From 1e3fcf5b38d67fb54102786be74af42be5c6792f Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Tue, 3 Jan 2023 08:49:54 -0800
Subject: Initial commit.
---
gfx-app/src/gfx_app.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 126 insertions(+)
create mode 100644 gfx-app/src/gfx_app.c
(limited to 'gfx-app/src')
diff --git a/gfx-app/src/gfx_app.c b/gfx-app/src/gfx_app.c
new file mode 100644
index 0000000..f3f0473
--- /dev/null
+++ b/gfx-app/src/gfx_app.c
@@ -0,0 +1,126 @@
+#include <gfx/gfx_app.h>
+
+#include <GLFW/glfw3.h>
+#include <log/log.h>
+#include <timer.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+/// Application state.
+typedef struct GfxApp {
+ void* app_state;
+ GfxAppCallbacks callbacks;
+ int max_fps;
+ double update_delta_time;
+ GLFWwindow* window;
+} GfxApp;
+
+/// Storing the application state in a global variable so that we can call the
+/// application's callbacks from GLFW callbacks.
+static GfxApp g_gfx_app;
+
+/// Called by GLFW when the window is resized.
+static void on_resize(GLFWwindow* window, int width, int height) {
+ (*g_gfx_app.callbacks.resize)(g_gfx_app.app_state, width, height);
+}
+
+/// Run the application's main loop.
+static void loop(GfxApp* app) {
+ assert(app);
+ assert(app->window);
+
+ const double min_frame_time =
+ app->max_fps > 0 ? 1.0 / (double)(app->max_fps) : 0.0;
+ const double update_dt = app->update_delta_time;
+ double time = 0.0;
+ double time_budget = 0.0;
+ Timer timer = timer_make();
+
+ // Warm up the rendering before entering the main loop. A renderer can compile
+ // shaders and do other initialization the first time it renders a scene.
+ (*app->callbacks.render)(app->app_state);
+ glfwSwapBuffers(app->window);
+
+ timer_start(&timer);
+ while (!glfwWindowShouldClose(app->window)) {
+ timer_tick(&timer);
+ time_budget += time_delta_to_sec(timer.delta_time);
+
+ while (time_budget >= update_dt) {
+ (*app->callbacks.update)(app->app_state, time, update_dt);
+ time += update_dt;
+ time_budget -= update_dt;
+ }
+
+ (*app->callbacks.render)(app->app_state);
+ glfwSwapBuffers(app->window);
+ glfwPollEvents();
+
+ const time_point frame_end = time_now();
+ const time_delta frame_time = time_diff(timer.last_tick, frame_end);
+ if (min_frame_time > 0.0 && frame_time < min_frame_time) {
+ time_sleep(min_frame_time - frame_time);
+ }
+ }
+}
+
+bool gfx_app_run(const GfxAppDesc* desc, const GfxAppCallbacks* callbacks) {
+ assert(desc);
+ assert(callbacks);
+
+ bool success = false;
+
+ g_gfx_app.callbacks = *callbacks;
+ g_gfx_app.max_fps = desc->max_fps;
+ g_gfx_app.update_delta_time = desc->update_delta_time;
+ g_gfx_app.window = 0;
+
+ if (!glfwInit()) {
+ LOGE("glfwInit() failed");
+ return false;
+ }
+
+ const int major = 4;
+ const int minor = 4;
+ glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_API);
+ glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, major);
+ glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, minor);
+ glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+ glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
+ // TODO: Test antialiasing later on.
+ // glfwWindowHint(GLFW_SAMPLES, 4);
+
+ g_gfx_app.window =
+ glfwCreateWindow(desc->width, desc->height, "space", NULL, NULL);
+ if (!g_gfx_app.window) {
+ LOGE("glfwCreateWindow() failed");
+ goto cleanup;
+ }
+ glfwMakeContextCurrent(g_gfx_app.window);
+
+ // Initialize the application's state before setting any callbacks.
+ if (!(*g_gfx_app.callbacks.init)(desc, &g_gfx_app.app_state)) {
+ LOGE("Failed to initialize application");
+ goto cleanup;
+ }
+
+ // Trigger an initial resize for convenience.
+ (*g_gfx_app.callbacks.resize)(g_gfx_app.app_state, desc->width, desc->height);
+
+ // Set GLFW callbacks now that the application has been initialized.
+ glfwSetWindowSizeCallback(g_gfx_app.window, on_resize);
+
+ loop(&g_gfx_app);
+
+ (*g_gfx_app.callbacks.shutdown)(g_gfx_app.app_state);
+
+ success = true;
+
+cleanup:
+ if (g_gfx_app.window) {
+ glfwDestroyWindow(g_gfx_app.window);
+ }
+ glfwTerminate();
+ return success;
+}
--
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