simplify gitignore
[vg.git] / src / vg / vg.h
index b076091d1c627ba252d32ccf81d38165b94895f9..77d27e2fb9f80553cacad4469608b79f82a4678d 100644 (file)
@@ -1,15 +1,28 @@
 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
 
+/*
+ * Memory model:
+ *    [global (.data)] [temp-stack] [system-stack] [game-heap]
+ *
+ *    1. Program starts: .data memory is loaded
+ *    2. System initialization: 
+ *       2a. the large heap buffer is allocated
+ *       2b. each engine system is initialized in order, using some of the 
+ *           system stack
+ *       2c. game systems are also put into here
+ */
+
+
 #ifndef VG_HEADER_H
 #define VG_HEADER_H
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <dirent.h>
-#include <string.h>
-#include <stdarg.h>
-#include <ctype.h>
-#include <math.h>
+#include "vg_platform.h"
+#include "vg_mem.h"
+
+#ifndef _WIN32
+#include <execinfo.h>
+#endif
+
 
 #if defined(VG_SERVER) || defined(VG_TOOLS)
  #define VG_NON_CLIENT
 
 #ifndef VG_SERVER
 #include "../../dep/glad/glad.h"
-#include "../../dep/glfw/glfw3.h"
-#endif
 
-#define STB_DS_IMPLEMENTATION
-#include "stb/stb_ds.h"
+#define GLFW_INCLUDE_GLCOREARB
+
+#ifdef _WIN32
+  #define GLFW_DLL
+#endif
 
-#define QOI_IMPLEMENTATION
-#include "phoboslab/qoi.h"
+#include "../../dep/glfw/glfw3.h"
+#endif
 
 #include "vg_stdint.h"
-#include "vg_platform.h"
 
 void vg_register_exit( void( *funcptr )(void), const char *name );
 
@@ -41,29 +54,6 @@ void vg_register_exit( void( *funcptr )(void), const char *name );
 #endif
 
 #ifndef VG_NON_CLIENT
-#include "vg_gldiag.h"
-#endif
-
-#ifndef VG_NON_CLIENT
-
-m4x4f vg_pv;
-
-#ifdef VG_CAPTURE_MODE
-int vg_window_x = 1920;
-int vg_window_y = 1080;
-#else
-int vg_window_x = 1366;
-int vg_window_y = 768;
-#endif
-
-v2f vg_mouse;
-v2f vg_mouse_wheel;
-v3f vg_mouse_ws;
-
-double vg_time,
-       vg_time_last,
-       vg_time_delta;
-
 
 struct vg
 {
@@ -72,148 +62,263 @@ struct vg
 
    vg_mutex     mux_context;
    vg_semaphore sem_allow_exec,
-                sem_exec_finished;
+                sem_exec_finished,
+                sem_loader,
+                sem_fatal;
    int exec_context;
 
    vg_mutex     mux_engine_status;
-   int engine_running;
+   enum engine_status
+   {
+      k_engine_status_none,
+      k_engine_status_running,
+      k_engine_status_crashed
+   }
+   engine_status;
+   const char *str_const_engine_err;
+   int          is_loaded;
+
+   /* Window information */
+   int window_x,
+       window_y,
+       samples;
+   float refresh_rate;
+
+   double mouse_pos[2];
+   v2f 
+       mouse_delta,
+       mouse_wheel;
+
+   /* Runtime */
+   double time,
+          time_delta,
+          frame_delta,
+          time_real,
+          time_real_last,
+          time_rate,
+          accumulator;
+
+   int fixed_iterations;
+
+   enum engine_stage
+   {
+      k_engine_stage_none,
+      k_engine_stage_update,
+      k_engine_stage_update_fixed,
+      k_engine_stage_rendering,
+      k_engine_stage_ui
+   }
+   engine_stage;
 
+   /* graphics */
+   m4x4f pv;
+   enum quality_profile
+   {
+      k_quality_profile_high = 0,
+      k_quality_profile_low = 1,
+   }
+   quality_profile;
 
