Day 21 complete

.gitignore

@@ -22,3 +22,5 @@ build
 
 **/*.dll
 data/test.out
+data/handmade_engine.symbols
+data/handmade_win32.exe

.vscode/launch.json

@@ -8,7 +8,7 @@
 			"type":"cppvsdbg",
 			"request": "launch",
 			"name" : "Debug handmade win32 msvc",
-			"program": "${workspaceFolder}/build/handmade_win32.exe",
+			"program": "${workspaceFolder}/data/handmade_win32.exe",
 			"args": [],
 			"cwd": "${workspaceFolder}/data",
 			"visualizerFile": "${workspaceFolder}/scripts/handmade.natvis"

HandmadeHero.10x

@@ -8,16 +8,16 @@
 		<ShowEmptyFolders>true</ShowEmptyFolders>
 		<IsVirtual>false</IsVirtual>
 		<IsFolder>false</IsFolder>
-		<BuildCommand>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(WorkspaceDirectory)/scripts/build.ps1 msvc dev optimized</BuildCommand>
+		<BuildCommand>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(WorkspaceDirectory)/scripts/build.ps1 msvc dev debug engine</BuildCommand>
-		<RebuildCommand></RebuildCommand>
+		<RebuildCommand>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(WorkspaceDirectory)/scripts/build.ps1 msvc dev debug platform</RebuildCommand>
 		<BuildFileCommand></BuildFileCommand>
 		<CleanCommand>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(WorkspaceDirectory)/scripts/clean.ps1</CleanCommand>
 		<BuildWorkingDirectory></BuildWorkingDirectory>
 		<CancelBuild></CancelBuild>
-		<RunCommand>$(WorkspaceDirectory)/build/handmade_win32.exe</RunCommand>
+		<RunCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</RunCommand>
 		<RunCommandWorkingDirectory>$(WorkspaceDirectory)/data</RunCommandWorkingDirectory>
-		<DebugCommand>$(WorkspaceDirectory)/build/handmade_win32.exe</DebugCommand>
+		<DebugCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</DebugCommand>
-		<ExePathCommand>$(WorkspaceDirectory)/build/handmade_win32.exe</ExePathCommand>
+		<ExePathCommand>$(WorkspaceDirectory)/data/handmade_win32.exe</ExePathCommand>
 		<DebugSln></DebugSln>
 		<UseVisualStudioEnvBat>true</UseVisualStudioEnvBat>
 		<Configurations>

HandmadeHero.vcxproj

@@ -17,28 +17,43 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Development|x64'">
     <IncludePath>$(ProjectDir)project;$(IncludePath)</IncludePath>
     <LibraryPath>$(ProjectDir)data;$(windir)System32;$(LibraryPath)</LibraryPath>
-    <NMakeBuildCommandLine>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(ProjectDir)scripts\build.ps1 msvc dev</NMakeBuildCommandLine>
+    <NMakeBuildCommandLine>pwsh -ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(ProjectDir)scripts\build.ps1 msvc dev engine</NMakeBuildCommandLine>
     <NMakeCleanCommandLine>pwsh ExecutionPolicy Bypass -NoProfile -NonInteractive -File $(ProjectDir)scripts\clean.ps1</NMakeCleanCommandLine>
     <NMakePreprocessorDefinitions>GEN_TIME;Build_Development;Build_Debug;$(NMakePreprocessorDefinitions)</NMakePreprocessorDefinitions>
     <ExternalIncludePath>$(VC_IncludePath);$(WindowsSDK_IncludePath)</ExternalIncludePath>
+    <NMakeReBuildCommandLine>
+    </NMakeReBuildCommandLine>
   </PropertyGroup>
   <ItemGroup>
     <ClInclude Include="project\engine.h" />
+    <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\types.hpp" />
     <ClInclude Include="project\platform\win32.h" />
+    <ClInclude Include="project\platform\win32.hpp" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="project\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>
     <None Include="docs\Day 001.md" />

HandmadeHero.vcxproj.user

@@ -6,6 +6,6 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Development|x64'">
     <LocalDebuggerWorkingDirectory>$(ProjectDir)data</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
-    <LocalDebuggerCommand>$(ProjectDir)build\handmade_win32.exe</LocalDebuggerCommand>
+    <LocalDebuggerCommand>$(ProjectDir)data\handmade_win32.exe</LocalDebuggerCommand>
   </PropertyGroup>
 </Project>

docs/Day 021.md

@@ -0,0 +1,15 @@
+# Day 21
+
+So I learned today the good reason why he doesn't use static variables; So that when he makes this library dynamically loaded we don't lose the state of the game on reload.  
+
+This day was extremely gratifying to get working.
+
+I went the extra mile than what Casey did and allow for name mangled symbols (for both clang and msvc).  
+It took a few more steps than his solution but I get to keep the eronomics of namespaces.
+
+After the linker finishes emitting, I use the build script to parse the .map file and extract the decorated symbols I need to load in the platform layer. Those are exported to a file called `handmade_engine.symbols` and then in the platform layer I load them up using an enum as the lookup table for the line the symbol will be in the file. From there its just loading up the symbol with GetProcAddress!
+
+![img](https://files.catbox.moe/sdebtc.png)
+![img](https://files.catbox.moe/ufkacl.png)
+![img](https://files.catbox.moe/zr52au.png)
+![img](https://files.catbox.moe/g3f1vv.png)

project/engine/engine.cpp

@@ -1,15 +1,21 @@
-#include "engine.hpp"
 //#include "win32.h"
+#include "engine.hpp"
+#include "platform/platform_engine_api.hpp"
+#include "handmade.hpp"
 
