Simplify game callbacks.

5 files changed, 82 insertions, 113 deletions

diff --git a/gfx-app/include/gfx/gfx_app.h b/gfx-app/include/gfx/gfx_app.h
index 0033bde..3c544fa 100644
--- a/gfx-app/include/gfx/gfx_app.h
+++ b/gfx-app/include/gfx/gfx_app.h
@@ -2,6 +2,7 @@
 
 #include <stdbool.h>
 
+/// Application settings.
 typedef struct GfxAppDesc {
   int          argc;    // Number of application arguments.
   const char** argv;    // Application arguments.
@@ -12,12 +13,19 @@ typedef struct GfxAppDesc {
   const char*  title;             // Window title.
 } GfxAppDesc;
 
+typedef bool (*GfxAppInit)(const GfxAppDesc*, void** app_state);
+typedef void (*GfxAppUpdate)(void* app_state, double t, double dt);
+typedef void (*GfxAppRender)(void* app_state);
+typedef void (*GfxAppResize)(void* app_state, int width, int height);
+typedef void (*GfxAppShutdown)(void* app_state);
+
+/// Application callback functions.
 typedef struct GfxAppCallbacks {
-  bool (*init)(const GfxAppDesc*, void** app_state);
-  void (*update)(void* app_state, double t, double dt);
-  void (*render)(void* app_state);
-  void (*resize)(void* app_state, int width, int height);
-  void (*shutdown)(void* app_state);
+  GfxAppInit     init;
+  GfxAppUpdate   update;
+  GfxAppRender   render;
+  GfxAppResize   resize;
+  GfxAppShutdown shutdown;
 } GfxAppCallbacks;
 
 /// Create a window with an OpenGL context and run the main loop.
@@ -25,3 +33,24 @@ bool gfx_app_run(const GfxAppDesc*, const GfxAppCallbacks*);
 
 /// Get the mouse coordinates relative to the app's window.
 void gfx_app_get_mouse_position(double* x, double* y);
+
+/// Define a main function that initializes and puts the application in a loop.
+/// See also: gfx_app_run().
+#define GFX_APP_MAIN(WIDTH, HEIGHT, MAX_FPS)                                 \
+  int main(int argc, const char** argv) {                                    \
+    gfx_app_run(                                                             \
+        &(GfxAppDesc){                                                       \
+            .argc              = argc,                                       \
+            .argv              = argv,                                       \
+            .width             = WIDTH,                                      \
+            .height            = HEIGHT,                                     \
+            .max_fps           = MAX_FPS,                                    \
+            .update_delta_time = MAX_FPS > 0 ? 1.0 / (double)MAX_FPS : 0.0}, \
+        &(GfxAppCallbacks){                                                  \
+            .init     = (GfxAppInit)app_init,                                \
+            .update   = (GfxAppUpdate)app_update,                            \
+            .render   = (GfxAppRender)app_render,                            \
+            .resize   = (GfxAppResize)app_resize,                            \
+            .shutdown = (GfxAppShutdown)app_end});                           \
+    return 0;                                                                \
+  }
diff --git a/gltfview/CMakeLists.txt b/gltfview/CMakeLists.txt
index de745ce..98c3b47 100644
--- a/gltfview/CMakeLists.txt
+++ b/gltfview/CMakeLists.txt
@@ -5,8 +5,7 @@ add_subdirectory(src/plugins)
 project(gltfview)
 
 add_executable(gltfview
-  src/game.c
-  src/main.c)
+  src/game.c)
 
 target_include_directories(gltfview PRIVATE
   src/)
diff --git a/gltfview/src/game.c b/gltfview/src/game.c
index 5ca9ad4..c331190 100644
--- a/gltfview/src/game.c
+++ b/gltfview/src/game.c
@@ -7,11 +7,17 @@
 #define _GNU_SOURCE 200112L // For readlink()
 
 #include "game.h"
+
 #include "plugins/plugin.h"
 
