Day 22 complete

.vscode/launch.json

@@ -8,9 +8,9 @@
 			"type":"cppvsdbg",
 			"request": "launch",
 			"name" : "Debug handmade win32 msvc",
-			"program": "${workspaceFolder}/data/handmade_win32.exe",
+			"program": "${workspaceFolder}/data/binaries/handmade_win32.exe",
 			"args": [],
-			"cwd": "${workspaceFolder}/data",
+			"cwd": "${workspaceFolder}/data/binaries/",
 			"visualizerFile": "${workspaceFolder}/scripts/handmade.natvis"
 		}
 	]

HandmadeHero.10x

@@ -14,10 +14,10 @@
 		<CleanCommand>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(WorkspaceDirectory)/scripts/clean.ps1</CleanCommand>
 		<BuildWorkingDirectory></BuildWorkingDirectory>
 		<CancelBuild></CancelBuild>
-		<RunCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</RunCommand>
-		<RunCommandWorkingDirectory>$(WorkspaceDirectory)/data</RunCommandWorkingDirectory>
-		<DebugCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</DebugCommand>
-		<ExePathCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</ExePathCommand>
+		<RunCommand>$(WorkspaceDirectory)/data/binaries/handmade_win32.exe</RunCommand>
+		<RunCommandWorkingDirectory>$(WorkspaceDirectory)/data/binaries</RunCommandWorkingDirectory>
+		<DebugCommand>$(WorkspaceDirectory)/data/binaries/handmade_win32.exe</DebugCommand>
+		<ExePathCommand>$(WorkspaceDirectory)/data/binaries/handmade_win32.exe</ExePathCommand>
 		<DebugSln></DebugSln>
 		<UseVisualStudioEnvBat>true</UseVisualStudioEnvBat>
 		<Configurations>

HandmadeHero.vcxproj

@@ -25,34 +25,25 @@
     </NMakeReBuildCommandLine>
   </PropertyGroup>
   <ItemGroup>
-    <ClInclude Include="project\engine.h" />
+    <ClInclude Include="project\engine\engine.hpp" />
+    <ClInclude Include="project\engine\engine_game_api.hpp" />
     <ClInclude Include="project\handmade.hpp" />
-    <ClInclude Include="project\platform\generics.h" />
     <ClInclude Include="project\platform\generics.hpp" />
-    <ClInclude Include="project\platform\grime.h" />
     <ClInclude Include="project\platform\grime.hpp" />
-    <ClInclude Include="project\platform\jsl.h" />
     <ClInclude Include="project\platform\jsl.hpp" />
-    <ClInclude Include="project\platform\macros.h" />
     <ClInclude Include="project\platform\macros.hpp" />
-    <ClInclude Include="project\platform\math_constants.h" />
     <ClInclude Include="project\platform\math_constants.hpp" />
-    <ClInclude Include="project\platform\platform.h" />
     <ClInclude Include="project\platform\platform.hpp" />
-    <ClInclude Include="project\platform\platform_engine_api.h" />
     <ClInclude Include="project\platform\platform_engine_api.hpp" />
-    <ClInclude Include="project\platform\platform_game_api.hpp" />
-    <ClInclude Include="project\platform\types.h" />
+    <ClInclude Include="project\platform\strings.hpp" />
     <ClInclude Include="project\platform\types.hpp" />
-    <ClInclude Include="project\platform\win32.h" />
     <ClInclude Include="project\platform\win32.hpp" />
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="project\engine.cpp" />
+    <ClCompile Include="project\engine\engine.cpp" />
     <ClCompile Include="project\handmade.cpp" />
     <ClCompile Include="project\handmade_engine.cpp" />
     <ClCompile Include="project\handmade_win32.cpp" />
-    <ClCompile Include="project\platform\platform_win32.cpp" />
     <ClCompile Include="project\platform\win32_platform.cpp" />
   </ItemGroup>
   <ItemGroup>
@@ -68,6 +59,9 @@
     <None Include="docs\Day 016.md" />
     <None Include="docs\Day 017.md" />
     <None Include="docs\Day 019.md" />
+    <None Include="docs\Day 020.md" />
+    <None Include="docs\Day 021.md" />
+    <None Include="docs\Day 022.md" />
     <None Include="scripts\build.ps1" />
     <None Include="scripts\clean.ps1" />
     <None Include="scripts\helpers\devshell.ps1" />

HandmadeHero.vcxproj.user

@@ -4,8 +4,8 @@
     <ShowAllFiles>true</ShowAllFiles>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Development|x64'">
-    <LocalDebuggerWorkingDirectory>$(ProjectDir)data</LocalDebuggerWorkingDirectory>
+    <LocalDebuggerWorkingDirectory>$(ProjectDir)data\binaries</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
-    <LocalDebuggerCommand>$(ProjectDir)data\handmade_win32.exe</LocalDebuggerCommand>
+    <LocalDebuggerCommand>$(ProjectDir)data\binaries\handmade_win32.exe</LocalDebuggerCommand>
   </PropertyGroup>
 </Project>

data/binaries/handmade_engine.symbols

@@ -0,0 +1,5 @@
+?on_module_reload@engine@@YAXPEAUMemory@1@PEAUModuleAPI@platform@@@Z
+?startup@engine@@YAXPEAUMemory@1@PEAUModuleAPI@platform@@@Z
+?shutdown@engine@@YAXPEAUMemory@1@PEAUModuleAPI@platform@@@Z
+?update_and_render@engine@@YAXPEAUInputState@1@PEAUOffscreenBuffer@1@PEAUMemory@1@PEAUModuleAPI@platform@@@Z
+?update_audio@engine@@YAXPEAUAudioBuffer@1@PEAUMemory@1@PEAUModuleAPI@platform@@@Z

docs/Day 022.md

@@ -0,0 +1,2 @@
+# Day 22
+

project/engine/engine.cpp

@@ -110,7 +110,7 @@ render_weird_graident(OffscreenBuffer* buffer, u32 x_offset, u32 y_offset )
 			u8 red   = 0;
 		#endif
 