 NS_ENGINE_BEGIN
 
 struct EngineState
 {
-	s32 WaveSwitch;
 	s32 WaveToneHz;
 	s32 ToneVolume;
 	s32 XOffset;
 	s32 YOffset;
+
+	b32 RendererPaused;
+
+	f32 SampleWaveSineTime;
+	b32 SampleWaveSwitch;
 };
 
 using GetSoundSampleValueFn = s16( EngineState* state, AudioBuffer* sound_buffer );
@@ -28,7 +34,7 @@ square_wave_sample_value( EngineState* state, AudioBuffer* sound_buffer )
 internal s16
 sine_wave_sample_value( EngineState* state, AudioBuffer* sound_buffer )
 {
-	local_persist f32 time = 0.f;
+	f32& time = state->SampleWaveSineTime;
 
 	s32 wave_period = sound_buffer->SamplesPerSecond / state->WaveToneHz;
 
@@ -104,7 +110,6 @@ render_weird_graident(OffscreenBuffer* buffer, u32 x_offset, u32 y_offset )
 			u8 red   = 0;
 		#endif
 
-
 			*pixel++ = u32(red << 16) | u32(green << 8) | blue;
 		}
 		wildcard += 0.5375f;
@@ -112,66 +117,55 @@ render_weird_graident(OffscreenBuffer* buffer, u32 x_offset, u32 y_offset )
 	}
 }
 
-b32 input_using_analog()
+Engine_API
+void on_module_reload( Memory* memory, platform::ModuleAPI* platfom_api )
 {
-	return false;
+
 }
 
-void startup()
+Engine_API
+void startup( Memory* memory, platform::ModuleAPI* platform_api )
 {
-}
-
-void shutdown()
-{
-}
-
-// TODO : I rather expose the back_buffer and sound_buffer using getters for access in any function.
-void update_and_render( InputState* input, OffscreenBuffer* back_buffer, Memory* memory )
-{
-	// Graphics & Input Test
-	local_persist u32 x_offset = 0;
-	local_persist u32 y_offset = 0;
-
-	// Wave Sound Test
-	local_persist bool wave_switch = false;
-
-#if 0
-	if ( input_using_analog() )
-	{
-		// TODO(Ed) : Use analog movement tuning
-	}
-	else
-	{
-		// TODO(Ed) : Use digital movement tuning
-	}
-#endif
-
 	EngineState* state = rcast( EngineState*, memory->Persistent );
-
-	do_once_start
 	assert( sizeof(EngineState) <= memory->PersistentSize );
 
 	state->ToneVolume = 1000;
-		state->WaveToneHz = 120;
 
 	state->XOffset = 0;
 	state->YOffset = 0;
-		state->WaveSwitch = false;
+
+	state->SampleWaveSwitch = false;
+	state->WaveToneHz = 120;
+	state->SampleWaveSineTime = 0.f;
+
+	state->RendererPaused = false;
 
 	#if Build_Debug && 0
 	{
 		using namespace platform;
 
 		char const* file_path = __FILE__;
-			Debug_FileContent file_content = debug_file_read_content( file_path );
+		Debug_FileContent file_content = platform_api->debug_file_read_content( file_path );
 		if ( file_content.Size )
 		{
-				debug_file_write_content( "test.out", file_content.Size, file_content.Data );
+			platform_api->debug_file_write_content( "test.out", file_content.Size, file_content.Data );
-				debug_file_free_content( & file_content );
+			platform_api->debug_file_free_content( & file_content );
 		}
 	}
 	#endif
-	do_once_end
+}
+
+Engine_API
+void shutdown( Memory* memory, platform::ModuleAPI* platform_api )
+{
+}
+
+Engine_API
+// TODO : I rather expose the back_buffer and sound_buffer using getters for access in any function.
+void update_and_render( InputState* input, OffscreenBuffer* back_buffer, Memory* memory, platform::ModuleAPI* platform_api )
+{
+	EngineState* state = rcast( EngineState*, memory->Persistent );
+	assert( sizeof(EngineState) <= memory->PersistentSize );
 
 	ControllerState* controller = & input->Controllers[0];
 
@@ -195,7 +189,6 @@ void update_and_render( InputState* input, OffscreenBuffer* back_buffer, Memory*
 	b32 toggle_wave_tone = false;
 
 	b32 pause_renderer  = false;
-	local_persist b32 renderer_paused = false;
 
 	f32 analog_threshold = 0.5f;
 
@@ -255,10 +248,10 @@ void update_and_render( InputState* input, OffscreenBuffer* back_buffer, Memory*
 		toggle_wave_tone |= pressed( keyboard->Space );
 	}
 
-	x_offset += 3 * move_right;
+	state->XOffset += 3 * move_right;
-	x_offset -= 3 * move_left;
+	state->XOffset -= 3 * move_left;
-	y_offset += 3 * move_down;
+	state->YOffset += 3 * move_down;
-	y_offset -= 3 * move_up;
+	state->YOffset -= 3 * move_up;
 
 	if ( raise_volume )
 	{
@@ -284,26 +277,27 @@ void update_and_render( InputState* input, OffscreenBuffer* back_buffer, Memory*
 
 	if ( toggle_wave_tone )
 	{
-		state->WaveSwitch ^= true;
+		state->SampleWaveSwitch ^= true;
 	}
-	render_weird_graident( back_buffer, x_offset, y_offset );
+	render_weird_graident( back_buffer, state->XOffset, state->YOffset );
 
 	if ( pause_renderer )
 	{
-		if ( renderer_paused )
+		if ( state->RendererPaused )
 		{
-			platform::set_pause_rendering(false);
+			platform_api->debug_set_pause_rendering(false);
-			renderer_paused = false;
+			state->RendererPaused = false;
 		}
 		else
 		{
-			platform::set_pause_rendering(true);
+			platform_api->debug_set_pause_rendering(true);
-			renderer_paused = true;
+			state->RendererPaused = true;
 		}
 	}
 }
 
