From 9cf6ae0cabea2c9681c802344ac9fe9b2ab8307d Mon Sep 17 00:00:00 2001
From: Brendan Hansen <brendan.f.hansen@gmail.com>
Date: Mon, 20 Dec 2021 18:06:41 -0600
Subject: [PATCH] added frame rate

---
 src/font.onyx |  6 ++++++
 src/main.onyx | 16 +++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/font.onyx b/src/font.onyx
index 6e91de4..fd8114b 100644
--- a/src/font.onyx
+++ b/src/font.onyx
@@ -108,6 +108,12 @@ alloca :: macro (size: u32) -> rawptr {
     return __stack_top;
 }
 
+font_print :: (font: Font, x, y: f32, format: str, va: ..any) {
+    buf: [1024] u8;
+    msg := conv.str_format_va(buf, format, va);
+    font_draw(font, x, y, msg);
+}
+
 font_draw :: (font: Font, x, y: f32, msg: str) {
     quads: ^stbtt_aligned_quad = alloca(msg.count * sizeof stbtt_aligned_quad);
     quad_num := 0;
diff --git a/src/main.onyx b/src/main.onyx
index e6be5af..1d99298 100644
--- a/src/main.onyx
+++ b/src/main.onyx
@@ -139,6 +139,8 @@ update :: (dt: f32) {
     update_world_matrix();
 }
 
+game_fps: i32;
+
 draw :: () {
     glClearColor(.7, .7, .9, 1);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
@@ -146,7 +148,7 @@ draw :: () {
     shader_use(world_shader);
     world_draw(world);
 
-    font_draw(font, 100, 100, "Hello!");
+    font_print(font, 0, 32, "FPS: {}", game_fps);
 
     glfwSwapBuffers(window);
 }
@@ -155,12 +157,24 @@ main_loop :: () {
     last := glfwGetTime();
     now  := last;
 
+    seconds := 0.0;
+    frame_count := 0;
+
     while !glfwWindowShouldClose(window) {
         glfwPollEvents();
 
         now = glfwGetTime();
         dt := now - last;
         last = now;
+
+        seconds += dt;
+        frame_count += 1;
+        if seconds >= 1 {
+            game_fps = ~~frame_count;
+            seconds -= 1;
+            frame_count = 0;
+        }
+
         update(~~dt);
         draw();
     }
-- 
2.25.1