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[vg.git] / src / vg / vg.h

/* 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 "vg_platform.h"
#include "vg_mem.h"

#ifndef _WIN32
#include <execinfo.h>
#endif


#if defined(VG_SERVER) || defined(VG_TOOLS)
 #define VG_NON_CLIENT
#endif

#ifndef VG_SERVER
#include "../../dep/glad/glad.h"

#define GLFW_INCLUDE_GLCOREARB

#ifdef _WIN32
  #define GLFW_DLL
#endif

#include "../../dep/glfw/glfw3.h"
#endif

#include "vg_stdint.h"

void vg_register_exit( void( *funcptr )(void), const char *name );

#include "vg_m.h"
#include "vg_io.h"
#include "vg_log.h"

#ifdef VG_STEAM
//#include "vg_steamworks.h"
#include "vg_steam.h"
#endif

#ifndef VG_NON_CLIENT

struct vg
{
   /* Engine sync */
   GLFWwindow* window;

   vg_mutex     mux_context;
   vg_semaphore sem_allow_exec,
                sem_exec_finished,
                sem_loader,
                sem_fatal;
   int exec_context;

   vg_mutex     mux_engine_status;
   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;
}
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(STR,...) vg_info(STR,vg_thread_info.purpose,##__VA_ARGS__)
#else
  #define VG_SYNC_LOG(...)
#endif

VG_STATIC void vg_fatal_exit_loop( const char *error );
VG_STATIC void vg_required( void *ptr, const char *path )
{
   if( !ptr )
   {
      vg_fatal_exit_loop( path );
   }
}


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 )
   {
      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_semaphore_post( &vg.sem_loader );
      }

      VG_SYNC_LOG( "[%d] about to kill\n");
      vg_thread_exit();
   }
   vg_mutex_unlock( &vg.mux_engine_status );
}

/*
 * 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 );

   vg_ensure_engine_running();

   /* 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.
 */
VG_STATIC void vg_release_thread_sync(void)
{
   if( vg_thread_info.purpose == k_thread_purpose_main )
      return;

   assert( vg_thread_info.purpose == k_thread_purpose_loader );

   /* signal that we are done */
   vg_thread_info.gl_context_level --;

   if( !vg_thread_info.gl_context_level )
   {
      VG_SYNC_LOG( "[%d] Releasing context.\n" );
      glfwMakeContextCurrent( NULL );
      vg_semaphore_post( &vg.sem_exec_finished );
   }
}

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 );

   vg_set_thread_name( "[vg] Main" );
   vg_thread_info.purpose = k_thread_purpose_main;
   vg_thread_info.gl_context_level = 1;
}

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_lines.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
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;

   GLenum err;
   while( (err = glGetError()) != GL_NO_ERROR )
   {
      vg_error( "(%s) OpenGL Error: #%d\n", src_info, err );
      fail = 1;
   }

   if( fail )
      vg_fatal_exit_loop( "OpenGL Error" );
}

void vg_mouse_callback( GLFWwindow* ptrW, double xpos, double 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;
}

void vg_framebuffer_resize_callback( GLFWwindow *ptrW, int w, int 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);
}

VG_STATIC void vg_bake_shaders(void)
{
   vg_acquire_thread_sync();

#if 0
   vg_function_push( (struct vg_cmd)
   {
      .name = "shaders",
      .function = vg_shaders_live_recompile
   });
#endif

   vg_shaders_compile();
   vg_release_thread_sync();
}

VG_STATIC void vg_preload(void);
VG_STATIC void vg_load(void);
VG_STATIC void vg_load_full(void)
{
   vg_preload();

   /* internal */
   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 */
   vg_load();

   vg_acquire_thread_sync();
   vg.is_loaded = 1;
   vg_release_thread_sync();
}

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();

   glfwInit();
   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_FALSE );
   glfwWindowHint( GLFW_CONTEXT_RELEASE_BEHAVIOR, GLFW_RELEASE_BEHAVIOR_FLUSH );
   
   glfwWindowHint( GLFW_RESIZABLE, GLFW_FALSE );
   glfwWindowHint( GLFW_DOUBLEBUFFER, GLFW_TRUE );
   
   glfwWindowHint( GLFW_SAMPLES, vg.samples );
   