-void update_audio( AudioBuffer* audio_buffer, Memory* memory )
+Engine_API
+void update_audio( AudioBuffer* audio_buffer, Memory* memory, platform::ModuleAPI* platform_api )
 {
 	EngineState* state = rcast( EngineState*, memory->Persistent );
 	do_once_start
@@ -311,11 +305,10 @@ void update_audio( AudioBuffer* audio_buffer, Memory* memory )
 	do_once_end
 
 	// TODO(Ed) : Allow sample offsets here for more robust platform options
-	if ( ! state->WaveSwitch )
+	if ( ! state->SampleWaveSwitch )
 		output_sound( state, audio_buffer, sine_wave_sample_value );
 	else
 		output_sound( state, audio_buffer, square_wave_sample_value );
 }
 
 NS_ENGINE_END
-

project/engine/engine.hpp

@@ -197,56 +197,3 @@ void input_mode_pop( InputMode* mode );
 void input_mode_pop( InputMode* mode );
 
 NS_ENGINE_END
-
-// TODO(Ed) : Move this to handmade game layer later.
-
-#define NS_HANDMADE_BEGIN namespace handmade {
-#define NS_HANDMADE_END   }
-
-NS_HANDMADE_BEGIN
-
-// We want a 'binding' to have multiple binds to active it (most likely)
-struct Actionable
-{
-	char const*                Name;
-	engine::InputBindCallback* Binds;
-	s32                        NumBinds;
-	char _PAD_[4];
-};
-
-struct ActionableMode
-{
-	
-};
-
-/*
-	Platform Layer:
-
-	Controller : Keyboard & Mouse, XPad, DSPad
-
-	---VV---
-
-	Engine Layer:
-
-	InputBinding callbacks (per-game-logic frame basis)
-	Push/Pop input modes (binding sets)
-
-	---VV---
-
-	Game Layer:
-
-	Actionables : Binding Sets where a raw input, or input interpretation leads to an player action.
-	ActionSet   : Actionables.Push/Pop -> Input.Push/Pop ?
-	Player : Controller, Actionables, ActionSets
-*/
-
-struct Player
-{
-	// So far just has an assigned controller.
-	engine::ControllerState* Controller;
-	
-	// Possilby some other stuff in the future.
-};
-
-NS_HANDMADE_END
-

project/engine/win32_engine.cpp

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

project/handmade.cpp

@@ -4,5 +4,5 @@
 
 #pragma once
 
-#include "engine.hpp"
+#include "engine/engine.hpp"
 

project/handmade.hpp

@@ -0,0 +1,67 @@
+#pragma once
+
+#include "engine/engine.hpp"
+
+#define NS_HANDMADE_BEGIN namespace handmade {
+#define NS_HANDMADE_END   }
+
+NS_HANDMADE_BEGIN
+
+struct Memory
+{
+	// Subscection of engine memory for the game to use.
+
+	void* Persistent;
+	u64   PersistentSize;
+
+	// void* Frame;
+	// u64   FrameSize;
+
+	void* Transient;
+	u64   TransientSize;
+};
+
+// We want a 'binding' to have multiple binds to active it (most likely)
+struct Actionable
+{
+	char const*                Name;
+	engine::InputBindCallback* Binds;
+	s32                        NumBinds;
+	char _PAD_[4];
+};
+
+struct ActionableMode
+{
+
+};
+
+/*
+	Platform Layer:
+
+	Controller : Keyboard & Mouse, XPad, DSPad
+
+	---VV---
+
+	Engine Layer:
+
+	InputBinding callbacks (per-game-logic frame basis)
+	Push/Pop input modes (binding sets)
+
+	---VV---
+
+	Game Layer:
+
+	Actionables : Binding Sets where a raw input, or input interpretation leads to an player action.
+	ActionSet   : Actionables.Push/Pop -> Input.Push/Pop ?
+	Player : Controller, Actionables, ActionSets
+*/
+
+struct Player
+{
+	// So far just has an assigned controller.
+	engine::ControllerState* Controller;
+
+	// Possilby some other stuff in the future.
+};
+
+NS_HANDMADE_END

project/handmade_engine.cpp

@@ -0,0 +1,19 @@
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-const-variable"
+#pragma clang diagnostic ignored "-Wswitch"
+#pragma clang diagnostic ignored "-Wunused-variable"
+#pragma clang diagnostic ignored "-Wunknown-pragmas"
+#pragma clang diagnostic ignored "-Wvarargs"
+#pragma clang diagnostic ignored "-Wunused-function"
+#pragma clang diagnostic ignored "-Wunused-but-set-variable"
+#endif
+
+#include "platform/grime.hpp"
+
+#if Build_Unity
+#	include "engine/engine.cpp"
+#	if SYSTEM_WINDOWS
+#		include "engine/win32_engine.cpp"
+#	endif
+#endif

project/handmade_win32.cpp

@@ -10,7 +10,5 @@
 #endif
 
 #if Build_Unity
-#include "handmade.cpp"
-#include "engine.cpp"
 #include "platform/win32_platform.cpp"
 #endif

