Workaround: Allow patching CreateInfos at runtime

Temporary workaround for Overlay Next.

Pull Request: https://projects.blender.org/blender/blender/pulls/128452

source/blender/draw/engines/overlay/overlay_next_shader.cc

@@ -16,13 +16,10 @@ ShaderModule::ShaderPtr ShaderModule::shader(
     const char *create_info_name,
     const FunctionRef<void(gpu::shader::ShaderCreateInfo &info)> patch)
 {
-  const gpu::shader::ShaderCreateInfo *info_ptr =
-      reinterpret_cast<const gpu::shader::ShaderCreateInfo *>(
-          GPU_shader_create_info_get(create_info_name));
-  BLI_assert(info_ptr != nullptr);
-
   /* Perform a copy for patching. */
-  gpu::shader::ShaderCreateInfo info = *info_ptr;
+  gpu::shader::ShaderCreateInfo info(create_info_name);
+  GPU_shader_create_info_get_unfinalized_copy(create_info_name,
+                                              reinterpret_cast<GPUShaderCreateInfo &>(info));
 
   patch(info);
 
@@ -45,8 +42,11 @@ ShaderModule::ShaderPtr ShaderModule::selectable_shader(const char *create_info_
   // this->shader_ = GPU_shader_create_from_info_name(create_info_name.c_str());
 
   /* WORKAROUND: ... but for now, we have to patch the create info used by the old engine. */
-  gpu::shader::ShaderCreateInfo info = *reinterpret_cast<const gpu::shader::ShaderCreateInfo *>(
-      GPU_shader_create_info_get(create_info_name));
+
+  /* Perform a copy for patching. */
+  gpu::shader::ShaderCreateInfo info(create_info_name);
+  GPU_shader_create_info_get_unfinalized_copy(create_info_name,
+                                              reinterpret_cast<GPUShaderCreateInfo &>(info));
 
   info.define("OVERLAY_NEXT");
 
@@ -74,8 +74,10 @@ ShaderModule::ShaderPtr ShaderModule::selectable_shader(
     const char *create_info_name,
     const FunctionRef<void(gpu::shader::ShaderCreateInfo &info)> patch)
 {
-  gpu::shader::ShaderCreateInfo info = *reinterpret_cast<const gpu::shader::ShaderCreateInfo *>(
-      GPU_shader_create_info_get(create_info_name));
+  /* Perform a copy for patching. */
+  gpu::shader::ShaderCreateInfo info(create_info_name);
+  GPU_shader_create_info_get_unfinalized_copy(create_info_name,
+                                              reinterpret_cast<GPUShaderCreateInfo &>(info));
 
   patch(info);
 

source/blender/gpu/GPU_shader.hh

@@ -56,6 +56,9 @@ GPUShader *GPU_shader_create_from_info_name(const char *info_name);
  */
 const GPUShaderCreateInfo *GPU_shader_create_info_get(const char *info_name);
 
+void GPU_shader_create_info_get_unfinalized_copy(const char *info_name,
+                                                 GPUShaderCreateInfo &r_info);
+
 /**
  * Error checking for user created shaders.
  * \return true is create info is valid.

source/blender/gpu/intern/gpu_shader.cc

@@ -261,6 +261,12 @@ const GPUShaderCreateInfo *GPU_shader_create_info_get(const char *info_name)
   return gpu_shader_create_info_get(info_name);
 }
 
+void GPU_shader_create_info_get_unfinalized_copy(const char *info_name,
+                                                 GPUShaderCreateInfo &r_info)
+{
+  gpu_shader_create_info_get_unfinalized_copy(info_name, r_info);
+}
+
 bool GPU_shader_create_info_check_error(const GPUShaderCreateInfo *_info, char r_error[128])
 {
   using namespace blender::gpu::shader;

source/blender/gpu/intern/gpu_shader_create_info.cc

@@ -31,9 +31,11 @@
 namespace blender::gpu::shader {
 
 using CreateInfoDictionnary = Map<StringRef, ShaderCreateInfo *>;
+using CreateInfoValueDictionnary = Map<StringRef, ShaderCreateInfo>;
 using InterfaceDictionnary = Map<StringRef, StageInterfaceInfo *>;
 
 static CreateInfoDictionnary *g_create_infos = nullptr;
+static CreateInfoValueDictionnary *g_create_infos_unfinalized = nullptr;
 static InterfaceDictionnary *g_interfaces = nullptr;
 
 /* -------------------------------------------------------------------- */
@@ -449,6 +451,7 @@ using namespace blender::gpu::shader;
 void gpu_shader_create_info_init()
 {
   g_create_infos = new CreateInfoDictionnary();
+  g_create_infos_unfinalized = new CreateInfoValueDictionnary();
   g_interfaces = new InterfaceDictionnary();
 
 #define GPU_SHADER_INTERFACE_INFO(_interface, _inst_name) \
@@ -577,7 +580,8 @@ void gpu_shader_create_info_init()
 #endif
   }
 
-  for (ShaderCreateInfo *info : g_create_infos->values()) {
+  for (auto [key, info] : g_create_infos->items()) {
+    g_create_infos_unfinalized->add_new(key, *info);
     info->finalize(true);
   }
 
@@ -595,6 +599,8 @@ void gpu_shader_create_info_exit()
   }
   delete g_create_infos;
 
+  delete g_create_infos_unfinalized;
+
   for (auto *value : g_interfaces->values()) {
     delete value;
   }
@@ -697,3 +703,16 @@ const GPUShaderCreateInfo *gpu_shader_create_info_get(const char *info_name)
   ShaderCreateInfo *info = g_create_infos->lookup(info_name);
   return reinterpret_cast<const GPUShaderCreateInfo *>(info);
 }
+
+void gpu_shader_create_info_get_unfinalized_copy(const char *info_name,
+                                                 GPUShaderCreateInfo &r_info)
+{
+  if (g_create_infos_unfinalized->contains(info_name) == false) {
+    std::string msg = std::string("Error: Cannot find shader create info named \"") + info_name +
+                      "\"\n";
+    BLI_assert_msg(0, msg.c_str());
+  }
+  else {
+    reinterpret_cast<ShaderCreateInfo &>(r_info) = g_create_infos_unfinalized->lookup(info_name);
+  }
+}

source/blender/gpu/intern/gpu_shader_create_info_private.hh

@@ -22,3 +22,6 @@ bool gpu_shader_create_info_compile(const char *name_starts_with_filter);
 
 /** Runtime create infos are not registered in the dictionary and cannot be searched. */
 const GPUShaderCreateInfo *gpu_shader_create_info_get(const char *info_name);
+
+void gpu_shader_create_info_get_unfinalized_copy(const char *info_name,
+                                                 GPUShaderCreateInfo &r_info);