obs-studio/libobs-opengl/GL/modules/FuncCpp_Style.lua

local common = require "CommonStyle"
local struct = require "FuncCpp_Struct"
local util = require "util"

local my_style = {}
my_style.header = {}
my_style.source = {}

----------------------------------------------------
-- Global styling functions.
function my_style.WriteLargeHeading(hFile, headingName)
	hFile:write(string.rep("/", 6 + #headingName), "\n")
	hFile:write("// ", headingName, "\n")
	hFile:write(string.rep("/", 6 + #headingName), "\n")
end

function my_style.WriteSmallHeading(hFile, headingName)
	hFile:write("// ", headingName, "\n")
end

------------------------------------------------------
-- Header styling functions

function my_style.header.GetFilename(basename, options)
	return basename .. ".hpp"
end

	local function GenIncludeGuardName(hFile, spec, options)
		local str = "FUNCTION_CPP_GENERATED_HEADER" ..
			spec.GetIncludeGuardString() .. "_HPP"

		if(#options.prefix > 0) then
			return options.prefix:upper() .. "_" .. str
		end
		
		return str
	end

function my_style.header.WriteBlockBeginIncludeGuard(hFile, spec, options)
	local inclGuard = GenIncludeGuardName(hFile, spec, options)
	
	hFile:fmt("#ifndef %s\n", inclGuard)
	hFile:fmt("#define %s\n", inclGuard)
end

function my_style.header.WriteBlockEndIncludeGuard(hFile, spec, options)
	hFile:fmt("#endif //%s\n", GenIncludeGuardName(hFile, spec, options))
end

function my_style.header.WriteInit(hFile, spec, options)
	hFile:rawwrite(spec.GetHeaderInit())
end

function my_style.header.WriteStdTypedefs(hFile, specData, spec, options)
	local defArray = common.GetStdTypedefs()
	hFile:write("#ifndef GL_LOAD_GEN_BASIC_OPENGL_TYPEDEFS\n")
	hFile:write("#define GL_LOAD_GEN_BASIC_OPENGL_TYPEDEFS\n")
	hFile:write("\n")
	hFile:inc()
	for _, def in ipairs(defArray) do
		hFile:write(def)
	end
	hFile:dec()
	hFile:write("\n")
	hFile:write("#endif /*GL_LOAD_GEN_BASIC_OPENGL_TYPEDEFS*/\n")
end

function my_style.header.WriteSpecTypedefs(hFile, specData, spec, options)
	hFile:push()
	common.WritePassthruData(hFile, specData.funcData.passthru)
	hFile:pop()
end

	local function StartNamespace(hFile, namespaceName)
		hFile:fmt("namespace %s\n", namespaceName or "")
		hFile:write("{\n")
		hFile:inc()
	end

	local function EndNamespace(hFile, namespaceName)
		hFile:dec()
		hFile:fmt("} //namespace %s\n", namespaceName or "")
	end

function my_style.header.WriteBlockBeginDecl(hFile, spec, options)
	if(#options.prefix > 0) then
		StartNamespace(hFile, options.prefix)
	end
	StartNamespace(hFile, spec.FuncNamePrefix())
end

function my_style.header.WriteBlockEndDecl(hFile, spec, options)
	EndNamespace(hFile, spec.FuncNamePrefix())
	if(#options.prefix > 0) then
		EndNamespace(hFile, options.prefix)
	end
end

	local extBlockNamespace = "exts"
	local extVariableTypeDefinition = [[
class LoadTest
{
private:
	//Safe bool idiom. Joy!
	typedef void (LoadTest::*bool_type)() const;
	void big_long_name_that_really_doesnt_matter() const {}
	
public:
	operator bool_type() const
	{
		return m_isLoaded ? &LoadTest::big_long_name_that_really_doesnt_matter : 0;
	}
	
	int GetNumMissing() const {return m_numMissing;}
	
	LoadTest() : m_isLoaded(false), m_numMissing(0) {}
	LoadTest(bool isLoaded, int numMissing) : m_isLoaded(isLoaded), m_numMissing(numMissing) {}
private:
	bool m_isLoaded;
	int m_numMissing;
};
]]