-			*pixel++ = u32(red << 16) | u32(green << 8) | blue;
+			*pixel++ = u32(red << 16) | u32(green/2 << 16) | blue/2 << 0;
 		}
 		wildcard += 0.5375f;
 		row += buffer->Pitch;

project/engine/engine.hpp

@@ -50,7 +50,6 @@ struct AudioBuffer
 	u32  RunningSampleIndex;
 	s32  SamplesPerSecond;
 	s32  NumSamples;
-	char _PAD_[4];
 };
 
 struct DigitalBtn
@@ -190,7 +189,6 @@ struct InputMode
 {
 	InputBindCallback* Binds;
 	s32                NumBinds;
-	char _PAD_[4];
 };
 
 void input_mode_pop( InputMode* mode );

project/engine/engine_game_api.hpp

@@ -0,0 +1,3 @@
+/*
+	This represents the API only accessible to the engine to fullfill for the game module.
+*/

project/engine/win32_engine.cpp

@@ -1,11 +0,0 @@
-#include "platform/win32.hpp"
-#include "engine.hpp"
-
-b32 WINAPI DllMain(
-	HINSTANCE instance,
-	DWORD reason_for_call,
-	LPVOID reserved
-)
-{
-	return true;
-}

project/handmade.hpp

@@ -27,7 +27,6 @@ struct Actionable
 	char const*                Name;
 	engine::InputBindCallback* Binds;
 	s32                        NumBinds;
-	char _PAD_[4];
 };
 
 struct ActionableMode

project/handmade_engine.cpp

@@ -13,7 +13,4 @@
 
 #if Build_Unity
 #	include "engine/engine.cpp"
-#	if SYSTEM_WINDOWS
-#		include "engine/win32_engine.cpp"
-#	endif
 #endif

project/platform/platform.hpp

@@ -16,6 +16,8 @@
 #pragma warning( disable: 4514 ) // Support for unused inline functions
 #pragma warning( disable: 4505 ) // Support for unused static functions
 #pragma warning( disable: 5045 ) // Compiler will insert Spectre mitigation for memory load if /Qspectre switch specified
+#pragma warning( disable: 5264 ) // Support for 'const' variables unused
+#pragma warning( disable: 4820 ) // Support auto-adding padding to structs
 
 // TODO(Ed) : REMOVE THESE WHEN HE GETS TO THEM
 #include <math.h> // TODO : Implement math ourselves
@@ -26,6 +28,7 @@
 #include "generics.hpp"
 #include "math_constants.hpp"
 #include "types.hpp"
+#include "strings.hpp"
 
 #define NS_PLATFORM_BEGIN namespace platform {
 #define NS_PLATFORM_END }
@@ -45,7 +48,12 @@ struct Debug_FileContent
 {
 	void* Data;
 	u32   Size;
-	char  _PAD_[4];
+	Byte  _PAD_[4];
+};
+
+struct BinaryModule
+{
+	void* OpaqueHandle;
 };
 
 using DebugFileFreeContentFn  = void ( Debug_FileContent* file_content );
@@ -53,9 +61,54 @@ using DebugFileReadContentFn  = Debug_FileContent ( char const* file_path );
 using DebugFileWriteContentFn = b32 ( char const* file_path, u32 content_size, void* content_memory );
 
 using DebugSetPauseRenderingFn = void (b32 value);
+
+// TODO(Ed): This also assumes the symbol name is always within size of the provided buffer, needs to fail if not.
+// Note: This is a temporary solution until there is more infrastructure for the engine to use.
+void get_symbol_from_module_table( Debug_FileContent symbol_table, u32 symbol_ID, char* symbol_name )
+{
+	struct Token
+	{
+		char const* Ptr;
+		u32         Len;
+		char _PAD_[4];
+	};
+
+	Token tokens[256] = {};
+	s32 idx = 0;
+
+	char const* scanner = rcast( char const*, symbol_table.Data );
+	u32 left = symbol_table.Size;
+	while ( left )
+	{
+		if ( *scanner == '\n' || *scanner == '\r' )
+		{
+			++ scanner;
+			-- left;
+		}
+		else
+		{
+			tokens[idx].Ptr = scanner;
+			while ( left && *scanner != '\r' && *scanner != '\n' )
+			{
+				-- left;
+				++ scanner;
+				++ tokens[idx].Len;
+			}
+			++ idx;
+		}
+	}
+
+	Token& token = tokens[symbol_ID];
+	while ( token.Len -- )
+	{
+		*symbol_name = *token.Ptr;
+		++ symbol_name;
+		++ token.Ptr;
+	}
+	*symbol_name = '\0';
+}
 #endif
 