project/platform/macros.hpp

@@ -61,6 +61,12 @@
 #	define assert( expression )
 #endif
 
+#ifdef COMPILER_CLANG
+#	define compiler_decorated_func_name __PRETTY_NAME__
+#elif defined(COMPILER_MSVC)
+#	define compiler_decorated_func_name __FUNCDNAME__
+#endif
+
 // TODO(Ed) : Add this sauce later
 #if 0
 #define congrats( message )

project/platform/platform.hpp

@@ -32,7 +32,11 @@
 
 NS_PLATFORM_BEGIN
 
-#if Build_Debug
+// On-Demand platform interface.
+// Everything exposed here should be based on a feature a game may want to provide a user
+// (Example: Letting the user change the refresh-rate of the monitor or the engine's target frame-rate)
+
+#if Build_Development
 /*
 	IMPORTANT : These are not for shipping code - they are blocking and the write isn't protected.
 */
@@ -44,34 +48,42 @@ struct Debug_FileContent
 	char  _PAD_[4];
 };
 
-void              debug_file_free_content ( Debug_FileContent* file_content );
+using DebugFileFreeContentFn  = void ( Debug_FileContent* file_content );
-Debug_FileContent debug_file_read_content ( char const* file_path );
+using DebugFileReadContentFn  = Debug_FileContent ( char const* file_path );
-b32               debug_file_write_content( char const* file_path, u32 content_size, void* content_memory );
+using DebugFileWriteContentFn = b32 ( char const* file_path, u32 content_size, void* content_memory );
-
-// Allows the engine or game to pause the renderering of any next frames.
-// ( Prevents blipping of the black buffer )
-void set_pause_rendering( b32 value );
 
+using DebugSetPauseRenderingFn = void (b32 value);
 #endif
 
-// On-Demand platform interface.
-// Everything exposed here should be based on a feature a game may want to provide a user
-// (Example: Letting the user change the refresh-rate of the monitor or the engine's target frame-rate)
-
 // TODO(Ed) : Implement this later when settings UI is setup.
 #pragma region Settings Exposure
 // Exposing specific properties for user configuration in settings
 
 // Returns the current monitor refresh rate.
-u32 get_monitor_refresh_rate();
+using GetMonitorRefreshRateFn = u32();
-
 // Sets the monitor refresh rate
-// Must be of the compatiable listing for the monitor the window surface is presenting to.
+// Must be of the compatiable listing for the monitor the window surface is presenting to
-void set_monitor_refresh_rate( u32 rate_in_hz );
+using SetMonitorRefreshRateFn = void ( u32 rate_in_hz );
 
-u32 get_engine_frame_target();
+using GetEngineFrameTargetFn = u32 ();
+using SetEngineFrameTargetFn = void ( u32 rate_in_hz );
 
-void set_engine_frame_target( u32 rate_in_hz );
+struct ModuleAPI
+{
+#if Build_Development
+	DebugFileFreeContentFn*  debug_file_free_content;
+	DebugFileReadContentFn*  debug_file_read_content;
+	DebugFileWriteContentFn* debug_file_write_content;
+
+	DebugSetPauseRenderingFn* debug_set_pause_rendering;
+#endif
+
+	GetMonitorRefreshRateFn* get_monitor_refresh_rate;
+	SetMonitorRefreshRateFn* set_monitor_refresh_rate;
+
+	GetEngineFrameTargetFn* get_engine_frame_target;
+	SetEngineFrameTargetFn* set_engine_frame_target;
+};
 
 #pragma endregion Settings Exposure
 

project/platform/platform_engine_api.hpp

@@ -2,20 +2,47 @@
 	This represents the API only accessible to the platform layer to fullfill for the engine layer.
 */
 #pragma once
-#include "engine.hpp"
+#include "engine/engine.hpp"
+
+#ifndef Engine_API
+#	define Engine_API
+#endif
 
 NS_ENGINE_BEGIN
 
-void startup();
+using OnModuleRelaodFn = void( Memory* memory, platform::ModuleAPI* platform_api );
-void shutdown();
+using StartupFn        = void( Memory* memory, platform::ModuleAPI* platform_api );
+using ShutdownFn       = void( Memory* memory, platform::ModuleAPI* platform_api );
 
 // Needs a contextual reference to four things:
 // Timing, Input, Bitmap Buffer
-void update_and_render( InputState* input, OffscreenBuffer* back_buffer,  Memory* memory );
+using UpdateAndRenderFn = void ( InputState* input, OffscreenBuffer* back_buffer, Memory* memory, platform::ModuleAPI* platform_api );
 
 // Audio timing is complicated, processing samples must be done at a different period from the rest of the engine's usual update.
 // IMPORTANT: This has very tight timing, and cannot be more than a millisecond in execution.
 // TODO(Ed) : Reduce timing pressure on performance by measuring it or pinging its time.
-void update_audio( AudioBuffer* audio_buffer, Memory* memory );
+using UpdateAudioFn = void ( AudioBuffer* audio_buffer, Memory* memory, platform::ModuleAPI* platform_api );
+
+struct ModuleAPI
+{
+	enum : u32
+	{
+		Sym_OnModuleReload,
+		Sym_Startup,
+		Sym_Shutdown,
+		Sym_UpdateAndRender,
+		Sym_UpdateAudio,
+	};
+
+	OnModuleRelaodFn* on_module_reload;
+	StartupFn*        startup;
+	ShutdownFn*       shutdown;
+
+	UpdateAndRenderFn* update_and_render;
+	UpdateAudioFn*     update_audio;
+
+	b32 IsValid;
+	char _PAD_[4];
+};
 