function my_style.header.WriteBlockBeginExtVarDecl(hFile, spec, options)
	StartNamespace(hFile, extBlockNamespace)
	hFile:writeblock(extVariableTypeDefinition)
	hFile:write("\n")
end

function my_style.header.WriteBlockEndExtVarDecl(hFile, spec, options)
	EndNamespace(hFile, extBlockNamespace)
end

	local function GenExtensionVarName(extName, spec, options)
		return "var_" .. extName;
	end

function my_style.header.WriteExtVariableDecl(hFile, extName,
	specData, spec, options)
	hFile:fmt("extern LoadTest %s;\n",
		GenExtensionVarName(extName, spec, options));
end

function my_style.header.WriteBlockBeginEnumDecl(hFile, spec, options)
	hFile:write("enum\n")
	hFile:write("{\n")
	hFile:inc()
end

function my_style.header.WriteBlockEndEnumDecl(hFile, spec, options)
	hFile:dec()
	hFile:write("};\n")
end

	local function GenEnumName(enum)
		return common.GetCppEnumName(enum)
	end

function my_style.header.WriteEnumDecl(hFile, enum, enumTable, spec, options,
	enumSeen)
	if(enumSeen[enum.name]) then
		hFile:fmt("//%s taken from ext: %s\n", enum.name, enumSeen[enum.name])
	else
	
		local enumName = GenEnumName(enum)
		local lenEnum = #enumName
		local numIndent = 33
		
		local numSpaces = numIndent - lenEnum
		if(numSpaces < 1) then
			numSpaces = 1
		end

		hFile:fmt("%s%s= %s,\n",
			enumName,
			string.rep(" ", numSpaces),
			common.ResolveEnumValue(enum, enumTable))
	end
end

function my_style.header.WriteBlockBeginFuncPtrDecl(hFile, spec, options)
	StartNamespace(hFile, "_detail")
end

function my_style.header.WriteBlockEndFuncPtrDecl(hFile, spec, options)
	EndNamespace(hFile, "_detail")
end

function my_style.header.WriteBlockBeginExtFuncPtrDecl(hFile, extName, spec, options)
	--Block containing all spec function declarations for a particular extension.
	--Useful for include-guards around extension function pointers.
end

function my_style.header.WriteBlockEndExtFuncPtrDecl(hFile, extName, spec, options)
	--Block containing all spec function declarations for a particular extension.
end

	local function GenFuncPtrName(func, spec, options)
		return func.name
	end

	local function GenFuncName(func, spec, options)
		return func.name
	end

	local function GenFuncPtrTypedefName(func, spec, options)
		return "PFN" .. GenFuncPtrName(func, spec, options):upper()
	end

	local function WriteFuncPtrTypedefStmt(hFile, func, spec, options)
		hFile:fmt("typedef %s (%s *%s)(%s);\n",
			common.GetFuncReturnType(func),
			spec.GetCodegenPtrType(),
			GenFuncPtrTypedefName(func, spec, options),
			common.GetFuncParamList(func))
	end

	local function GenFuncPtrDefDirect(func, spec, options)
		return string.format("%s (%s *%s)(%s)",
			common.GetFuncReturnType(func),
			spec.GetCodegenPtrType(),
			GenFuncPtrName(func, spec, options),
			common.GetFuncParamList(func, true))
	end

	local function GenFuncPtrDefTypedef(func, spec, options)
		return string.format("%s %s",
			GenFuncPtrTypedefName(func, spec, options),
			GenFuncPtrName(func, spec, options))
	end

function my_style.header.WriteFuncPtrDecl(hFile, func, spec, options)
	hFile:write("extern ",
		GenFuncPtrDefDirect(func, spec, options),
		";\n")
end

function my_style.header.WriteBlockBeginFuncDecl(hFile, spec, options)
end

function my_style.header.WriteBlockEndFuncDecl(hFile, spec, options)
end

function my_style.header.WriteBlockBeginExtFuncDecl(hFile, extName, spec, options)
	--Block containing all spec function declarations for a particular extension.
	--Useful for include-guards around extension function pointers.
end

function my_style.header.WriteBlockEndExtFuncDecl(hFile, extName, spec, options)
	--Block containing all spec function declarations for a particular extension.
end