-// TODO(Ed) : Implement this later when settings UI is setup.
 #pragma region Settings Exposure
 // Exposing specific properties for user configuration in settings
 
@@ -68,6 +121,13 @@ using SetMonitorRefreshRateFn = void ( u32 rate_in_hz );
 using GetEngineFrameTargetFn = u32 ();
 using SetEngineFrameTargetFn = void ( u32 rate_in_hz );
 
+// This module api will be used to manage the editor and game modules from the engine side,
+// without the platform layer needing to know about it.
+
+using LoadBinaryModuleFn   = BinaryModule ( char const* module_path );
+using UnloadBinaryModuleFn = void ( BinaryModule* module );
+using GetModuleProcedureFn = void* ( BinaryModule module, char const* symbol );
+
 struct ModuleAPI
 {
 #if Build_Development
@@ -83,6 +143,10 @@ struct ModuleAPI
 
 	GetEngineFrameTargetFn* get_engine_frame_target;
 	SetEngineFrameTargetFn* set_engine_frame_target;
+
+	LoadBinaryModuleFn*   load_binary_module;
+	UnloadBinaryModuleFn* unload_binary_module;
+	GetModuleProcedureFn* get_module_procedure;
 };
 
 #pragma endregion Settings Exposure

project/platform/platform_engine_api.hpp

@@ -42,7 +42,6 @@ struct ModuleAPI
 	UpdateAudioFn*     update_audio;
 
 	b32 IsValid;
-	char _PAD_[4];
 };
 
 NS_ENGINE_END

project/platform/platform_game_api.hpp

@@ -1,3 +0,0 @@
-/*
-	This represents the API only accessible to the platform layer to fullfill for the game layer.
-*/

project/platform/strings.hpp

@@ -0,0 +1,190 @@
+#include "macros.hpp"
+#include "types.hpp"
+
+void str_append( u32 dest_len, char* dest, u32 src_len, char const* src );
+void str_concat( u32 dest_size, char* dest
+	, u32 str_a_len, char const* str_a
+	, u32 str_b_len, char const* str_b );
+u32 str_length( char const* str );
+
+#define str_ascii( str ) { sizeof( str ) - 1, str }
+
+// Length tracked raw strings.
+struct Str
+{
+	u32   Len;
+	char* Data;
+
+	void append( u32 src_len, char const* src ) {
+		str_append( Len, Data, src_len, src );
+	}
+	void append( Str const src ) {
+		str_append( Len, Data, src.Len, src.Data );
+	}
+
+	static
+	void concast( u32 dest_size, Str* dest, Str const str_a, Str const str_b )
+	{
+		str_concat( dest_size, dest->Data
+			, str_a.Len, str_a.Data
+			, str_b.Len, str_b.Data );
+		dest->Len = str_a.Len + str_b.Len;
+	}
+
+	operator char*() const {
+		return Data;
+	}
+	char& operator []( u32 idx ) {
+		return Data[idx];
+	}
+	char const& operator []( u32 idx ) const {
+		return Data[idx];
+	}
+};
+
+template< u32 capacity >
+// Fixed length raw strings.
+struct StrFixed
+{
+	constexpr static u32 Capacity = capacity;
+
+	u32  Len;
+	char Data[capacity];
+
+	void append( u32 src_len, char const* src ) {
+		str_append( Len, Data, src_len, src );
+	}
+	void append( Str const src ) {
+		str_append( Len, Data, src.Len, src.Data );
+	}
+
+	void concat( Str const str_a, Str const str_b )
+	{
+		str_concat( Capacity, Data
+			, str_a.Len, str_a.Data
+			, str_b.Len, str_b.Data );
+		Len = str_a.Len + str_b.Len;
+	}
+
+	operator char*()           { return Data;}
+	operator char const*()     { return Data; }
+	operator Str()             { return { Len, Data }; }
+	operator Str const() const { return { Len, Data }; }
+	char& operator []( u32 idx ) {
+		assert( idx < Capacity );
+		return Data[idx];
+	}
+	char const& operator []( u32 idx ) const {
+		assert( idx < Capacity );
+		return Data[idx];
+	}
+};
+
+inline
+void str_append( u32 dest_len, char* dest, u32 src_len, char const* src )
+{
+	assert( dest_len > 0 );
+	assert( dest != nullptr );
+	assert( src_len > 0 );
+	assert( src != nullptr );
+	assert( dest_len >= src_len );
+
+	char* dest_end = dest + dest_len;
+	assert( *dest_end == '\0' );
+
+	u32 left = src_len;
+	while ( left-- )
+	{
+		*dest = *src;
+		++ dest;
+		++ src;
+	}
+}
+
+void str_concat( u32 dest_size, char* dest
+	, u32 str_a_len, char const* str_a
+	, u32 str_b_len, char const* str_b )
+{
+	assert( dest_size > 0 );
+	assert( dest != nullptr );
+	assert( *dest == '\0' );
+	assert( str_a_len > 0 );
+	assert( str_a != nullptr );
+	assert( str_b_len > 0 );
+	assert( str_b != nullptr );
+	assert( str_a_len + str_b_len < dest_size );
+
+	char* dest_a = dest;
+	char* dest_b = dest + str_a_len;
+	if ( str_a_len > str_b_len )
+	{
+		u32 left = str_a_len;
+		while ( left-- )
+		{
+			*dest_a   = *str_a;
+			*dest_b = *str_b;
+
+			++ dest_a;
+			++ dest_b;
+			++ str_a;
+			++ str_b;
+		}
+
+		left = str_a_len - str_b_len;
+		while ( left-- )
+		{
+			*dest_b = *str_b;
+			++ dest_b;
+			++ str_b;
+		}
+	}
+	else if ( str_a_len < str_b_len )
+	{
+		u32   left   = str_b_len;
+		while ( left-- )
+		{
+			*dest_a = *str_a;
+			*dest_b = *str_b;
+			++ dest_a;
+			++ dest_b;
+			++ str_a;
+			++ str_b;
+		}
+
+		left = str_b_len - str_a_len;
+		while ( left-- )
+		{
+			*dest_a = *str_a;
+			++ dest_a;
+			++ str_a;
+		}
+	}
+	else
+	{
+		u32 left = str_a_len;
+		while ( left-- )
+		{
+			*dest_a = *str_a;
+			*dest_b = *str_b;
+			++ dest_a;
+			++ str_a;
+			++ dest_b;
+			++ str_b;
+		}
+	}
+}
+
+inline
+u32 str_length( char const* str )
+{
+	assert( str != nullptr );
+
+	u32 result = 0;
+	while ( *str != '\0' )
+	{
+		++ result;
+		++ str;
+	}
+
+	return result;
+}