    /* Gamepad */
    GLFWgamepadstate  gamepad;
    int                               gamepad_ready;
    const char       *gamepad_name;
    int                               gamepad_id;
+   int               gamepad_use_trackpad_look;
 }
-static vg;
+VG_STATIC vg = { .time_rate = 1.0 };
+
+struct vg_thread_info
+{
+   enum vg_thread_purpose
+   {
+      k_thread_purpose_nothing,
+      k_thread_purpose_main,
+      k_thread_purpose_loader
+   }
+   purpose;
+
+   int gl_context_level;
+};
+
+static VG_THREAD_LOCAL struct vg_thread_info vg_thread_info;
 
 
 //#define VG_SYNC_DEBUG
 
 #ifdef VG_SYNC_DEBUG
-  #define VG_SYNC_LOG(...) vg_info(__VA_ARGS__)
+  #define VG_SYNC_LOG(STR,...) vg_info(STR,vg_thread_info.purpose,##__VA_ARGS__)
 #else
   #define VG_SYNC_LOG(...)
 #endif
 
-/*
- * Sync execution so that the OpenGL context is switched onto this thread.
- * Anything after this call will be in a valid context.
- */
-static int vg_acquire_thread_sync( int id )
+VG_STATIC void vg_fatal_exit_loop( const char *error );
+VG_STATIC void vg_required( void *ptr, const char *path )
 {
-   if( id == 0 )
+   if( !ptr )
    {
-      /* no action */
-      return 1;
+      vg_fatal_exit_loop( path );
    }
-   else
+}
+
+
+VG_STATIC void vg_ensure_engine_running(void)
+{
+   /* Check if the engine is no longer running */
+   vg_mutex_lock( &vg.mux_engine_status );
+   if( vg.engine_status != k_engine_status_running )
    {
-      /* Check if the engine is no longer running */
-      vg_mutex_lock( &vg.mux_engine_status );
-      if( !vg.engine_running )
+      VG_SYNC_LOG( "[%d] Engine is no longer running\n");
+      vg_mutex_unlock( &vg.mux_engine_status );
+
+      /* Safe to disregard loader thread from this point on, elswhere */
+      if( vg_thread_info.purpose == k_thread_purpose_loader )
       {
-         VG_SYNC_LOG( "[%d] Engine is no longer running\n", id );
-         vg_mutex_unlock( &vg.mux_engine_status );
-         return 0;
+         vg_semaphore_post( &vg.sem_loader );
       }
-      vg_mutex_unlock( &vg.mux_engine_status );
 
+      VG_SYNC_LOG( "[%d] about to kill\n");
+      vg_thread_exit();
+   }
+   vg_mutex_unlock( &vg.mux_engine_status );
+}
 
-      vg_mutex_lock( &vg.mux_context );
-      VG_SYNC_LOG( "[%d] Signal to sync.\n", id );
-      vg.exec_context = id;
-      vg_mutex_unlock( &vg.mux_context );
-      
-      /* wait until told we can go */
-      VG_SYNC_LOG( "[%d] Waiting to acuire sync.\n", id );
-      vg_semaphore_wait( &vg.sem_allow_exec );
-      glfwMakeContextCurrent( vg.window );
+/*
+ * Sync execution so that the OpenGL context is switched onto this thread.
+ * Anything after this call will be in a valid context.
+ */
+VG_STATIC void vg_acquire_thread_sync(void)
+{
+   /* We dont want to do anything if this is the main thread */
+   if( vg_thread_info.purpose == k_thread_purpose_main )
+      return;
+
+   assert( vg_thread_info.purpose == k_thread_purpose_loader );
 
-      /* context now valid to work in while we hold up main thread */
-      VG_SYNC_LOG( "[%d] Context acquired.\n", id );
+   vg_ensure_engine_running();
 
-      return 1;
+   /* Check if thread already has the context */
+   if( vg_thread_info.gl_context_level )
+   {
+      vg_thread_info.gl_context_level ++;
+      VG_SYNC_LOG( "[%d] We already have sync here\n" );
+      return;
    }
+
+   vg_mutex_lock( &vg.mux_context );
+   VG_SYNC_LOG( "[%d] Signal to sync.\n" );
+   vg.exec_context = 1;
+   vg_mutex_unlock( &vg.mux_context );
+   
+   /* wait until told we can go */
+   VG_SYNC_LOG( "[%d] Waiting to acuire sync.\n" );
+   vg_semaphore_wait( &vg.sem_allow_exec );
+   glfwMakeContextCurrent( vg.window );
+
+   /* context now valid to work in while we hold up main thread */
+   VG_SYNC_LOG( "[%d] Context acquired.\n" );
+   vg_thread_info.gl_context_level ++;
 }
 
