a-game

commit dd1e59ec2efc9f5403dacbc0891276461618de6b
parent 1a32b2e02ebabb8a421fb514d87fb0180b15ed2d
Author: amin <dev@aminmesbah.com>
Date:   Tue, 30 Apr 2019 00:53:49 +0000

Allocate a big block of game memory

Note that this will break the Windows platform layer until I get around
to fixing it.

FossilOrigin-Name: 5ea913d2b41882f0c05977bf89d693692ba678ac8a73fafb612c7144c8353157
Diffstat:
M
src/game.c
 | 
20
+++++++++++---------
M
src/game.h
 | 
1
+
M
src/platform.h
 | 
6
+++++-
M
src/platform_linux.c
 | 
14
++++++++++++--

4 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/src/game.c b/src/game.c
@@ -14,8 +14,8 @@ void game_load_opengl_symbols(void)
 
 internal void game_init(struct GameMemory *game_memory, v2u framebuffer)
 {
-    struct GameState *game_state = game_memory->game_state;
-
+    assert(sizeof(struct GameState) <= game_memory->buffer_size);
+    struct GameState *game_state = (struct GameState *)game_memory->buffer;
 
     // init player
     game_state->player.pos = (struct AbsolutePos) {
@@ -295,7 +295,8 @@ internal bool wall_is_internal(u32 *tiles, segment wall)
 // to change this in the future.
 void game_update_and_render(struct GameMemory *game_memory, struct GameInput *game_input, v2u framebuffer)
 {
-    struct GameState *game_state = game_memory->game_state;
+    assert(sizeof(struct GameState) <= game_memory->buffer_size);
+    struct GameState *game_state = (struct GameState *)game_memory->buffer;
 
     rect viewport = {0};
     f32 ppm = 0.0f;
@@ -644,15 +645,15 @@ void game_update_and_render(struct GameMemory *game_memory, struct GameInput *ga
                 v2 delta_to_nearest_collision = math_v2f_m(player_delta, smallest_distance_scale_factor);
                 v2 nearest_collision_p = math_v2_a(player->pos.local, delta_to_nearest_collision);
 
-                f32 epsilon = 0.0001f;
+                f32 collision_epsilon = 0.0001f;
                 rect local_inhabitable_region = {
                     .min = {
-                        math_min(player->pos.local.x, nearest_collision_p.x + epsilon),
-                        math_min(player->pos.local.y, nearest_collision_p.y + epsilon),
+                        math_min(player->pos.local.x, nearest_collision_p.x + collision_epsilon),
+                        math_min(player->pos.local.y, nearest_collision_p.y + collision_epsilon),
                     },
                     .max = {
-                        math_max(player->pos.local.x, nearest_collision_p.x - epsilon),
-                        math_max(player->pos.local.y, nearest_collision_p.y - epsilon),
+                        math_max(player->pos.local.x, nearest_collision_p.x - collision_epsilon),
+                        math_max(player->pos.local.y, nearest_collision_p.y - collision_epsilon),
                     },
                 };
 
@@ -703,7 +704,8 @@ void game_update_and_render(struct GameMemory *game_memory, struct GameInput *ga
 
 internal void game_cleanup(struct GameMemory *game_memory)
 {
-    struct GameState *game_state = game_memory->game_state;
+    assert(sizeof(struct GameState) <= game_memory->buffer_size);
+    struct GameState *game_state = (struct GameState *)game_memory->buffer;
     glDeleteVertexArrays(1, &game_state->renderer.vao);
     glDeleteBuffers(1, &game_state->renderer.quad_vbo);
     glDeleteBuffers(1, &game_state->renderer.quad_ebo);
diff --git a/src/game.h b/src/game.h
@@ -52,6 +52,7 @@ struct GameState
 {
     struct RendererState renderer;
     struct Entity player;
+    struct Room *rooms;
 };
 
 internal void game_init(struct GameMemory *game_memory, v2u framebuffer);
diff --git a/src/platform.h b/src/platform.h
@@ -4,6 +4,9 @@
 
 #include "types.h"
 
+#define KIBIBYTES(n) (n) * 1024LL
+#define MEBIBYTES(n) KIBIBYTES((n) * 1024LL)
+
 enum InputKeyAction
 {
     KEY_RELEASE,
@@ -30,7 +33,8 @@ struct PlatformApi
 
 struct GameMemory
 {
-    struct GameState *game_state;
+    u64 buffer_size;
+    void *buffer;
     struct PlatformApi platform;
 };
 
diff --git a/src/platform_linux.c b/src/platform_linux.c
@@ -50,13 +50,20 @@ int main(void)
     srand((uint32_t)time(NULL));
 #endif
 
-    struct GameState game_state = {0};
     struct GameMemory game_memory = {
-        .game_state = &game_state,
+        .buffer_size = MEBIBYTES(64),
         .platform = {
             &linux_read_entire_file,
         },
     };
+    // TODO: replace with mmap
+    game_memory.buffer = malloc(game_memory.buffer_size);
+    if (!game_memory.buffer)
+    {
+        fprintf(stderr, "Game memory allocation failed\n");
+        glfwTerminate();
+        return -1;
+    }
 
     struct GameInput game_input = {0};
     glfwSetWindowUserPointer(window, &game_input);
@@ -117,6 +124,9 @@ int main(void)
 
     game_cleanup(&game_memory);
 
+    // TODO: replace with munmap
+    free(game_memory.buffer);
+
     glfwDestroyWindow(window);
     glfwTerminate();
     return 0;