+#include <gfx/gfx.h>
+#include <gfx/gfx_app.h>
 #include <gfx/render_backend.h>
+#include <gfx/renderer.h>
 #include <gfx/scene/camera.h>
+#include <gfx/scene/node.h>
 #include <gfx/scene/object.h>
+#include <gfx/scene/scene.h>
 
 #include <error.h>
 #include <log/log.h>
@@ -21,6 +27,7 @@
 #include <assert.h>
 #include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 #include <linux/limits.h>
 
@@ -28,18 +35,32 @@
 
 #undef _GNU_SOURCE
 
-// Plugin to load if no plugin is provided.
-static const char* DEFAULT_PLUGIN = "texture_view";
+static const int WIDTH   = 1350;
+static const int HEIGHT  = 900;
+static const int MAX_FPS = 60;
 
-bool game_new(Game* game, int argc, const char** argv) {
-  assert(game);
+void app_end(Game* game);
+
+bool app_init(const GfxAppDesc* desc, void** app_state) {
+  assert(desc);
+
+  if (desc->argc <= 1) {
+    LOGE("Usage: %s <plugin> [plugin args]", desc->argv[0]);
+    return false;
+  }
+
+  Game* game = calloc(1, sizeof(Game));
+  if (!game) {
+    LOGE("Failed to allocate game state");
+    return false;
+  }
 
-  // Syntax: game [plugin] <plugin args>
+  // Syntax: game <plugin> [plugin args]
   //
-  // Here we consume the [plugin] arg so that plugins receive the remainder
+  // Here we consume the <plugin> arg so that plugins receive the remainder
   // args starting from 0.
-  game->argc = argc - 1;
-  game->argv = argv + 1;
+  game->argc = desc->argc - 1;
+  game->argv = desc->argv + 1;
 
   char exe_path_buf[NAME_MAX] = {0};
   if (readlink("/proc/self/exe", exe_path_buf, sizeof(exe_path_buf)) == -1) {
@@ -59,7 +80,7 @@ bool game_new(Game* game, int argc, const char** argv) {
     goto cleanup;
   }
 
-  const char* plugin = argc > 1 ? argv[1] : DEFAULT_PLUGIN;
+  const char* plugin = desc->argv[1];
   if (!(game->plugin = load_plugin(game->plugin_engine, plugin))) {
     goto cleanup;
   }
@@ -91,15 +112,16 @@ bool game_new(Game* game, int argc, const char** argv) {
     }
   }
 
+  *app_state = game;
   return true;
 
 cleanup:
   LOGE("Gfx error: %s", get_error());
-  game_end(game);
+  app_end(game);
   return false;
 }
 
-void game_end(Game* game) {
+void app_end(Game* game) {
   assert(game);
   if (game->gfx) {
     gfx_destroy(&game->gfx);
@@ -112,7 +134,7 @@ void game_end(Game* game) {
   }
 }
 
-void game_update(Game* game, double t, double dt) {
+void app_update(Game* game, double t, double dt) {
   plugin_engine_update(game->plugin_engine);
   if (plugin_reloaded(game->plugin) &&
       plugin_resolve(game->plugin, plugin_init, "init")) {
@@ -129,7 +151,7 @@ void game_update(Game* game, double t, double dt) {
   }
 }
 
-void game_render(const Game* game) {
+void app_render(const Game* game) {
   RenderBackend* render_backend = gfx_get_render_backend(game->gfx);
   Renderer*      renderer       = gfx_get_renderer(game->gfx);
 
@@ -149,7 +171,7 @@ void game_render(const Game* game) {
   gfx_end_frame(render_backend);
 }
 
-void game_set_viewport(Game* game, int width, int height) {
+void app_resize(Game* game, int width, int height) {
   RenderBackend* render_backend = gfx_get_render_backend(game->gfx);
   gfx_set_viewport(render_backend, width, height);
 