 /*
  * Signify that we are done with the OpenGL context in this thread.
  * Anything after this call will be in an undefined context.
  */
-static void vg_release_thread_sync( int id )
+VG_STATIC void vg_release_thread_sync(void)
 {
-   if( id == 0 )
-   {
-      vg_mutex_lock( &vg.mux_context );
-
-      if( vg.exec_context != 0 )
-      {
-         VG_SYNC_LOG( "[%d] Allowing content (%d).\n", id, vg.exec_context );
+   if( vg_thread_info.purpose == k_thread_purpose_main )
+      return;
 
-         /* allow operations to go */
-         glfwMakeContextCurrent( NULL );
-         vg_semaphore_post( &vg.sem_allow_exec );
+   assert( vg_thread_info.purpose == k_thread_purpose_loader );
 
-         /* wait for operations to complete */
-         VG_SYNC_LOG( "[%d] Waiting for content (%d).\n", id, vg.exec_context );
-         vg_semaphore_wait( &vg.sem_exec_finished );
-         
-         /* re-engage main thread */
-         VG_SYNC_LOG( "[%d] Re-engaging.\n", id );
-         vg.exec_context = 0;
-         glfwMakeContextCurrent( vg.window );
-      }
+   /* signal that we are done */
+   vg_thread_info.gl_context_level --;
 
-      vg_mutex_unlock( &vg.mux_context );
-   }
-   else
+   if( !vg_thread_info.gl_context_level )
    {
-      /* signal that we are done */
-      VG_SYNC_LOG( "[%d] Releasing context.\n", id );
+      VG_SYNC_LOG( "[%d] Releasing context.\n" );
       glfwMakeContextCurrent( NULL );
       vg_semaphore_post( &vg.sem_exec_finished );
    }
 }
 
-static void vg_opengl_sync_init(void)
+VG_STATIC void vg_run_synced_content(void)
+{
+   assert( vg_thread_info.purpose == k_thread_purpose_main );
+
+   vg_mutex_lock( &vg.mux_context );
+
+   if( vg.exec_context != 0 )
+   {
+      VG_SYNC_LOG( "[%d] Allowing content (%d).\n", vg.exec_context );
+
+      /* allow operations to go */
+      vg_thread_info.gl_context_level = 0;
+      glfwMakeContextCurrent( NULL );
+      vg_semaphore_post( &vg.sem_allow_exec );
+
+      /* wait for operations to complete */
+      VG_SYNC_LOG( "[%d] Waiting for content (%d).\n", vg.exec_context );
+      vg_semaphore_wait( &vg.sem_exec_finished );
+      
+      /* check if we killed the engine */
+      vg_ensure_engine_running();
+      
+      /* re-engage main thread */
+      VG_SYNC_LOG( "[%d] Re-engaging.\n" );
+      vg.exec_context = 0;
+      glfwMakeContextCurrent( vg.window );
+      vg_thread_info.gl_context_level = 1;
+   }
+
+   vg_mutex_unlock( &vg.mux_context );
+}
+
+VG_STATIC void vg_opengl_sync_init(void)
 {
    vg_semaphore_init( &vg.sem_allow_exec, 0 );
    vg_semaphore_init( &vg.sem_exec_finished, 0 );
+   vg_semaphore_init( &vg.sem_loader, 1 );
+   vg_semaphore_init( &vg.sem_fatal, 1 );
    vg_mutex_init( &vg.mux_context );
-}
 
-static void vg_opengl_sync_free(void)
-{
-   vg_semaphore_free( &vg.sem_allow_exec );
-   vg_semaphore_free( &vg.sem_exec_finished );
-   vg_mutex_free( &vg.mux_context );
+   vg_set_thread_name( "[vg] Main" );
+   vg_thread_info.purpose = k_thread_purpose_main;
+   vg_thread_info.gl_context_level = 1;
 }
 
-
-int vg_checkgl( const char *src_info );
+VG_STATIC void vg_checkgl( const char *src_info );
 #define VG_STRINGIT( X ) #X
 #define VG_CHECK_GL_ERR() vg_checkgl( __FILE__ ":L" VG_STRINGIT(__LINE__) )
 