project/platform/types.hpp

@@ -97,6 +97,9 @@ static_assert( sizeof( uptr ) == sizeof( sptr ), "sizeof(uptr) != sizeof(sptr)"
 typedef float  f32;
 typedef double f64;
 
+struct Byte {};
+static_assert( sizeof( Byte ) == 1, "Unit type must be 1 byte in size" );
+
 static_assert( sizeof( f32 ) == 4, "sizeof(f32) != 4" );
 static_assert( sizeof( f64 ) == 8, "sizeof(f64) != 8" );
 

project/platform/win32_platform.cpp

@@ -101,6 +101,16 @@ struct DirectSoundBuffer
 
 
 #pragma region Static Data
+
+global StrFixed< S16_MAX > Path_Root;
+global StrFixed< S16_MAX > Path_Binaries;
+
+constexpr Str FName_Engine_DLL       = str_ascii("handmade_engine.dll");
+constexpr Str FName_Engine_DLL_InUse = str_ascii("handmade_engine_in_use.dll");
+
+global StrFixed< S16_MAX > Path_Engine_DLL;
+global StrFixed< S16_MAX > Path_Engine_DLL_InUse;
+
 // TODO(Ed) : This is a global for now.
 global b32 Running         = false;
 global b32 Pause_Rendering = false;
@@ -130,7 +140,7 @@ global u32 Engine_Refresh_Hz      = Monitor_Refresh_Hz / 2;
 global f32 Engine_Frame_Target_MS = 1000.f / scast(f32, Engine_Refresh_Hz);
 #pragma endregion Static Data
 
-
+#pragma region Internal
 #if Build_Debug
 struct DebugTimeMarker
 {
@@ -145,82 +155,6 @@ struct DebugTimeMarker
 	DWORD ExpectedFlipCursor;
 };
 
-void debug_file_free_content( Debug_FileContent* content )
-{
-	if ( content->Data)
-	{
-		VirtualFree( content->Data, 0, MEM_Release);
-		*content = {};
-	}
-}
-
-Debug_FileContent debug_file_read_content( char const* file_path )
-{
-	Debug_FileContent result {};
-
-	HANDLE file_handle = CreateFileA( file_path
-		, GENERIC_READ, FILE_SHARE_READ, 0
-		, OPEN_EXISTING, 0, 0
-	);
-	if ( file_handle == INVALID_HANDLE_VALUE )
-	{
-		// TODO(Ed) : Logging
-		return result;
-	}
-
-	GetFileSizeEx( file_handle, rcast(LARGE_INTEGER*, &result.Size) );
-	if ( result.Size == 0 )
-	{
-		// TODO(Ed) : Logging
-		return result;
-	}
-	result.Data = VirtualAlloc( 0, result.Size, MEM_Commit_Zeroed | MEM_Reserve, Page_Read_Write );
-
-	u32 bytes_read;
-	if ( ReadFile( file_handle, result.Data, result.Size, rcast(LPDWORD, &bytes_read), 0 ) == false )
-	{
-		// TODO(Ed) : Logging
-		return {};
-	}
-
-	if ( bytes_read != result.Size )
-	{
-		// TODO : Logging
-		return {};
-	}
-
-	CloseHandle( file_handle );
-	return result;
-}
-
-b32 debug_file_write_content( char const* file_path, u32 content_size, void* content_memory )
-{
-	HANDLE file_handle = CreateFileA( file_path
-		, GENERIC_WRITE, 0, 0
-		, CREATE_ALWAYS, 0, 0
-	);
-	if ( file_handle == INVALID_HANDLE_VALUE )
-	{
-		// TODO : Logging
-		return false;
-	}
-
-	DWORD bytes_written;
-	if ( WriteFile( file_handle, content_memory, content_size, & bytes_written, 0 ) == false )
-	{
-		// TODO : Logging
-		return false;
-	}
-
-	CloseHandle( file_handle );
-	return true;
-}
-
-void debug_set_pause_rendering( b32 value )
-{
-	Pause_Rendering = value;
-}
-
 internal void
 debug_draw_vertical( s32 x_pos, s32 top, s32 bottom, s32 color )
 {
@@ -748,84 +682,144 @@ process_pending_window_messages( engine::KeyboardState* keyboard )
 		}
 	}
 }
+#pragma endregion Internal
 