@@ -162,3 +184,5 @@ void game_set_viewport(Game* game, int width, int height) {
   Camera* camera     = gfx_get_camera_camera(game->camera);
   camera->projection = projection;
 }
+
+GFX_APP_MAIN(WIDTH, HEIGHT, MAX_FPS);
diff --git a/gltfview/src/game.h b/gltfview/src/game.h
index 2a7b7ef..53725c7 100644
--- a/gltfview/src/game.h
+++ b/gltfview/src/game.h
@@ -1,19 +1,13 @@
+/*
+ * Header file defining the game state, included by plugins.
+ */
 #pragma once
 
-#include <gfx/gfx.h>
-#include <gfx/render_backend.h>
-#include <gfx/renderer.h>
-#include <gfx/scene/camera.h>
-#include <gfx/scene/node.h>
-#include <gfx/scene/scene.h>
-
-#include <stdbool.h>
-
-typedef struct Plugin       Plugin;
 typedef struct PluginEngine PluginEngine;
-
-/// The delta time the game should be updated with.
-static const double game_dt = 1.0 / 60.0;
+typedef struct Plugin       Plugin;
+typedef struct Gfx          Gfx;
+typedef struct Scene        Scene;
+typedef struct SceneCamera  SceneCamera;
 
 /// Game state.
 typedef struct {
@@ -22,16 +16,6 @@ typedef struct {
   PluginEngine* plugin_engine;
   Plugin*       plugin;
   Gfx*          gfx;
-  Scene*        scene;
-  SceneCamera*  camera;
+  Scene*        scene;  // TODO: Move scene graph to plugin?
+  SceneCamera*  camera; // TODO: Move too.
 } Game;
-
-bool game_new(Game*, int argc, const char** argv);
-
-void game_end(Game*);
-
-void game_update(Game*, double t, double dt);
-
-void game_render(const Game*);
-
-void game_set_viewport(Game*, int width, int height);
diff --git a/gltfview/src/main.c b/gltfview/src/main.c
deleted file mode 100644
index f4863b4..0000000
--- a/gltfview/src/main.c
+++ /dev/null
@@ -1,67 +0,0 @@
-#include "game.h"
-
-#include <gfx/gfx_app.h>
-#include <log/log.h>
-
-#include <stdlib.h>
-
-static bool init(const GfxAppDesc* desc, void** app_state) {
-  Game* game = calloc(1, sizeof(Game));
-  if (!game) {
-    LOGE("Failed to allocate game state");
-    return false;
-  }
-  if (!game_new(game, desc->argc, desc->argv)) {
-    LOGE("Failed to initialize game");
-    return false;
-  }
-  *app_state = game;
-  return true;
-}
-
-static void shutdown(void* app_state) {
-  assert(app_state);
-  Game* game = (Game*)(app_state);
-  game_end(game);
-}
-
-static void update(void* app_state, double t, double dt) {
-  assert(app_state);
-  Game* game = (Game*)(app_state);
-  game_update(game, t, dt);
-}
-
-static void render(void* app_state) {
-  assert(app_state);
-  Game* game = (Game*)(app_state);
-  game_render(game);
-}
-
-static void resize(void* app_state, int width, int height) {
-  assert(app_state);
-  Game* game = (Game*)(app_state);
-  game_set_viewport(game, width, height);
-}
-
-int main(int argc, const char** argv) {
-  const int initial_width  = 1350;
-  const int initial_height = 900;
-  const int max_fps        = 60;
-
-  gfx_app_run(
-      &(GfxAppDesc){
-          .argc              = argc,
-          .argv              = argv,
-          .width             = initial_width,
-          .height            = initial_height,
-          .max_fps           = max_fps,
-          .update_delta_time = max_fps > 0 ? 1.0 / (double)max_fps : 0.0},
-      &(GfxAppCallbacks){
-          .init     = init,
-          .update   = update,
-          .render   = render,
-          .resize   = resize,
-          .shutdown = shutdown});
-
-  return 0;
-}