+#include "vg_console.h"
+#include "vg_profiler.h"
 #include "vg_audio.h"
 #include "vg_shader.h"
 #include "vg_tex.h"
 #include "vg_input.h"
 #include "vg_ui.h"
-#include "vg_console.h"
 #include "vg_lines.h"
-#include "vg_debug.h"
 #include "vg_loader.h"
+#include "vg_opt.h"
+
+/* Diagnostic */
+VG_STATIC struct vg_profile vg_prof_update = {.name="update()"},
+                            vg_prof_render = {.name="render()"};
 
 #define VG_GAMELOOP
-static void vg_register(void) VG_GAMELOOP;
-static void vg_start(void) VG_GAMELOOP;
-static void vg_update(int loaded) VG_GAMELOOP;
-static void vg_framebuffer_resize(int w, int h) VG_GAMELOOP;
-static void vg_render(void) VG_GAMELOOP;
-static void vg_ui(void) VG_GAMELOOP;
-
-int vg_checkgl( const char *src_info )
+VG_STATIC void vg_register(void) VG_GAMELOOP;
+VG_STATIC void vg_start(void) VG_GAMELOOP;
+
+VG_STATIC void vg_update(int loaded) VG_GAMELOOP;
+VG_STATIC void vg_update_fixed(int loaded) VG_GAMELOOP;
+VG_STATIC void vg_update_post(int loaded) VG_GAMELOOP;
+
+VG_STATIC void vg_framebuffer_resize(int w, int h) VG_GAMELOOP;
+VG_STATIC void vg_render(void) VG_GAMELOOP;
+VG_STATIC void vg_ui(void) VG_GAMELOOP;
+
+VG_STATIC void vg_checkgl( const char *src_info )
 {
    int fail = 0;
 
@@ -224,77 +329,107 @@ int vg_checkgl( const char *src_info )
       fail = 1;
    }
 
-   return fail;
+   if( fail )
+      vg_fatal_exit_loop( "OpenGL Error" );
 }
 
-
-
 void vg_mouse_callback( GLFWwindow* ptrW, double xpos, double ypos )
 {
-   vg_mouse[0] = xpos;
-   vg_mouse[1] = ypos;
+   vg.mouse_delta[0] += xpos - vg.mouse_pos[0];
+   vg.mouse_delta[1] += ypos - vg.mouse_pos[1];
+
+   vg.mouse_pos[0] = xpos;
+   vg.mouse_pos[1] = ypos;
 }
 
 void vg_scroll_callback( GLFWwindow* ptrW, double xoffset, double yoffset )
 {
-   vg_mouse_wheel[0] += xoffset;
-   vg_mouse_wheel[1] += yoffset;
+   vg.mouse_wheel[0] += xoffset;
+   vg.mouse_wheel[1] += yoffset;
 }
 
 void vg_framebuffer_resize_callback( GLFWwindow *ptrW, int w, int h )
 {
-   vg_window_x = w;
-   vg_window_y = h;
+   if( !w || !h )
+   {
+      vg_warn( "Got a invalid framebuffer size: %dx%d... ignoring\n", w, h );
+      return;
+   }
+
+   vg.window_x = w;
+   vg.window_y = h;
 
    vg_framebuffer_resize(w,h);
 }
 
-static int vg_bake_shaders(void)
+VG_STATIC void vg_bake_shaders(void)
 {
-   if( vg_acquire_thread_sync(1) )
-   {
-      if( !vg_shaders_recompile() )
-      {
-         vg_shaders_free(NULL);
-         vg_release_thread_sync(1);
-         return 0;
-      }
-      else
-      {
-         vg_release_thread_sync(1);
+   vg_acquire_thread_sync();
 
-         if( !vg_loader_highwater( vg_shaders_free, NULL ) )         return 0;
-         else return 1;
-      }
-   }
+#if 0
+   vg_function_push( (struct vg_cmd)
+   {
+      .name = "shaders",
+      .function = vg_shaders_live_recompile
+   });
+#endif
 
-   return 0;
+   vg_shaders_compile();
+   vg_release_thread_sync();
 }
 
-int vg_preload(void);
-int vg_load(void);
-static int vg_load_full(void)
+VG_STATIC void vg_preload(void);
+VG_STATIC void vg_load(void);
+VG_STATIC void vg_load_full(void)
 {
-   if( !vg_preload() )                                               return 0;
+   vg_preload();
 