function my_style.header.WriteFuncDecl(hFile, func, spec, options)
	hFile:fmt("inline %s %s(%s){",
			common.GetFuncReturnType(func),
			GenFuncName(func, spec, options),
			common.GetFuncParamList(func, true))

	if(common.DoesFuncReturnSomething(func)) then
		hFile:rawfmt('_detail::%s(%s);',
			GenFuncPtrName(func, spec, options),
			common.GetFuncParamCallList(func))
	else
		hFile:rawfmt('return _detail::%s(%s);',
			GenFuncPtrName(func, spec, options),
			common.GetFuncParamCallList(func))
	end

		
	hFile:rawwrite("}\n")
end



function my_style.header.WriteBlockBeginSysDecl(hFile, spec, options)
	StartNamespace(hFile, "sys")
end

function my_style.header.WriteBlockEndSysDecl(hFile, spec, options)
	EndNamespace(hFile, "sys")
end

function my_style.header.WriteUtilityDecls(hFile, spec, options)
	--Write declarations for public utility stuff. Enums for return values, etc.
end

function my_style.header.WriteMainLoaderFuncDecl(hFile, spec, options)
	hFile:fmt("%s::LoadTest LoadFunctions(%s);\n", extBlockNamespace, spec.GetLoaderParams())
end

function my_style.header.WriteVersioningFuncDecls(hFile, spec, options)
	hFile:writeblock([[
int GetMinorVersion();
int GetMajorVersion();
bool IsVersionGEQ(int majorVersion, int minorVersion);
]])
end

--------------------------------------------------
-- Source code styling functions.
function my_style.source.GetFilename(basename, options)
	return basename .. ".cpp"
end

function my_style.source.WriteIncludes(hFile, basename, spec, options)
	hFile:writeblock([[
#include <algorithm>
#include <vector>
#include <string.h>
#include <stddef.h>
]])

	local base = util.ParsePath(my_style.header.GetFilename(basename, options))
	hFile:fmt('#include "%s"\n', base)
end

function my_style.source.WriteLoaderData(hFile, spec, options)
	hFile:writeblock(spec.GetLoaderFunc())
end

function my_style.source.WriteBlockBeginDef(hFile, spec, options)
	if(#options.prefix > 0) then
		StartNamespace(hFile, options.prefix)
	end
	StartNamespace(hFile, spec.FuncNamePrefix())
end

function my_style.source.WriteBlockEndDef(hFile, spec, options)
	EndNamespace(hFile, spec.FuncNamePrefix())
	if(#options.prefix > 0) then
		EndNamespace(hFile, options.prefix)
	end
end

function my_style.source.WriteBlockBeginExtVarDef(hFile, spec, options)
	StartNamespace(hFile, extBlockNamespace)
end

function my_style.source.WriteBlockEndExtVarDef(hFile, spec, options)
	EndNamespace(hFile, extBlockNamespace)
end

function my_style.source.WriteExtVariableDef(hFile, extName,
	specData, spec, options)
	hFile:fmt("LoadTest %s;\n",
		GenExtensionVarName(extName, spec, options));
end

function my_style.source.WriteBlockBeginPtrDefs(hFile, spec, options)
	StartNamespace(hFile, "_detail")
end

function my_style.source.WriteBlockEndPtrDefs(hFile, spec, options)
	EndNamespace(hFile, "_detail")
end

function my_style.source.WriteBlockBeginExtFuncPtrDef(hFile, extName, spec, options)
end

function my_style.source.WriteBlockEndExtFuncPtrDef(hFile, extName, spec, options)
end

function my_style.source.WriteFuncPtrDef(hFile, func, spec, options)
	WriteFuncPtrTypedefStmt(hFile, func, spec, options)
	hFile:write(GenFuncPtrDefTypedef(func, spec, options),
		" = 0;\n")
end

	local function GenExtLoaderFuncName(extName, spec, options)
		return "Load_" .. extName;
	end

function my_style.source.WriteBlockBeginExtLoader(hFile, extName, spec, options)
	hFile:fmt("static int %s()\n", GenExtLoaderFuncName(extName, spec, options))
	hFile:write("{\n")
	hFile:inc()
	hFile:write("int numFailed = 0;\n")
end