 NS_ENGINE_END

project/platform/platform_game_api.hpp

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

project/platform/win32.hpp

@@ -113,6 +113,14 @@ enum XI_State : DWORD
 	XI_PluggedIn = ERROR_SUCCESS,
 };
 
+
+template< typename ProcSignature >
+ProcSignature* get_procedure_from_library( HMODULE library_module, char const* symbol )
+{
+	void* address = rcast( void*, GetProcAddress( library_module, symbol ) );
+	return rcast( ProcSignature*, address );
+}
+
 #pragma region XInput
 WIN_LIB_API DWORD WINAPI XInputGetState
 (
@@ -151,11 +159,14 @@ xinput_load_library_bindings()
 {
 	HMODULE xinput_lib = LoadLibraryA( XINPUT_DLL_A );
 
-#pragma warning( push )
+	XInputGetStateFn* get_state = get_procedure_from_library< XInputGetStateFn >( xinput_lib, "XInputGetState" );
-#pragma warning( disable: 4191 )
+	XInputSetStateFn* set_state = get_procedure_from_library< XInputSetStateFn >( xinput_lib, "XInputSetState" );
-	xinput_get_state = rcast( XInputGetStateFn*, GetProcAddress( xinput_lib, "XInputGetState" ));
+
-	xinput_set_state = rcast( XInputSetStateFn*, GetProcAddress( xinput_lib, "XInputSetState" ));
+	if ( get_state )
-#pragma warning( pop )
+		xinput_get_state = get_state;
+
+	if ( set_state )
+		xinput_set_state = set_state;
 }
 #pragma endregion XInput
 

project/platform/win32_platform.cpp

@@ -23,7 +23,7 @@
 #include "win32.hpp"
 
 // Engine layer headers
-#include "engine.hpp"
+#include "engine/engine.hpp"
 #include "platform_engine_api.hpp"
 
 // Standard-Library stand-ins
@@ -216,7 +216,7 @@ b32 debug_file_write_content( char const* file_path, u32 content_size, void* con
 	return true;
 }
 
-void set_pause_rendering( b32 value )
+void debug_set_pause_rendering( b32 value )
 {
 	Pause_Rendering = value;
 }
@@ -425,15 +425,12 @@ init_sound(HWND window_handle, DirectSoundBuffer* sound_buffer )
 	}
 
 	// Get direct sound object
-#pragma warning( push )
+	direct_sound_create = get_procedure_from_library< DirectSoundCreateFn >( sound_library, "DirectSoundCreate" );
-#pragma warning( disable: 4191 )
-	direct_sound_create = rcast( DirectSoundCreateFn*, GetProcAddress( sound_library, "DirectSoundCreate" ));
 	if ( ! ensure( direct_sound_create, "Failed to get direct_sound_create_procedure" ) )
 	{
 		// TOOD : Diagnostic
 		return;
 	}
-#pragma warning( pop )
 
 	LPDIRECTSOUND direct_sound;
 	if ( ! SUCCEEDED(direct_sound_create( 0, & direct_sound, 0 )) )
@@ -751,6 +748,131 @@ process_pending_window_messages( engine::KeyboardState* keyboard )
 		}
 	}
 }
+
+#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 )
+{
+	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';
+}
+
+// Right now they are just the data directory
+#define Path_To_Symbol_Tables
+
+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 );
+
+	// Engine
+	Lib_Handmade_Engine = LoadLibraryA( "handmade_engine_temp.dll" );
+	if ( ! Lib_Handmade_Engine )
+	{
+		return {};
+	}
+
+	constexpr char const*
+	handmade_engine_symbols = Path_To_Symbol_Tables "handmade_engine.symbols";
+
+	Debug_FileContent symbol_table = debug_file_read_content( handmade_engine_symbols );
+	if ( symbol_table.Size == 0 )
+	{
+		fatal( "Failed to laod symbol table for handmade engine module!" );
+		return {};
+	}
+
+	// TODO(Ed) : Clean this up later when Casey makes strings. (If he doesn't we'll do it)
+	char symbol_on_module_reload[256];
+	char symboL_startup[256];
+	char symboL_shutdown[256];
+	char symboL_update_and_render[256];
+	char symbol_update_audio[256];
+	get_symbol_from_module_table( symbol_table, ModuleAPI::Sym_OnModuleReload,  symbol_on_module_reload );
+	get_symbol_from_module_table( symbol_table, ModuleAPI::Sym_Startup,         symboL_startup );
+	get_symbol_from_module_table( symbol_table, ModuleAPI::Sym_Shutdown,        symboL_shutdown );
+	get_symbol_from_module_table( symbol_table, ModuleAPI::Sym_UpdateAndRender, symboL_update_and_render );
+	get_symbol_from_module_table( symbol_table, ModuleAPI::Sym_UpdateAudio,     symbol_update_audio );
+
+	debug_file_free_content( & symbol_table );
+
+	engine::ModuleAPI engine_api {};
+	engine_api.on_module_reload  = get_procedure_from_library< engine::OnModuleRelaodFn > ( Lib_Handmade_Engine, symbol_on_module_reload );
+	engine_api.startup           = get_procedure_from_library< engine::StartupFn >        ( Lib_Handmade_Engine, symboL_startup );
+	engine_api.shutdown          = get_procedure_from_library< engine::ShutdownFn >       ( Lib_Handmade_Engine, symboL_shutdown );
+	engine_api.update_and_render = get_procedure_from_library< engine::UpdateAndRenderFn >( Lib_Handmade_Engine, symboL_update_and_render );
+	engine_api.update_audio      = get_procedure_from_library< engine::UpdateAudioFn >    ( Lib_Handmade_Engine, symbol_update_audio );
+
+	engine_api.IsValid =
+			engine_api.on_module_reload
+		&&	engine_api.startup
+		&&	engine_api.shutdown
+		&&	engine_api.update_and_render
+		&&	engine_api.update_audio;
+	if ( engine_api.IsValid )
+	{
+		OutputDebugStringA( "Loaded engine module API\n" );
+	}
+	return engine_api;
+}
+
+void unload_engine_module_api( engine::ModuleAPI* engine_api )
+{
+	if ( engine_api->IsValid )
+	{
+		FreeLibrary( Lib_Handmade_Engine );
+		*engine_api = {};
+		OutputDebugStringA( "Unloaded engine module API\n" );
+	}
+}
+
 NS_PLATFORM_END
 