    /* internal */
-   if( !vg_gamepad_init() )                                          return 0;
-   if( !vg_loader_highwater( NULL, NULL ) )                          return 0;
-
-   if( !vg_lines_init() )                                            return 0;
-   if( !vg_loader_highwater( vg_lines_free, NULL ) )                 return 0;
-
-   if( !vg_audio_init() )                                            return 0;
-   if( !vg_loader_highwater( vg_audio_free, NULL ) )                 return 0;
+   vg_loader_highwater( vg_gamepad_init, NULL, NULL );
+   vg_loader_highwater( vg_lines_init, NULL, NULL );
+   vg_loader_highwater( vg_audio_init, vg_audio_free, NULL );
+   vg_loader_highwater( vg_profiler_init, NULL, NULL );
 
    /* client */
-   if( !vg_load() )                                                  return 0;
+   vg_load();
 
-   return 1;
+   vg_acquire_thread_sync();
+   vg.is_loaded = 1;
+   vg_release_thread_sync();
 }
 
-static void vg_enter( int argc, char *argv[], const char *window_name )
+VG_STATIC void vg_enter( int argc, char *argv[], const char *window_name )
 {
+   char *arg;
+   while( vg_argp( argc, argv ) )
+   {
+      if( (arg = vg_opt_arg( 'w' )) )
+      {
+         vg.window_x = atoi( arg );
+      }
+
+      if( (arg = vg_opt_arg( 'h' )) )
+      {
+         vg.window_y = atoi( arg );
+      }
+
+      if( (arg = vg_long_opt_arg( "samples" )) )
+      {
+         vg.samples = VG_MAX( 0, VG_MIN( 8, atoi( arg ) ) );
+      }
+
+      if(  vg_long_opt( "use-libc-malloc" ) )
+      {
+         vg_mem.use_libc_malloc = atoi( arg );
+      }
+
+      if( vg_long_opt( "high-performance" ) )
+      {
+         vg.quality_profile = k_quality_profile_low;
+      }
+   }
+   
+   vg_alloc_quota();
    vg_log_init();
    vg_console_init();
 
@@ -302,14 +437,13 @@ static void vg_enter( int argc, char *argv[], const char *window_name )
    glfwWindowHint( GLFW_CONTEXT_VERSION_MAJOR, 3 );
    glfwWindowHint( GLFW_CONTEXT_VERSION_MINOR, 3 );
    glfwWindowHint( GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE );
-   glfwWindowHint( GLFW_OPENGL_DEBUG_CONTEXT, GL_TRUE );
+   //glfwWindowHint( GLFW_OPENGL_DEBUG_CONTEXT, GL_FALSE );
+   glfwWindowHint( GLFW_CONTEXT_RELEASE_BEHAVIOR, GLFW_RELEASE_BEHAVIOR_FLUSH );
    
-   glfwWindowHint( GLFW_RESIZABLE, GLFW_TRUE );
+   glfwWindowHint( GLFW_RESIZABLE, GLFW_FALSE );
    glfwWindowHint( GLFW_DOUBLEBUFFER, GLFW_TRUE );
    
-#if 0
-   glfwWindowHint(GLFW_SAMPLES,4);
-#endif
+   glfwWindowHint( GLFW_SAMPLES, vg.samples );
    
    GLFWmonitor *monitor_primary = glfwGetPrimaryMonitor();
    
@@ -317,20 +451,48 @@ static void vg_enter( int argc, char *argv[], const char *window_name )
    glfwWindowHint( GLFW_RED_BITS, mode->redBits );
    glfwWindowHint( GLFW_GREEN_BITS, mode->greenBits );
    glfwWindowHint( GLFW_BLUE_BITS, mode->blueBits );
-   
-   /* This is set like this because of an OS issue */
-   int refresh_rate = mode->refreshRate;
-   if( refresh_rate < 28 || refresh_rate >= 144 )
-      refresh_rate = 60;
-   glfwWindowHint( GLFW_REFRESH_RATE, refresh_rate );
-
-   if( !(vg.window = glfwCreateWindow( vg_window_x, vg_window_y, 
-                                       window_name, NULL, NULL)) )
+
+   glfwWindowHint( GLFW_REFRESH_RATE, mode->refreshRate );
+
+   if( !vg.window_x )
+      vg.window_x = mode->width;
+
+   if( !vg.window_y )
+      vg.window_y = mode->height;
+
+   vg.refresh_rate = mode->refreshRate;
+
+   if( (vg.window = glfwCreateWindow(  vg.window_x, vg.window_y,
+                                       window_name, monitor_primary, NULL)) )
+   {
+      glfwGetFramebufferSize( vg.window, &vg.window_x, &vg.window_y );
+      vg_success( "Window created (%dx%d)\n", vg.window_x, vg.window_y );
+   }
+   else
    {
       vg_error( "GLFW Failed to initialize\n" );
       return;
    }
    