 #pragma region Platfom API
-u32 get_monitor_refresh_rate();
-
-#pragma endregion Platform API
-
-// TODO(Ed): This also assumes the symbol name is always within size of the provided buffer, needs to fail if not.
-void get_symbol_from_module_table( Debug_FileContent symbol_table, u32 symbol_ID, char* symbol_name )
+#if Build_Development
+void debug_file_free_content( Debug_FileContent* content )
 {
-	struct Token
+	if ( content->Data)
 	{
-		char const* Ptr;
-		u32         Len;
-		char _PAD_[4];
-	};
-
-	Token tokens[256] = {};
-	s32 idx = 0;
-
-	char const* scanner = rcast( char const*, symbol_table.Data );
-	u32 left = symbol_table.Size;
-	while ( left )
-	{
-		if ( *scanner == '\n' || *scanner == '\r' )
-		{
-			++ scanner;
-			-- left;
-		}
-		else
-		{
-			tokens[idx].Ptr = scanner;
-			while ( left && *scanner != '\r' && *scanner != '\n' )
-			{
-				-- left;
-				++ scanner;
-				++ tokens[idx].Len;
-			}
-			++ idx;
-		}
+		VirtualFree( content->Data, 0, MEM_Release);
+		*content = {};
 	}
-
-	Token& token = tokens[symbol_ID];
-	while ( token.Len -- )
-	{
-		*symbol_name = *token.Ptr;
-		++ symbol_name;
-		++ token.Ptr;
-	}
-	*symbol_name = '\0';
 }
 
-// Right now they are just the data directory
-#define Path_To_Symbol_Tables
+Debug_FileContent debug_file_read_content( char const* file_path )
+{
+	Debug_FileContent result {};
 
+	HANDLE file_handle = CreateFileA( file_path
+		, GENERIC_READ, FILE_SHARE_READ, 0
+		, OPEN_EXISTING, 0, 0
+	);
+	if ( file_handle == INVALID_HANDLE_VALUE )
+	{
+		// TODO(Ed) : Logging
+		return result;
+	}
+
+	GetFileSizeEx( file_handle, rcast(LARGE_INTEGER*, &result.Size) );
+	if ( result.Size == 0 )
+	{
+		// TODO(Ed) : Logging
+		return result;
+	}
+	result.Data = VirtualAlloc( 0, result.Size, MEM_Commit_Zeroed | MEM_Reserve, Page_Read_Write );
+
+	u32 bytes_read;
+	if ( ReadFile( file_handle, result.Data, result.Size, rcast(LPDWORD, &bytes_read), 0 ) == false )
+	{
+		// TODO(Ed) : Logging
+		return {};
+	}
+
+	if ( bytes_read != result.Size )
+	{
+		// TODO : Logging
+		return {};
+	}
+
+	CloseHandle( file_handle );
+	return result;
+}
+
+b32 debug_file_write_content( char const* file_path, u32 content_size, void* content_memory )
+{
+	HANDLE file_handle = CreateFileA( file_path
+		, GENERIC_WRITE, 0, 0
+		, CREATE_ALWAYS, 0, 0
+	);
+	if ( file_handle == INVALID_HANDLE_VALUE )
+	{
+		// TODO : Logging
+		return false;
+	}
+
+	DWORD bytes_written;
+	if ( WriteFile( file_handle, content_memory, content_size, & bytes_written, 0 ) == false )
+	{
+		// TODO : Logging
+		return false;
+	}
+
+	CloseHandle( file_handle );
+	return true;
+}
+
+void debug_set_pause_rendering( b32 value )
+{
+	Pause_Rendering = value;
+}
+#endif
+
+u32 get_monitor_refresh_rate();
+
+BinaryModule load_binary_module( char const* module_path )
+{
+	HMODULE lib = LoadLibraryA( module_path );
+	return BinaryModule { scast(void*, lib) };
+}
+
+void unload_binary_module( BinaryModule* module )
+{
+	FreeLibrary( scast(HMODULE, module->OpaqueHandle) );
+	*module = {};
+}
+
+void* get_binary_module_symbol( BinaryModule module, char const* symbol_name )
+{
+	return rcast(void*, GetProcAddress( scast(HMODULE, module.OpaqueHandle), symbol_name ));
+}
+#pragma endregion Platform API
+
+FILETIME file_get_last_write_time( char const* path )
+{
+	WIN32_FIND_DATAA dll_file_info = {};
+	HANDLE dll_file_handle = FindFirstFileA( path, & dll_file_info );
+	if ( dll_file_handle == INVALID_HANDLE_VALUE )
+	{
+		FindClose( dll_file_handle );
+	}
+
+	return dll_file_info.ftLastWriteTime;
+}
+
+#pragma region Engine Module API
 global HMODULE Lib_Handmade_Engine = nullptr;
 
 engine::ModuleAPI load_engine_module_api()
 {
 	using ModuleAPI = engine::ModuleAPI;
 
-	// TODO(Ed) : Need proper paything to the dll (not assume is in the base directory).
-
-	CopyFileA( "handmade_engine.dll", "handmade_engine_temp.dll", FALSE );
+	CopyFileA( Path_Engine_DLL, Path_Engine_DLL_InUse, FALSE );
 
