medfall

commit 0d9583a7aed34d8d1e55830a11ba636c80e831ea
parent 73c719c4e53842ed1dfc41bc68b54d83fcbd7f0a
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Wed Sep  2 22:25:47 +0200

Use a memory arena for persistent memory

Diffstat:
Makefile
 | 
4
++--
bsp.cc
 | 
6
+-----
game.h
 | 
20
+++++---------------
hm.cc
 | 
6
++----
main.cc
 | 
13
++++++++-----
5 files changed, 18 insertions(+), 31 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,8 +1,8 @@
 all: medfall bsp.so hm.so pp
 
-OBJS = main.o gl.o
+OBJS = main.o gl.o memory_arena.o
 BSPOBJS = bsp.o bsp_renderer.o gl.o memory_arena.o immediate.o
-HMOBJS = hm.o heightmap.o terrain_manager.o work_queue.o stb_image.o stb_perlin.o immediate.o stb_truetype.o
+HMOBJS = hm.o heightmap.o terrain_manager.o memory_arena.o work_queue.o immediate.o stb_truetype.o stb_image.o stb_perlin.o
 PPOBJS = pp.o stb_image.o stb_image_write.o
 
 WARNINGS = -Wall -Wextra -Wno-unused-parameter -Wno-unused-function -Wno-write-strings -Wno-char-subscripts
diff --git a/bsp.cc b/bsp.cc
@@ -270,9 +270,7 @@ static const glm::mat4 P( glm::perspective( glm::radians( 120.0f ), 640.0f / 480
 extern "C" GAME_INIT( game_init ) {
 	state->bsp = BSP( "acidwdm2.bsp" );
 
-	u8 * memory = reserve_persistent( mem, megabytes( 10 ) );
-	MemoryArena arena;
-	memarena_init( &arena, memory, megabytes( 10 ) );
+	MemoryArena arena = memarena_push_arena( &mem->persistent_arena, megabytes( 10 ) );
 
 	state->pos = glm::vec3( 0, -100, 450 );
 	state->angles = glm::radians( ( glm::vec3( -90, 135, 0 ) ) );
@@ -288,8 +286,6 @@ extern "C" GAME_INIT( game_init ) {
 }
 
 extern "C" GAME_FRAME( game_frame ) {
-	GameState * state = ( GameState * ) mem.persistent;
-
 	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 
 	const int fb = input->keys[ 'w' ] - input->keys[ 's' ];
diff --git a/game.h b/game.h
@@ -10,6 +10,7 @@
 #include "bsp_renderer.h"
 #include "immediate.h"
 #include "work_queue.h"
+#include "memory_arena.h"
 #include "keys.h"
 #include "stb_truetype.h"
 
@@ -41,29 +42,18 @@ struct GameState {
 };
 
 struct GameMemory {
-	size_t persistent_size;
-	size_t persistent_used;
-	u8 * persistent;
+	MemoryArena persistent_arena;
+	GameState * state;
 };
 
-inline u8 * reserve_persistent( GameMemory & mem, const size_t size ) {
-	assert( mem.persistent_used + size <= mem.persistent_size );
-	assert( mem.persistent_used + size > mem.persistent_used );
-
-	u8 * result = mem.persistent + mem.persistent_used;
-	mem.persistent_used += size;
-
-	return result;
-}
-
 struct GameInput {
 	bool keys[ KEY_COUNT ];
 };
 
-#define GAME_INIT( name ) void name( GameState * state, GameMemory & mem )
+#define GAME_INIT( name ) void name( GameState * const state, GameMemory * const mem )
 typedef GAME_INIT( GameInit );
 
-#define GAME_FRAME( name ) void name( GameMemory & mem, const GameInput * const input, const float dt )
+#define GAME_FRAME( name ) void name( GameState * const state, GameMemory * const mem, const GameInput * const input, const float dt )
 typedef GAME_FRAME( GameFrame );
 
 #endif // _GAME_H_
diff --git a/hm.cc b/hm.cc
@@ -115,7 +115,7 @@ extern "C" GAME_INIT( game_init ) {
 
 	// TODO: persistent memory should be an arena
 	const size_t triangles = 65536;
-	ImmediateTriangle * immediate_memory = ( ImmediateTriangle * ) reserve_persistent( mem, sizeof( ImmediateTriangle ) * triangles );
+	ImmediateTriangle * immediate_memory = memarena_push_many( &mem->persistent_arena, ImmediateTriangle, triangles );
 	immediate_init( &state->test_immediate, immediate_memory, triangles );
 
 	const float aspect = 640.0f / 480.0f;
@@ -153,7 +153,7 @@ extern "C" GAME_INIT( game_init ) {
 	// TODO
 	u8 * const arial = file_get_contents( "Arial.ttf" );
 
-	u8 * const font_memory = reserve_persistent( mem, 512 * 256 );
+	u8 * const font_memory = memarena_push_size( &mem->persistent_arena, 512 * 256 );
 	const int offset = stbtt_GetFontOffsetForIndex( arial, 0 );
 	const int ok = stbtt_BakeFontBitmap( arial, offset, 48, font_memory, 512, 512, ' ', 127 - ' ', state->test_chars );
 	assert( ok > 0 );
@@ -219,8 +219,6 @@ static void draw_string( const GameState * state,
 }
 
 extern "C" GAME_FRAME( game_frame ) {
-	GameState * state = ( GameState * ) mem.persistent;
-
 	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 
 	const int fb = input->keys[ 'w' ] - input->keys[ 's' ];
diff --git a/main.cc b/main.cc
@@ -74,16 +74,19 @@ int main( int argc, char ** argv ) {
 
 	Game game = load_game( game_library_path );
 	GameMemory mem = { };
-	mem.persistent_size = megabytes( 64 );
-	mem.persistent = new u8[ mem.persistent_size ];
 
-	GameState * state = ( GameState * ) reserve_persistent( mem, sizeof( GameState ) );
+	const size_t persistent_size = megabytes( 64 );
+	u8 * const persistent_memory = new u8[ persistent_size ];
+	memarena_init( &mem.persistent_arena, persistent_memory, persistent_size );
+
+	GameState * state = memarena_push_type( &mem.persistent_arena, GameState );
+	mem.state = state;
 
 	GameInput input = { };
 
 	GLFWwindow * const window = GL::init();
 
-	game.init( state, mem );
+	game.init( state, &mem );
 
 	const float program_start_time = glfwGetTime();
 	float last_frame_time = program_start_time;
@@ -119,7 +122,7 @@ int main( int argc, char ** argv ) {
 		input.keys[ KEY_RIGHTARROW ] = glfwGetKey( window, GLFW_KEY_RIGHT );
 
 		if( game.frame ) {
-			game.frame( mem, &input, dt );
+			game.frame( state, &mem, &input, dt );
 		}
 
 		glfwSwapBuffers( window );