function my_style.source.WriteBlockEndExtLoader(hFile, extName, spec, options)
	hFile:write "return numFailed;\n"
	hFile:dec()
	hFile:write("}\n")
end

function my_style.source.WriteExtFuncLoader(hFile, func, spec, options)
	hFile:fmt('%s = reinterpret_cast<%s>(%s("%s%s"));\n',
		GenFuncPtrName(func, spec, options),
		GenFuncPtrTypedefName(func, spec, options),
		common.GetProcAddressName(spec),
		spec.FuncNamePrefix(), func.name)
	hFile:fmt('if(!%s) ++numFailed;\n', GenFuncPtrName(func, spec, options))
end

function my_style.source.WriteBlockBeginCoreFuncPtrDef(hFile, version, spec, options)
end

function my_style.source.WriteBlockEndCoreFuncPtrDef(hFile, version, spec, options)
end

	local function GenCoreLoaderFuncName(version, spec, options)
		return "LoadCoreFunctions"
	end

function my_style.source.WriteBlockBeginCoreLoader(hFile, version, spec, options)
	hFile:fmt("static int %s()\n", GenCoreLoaderFuncName(version, spec, options))
	hFile:write("{\n")
	hFile:inc()
	hFile:write("int numFailed = 0;\n")

end

function my_style.source.WriteBlockEndCoreLoader(hFile, version, spec, options)
	hFile:write "return numFailed;\n"
	hFile:dec()
	hFile:write("}\n")
end

function my_style.source.WriteCoreFuncLoader(hFile, func, spec, options)
	hFile:fmt('%s = reinterpret_cast<%s>(%s("%s%s"));\n',
		GenFuncPtrName(func, spec, options),
		GenFuncPtrTypedefName(func, spec, options),
		common.GetProcAddressName(spec),
		spec.FuncNamePrefix(), func.name)
		
	--Special hack for DSA_EXT functions in core functions.
	--They do not count against the loaded count.
	if(func.name:match("EXT$")) then
		hFile:write("//An EXT_direct_state_access-based function. Don't count it if it fails to load.\n")
	else
		hFile:fmt('if(!%s) ++numFailed;\n', GenFuncPtrName(func, spec, options))
	end
end

function my_style.source.WriteExtStringFuncDef(hFile, specData, spec, options, funcSeen)
	if(funcSeen[spec.GetExtStringFuncName()]) then
		return
	end
	
	--Check to see if its something we have to load.
	local function FindFuncName(funcName)
		for _, func in ipairs(specData.funcData.functions) do
			if(func.name == funcName) then
				return func
			end
		end
		
		return nil
	end
	
	local extStringFunc = FindFuncName(spec.GetExtStringFuncName())

	if(extStringFunc) then
		hFile:write("\n")
		WriteFuncPtrTypedefStmt(hFile, extStringFunc, spec, options)
		hFile:write("static ", GenFuncPtrDefTypedef(extStringFunc, spec, options),
			" = 0;\n")
		hFile:write("\n")
	end
end

function my_style.source.WriteBlockBeginSysDef(hFile, spec, options)
	StartNamespace(hFile, "sys")
end

function my_style.source.WriteBlockEndSysDef(hFile, spec, options)
	EndNamespace(hFile, "sys")
end

function my_style.source.WriteUtilityDefs(hFile, specData, spec, options)
	--Write our mapping table definitions.
	StartNamespace(hFile)
	hFile:writeblock[[
typedef int (*PFN_LOADEXTENSION)();
struct MapEntry
{
	MapEntry(const char *_extName, exts::LoadTest *_extVariable)
		: extName(_extName)
		, extVariable(_extVariable)
		, loaderFunc(0)
		{}
		
	MapEntry(const char *_extName, exts::LoadTest *_extVariable, PFN_LOADEXTENSION _loaderFunc)
		: extName(_extName)
		, extVariable(_extVariable)
		, loaderFunc(_loaderFunc)
		{}
	
	const char *extName;
	exts::LoadTest *extVariable;
	PFN_LOADEXTENSION loaderFunc;
};

struct MapCompare
{
	MapCompare(const char *test_) : test(test_) {}
	bool operator()(const MapEntry &other) { return strcmp(test, other.extName) == 0; }
	const char *test;
};

]]