+   /* We need 3.1.2 for correct VSync on windows */
+   {
+      int vmaj, vmin, vrev;
+      glfwGetVersion( &vmaj, &vmin, &vrev );
+
+      if( vmaj < 3 || 
+         (vmaj == 3 && vmin  < 1) || 
+         (vmaj == 3 && vmin == 1 && vrev < 2 ) )
+      {
+         vg_error( "GLFW out of date (%d.%d.%d); (3.1.2 is required)\n",
+                    vmaj, vmin, vrev );
+
+         glfwTerminate();
+         return;
+      }
+      
+      vg_success( "GLFW Version %d.%d.%d\n", vmaj, vmin, vrev );
+   }
+   
    glfwMakeContextCurrent( vg.window );
    glfwSwapInterval( 1 );
 
@@ -342,9 +504,10 @@ static void vg_enter( int argc, char *argv[], const char *window_name )
    
    glfwSetCharCallback( vg.window, console_proc_wchar );
    glfwSetKeyCallback( vg.window, console_proc_key );
-#if 0
-   glfwSetInputMode(vg_window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
-#endif
+   glfwSetInputMode( vg.window, GLFW_CURSOR, GLFW_CURSOR_DISABLED );
+
+   if( glfwRawMouseMotionSupported() )
+      glfwSetInputMode( vg.window, GLFW_RAW_MOUSE_MOTION, GLFW_TRUE );
 
    if( !gladLoadGLLoader((GLADloadproc)glfwGetProcAddress) ) 
    {
@@ -355,45 +518,41 @@ static void vg_enter( int argc, char *argv[], const char *window_name )
 
    const unsigned char* glver = glGetString( GL_VERSION );
    vg_success( "Load setup complete, OpenGL version: %s\n", glver );
-   vg_run_gfx_diagnostics();
-
-   if( !ui_default_init() )
-      goto il_exit_ui;
 
-   if( !vg_loader_init() )
-      goto il_exit_loader;
+   /* init systems 
+    * -----------------------------------------------------------------------*/
+   ui_init_context();
+   vg_loader_init();
 
    vg_mutex_init( &vg.mux_engine_status );
-   vg.engine_running = 1;
+   vg.engine_status = k_engine_status_running;
 
    vg_opengl_sync_init();
    vg_loader_start();
 
-   int loaded = 0;
+   vg.accumulator = 0.75f * (1.0f/60.0f);
 
+   int loaded = 0;
    while(1)
    {
-      vg_acquire_thread_sync( 0 );
-
       if( glfwWindowShouldClose( vg.window ) )
-      {
          break;
-      }
 
-      v2_copy( (v2f){ 0.0f, 0.0f }, vg_mouse_wheel );
+      v2_zero( vg.mouse_wheel );
+      v2_zero( vg.mouse_delta );
+
       glfwPollEvents();
 
-      vg_time_last = vg_time;
-      vg_time = glfwGetTime();
-      vg_time_delta = vg_minf( vg_time - vg_time_last, 0.1f );
+      vg.time_real_last = vg.time_real;
+      vg.time_real = glfwGetTime();
+      vg.frame_delta = vg.time_real-vg.time_real_last;
       
