), WGPU_STRLEN};
552 WGPUShaderSourceWGSL wgsl_desc = {};
553 wgsl_desc.chain.sType = WGPUSType_ShaderSourceWGSL;
554 wgsl_desc.code = {vs_source.c_str(), WGPU_STRLEN};
555 descriptor.nextInChain = (WGPUChainedStruct*)&wgsl_desc;
557 effect.vs_module = wgpuDeviceCreateShaderModule(device, &descriptor);
560 WGPUCompilationInfoCallbackInfo callbackInfo = {};
561 callbackInfo.nextInChain =
nullptr;
562 callbackInfo.callback = compile_callback;
563 callbackInfo.mode = WGPUCallbackMode_AllowProcessEvents;
564 callbackInfo.userdata1 =
static_cast<void*
>(& vs_source);
565 wgpuShaderModuleGetCompilationInfo(effect.vs_module, callbackInfo);
568 std::vector<Cogs::WebGPUConstantBufferBinding> bindings = extractConstantBindingLayout(vs_source, WGPUShaderStage_Vertex);
569 addConstantBufferBindings(effect, bindings);
571 effect.num_attribs = extractVertexAttribLocation(vs_source, effect.semanticSlotBindings, effect.maxVertexAttribs);
575 if (fsSource.content.size()) {
576 std::string fs_source;
577 fs_source = definitions_source + fsSource.content;
580 LOG_INFO(logger,
"Compiling WebGPU FS:\n%s", fs_source.c_str());
583 WGPUShaderModuleDescriptor descriptor = {};
584 descriptor.label = {effect_desc.
name.
data(), WGPU_STRLEN};
585 WGPUShaderSourceWGSL wgsl_desc = {};
586 wgsl_desc.chain.sType = WGPUSType_ShaderSourceWGSL;
587 wgsl_desc.code = {fs_source.c_str(), WGPU_STRLEN};
588 descriptor.nextInChain = (WGPUChainedStruct*)&wgsl_desc;
590 effect.fs_module = wgpuDeviceCreateShaderModule(device, &descriptor);
593 WGPUCompilationInfoCallbackInfo callbackInfo = {};
594 callbackInfo.nextInChain =
nullptr;
595 callbackInfo.callback = compile_callback;
596 callbackInfo.mode = WGPUCallbackMode_AllowProcessEvents;
597 callbackInfo.userdata1 =
static_cast<void*
>(& fs_source);
598 wgpuShaderModuleGetCompilationInfo(effect.fs_module, callbackInfo);
601 std::vector<Cogs::WebGPUConstantBufferBinding> bindings = extractConstantBindingLayout(fs_source, WGPUShaderStage_Fragment);
602 addConstantBufferBindings(effect, bindings);
604 return this->effects.addResource(std::move(effect));
611 for (
size_t i = 0; i < effect.num_bindings; i++) {
612 if (effect.constantBufferBindings[i].nameHash == nameHash) {
613 return encodeConstantBufferBindingHandle(effect.constantBufferBindings[i]);
623 if (HandleIsValid(constantBuffer)) {
629 bool EffectsWebGPU::addConstantBufferBindings(
EffectWebGPU& effect,
const std::vector<Cogs::WebGPUConstantBufferBinding>& bindings) {
630 for (
auto binding : bindings) {
633 for (slot = 0; slot < effect.num_bindings; slot++) {
634 auto& curr = effect.constantBufferBindings[slot];
635 if (curr.nameHash == binding.nameHash) {
636 if (curr.group == binding.group && curr.bg_ent.binding == binding.bg_ent.binding) {
637 curr.bg_ent.visibility = curr.bg_ent.visibility | binding.bg_ent.visibility;
641 LOG_ERROR(logger,
"Inconsistent binding location");
648 if (effect.num_bindings < EffectWebGPU::maxConstantBuffers) {
649 effect.constantBufferBindings[effect.num_bindings++] = binding;
652 LOG_ERROR(logger,
"Number of bindings exceed EffectWebGPU::maxConstantBuffers=%zu", EffectWebGPU::maxConstantBuffers);
660 const WebGPUConstantBufferBinding* EffectsWebGPU::getConstantBufferBindings(EffectHandle effectHandle,
size_t& num_bindings) {
661 const EffectWebGPU& effect = effects[effectHandle];
662 num_bindings = effect.num_bindings;
663 return effect.constantBufferBindings;
667 std::string constantBufferName = std::string(name);
669 if (HandleIsValid(constantBuffer)) {
676 std::string constantBufferName = std::string(name);
677 if (!constantBufferName.ends_with(
"Sampler")) {
678 constantBufferName +=
"Sampler";
682 if (HandleIsValid(constantBuffer)) {
686 if (constantBufferName.ends_with(
"TextureSampler")) {
687 constantBufferName.erase(constantBufferName.length() - strlen(
"TextureSampler"));
TextureBindingHandle getTextureBinding(EffectHandle effectHandle, const StringView &name, const unsigned int slot) override
Get a handle to a texture object binding, mapping how to bind textures to the given effect.
virtual void releaseEffect(EffectHandle effectHandle) override
Release the effect with the given handle, freeing all resources generated during program loading.
BufferBindingHandle getBufferBinding(EffectHandle effectHandle, const StringView &name) override
Get a handle to a buffer binding.
virtual EffectHandle loadComputeEffect(const StringView &, EffectFlags::EEffectFlags) override
Load the compute shader with the given file name and create an effect.
ConstantBufferBindingHandle getConstantBufferBinding(EffectHandle effectHandle, const StringView &name) override
Get a handle to a constant buffer binding, mapping how to bind a constant buffer to the given effect.
virtual void releaseResources() override
Release all allocated effect resources.
SamplerStateBindingHandle getSamplerStateBinding(EffectHandle effectHandle, const StringView &, const unsigned int slot) override
Get a handle to a sampler state object binding, mapping how to bind the sampler state to the given ef...
Log implementation class.
void log(const Category category, uint32_t errorNumber, _Printf_format_string_ const char *fmt,...) const VALIDATE_ARGS(4)
Log a formatted message.
Provides a weakly referenced view over the contents of a string.
constexpr const char * data() const noexcept
Get the sequence of characters referenced by the string view.
constexpr Log getLogger(const char(&name)[LEN]) noexcept
@ Unspecified
The default error number for legacy logger usage.
Category
Logging categories used to filter log messages.
Contains all Cogs related functionality.
constexpr size_t hash() noexcept
Simple getter function that returns the initial value for fnv1a hashing.
std::vector< PreprocessorDefinition > PreprocessorDefinitions
A set of preprocessor definitions.
Contains an effect description used to load a single effect.
EffectFlags::EEffectFlags flags
Effect loading flags.
PreprocessorDefinitions definitions
Definitions.
StringView name
Name of the effect. Used for tracking purposes, like naming shader dumps.
EEffectFlags
Effect source flags.
@ LogShaderSource
Log the contents of the shader on error.
static const Handle_t NoHandle
Represents a handle to nothing.
handle_type handle
Internal resource handle.