	--Write the table initialization function.
	hFile:write "void InitializeMappingTable(std::vector<MapEntry> &table)\n"
	hFile:write "{\n"
	hFile:inc()
	hFile:fmt("table.reserve(%i);\n", #options.extensions)
	for _, extName in ipairs(options.extensions) do
		if(#specData.extdefs[extName].funcs > 0) then
			hFile:fmt('table.push_back(MapEntry("%s", &exts::%s, _detail::%s));\n',
				spec.ExtNamePrefix() .. extName,
				GenExtensionVarName(extName, spec, options),
				GenExtLoaderFuncName(extName, spec, options))
		else
			hFile:fmt('table.push_back(MapEntry("%s", &exts::%s));\n',
				spec.ExtNamePrefix() .. extName,
				GenExtensionVarName(extName, spec, options))
		end
	end
	hFile:dec()
	hFile:write "}\n"
	hFile:write "\n"
	
	--Write the function to clear the extension variables.
	hFile:fmt("void ClearExtensionVars()\n")
	hFile:write("{\n")
	hFile:inc()
	for _, extName in ipairs(options.extensions) do
		hFile:fmt('exts::%s = exts::LoadTest();\n',
			GenExtensionVarName(extName, spec, options))
	end
	hFile:dec()
	hFile:write("}\n")
	hFile:write "\n"
	
	--Write a function that loads an extension by name. It is called when
	--processing, so it should also set the extension variable based on the load.
	hFile:writeblock([[
void LoadExtByName(std::vector<MapEntry> &table, const char *extensionName)
{
	std::vector<MapEntry>::iterator entry = std::find_if(table.begin(), table.end(), MapCompare(extensionName));
	
	if(entry != table.end())
	{
		if(entry->loaderFunc)
			(*entry->extVariable) = exts::LoadTest(true, entry->loaderFunc());
		else
			(*entry->extVariable) = exts::LoadTest(true, 0);
	}
}
]])
	EndNamespace(hFile)
	hFile:write "\n"
end

	local function GenQualifier(spec, options)
		local ret = ""
		if(#options.prefix > 0) then
			ret = options.prefix .. "::"
		end
		ret = ret .. spec.FuncNamePrefix() .. "::"
		return ret
	end

	local function GenQualifiedEnumName(enum, spec, options)
		return GenQualifier(spec, options) .. GenEnumName(enum, spec, options)
	end
	
	local function GenQualifiedFuncPtrName(func, spec, options)
		return GenQualifier(spec, options) .. "_detail::"
			.. GenFuncPtrName(func, spec, options)
	end
	
	local function WriteAncillaryFuncs(hFile, specData, spec, options)
		local indexed = spec.GetIndexedExtStringFunc(options);
		if(indexed) then
			for _, func in ipairs(specData.funcData.functions) do
				if(indexed[1] == func.name) then
					indexed[1] = func
				end
				if(indexed[3] == func.name) then
					indexed[3] = func
				end
			end
			for _, enum in ipairs(specData.enumerators) do
				if(indexed[2] == enum.name) then
					indexed[2] = enum
				end
				if(indexed[4] == enum.name) then
					indexed[4] = enum
				end
			end
		
			hFile:writeblock([[
static void ProcExtsFromExtList(std::vector<MapEntry> &table)
{
	GLint iLoop;
	GLint iNumExtensions = 0;
	]] .. GenQualifiedFuncPtrName(indexed[1], spec, options)
	.. [[(]] .. GenQualifiedEnumName(indexed[2], spec, options)
	.. [[, &iNumExtensions);

	for(iLoop = 0; iLoop < iNumExtensions; iLoop++)
	{
		const char *strExtensionName = (const char *)]] ..
		GenQualifiedFuncPtrName(indexed[3], spec, options) ..
		[[(]] .. GenQualifiedEnumName(indexed[4], spec, options) .. [[, iLoop);
		LoadExtByName(table, strExtensionName);
	}
}
]])
		else
			hFile:writeblock(common.GetProcessExtsFromStringFunc(
				"LoadExtByName(table, %s)", ", std::vector<MapEntry> &table"))
		end
		
		hFile:write "\n"