 	// Engine
-	Lib_Handmade_Engine = LoadLibraryA( "handmade_engine_temp.dll" );
+	Lib_Handmade_Engine = LoadLibraryA( Path_Engine_DLL_InUse );
 	if ( ! Lib_Handmade_Engine )
 	{
 		return {};
 	}
 
-	constexpr char const*
-	handmade_engine_symbols = Path_To_Symbol_Tables "handmade_engine.symbols";
+	constexpr Str fname_handmade_engine_symbols = str_ascii("handmade_engine.symbols");
 
-	Debug_FileContent symbol_table = debug_file_read_content( handmade_engine_symbols );
+	StrFixed< S16_MAX > path_handmade_engine_symbols { 0, {} };
+	path_handmade_engine_symbols.concat( Path_Binaries, fname_handmade_engine_symbols );
+
+	Debug_FileContent symbol_table = debug_file_read_content( path_handmade_engine_symbols );
 	if ( symbol_table.Size == 0 )
 	{
-		fatal( "Failed to laod symbol table for handmade engine module!" );
+		fatal( "Failed to load symbol table for handmade engine module!" );
 		return {};
 	}
 
@@ -872,6 +866,7 @@ void unload_engine_module_api( engine::ModuleAPI* engine_api )
 		OutputDebugStringA( "Unloaded engine module API\n" );
 	}
 }
+#pragma endregion Engine Module API
 
 NS_PLATFORM_END
 
@@ -910,6 +905,10 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 		platform_api.set_monitor_refresh_rate = nullptr;
 		platform_api.get_engine_frame_target  = nullptr;
 		platform_api.set_engine_frame_target  = nullptr;
+
+		platform_api.load_binary_module	  = & load_binary_module;
+		platform_api.unload_binary_module = & unload_binary_module;
+		platform_api.get_module_procedure = & get_binary_module_symbol;
 	}
 
 	// Memory
@@ -940,9 +939,6 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 		}
 	}
 
-	// Load engine module
-	engine::ModuleAPI engine_api = load_engine_module_api();
-
 	WNDCLASSW window_class {};
 	HWND window_handle = nullptr;
 	{
@@ -983,6 +979,41 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 	// WinDimensions dimensions = get_window_dimensions( window_handle );
 	resize_dib_section( &Surface_Back_Buffer, 1280, 720 );
 
+	// Setup pathing
+	// TODO(Ed): This will not support long paths, NEEDS to be changed to support long paths.
+	{
+		char path_buffer[S16_MAX];
+		GetModuleFileNameA( 0, path_buffer, sizeof(path_buffer) );
+
+		if ( GetCurrentDirectoryA( S16_MAX, Path_Binaries ) == 0 )
+		{
+			fatal( "Failed to get the root directory!" );
+		}
+		Path_Binaries.Len = str_length( Path_Binaries );
+		Path_Binaries[ Path_Binaries.Len ] = '\\';
+		++ Path_Binaries.Len;
+
+		if ( SetCurrentDirectoryA( ".." ) == 0 )
+		{
+			fatal( "Failed to set current directory to root!");
+		}
+
+		if ( GetCurrentDirectoryA( S16_MAX, Path_Root.Data ) == 0 )
+		{
+			fatal( "Failed to get the root directory!" );
+		}
+		Path_Root.Len = str_length(Path_Root.Data);
+		Path_Root.Data[ Path_Root.Len ] = '\\';
+		++ Path_Root.Len;
+
+		Path_Engine_DLL.      concat( Path_Binaries, FName_Engine_DLL );
+		Path_Engine_DLL_InUse.concat( Path_Binaries, FName_Engine_DLL_InUse );
+	}
+
+	// Load engine module
+	FILETIME          engine_api_load_time = file_get_last_write_time( Path_Engine_DLL );
+	engine::ModuleAPI engine_api           = load_engine_module_api();
+
 	b32   sound_is_valid       = false;
 	DWORD ds_cursor_byte_delta = 0;
 	f32   ds_latency_ms        = 0;
@@ -1091,8 +1122,6 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 	OutputDebugStringA( text_buffer );
 #endif
 
-	u64 module_reload_counter = 0;
-
 	Running = true;
 #if 0
 // This tests the play & write cursor update frequency.
@@ -1109,13 +1138,13 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 #endif
 	while( Running )
 	{
-		if ( module_reload_counter > 120 )
+		FILETIME engine_api_current_time = file_get_last_write_time( Path_Engine_DLL );
+		if ( CompareFileTime( & engine_api_load_time, & engine_api_current_time ) != 0 )
 		{
+			engine_api_load_time = engine_api_current_time;
 			unload_engine_module_api( & engine_api );
 			engine_api = load_engine_module_api();
-			module_reload_counter = 0;
 		}
-		++ module_reload_counter;
 
 		process_pending_window_messages( new_keyboard );
 
@@ -1490,6 +1519,9 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 
 	engine_api.shutdown( & engine_memory, & platform_api );
 