 int CALLBACK
@@ -774,6 +896,22 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 
 	QueryPerformanceFrequency( rcast(LARGE_INTEGER*, & Performance_Counter_Frequency) );
 
+	// Prepare platform API
+	ModuleAPI platform_api {};
+	{
+	#if Build_Development
+		platform_api.debug_file_free_content  = & debug_file_free_content;
+		platform_api.debug_file_read_content  = & debug_file_read_content;
+		platform_api.debug_file_write_content = & debug_file_write_content;
+
+		platform_api.debug_set_pause_rendering = & debug_set_pause_rendering;
+	#endif
+		platform_api.get_monitor_refresh_rate = nullptr;
+		platform_api.set_monitor_refresh_rate = nullptr;
+		platform_api.get_engine_frame_target  = nullptr;
+		platform_api.set_engine_frame_target  = nullptr;
+	}
+
 	// Memory
 	engine::Memory engine_memory {};
 	{
@@ -802,6 +940,9 @@ 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;
 	{
@@ -935,6 +1076,8 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 		}
 	}
 
+	engine_api.startup( & engine_memory, & platform_api );
+
 	u64 last_frame_clock = timing_get_wall_clock();
 	u64 last_frame_cycle = __rdtsc();
 	u64 flip_wall_clock = last_frame_clock;
@@ -942,8 +1085,14 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 #if Build_Development
 	u64 startup_cycles = last_frame_cycle - launch_cycle;
 	f32 startup_ms     = timing_get_ms_elapsed( launch_clock, last_frame_clock );
+
+	char text_buffer[256];
+	sprintf_s( text_buffer, sizeof(text_buffer), "Startup MS: %f\n", startup_ms );
+	OutputDebugStringA( text_buffer );
 #endif
 
+	u64 module_reload_counter = 0;
+
 	Running = true;
 #if 0
 // This tests the play & write cursor update frequency.
@@ -960,6 +1109,14 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 #endif
 	while( Running )
 	{
+		if ( module_reload_counter > 120 )
+		{
+			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 );
 
 		// TODO(Ed): Offload polling to these functions later.
@@ -1107,7 +1264,7 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 		}
 
 		// Engine's logical iteration and rendering process
-		engine::update_and_render( & input, rcast(engine::OffscreenBuffer*, & Surface_Back_Buffer.Memory), & engine_memory );
+		engine_api.update_and_render( & input, rcast(engine::OffscreenBuffer*, & Surface_Back_Buffer.Memory), & engine_memory, & platform_api );
 
 		u64   audio_frame_start = timing_get_wall_clock();
 		f32   flip_to_audio_ms  = timing_get_ms_elapsed( flip_wall_clock, audio_frame_start );
@@ -1194,7 +1351,7 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 			sound_buffer.RunningSampleIndex = ds_sound_buffer.RunningSampleIndex;
 			sound_buffer.SamplesPerSecond   = ds_sound_buffer.SamplesPerSecond;
 			sound_buffer.Samples            = ds_sound_buffer.Samples;
-			engine::update_audio( & sound_buffer, & engine_memory );
+			engine_api.update_audio( & sound_buffer, & engine_memory, & platform_api );
 
 			DebugTimeMarker* marker = & debug_markers[ debug_marker_index ];
 			marker->OutputPlayCusror   = ds_play_cursor;
@@ -1331,7 +1488,7 @@ WinMain( HINSTANCE instance, HINSTANCE prev_instance, LPSTR commandline, int sho
 		#endif
 	}
 
-	engine::shutdown();
+	engine_api.shutdown( & engine_memory, & platform_api );
 
 	if ( jsl_num_devices > 0 )
 	{

scripts/build.ps1

@@ -14,6 +14,9 @@ Push-Location $path_root
 	   $debug 	     = $null
 	   $analysis	 = $false
 	   $dev          = $false
+	   $platform     = $null
+	   $engine       = $null
+	   $game         = $null
 
 [array] $vendors = @( "clang", "msvc" )
 
@@ -26,11 +29,14 @@ if ( $args ) { $args | ForEach-Object {
 		"debug"               { $debug     = $true }
 		"analysis"            { $analysis  = $true }
 		"dev"                 { $dev       = $true }
+		"platform"            { $platform  = $true }
+		"engine"              { $engine    = $true }
+		"game"                { $game      = $true }
 	}
 }}
 #endregion Argument
 