   GLFWmonitor *monitor_primary = glfwGetPrimaryMonitor();
   
   const GLFWvidmode *mode = glfwGetVideoMode( monitor_primary );
   glfwWindowHint( GLFW_RED_BITS, mode->redBits );
   glfwWindowHint( GLFW_GREEN_BITS, mode->greenBits );
   glfwWindowHint( GLFW_BLUE_BITS, mode->blueBits );

   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 );

   glfwSetWindowSizeLimits( vg.window, 800, 600, GLFW_DONT_CARE,GLFW_DONT_CARE);
   glfwSetFramebufferSizeCallback( vg.window, vg_framebuffer_resize_callback );

   glfwSetCursorPosCallback( vg.window, vg_mouse_callback );
   glfwSetScrollCallback( vg.window, vg_scroll_callback );
   
   glfwSetCharCallback( vg.window, console_proc_wchar );
   glfwSetKeyCallback( vg.window, console_proc_key );
   glfwSetInputMode( vg.window, GLFW_CURSOR, GLFW_CURSOR_DISABLED );

   if( glfwRawMouseMotionSupported() )
      glfwSetInputMode( vg.window, GLFW_RAW_MOUSE_MOTION, GLFW_TRUE );

   if( !gladLoadGLLoader((GLADloadproc)glfwGetProcAddress) ) 
   {
      vg_error( "Glad Failed to initialize\n" );
      glfwTerminate();
      return;
   }

   const unsigned char* glver = glGetString( GL_VERSION );
   vg_success( "Load setup complete, OpenGL version: %s\n", glver );

   /* init systems 
    * -----------------------------------------------------------------------*/
   ui_init_context();
   vg_loader_init();

   vg_mutex_init( &vg.mux_engine_status );
   vg.engine_status = k_engine_status_running;

   vg_opengl_sync_init();
   vg_loader_start();

   vg.accumulator = 0.75f * (1.0f/60.0f);

   int loaded = 0;
   while(1)
   {
      if( glfwWindowShouldClose( vg.window ) )
         break;

      v2_zero( vg.mouse_wheel );
      v2_zero( vg.mouse_delta );

      glfwPollEvents();

      vg.time_real_last = vg.time_real;
      vg.time_real = glfwGetTime();
      vg.frame_delta = vg.time_real-vg.time_real_last;
      
      /* scaled time */
      vg.time_delta = vg.frame_delta * vg.time_rate;
      vg.time += vg.time_delta;
      
      if( vg.is_loaded )
      {
         if( !loaded )
         {
            vg_start();
            loaded = 1;
         }
      }
      else
      {
         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;
         }
      }
      vg_lines.allow_input = 1;

      /* 
       * 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( vg.window_x, vg.window_y );

            /* TODO */
            ui_set_mouse( vg.mouse_pos[0], vg.mouse_pos[1], 0 );
            
            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_draw( NULL );
         }
      }

      vg_profile_end( &vg_prof_render );

      glfwSwapBuffers( vg.window );
      vg_run_synced_content();
   }

   vg_console_write_persistent();

   vg_mutex_lock( &vg.mux_engine_status );
   vg.engine_status = k_engine_status_none;
   vg_mutex_unlock( &vg.mux_engine_status );

   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_error( "---------------- gnu backtrace -------------\n" );
   }

   free( strings );

#endif

   vg_error( "Fatal error: %s\n", error );
   assert( vg_semaphore_trywait( &vg.sem_fatal ) );

   vg_mutex_lock( &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 );

      /* 
       * 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_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 );

      /* 
       * 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);

      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

/*
 * Graphic cards will check these to force it to use the GPU
 */
u32 NvOptimusEnablement = 0x00000001;
int AmdPowerXpressRequestHighPerformance = 1;

#endif