+	unload_engine_module_api( & engine_api );
+	DeleteFileA( Path_Engine_DLL_InUse );
+
 	if ( jsl_num_devices > 0 )
 	{
 		for ( u32 jsl_device_index = 0; jsl_device_index < jsl_num_devices; ++ jsl_device_index )

scripts/build.ps1

@@ -51,7 +51,7 @@ write-host "Building HandmadeHero with $vendor"
 
 if ( $dev ) {
 	if ( $debug -eq $null ) {
-		# $debug = $true
+		$debug = $true
 	}
 
 	if ( $optimize -eq $null ) {
@@ -194,9 +194,12 @@ if ( $vendor -match "clang" )
 		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$binary )
 		Write-Host "build-simple: clang"
 
-		$object = $binary -replace '\.exe', '.obj'
-		$pdb    = $binary -replace '\.exe', '.pdb'
-		$map    = $binary -replace '\.exe', '.map'
+		$object = $unit -replace '\.cpp', '.obj'
+		$map    = $unit -replace '\.cpp', '.map'
+
+		# The PDB file has to also be time-stamped so that we can reload the DLL at runtime
+		$timestamp = Get-Date -Format "yyyy-MM-dd_HH-mm-ss"
+		$pdb       = $binary -replace '\.(exe|dll)$', "_$timestamp.pdb"
 
 		$compiler_args += @(
 			$flag_no_color_diagnostics,
@@ -275,6 +278,7 @@ if ( $vendor -match "msvc" )
 	$flag_dll_debug 			     = '/LDd'
 	$flag_linker 		             = '/link'
 	$flag_link_dll                   = '/DLL'
+	$flag_link_no_incremental 	     = '/INCREMENTAL:NO'
 	$flag_link_mapfile 				 = '/MAP:'
 	$flag_link_optimize_references   = '/OPT:REF'
 	$flag_link_win_debug 	         = '/DEBUG'
@@ -309,9 +313,14 @@ if ( $vendor -match "msvc" )
 		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$binary )
 		Write-Host "build-simple: msvc"
 
-		$object = $binary -replace '\.(exe|dll)$', '.obj'
-		$pdb    = $binary -replace '\.(exe|dll)$', '.pdb'
-		$map    = $binary -replace '\.(exe|dll)$', '.map'
+		$object = $unit -replace '\.(cpp)$', '.obj'
+		$map    = $unit -replace '\.(cpp)$', '.map'
+		$object = $object -replace '\bproject\b', 'build'
+		$map    = $map    -replace '\bproject\b', 'build'
+
+		# The PDB file has to also be time-stamped so that we can reload the DLL at runtime
+		$timestamp = Get-Date -Format "yyyy-MM-dd_HH-mm-ss"
+		$pdb       = $binary -replace '\.(exe|dll)$', "_$timestamp.pdb"
 
 		$compiler_args += @(
 			$flag_nologo,
@@ -355,6 +364,7 @@ if ( $vendor -match "msvc" )
 		$linker_args += @(
 			$flag_nologo,
 			$flag_link_win_machine_64,
+			$flag_link_no_incremental,
 			( $flag_link_win_path_output + $binary )
 		)
 		if ( $debug ) {
@@ -383,6 +393,7 @@ if ( $vendor -match "msvc" )
 $path_project  = Join-Path $path_root    'project'
 $path_build    = Join-Path $path_root    'build'
 $path_data     = Join-Path $path_root	 'data'
+$path_binaries = Join-Path $path_data    'binaries'
 $path_deps     = Join-Path $path_project 'dependencies'
 $path_gen      = Join-Path $path_project 'gen'
 $path_platform = Join-Path $path_project 'platform'
@@ -398,6 +409,10 @@ if ( (Test-Path $path_deps) -eq $false ) {
 	& $update_deps
 }
 
+if ( (Test-Path $path_binaries) -eq $false ) {
+	New-Item $path_binaries -ItemType Directory
+}
+
 #region Handmade Generate
 if ( $false ) {
 	$includes = @(
@@ -464,6 +479,13 @@ else {
 
 if ( $engine )
 {
+	# Delete old PDBs 
+	$pdb_files = Get-ChildItem -Path $path_binaries -Filter "handmade_engine_*.pdb"
+	foreach ($file in $pdb_files) {
+		Remove-Item -Path $file.FullName -Force
+		Write-Host "Deleted $file" -ForegroundColor Green
+	}
+
 	$engine_compiler_args = $compiler_args
 	$engine_compiler_args += ($flag_define + 'Build_DLL=1' )
 
@@ -481,15 +503,19 @@ if ( $engine )
 		$flag_link_optimize_references
 	)
 
-	$unit            = Join-Path $path_project 'handmade_engine.cpp'
-	$dynamic_library = Join-Path $path_build   'handmade_engine.dll'
+	$unit            = Join-Path $path_project  'handmade_engine.cpp'
+	$dynamic_library = Join-Path $path_binaries 'handmade_engine.dll'
 
 	build-simple $includes $engine_compiler_args $linker_args $unit $dynamic_library
 
 	if ( Test-Path $dynamic_library )
 	{
-		$data_path = Join-Path $path_data 'handmade_engine.dll'
-		move-item $dynamic_library $data_path -Force
+		# $data_path = Join-Path $path_data 'handmade_engine.dll'
+		# move-item $dynamic_library $data_path -Force
+		$path_lib = $dynamic_library -replace '\.dll', '.lib'
+		$path_exp = $dynamic_library -replace '\.dll', '.exp'
+		Remove-Item $path_lib -Force
+		Remove-Item $path_exp -Force
 