-      enum loader_status load_status = vg_loader_status();
-
-      if( load_status == k_loader_status_complete )
+      /* scaled time */
+      vg.time_delta = vg.frame_delta * vg.time_rate;
+      vg.time += vg.time_delta;
+      
+      if( vg.is_loaded )
       {
-         glClearColor( 0.0f,sinf(vg_time*20.0)*0.5f+0.5f,0.0f,1.0f );
-         glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
-         
          if( !loaded )
          {
             vg_start();
@@ -402,66 +561,244 @@ static void vg_enter( int argc, char *argv[], const char *window_name )
       }
       else
       {
-         if( load_status == k_loader_status_fail )
+         vg_loader_render();
+      }
+
+      /* 
+       * Game logic 
+       * -------------------------------------------------------
+       */
+      vg_profile_begin( &vg_prof_update );
+      vg_update_inputs();
+
+      vg.engine_stage = k_engine_stage_update;
+      vg_update( loaded );
+
+      /* Fixed update loop */
+      vg.engine_stage = k_engine_stage_update_fixed;
+      vg.accumulator += vg.time_delta;
+
+      vg.fixed_iterations = 0;
+      vg_lines.allow_input = 1;
+      while( vg.accumulator >= (VG_TIMESTEP_FIXED-0.00125) )
+      {
+         vg_update_fixed( loaded );
+         vg_lines.allow_input = 0;
+
+         vg.accumulator -= VG_TIMESTEP_FIXED;
+         vg.accumulator  = VG_MAX( 0.0, vg.accumulator );
+
+         vg.fixed_iterations ++;
+         if( vg.fixed_iterations == 8 )
          {
             break;
          }
-         else
-         {
-            vg_loader_render();
-         }
       }
+      vg_lines.allow_input = 1;
 
-      vg_update_inputs();
-      vg_update( loaded );
+      /* 
+       * Rendering 
+       * ---------------------------------------------
+       */
+      vg.engine_stage = k_engine_stage_update;
+      vg_update_post( loaded );
+      vg_profile_end( &vg_prof_update );
+
+      vg_profile_begin( &vg_prof_render );
 
       if( loaded )
       {
+         /* render */
+         vg.engine_stage = k_engine_stage_rendering;
          vg_render();
 
          /* ui */
+         vg.engine_stage = k_engine_stage_ui;
          {
-            ui_begin( &ui_global_ctx, vg_window_x, vg_window_y );
-            ui_set_mouse( &ui_global_ctx, vg_mouse[0], vg_mouse[1], 
-                  vg_get_button_state( "primary" ) );
+            ui_begin( vg.window_x, vg.window_y );
+
+            /* TODO */
+            ui_set_mouse( vg.mouse_pos[0], vg.mouse_pos[1], 0 );
             
-            audio_debug_ui( vg_pv );
+            vg_profile_drawn( 
+                  (struct vg_profile *[]){&vg_prof_update,&vg_prof_render}, 2,
+                  (1.0f/(float)vg.refresh_rate)*1000.0f, 
+                  (ui_rect){ 4, 4, 250, 0 }, 0
+            );
+
+            if( vg_profiler )
+            {
+               
+               char perf[128];
+               
+               snprintf( perf, 127, 
+                     "x: %d y: %d\n"
+                     "refresh: %.1f (%.1fms)\n"
+                     "samples: %d\n"
+                     "iterations: %d (acc: %.3fms%%)\n",
+                     vg.window_x, vg.window_y, 
+                     vg.refresh_rate, (1.0f/vg.refresh_rate)*1000.0f,
+                     vg.samples, 
+                     vg.fixed_iterations, 
+                     (vg.accumulator/VG_TIMESTEP_FIXED)*100.0f );
+
+               ui_text( (ui_rect){258, 4+24+12,0,0},perf, 1,0);
+            }
+
+            audio_debug_ui( vg.pv );
             vg_ui();
             vg_console_draw();
             
-            ui_resolve( &ui_global_ctx );
-            ui_draw( &ui_global_ctx, NULL );
+            ui_resolve();
+            ui_draw( NULL );
          }
       }
 
+      vg_profile_end( &vg_prof_render );
 
+      glfwSwapBuffers( vg.window );
+      vg_run_synced_content();
+   }
 
+   vg_console_write_persistent();
 
-      glfwSwapBuffers( vg.window );
+   vg_mutex_lock( &vg.mux_engine_status );
+   vg.engine_status = k_engine_status_none;
+   vg_mutex_unlock( &vg.mux_engine_status );
 