		return indexed
	end

	
	local function WriteInMainFuncLoader(hFile, func, spec, options)
		hFile:fmt('_detail::%s = reinterpret_cast<_detail::%s>(%s("%s%s"));\n',
			GenFuncPtrName(func, spec, options),
			GenFuncPtrTypedefName(func, spec, options),
			common.GetProcAddressName(spec),
			spec.FuncNamePrefix(), func.name)
		hFile:fmt('if(!_detail::%s) return exts::LoadTest();\n',
			GenFuncPtrName(func, spec, options))
	end

function my_style.source.WriteMainLoaderFunc(hFile, specData, spec, options)
	StartNamespace(hFile)
	local indexed = WriteAncillaryFuncs(hFile, specData, spec, options)
	EndNamespace(hFile)
	
	hFile:write "\n"
	
	hFile:fmt("exts::LoadTest LoadFunctions(%s)\n", spec.GetLoaderParams())
	hFile:write("{\n")
	hFile:inc()
	hFile:writeblock[[
ClearExtensionVars();
std::vector<MapEntry> table;
InitializeMappingTable(table);
]]
	hFile:write("\n")
	
	if(indexed) then
		WriteInMainFuncLoader(hFile, indexed[1], spec, options)
		WriteInMainFuncLoader(hFile, indexed[3], spec, options)
		hFile:write("\n")
		hFile:write("ProcExtsFromExtList(table);\n")
	else
		local extListName, needLoad = spec.GetExtStringFuncName()
		if(needLoad) then
			for _, func in ipairs(specData.funcData.functions) do
				if(extListName == func.name) then
					extListName = func
					break
				end
			end
			
			WriteInMainFuncLoader(hFile, extListName, spec, options)
			
			extListName = GenQualifiedFuncPtrName(extListName, spec, options);
		end

		local function EnumResolve(enumName)
			return GenQualifiedEnumName(specData.enumtable[enumName], spec, options)
		end
		
		hFile:write "\n"
		hFile:fmt("ProcExtsFromExtString((const char *)%s(%s), table);\n",
			extListName,
			spec.GetExtStringParamList(EnumResolve))
	end
	
	if(options.version) then
		hFile:write "\n"
		hFile:fmt("int numFailed = _detail::%s();\n",
			GenCoreLoaderFuncName(options.version, spec, options))
		
		hFile:write("return exts::LoadTest(true, numFailed);\n")
	else
		hFile:fmt("return exts::LoadTest(true, 0);\n")
	end


	hFile:dec()
	hFile:write("}\n")
end

function my_style.source.WriteVersioningFuncs(hFile, specData, spec, options)
	hFile:fmt("static int g_major_version = 0;\n")
	hFile:fmt("static int g_minor_version = 0;\n")
	hFile:write "\n"
	
	if(tonumber(options.version) >= 3.0) then
		hFile:writeblock([[
static void GetGLVersion()
{
	_detail::GetIntegerv(MAJOR_VERSION, &g_major_version);
	_detail::GetIntegerv(MINOR_VERSION, &g_minor_version);
}
]])
	else
		hFile:writeblock(common.GetParseVersionFromString())
		hFile:write "\n"
		
		hFile:writeblock([[
static void GetGLVersion()
{
	ParseVersionFromString(&g_major_version, &g_minor_version, (const char *)_detail::GetString(VERSION));
}
]])
	end
	
	hFile:write "\n"
	hFile:writeblock([[
int GetMajorVersion()
{
	if(g_major_version == 0)
		GetGLVersion();
	return g_major_version;
}
]])
	hFile:write "\n"

	hFile:writeblock([[
int GetMinorVersion()
{
	if(g_major_version == 0) //Yes, check the major version to get the minor one.
		GetGLVersion();
	return g_minor_version;
}
]])
	hFile:write "\n"
	
	hFile:writeblock([[
bool IsVersionGEQ(int majorVersion, int minorVersion)
{
	if(g_major_version == 0)
		GetGLVersion();
		
	if(majorVersion > g_major_version) return true;
	if(majorVersion < g_major_version) return false;
	if(minorVersion >= g_minor_version) return true;
	return false;
}
]])

end


--------------------------------------------------
-- Style retrieval machinery

local function Create()
	return common.DeepCopyTable(my_style), struct
end

return { Create = Create }