 		# We need to generate the symbol table so that we can lookup the symbols we need when loading/reloading the library at runtime.
 		# This is done by sifting through the emitter.map file from the linker for the base symbol names
@@ -505,6 +531,8 @@ if ( $engine )
 
 		$path_engine_map = Join-Path $path_build 'handmade_engine.map'
 
+		$maxNameLength = ($engine_symbols | Measure-Object -Property Length -Maximum).Maximum
+
 		$engine_symbol_table = @()
 		$engine_symbol_list  = @()
 		Get-Content -Path $path_engine_map | ForEach-Object {
@@ -526,17 +554,27 @@ if ( $engine )
 
 		write-host "Engine Symbol Table:" -ForegroundColor Green
 		$engine_symbol_table | ForEach-Object {
-			write-host "`t$_" -ForegroundColor Green
+			$split         = $_ -split ', ', 2
+			$paddedName    = $split[0].PadRight($maxNameLength)
+			$decoratedName = $split[1]
+			write-host "`t$paddedName, $decoratedName" -ForegroundColor Green
 		}
 
 		# Write the symbol table to a file
-		$path_engine_symbols = Join-Path $path_data 'handmade_engine.symbols'
+		$path_engine_symbols = Join-Path $path_binaries 'handmade_engine.symbols'
 		$engine_symbol_list | Out-File -Path $path_engine_symbols
 	}
 }
 
 if ( $platform )
 {
+	# Delete old PDBs 
+	$pdb_files = Get-ChildItem -Path $path_binaries -Filter "handmade_win32_*.pdb"
+	foreach ($file in $pdb_files) {
+		Remove-Item -Path $file.FullName -Force
+		Write-Host "Deleted $file" -ForegroundColor Green
+	}
+
 	$platform_compiler_args  = $compiler_args
 	$platform_compiler_args += ($flag_define + 'Build_DLL=0' )
 
@@ -552,16 +590,23 @@ if ( $platform )
 		$flag_link_optimize_references
 	)
 
-	$unit       = Join-Path $path_project 'handmade_win32.cpp'
-	$executable = Join-Path $path_build   'handmade_win32.exe'
+	$unit       = Join-Path $path_project  'handmade_win32.cpp'
+	$executable = Join-Path $path_binaries 'handmade_win32.exe'
 
 	build-simple $includes $platform_compiler_args $linker_args $unit $executable
 
-	if ( Test-Path $executable )
-	{
-		$data_path = Join-Path $path_data 'handmade_win32.exe'
-		move-item $executable $data_path -Force
-	}
+	# if ( Test-Path $executable )
+	# {
+	# 	$data_path = Join-Path $path_data 'handmade_win32.exe'
+	# 	move-item $executable $data_path -Force
+	# }
+}
+
+$path_jsl_dll = Join-Path $path_binaries 'JoyShockLibrary.dll'
+if ( (Test-Path $path_jsl_dll) -eq $false )
+{
+	$path_jsl_dep_dll = Join-Path $path_deps 'JoyShockLibrary/x64/JoyShockLibrary.dll'
+	Copy-Item $path_jsl_dep_dll $path_jsl_dll
 }
 #endregion Handmade Runtime
 

scripts/clean.ps1

@@ -3,8 +3,13 @@ $path_root = git rev-parse --show-toplevel
 
 $path_project      = join-path $path_root    "project"
 $path_build 	   = join-path $path_root    "build"
+$path_data 	       = join-path $path_root    "data"
 $path_dependencies = join-path $path_project "dependencies"
+$path_binaries     = join-path $path_data    "binaries"
 
 if ( Test-Path $path_build ) {
 	Remove-Item -verbose $path_build -Recurse
 }
+if ( Test-Path $path_binaries ) {
+	Remove-Item -verbose $path_binaries -Recurse
+}

scripts/update_deps.ps1

@@ -4,6 +4,7 @@ $path_root = & git rev-parse --show-toplevel
 $path_data         = Join-Path $path_root         "data"
 $path_project      = Join-Path $path_root         "project"
 $path_deps         = Join-Path $path_project      "dependencies"
+$path_binaries     = Join-Path $path_data         "binaries"
 $path_deps_windows = Join-Path $path_deps         "windows"
 $path_temp         = Join-Path $path_deps         "temp"
 $path_platform     = Join-Path $path_project      "platform"
@@ -15,6 +16,10 @@ if (Test-Path $path_deps) {
 }
 New-Item -ItemType Directory -Path $path_temp
 
+if ( -not (Test-Path $path_binaries) ) {
+	New-Item -ItemType Directory -Path $path_binaries
+}
+
 $url_gencpp      = "https://github.com/Ed94/gencpp/releases/download/latest/gencpp_singleheader.zip"
 $path_gencpp_zip = Join-Path $path_temp "gencpp_singleheader.zip"
 
@@ -59,7 +64,7 @@ $jsl_lib_files = (Get-ChildItem (Join-Path $path_temp "JSL\x64") -Recurse -Inclu
 Move-Item $jsl_lib_files -Destination $path_jsl_lib -Force
 
 $path_jsl_dll  = Join-Path $path_jsl_lib "JoyShockLibrary.dll"
-Move-Item  $path_jsl_dll $path_data -Force
+Copy-Item  $path_jsl_dll $path_binaries -Force
 #endregion JoyShockLibrary
 
 Remove-Item $path_temp -Recurse -Force