-#region Configuration
+#region Toolchain Configuration
 if ($IsWindows) {
 	# This HandmadeHero implementation is only designed for 64-bit systems
     & $devshell -arch amd64
@@ -45,7 +51,7 @@ write-host "Building HandmadeHero with $vendor"
 
 if ( $dev ) {
 	if ( $debug -eq $null ) {
-		$debug = $true
+		# $debug = $true
 	}
 
 	if ( $optimize -eq $null ) {
@@ -129,10 +135,20 @@ if ( $vendor -match "clang" )
 	$flag_exceptions_disabled		   = '-fno-exceptions'
 	$flag_preprocess 			       = '-E'
 	$flag_include                      = '-I'
+	$flag_section_data                 = '-fdata-sections'
+	$flag_section_functions            = '-ffunction-sections'
 	$flag_library					   = '-l'
 	$flag_library_path				   = '-L'
 	$flag_linker                       = '-Wl,'
-	$flag_link_mapfile 				 = '-Map'
+	if ( $IsWindows ) {
+		$flag_link_dll                 = '/DLL'
+		$flag_link_mapfile 		       = '/MAP:'
+		$flag_link_optimize_references = '/OPT:REF'
+	}
+	if ( $IsLinux ) {
+		$flag_link_mapfile              = '--Map='
+		$flag_link_optimize_references  = '--gc-sections'
+	}
 	$flag_link_win_subsystem_console    = '/SUBSYSTEM:CONSOLE'
 	$flag_link_win_subsystem_windows    = '/SUBSYSTEM:WINDOWS'
 	$flag_link_win_machine_32           = '/MACHINE:X86'
@@ -175,12 +191,12 @@ if ( $vendor -match "clang" )
 
 	function build-simple
 	{
-		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$executable )
+		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$binary )
 		Write-Host "build-simple: clang"
 
-		$object = $executable -replace '\.exe', '.obj'
+		$object = $binary -replace '\.exe', '.obj'
-		$pdb    = $executable -replace '\.exe', '.pdb'
+		$pdb    = $binary -replace '\.exe', '.pdb'
-		$map    = $executable -replace '\.exe', '.map'
+		$map    = $binary -replace '\.exe', '.map'
 
 		$compiler_args += @(
 			$flag_no_color_diagnostics,
@@ -188,6 +204,8 @@ if ( $vendor -match "clang" )
 			$flag_target_arch, $target_arch,
 			$flag_wall,
 			$flag_preprocess_non_intergrated,
+			$flag_section_data,
+			$flag_section_functions,
 			( $flag_path_output + $object )
 		)
 		if ( $optimized ) {
@@ -214,12 +232,12 @@ if ( $vendor -match "clang" )
 
 		$linker_args += @(
 			$flag_link_win_machine_64,
-			$( $flag_link_win_path_output + $executable )
+			$( $flag_link_win_path_output + $binary )
 		)
 		if ( $debug ) {
 			$linker_args += $flag_link_win_debug
 			$linker_args += $flag_link_win_pdb + $pdb
-			# $linker_args += $flag_link_mapfile + $map
+			$linker_args += $flag_link_mapfile + $map
 		}
 
 		$libraries | ForEach-Object {
@@ -227,7 +245,7 @@ if ( $vendor -match "clang" )
 		}
 
 		$linker_args += $object
-		run-linker $linker $executable $linker_args
+		run-linker $linker $binary $linker_args
 
 		# $compiler_args += $unit
 		# $linker_args | ForEach-Object {
@@ -256,6 +274,7 @@ if ( $vendor -match "msvc" )
 	$flag_dll 				         = '/LD'
 	$flag_dll_debug 			     = '/LDd'
 	$flag_linker 		             = '/link'
+	$flag_link_dll                   = '/DLL'
 	$flag_link_mapfile 				 = '/MAP:'
 	$flag_link_optimize_references   = '/OPT:REF'
 	$flag_link_win_debug 	         = '/DEBUG'
@@ -287,12 +306,12 @@ if ( $vendor -match "msvc" )
 	# This works because this project uses a single unit to build
 	function build-simple
 	{
-		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$executable )
+		param( [array]$includes, [array]$compiler_args, [array]$linker_args, [string]$unit, [string]$binary )
 		Write-Host "build-simple: msvc"
 
-		$object = $executable -replace '\.exe', '.obj'
+		$object = $binary -replace '\.(exe|dll)$', '.obj'
-		$pdb    = $executable -replace '\.exe', '.pdb'
+		$pdb    = $binary -replace '\.(exe|dll)$', '.pdb'
-		$map    = $executable -replace '\.exe', '.map'
+		$map    = $binary -replace '\.(exe|dll)$', '.map'
 
 		$compiler_args += @(
 			$flag_nologo,
@@ -336,18 +355,18 @@ if ( $vendor -match "msvc" )
 		$linker_args += @(
 			$flag_nologo,
 			$flag_link_win_machine_64,
-			( $flag_link_win_path_output + $executable )
+			( $flag_link_win_path_output + $binary )
 		)
 		if ( $debug ) {
 			$linker_args += $flag_link_win_debug
 			$linker_args += $flag_link_win_pdb + $pdb
-			# $linker_args += $flag_link_mapfile + $map
+			$linker_args += $flag_link_mapfile + $map
 		}
 		else {
 		}
 
 		$linker_args += $object
-		run-linker $linker $executable $linker_args
+		run-linker $linker $binary $linker_args
 
 		# $compiler_args += $unit
 		# $compiler_args += $flag_linker
@@ -360,11 +379,14 @@ if ( $vendor -match "msvc" )
 }
 #endregion Configuration
 
+#region Building
 $path_project  = Join-Path $path_root    'project'
 $path_build    = Join-Path $path_root    'build'
+$path_data     = Join-Path $path_root	 'data'
 $path_deps     = Join-Path $path_project 'dependencies'
 $path_gen      = Join-Path $path_project 'gen'
 $path_platform = Join-Path $path_project 'platform'
+$path_engine   = Join-Path $path_project 'engine'
 