-      if( VG_CHECK_GL_ERR() )
-         break;
+   vg_loader_free();
+
+   vg_success( "If you see this it means everything went.. \"well\".....\n" );
+   glfwTerminate();
+}
+
+/*
+ * Immediately transfer away from calling thread into a safe loop, signal for 
+ * others to shutdown, then free everything once the user closes the window.
+ *
+ * FIXME(bug): glfwWindowShouldClose() never returns 1 in windows via wine, ONLY
+ *             when calling the program from outside its normal directory.
+ */
+VG_STATIC void vg_fatal_exit_loop( const char *error )
+{
+   /* 
+    *    https://www.gnu.org/software/libc/manual/html_node/Backtraces.html
+    *    thanks gnu <3
+    *
+    *    TODO: this on windows?
+    */
+
+#ifndef _WIN32
+
+   void *array[20];
+   char **strings;
+   int size, i;
+
+   size = backtrace( array, 20 );
+   strings = backtrace_symbols( array, size );
+
+   if( strings != NULL )
+   {
+      vg_error( "---------------- gnu backtrace -------------\n" );
+
+      for( int i=0; i<size; i++ )
+         vg_info( "%s\n", strings[i] );
 
-      vg_release_thread_sync( 0 );
+      vg_error( "---------------- gnu backtrace -------------\n" );
    }
 
-   vg_console_write_persistent();
+   free( strings );
+
+#endif
+
+   vg_error( "Fatal error: %s\n", error );
+   assert( vg_semaphore_trywait( &vg.sem_fatal ) );
 
    vg_mutex_lock( &vg.mux_engine_status );
-   vg.engine_running = 0;
-   vg_mutex_unlock( &vg.mux_engine_status );
 
+   if( vg.engine_status == k_engine_status_none )
+   {
+      vg_mutex_unlock( &vg.mux_engine_status );
+
+      /* TODO: Correct shutdown before other systems */
+      exit(0);
+   }
+   else
+   {
+      vg_mutex_unlock( &vg.mux_engine_status );
 
-   vg_loader_free();
-   vg_opengl_sync_free();
+      /* 
+       * if main
+       *    if loader running
+       *       wait until loader checks in, it will die
+       *    else
+       *       pass immediately
+       * else
+       *    if have context
+       *       pass immediately
+       *    else
+       *       wait for main to get to us, it will never be used again
+       *
+       * undefined behaviour:
+       *    fatal_exit_loop is called in both threads, preventing an appropriate
+       *                    reaction to the crash. This *should* be made
+       *                    obvious by the assertion
+       */
+      vg_acquire_thread_sync();
 
-   vg_mutex_free( &vg.mux_engine_status );
+      vg_mutex_lock( &vg.mux_engine_status );
+      vg.engine_status = k_engine_status_crashed;
+      vg.str_const_engine_err = error;
+      vg_mutex_unlock( &vg.mux_engine_status );
 
-il_exit_loader:
-   ui_default_free();
+      /* 
+       * Wait for loader to finish what it was doing, if it was running.
+       * Then we can continue in our nice error screen
+       */
+      if( vg_thread_info.purpose == k_thread_purpose_main )
+      {
+         vg_semaphore_wait( &vg.sem_loader );
+      }
+      vg_audio_free(NULL);
 
-il_exit_ui:
-   glfwTerminate();
+      while(1)
+      {
+         if( glfwWindowShouldClose( vg.window ) )
+            break;
+
+         if( glfwGetKey( vg.window, GLFW_KEY_ESCAPE ) )
+            break;
+
+         glfwPollEvents();
+         
+         glBindFramebuffer( GL_FRAMEBUFFER, 0 );
+         glEnable(GL_BLEND);
+         glDisable(GL_DEPTH_TEST);
+         glBlendFunc(GL_ONE_MINUS_DST_ALPHA, GL_DST_ALPHA);
+         glBlendEquation(GL_FUNC_ADD);
+
+         glClearColor( 0.15f + sinf(glfwGetTime())*0.1f, 0.0f, 0.0f,1.0f );
+         glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
+         glViewport( 0,0, vg.window_x, vg.window_y );
+
+         vg_render_log();
+
+         glfwSwapBuffers( vg.window );
+      }
+
+      /* Can now shutdown and EXIT */
+      vg_loader_free();
+      glfwTerminate();
+      exit(0);
+   }
+}
+
+#else
+
+VG_STATIC void vg_fatal_exit_loop( const char *error )
+{
+   vg_error( "Fatal error: %s\n", error );
+   exit(0);
 }
 
 #endif