WebGPU: Make GPUProgrammableStage.entryPoint optional (#20773)

Author: beaufortfrancois

src/library_webgpu.js

@@ -311,15 +311,16 @@ var LibraryWebGPU = {
     makeProgrammableStageDescriptor: (ptr) => {
       if (!ptr) return undefined;
       {{{ gpu.makeCheckDescriptor('ptr') }}}
-      return {
+      var desc = {
         "module": WebGPU.mgrShaderModule.get(
           {{{ makeGetValue('ptr', C_STRUCTS.WGPUProgrammableStageDescriptor.module, '*') }}}),
-        "entryPoint": UTF8ToString(
-          {{{ makeGetValue('ptr', C_STRUCTS.WGPUProgrammableStageDescriptor.entryPoint, '*') }}}),
         "constants": WebGPU.makePipelineConstants(
           {{{ gpu.makeGetU32('ptr', C_STRUCTS.WGPUProgrammableStageDescriptor.constantCount) }}},
           {{{ makeGetValue('ptr', C_STRUCTS.WGPUProgrammableStageDescriptor.constants, '*') }}}),
       };
+      var entryPointPtr = {{{ makeGetValue('ptr', C_STRUCTS.WGPUProgrammableStageDescriptor.entryPoint, '*') }}};
+      if (entryPointPtr) desc["entryPoint"] = UTF8ToString(entryPointPtr);
+      return desc;
     },
 
     // Map from enum string back to enum number, for callbacks.
@@ -1323,18 +1324,19 @@ var LibraryWebGPU = {
     function makeVertexState(viPtr) {
       if (!viPtr) return undefined;
       {{{ gpu.makeCheckDescriptor('viPtr') }}}
-      return {
+      var desc = {
         "module": WebGPU.mgrShaderModule.get(
           {{{ makeGetValue('viPtr', C_STRUCTS.WGPUVertexState.module, '*') }}}),
-        "entryPoint": UTF8ToString(
-          {{{ makeGetValue('viPtr', C_STRUCTS.WGPUVertexState.entryPoint, '*') }}}),
         "constants": WebGPU.makePipelineConstants(
           {{{ gpu.makeGetU32('viPtr', C_STRUCTS.WGPUVertexState.constantCount) }}},
           {{{ makeGetValue('viPtr', C_STRUCTS.WGPUVertexState.constants, '*') }}}),
         "buffers": makeVertexBuffers(
           {{{ gpu.makeGetU32('viPtr', C_STRUCTS.WGPUVertexState.bufferCount) }}},
           {{{ makeGetValue('viPtr', C_STRUCTS.WGPUVertexState.buffers, '*') }}}),
-      };
+        };
+      var entryPointPtr = {{{ makeGetValue('viPtr', C_STRUCTS.WGPUVertexState.entryPoint, '*') }}};
+      if (entryPointPtr) desc["entryPoint"] = UTF8ToString(entryPointPtr);
+      return desc;
     }
 
     function makeMultisampleState(msPtr) {
@@ -1350,18 +1352,19 @@ var LibraryWebGPU = {
     function makeFragmentState(fsPtr) {
       if (!fsPtr) return undefined;
       {{{ gpu.makeCheckDescriptor('fsPtr') }}}
-      return {
+      var desc = {
         "module": WebGPU.mgrShaderModule.get(
           {{{ makeGetValue('fsPtr', C_STRUCTS.WGPUFragmentState.module, '*') }}}),
-        "entryPoint": UTF8ToString(
-          {{{ makeGetValue('fsPtr', C_STRUCTS.WGPUFragmentState.entryPoint, '*') }}}),
         "constants": WebGPU.makePipelineConstants(
           {{{ gpu.makeGetU32('fsPtr', C_STRUCTS.WGPUFragmentState.constantCount) }}},
           {{{ makeGetValue('fsPtr', C_STRUCTS.WGPUFragmentState.constants, '*') }}}),
         "targets": makeColorStates(
           {{{ gpu.makeGetU32('fsPtr', C_STRUCTS.WGPUFragmentState.targetCount) }}},
           {{{ makeGetValue('fsPtr', C_STRUCTS.WGPUFragmentState.targets, '*') }}}),
-      };
+        };
+      var entryPointPtr = {{{ makeGetValue('fsPtr', C_STRUCTS.WGPUFragmentState.entryPoint, '*') }}};
+      if (entryPointPtr) desc["entryPoint"] = UTF8ToString(entryPointPtr);
+      return desc;
     }
 
     var desc = {

system/include/webgpu/webgpu.h

@@ -1110,7 +1110,7 @@ typedef struct WGPUImageCopyTexture {
 typedef struct WGPUProgrammableStageDescriptor {
     WGPUChainedStruct const * nextInChain;
     WGPUShaderModule module;
-    char const * entryPoint;
+    WGPU_NULLABLE char const * entryPoint;
     size_t constantCount;
     WGPUConstantEntry const * constants;
 } WGPUProgrammableStageDescriptor WGPU_STRUCTURE_ATTRIBUTE;
@@ -1199,7 +1199,7 @@ typedef struct WGPURenderPassDescriptor {
 typedef struct WGPUVertexState {
     WGPUChainedStruct const * nextInChain;
     WGPUShaderModule module;
-    char const * entryPoint;
+    WGPU_NULLABLE char const * entryPoint;
     size_t constantCount;
     WGPUConstantEntry const * constants;
     size_t bufferCount;
@@ -1209,7 +1209,7 @@ typedef struct WGPUVertexState {
 typedef struct WGPUFragmentState {
     WGPUChainedStruct const * nextInChain;
     WGPUShaderModule module;
-    char const * entryPoint;
+    WGPU_NULLABLE char const * entryPoint;
     size_t constantCount;
     WGPUConstantEntry const * constants;
     size_t targetCount;

system/include/webgpu/webgpu_cpp.h

@@ -1637,7 +1637,7 @@ namespace wgpu {
     struct ProgrammableStageDescriptor {
         ChainedStruct const * nextInChain = nullptr;
         ShaderModule module;
-        char const * entryPoint;
+        char const * entryPoint = nullptr;
         size_t constantCount = 0;
         ConstantEntry const * constants;
     };
@@ -1726,7 +1726,7 @@ namespace wgpu {
     struct VertexState {
         ChainedStruct const * nextInChain = nullptr;
         ShaderModule module;
-        char const * entryPoint;
+        char const * entryPoint = nullptr;
         size_t constantCount = 0;
         ConstantEntry const * constants;
         size_t bufferCount = 0;
@@ -1736,7 +1736,7 @@ namespace wgpu {
     struct FragmentState {
         ChainedStruct const * nextInChain = nullptr;
         ShaderModule module;
-        char const * entryPoint;
+        char const * entryPoint = nullptr;
         size_t constantCount = 0;
         ConstantEntry const * constants;
         size_t targetCount;

test/webgpu_basic_rendering.cpp

@@ -110,7 +110,6 @@ void init() {
 
         wgpu::FragmentState fragmentState{};
         fragmentState.module = shaderModule;
-        fragmentState.entryPoint = "main_f";
         fragmentState.targetCount = 1;
         fragmentState.targets = &colorTargetState;
 
@@ -121,7 +120,6 @@ void init() {
         wgpu::RenderPipelineDescriptor descriptor{};
         descriptor.layout = device.CreatePipelineLayout(&pl);
         descriptor.vertex.module = shaderModule;
-        descriptor.vertex.entryPoint = "main_v";
         descriptor.fragment = &fragmentState;
         descriptor.primitive.topology = wgpu::PrimitiveTopology::TriangleList;
         descriptor.depthStencil = &depthStencilState;