 $update_deps = Join-Path $PSScriptRoot 'update_deps.ps1'
 
@@ -376,21 +398,21 @@ if ( (Test-Path $path_deps) -eq $false ) {
 	& $update_deps
 }
 
-$includes = @(
+#region Handmade Generate
+if ( $false ) {
+	$includes = @(
 		$path_project,
 		$path_gen,
 		# $path_deps,
 		$path_platform
-)
+	)
-$compiler_args = @()
+	$compiler_args = @()
-$compiler_args += ( $flag_define + 'GEN_TIME' )
+	$compiler_args += ( $flag_define + 'GEN_TIME' )
 
-$linker_args = @(
+	$linker_args = @(
 		$flag_link_win_subsystem_console
-)
+	)
 
-#region Handmade Generate
-if ( $false ) {
 	$unit       = Join-Path $path_gen   'handmade_gen.cpp'
 	$executable = Join-Path $path_build 'handmade_gen.exe'
 
@@ -408,10 +430,7 @@ if ( $false ) {
 
 #region Handmade Runtime
 $includes = @(
-	$path_project,
+	$path_project
-	$path_gen,
-	$path_deps,
-	$path_platform
 )
 
 # Microsoft
@@ -423,9 +442,6 @@ $lib_winmm  = 'Winmm.lib'
 # Github
 $lib_jsl = Join-Path $path_deps 'JoyShockLibrary/x64/JoyShockLibrary.lib'
 
-$unit       = Join-Path $path_project 'handmade_win32.cpp'
-$executable = Join-Path $path_build   'handmade_win32.exe'
-
 $stack_size = 1024 * 1024 * 4
 
 $compiler_args = @(
@@ -436,9 +452,6 @@ $compiler_args = @(
 	$flag_warnings_as_errors
 	$flag_optimize_intrinsics
 
-	($flag_define + 'Build_DLL=0' )
-
-	# For now this script only supports unity builds... (for the full binary)
 	($flag_define + 'Build_Unity=1' )
 )
 
@@ -449,7 +462,85 @@ else {
 	$compiler_args += ( $flag_define + 'Build_Development=0' )
 }
 
-$linker_args = @(
+if ( $engine )
+{
+	$engine_compiler_args = $compiler_args
+	$engine_compiler_args += ($flag_define + 'Build_DLL=1' )
+
+	if ( $vendor -eq 'msvc' )
+	{
+		$engine_compiler_args += ($flag_define + 'Engine_API=__declspec(dllexport)')
+	}
+	if ( $vendor -eq 'clang' )
+	{
+		$engine_compiler_args += ($flag_define + 'Engine_API=__attribute__((visibility("default")))')
+	}
+
+	$linker_args = @(
+		$flag_link_dll,
+		$flag_link_optimize_references
+	)
+
+	$unit            = Join-Path $path_project 'handmade_engine.cpp'
+	$dynamic_library = Join-Path $path_build   '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
+
+		# 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
+		# and mapping them to their found decorated name
+
+		$engine_symbols = @(
+			'on_module_reload',
+			'startup',
+			'shutdown',
+			'update_and_render',
+			'update_audio'
+		)
+
+		$path_engine_map = Join-Path $path_build 'handmade_engine.map'
+
+		$engine_symbol_table = @()
+		$engine_symbol_list  = @()
+		Get-Content -Path $path_engine_map | ForEach-Object {
+			# Split each line by whitespace
+			$tokens = $_ -split '\s+', 3
+
+			# Extract only the decorated name using regex for both MSVC and Clang conventions
+			$decoratedName = ($tokens[2] -match '(\?[\w@]+|_Z[\w@]+)' ) ? $matches[1] : $null
+
+			# Check each regular name against the current line
+			foreach ($name in $engine_symbols) {
+				if ($decoratedName -like "*$name*") {
+					$engine_symbol_table += $name + ', ' + $decoratedName
+					$engine_symbol_list  += $decoratedName
+					$engine_symbols = $engine_symbols -ne $name  # Remove the found symbol from the array
+				}
+			}
+		}
+
+		write-host "Engine Symbol Table:" -ForegroundColor Green
+		$engine_symbol_table | ForEach-Object {
+			write-host "`t$_" -ForegroundColor Green
+		}
+
+		# Write the symbol table to a file
+		$path_engine_symbols = Join-Path $path_data 'handmade_engine.symbols'
+		$engine_symbol_list | Out-File -Path $path_engine_symbols
+	}
+}
+
+if ( $platform )
+{
+	$platform_compiler_args  = $compiler_args
+	$platform_compiler_args += ($flag_define + 'Build_DLL=0' )
+
+	$linker_args = @(
 		$lib_gdi32,
 		# $lib_xinput,
 		$lib_user32,
@@ -459,9 +550,20 @@ $linker_args = @(
 
 		$flag_link_win_subsystem_windows
 		$flag_link_optimize_references
-)
+	)
 
-build-simple $includes $compiler_args $linker_args $unit $executable
+	$unit       = Join-Path $path_project 'handmade_win32.cpp'
+	$executable = Join-Path $path_build   '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
+	}
+}
 #endregion Handmade Runtime
 
 Pop-Location
+#endregion Building

scripts/helpers/devshell.ps1

@@ -23,5 +23,6 @@ if ( -not (Test-Path $vs_devshell) ) {
 
 # Launch the Visual Studio Developer Shell
 Push-Location
+write-host @args
 & $vs_devshell @args
 Pop-Location