SDL2_TTF; FPS Counter, downgrade EMSDK to 3.1.43

.cargo/config.toml

@@ -5,7 +5,7 @@ rustflags = [
     #"-C", "link-args=-O3 --closure 1",
     "-C", "link-args=-sASYNCIFY -sALLOW_MEMORY_GROWTH=1",
     # "-C", "link-args=-sALLOW_MEMORY_GROWTH=1",
-    "-C", "link-args=-sUSE_SDL=2 -sUSE_SDL_IMAGE=2 -sSDL2_IMAGE_FORMATS=['png']",
+    "-C", "link-args=-sUSE_SDL=2 -sUSE_SDL_IMAGE=2 -sUSE_SDL_TTF=2 -sSDL2_IMAGE_FORMATS=['png']",
     # USE_OGG, USE_VORBIS for OGG/VORBIS usage
     "-C", "link-args=--preload-file assets/",
 ]

.vscode/settings.json

@@ -1,5 +1,8 @@
 {
     "rust-analyzer.linkedProjects": [
         "./Cargo.toml"
+    ],
+    "cSpell.words": [
+        "rwops"
     ]
 }

Cargo.lock

@@ -101,6 +101,7 @@ version = "0.1.0"
 dependencies = [
  "colors-transform",
  "lazy_static",
+ "libc",
  "rand",
  "sdl2",
  "spin_sleep",
@@ -215,9 +216,9 @@ checksum = "e5ea92a5b6195c6ef2a0295ea818b312502c6fc94dde986c5553242e18fd4ce2"
 
 [[package]]
 name = "sdl2"
-version = "0.36.0"
+version = "0.35.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8356b2697d1ead5a34f40bcc3c5d3620205fe0c7be0a14656223bfeec0258891"
+checksum = "f7959277b623f1fb9e04aea73686c3ca52f01b2145f8ea16f4ff30d8b7623b1a"
 dependencies = [
  "bitflags",
  "lazy_static",
@@ -227,9 +228,9 @@ dependencies = [
 
 [[package]]
 name = "sdl2-sys"
-version = "0.36.0"
+version = "0.35.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26bcacfdd45d539fb5785049feb0038a63931aa896c7763a2a12e125ec58bd29"
+checksum = "e3586be2cf6c0a8099a79a12b4084357aa9b3e0b0d7980e3b67aaf7a9d55f9f0"
 dependencies = [
  "cfg-if",
  "libc",

Cargo.toml

@@ -9,8 +9,11 @@ edition = "2021"
 colors-transform = "0.2.11"
 lazy_static = "1.4.0"
 rand = "0.8.5"
-sdl2 = { version = "0.36", features = ["image", "ttf", "mixer"] }
+sdl2 = { version = "0.35", features = ["image", "ttf"] }
 spin_sleep = "1.1.1"
 tracing = { version = "0.1.37", features = ["max_level_debug", "release_max_level_debug"]}
 tracing-error = "0.2.0"
 tracing-subscriber = {version = "0.3.17", features = ["env-filter"]}
+
+[target.'cfg(target_os = "emscripten")'.dependencies]
+libc = "0.2.16"

scripts/build.sh

@@ -37,12 +37,11 @@ fi
 
 if [ "$skip_emsdk" = 'false' ]; then
     echo "Activating Emscripten"
-    ./../emsdk/emsdk activate latest
+    # SDL2-TTF requires 3.1.43, fails to build on latest
+    ./../emsdk/emsdk activate 3.1.43
     source ../emsdk/emsdk_env.sh
 fi
 
-# export EMCC_CFLAGS="-s USE_SDL=2"
-
 echo "Building WASM with Emscripten"
 build_type='debug'
 if [ "$release" = 'true' ]; then

src/main.rs

@@ -1,12 +1,16 @@
 use std::process;
 use std::time::Duration;
 
+use sdl2::rwops::RWops;
+use sdl2::ttf;
 use sdl2::event::Event;
 use sdl2::image::LoadTexture;
 use sdl2::keyboard::Keycode;
 use sdl2::pixels::Color;
 use sdl2::rect::{Point, Rect};
 
+
+static FONT_DATA: &[u8] = include_bytes!("../assets/TerminalVector.ttf");
 static BLACK: Color = Color::RGB(0, 0, 0);
 
 #[cfg(target_os = "emscripten")]
@@ -35,6 +39,18 @@ fn sleep(ms: u32) {
     emscripten::emscripten::sleep(ms);
 }
 
+#[cfg(not(target_os = "emscripten"))]
+fn ttf_context() -> ttf::Sdl2TtfContext {
+    ttf::init().unwrap()
+}
+
+// Honestly, I don't know why this is necessary. I'm just copying from https://github.com/aelred/tetris/blob/0ad88153db1ca7962b42277504c0f7f9f3c675a9/tetris-sdl/src/main.rs#L88-L92
+#[cfg(target_os = "emscripten")]
+fn ttf_context() -> &'static ttf::Sdl2TtfContext {
+    // Deliberately leak so we get a static lifetime
+    Box::leak(Box::new(ttf::init().unwrap()))
+}
+
 fn main() {
     let ctx = sdl2::init().unwrap();
     let video_ctx = ctx.video().unwrap();
@@ -57,11 +73,13 @@ fn main() {
     let texture_creator = canvas.texture_creator();
     let mut point = Point::new(0, 0);
 
+    let ttf_ctx = ttf_context();
+
     let mut prev = now();
 
-    // let ctx = Rc::new(RefCell::new(ctx));
+    let font_data = RWops::from_bytes(FONT_DATA).unwrap();
-    // let canvas = Rc::new(RefCell::new(canvas));
+    let font_size = 32;
-    // let texture_creator = Rc::new(texture_creator);
+    let font = ttf_ctx.load_font_from_rwops(font_data, font_size).unwrap();
 
     let fruit_atlas = texture_creator
         .load_texture("./assets/fruit.png")
@@ -135,6 +153,14 @@ fn main() {
         canvas.set_draw_color(BLACK);
         canvas.clear();
 
+        // draw fps counter
+        let surface = font
+            .render(&format!("{:.2}", avg_fps))
+            .blended(Color::RGBA(255, 255, 255, 255))
+            .unwrap();
+        let texture = texture_creator.create_texture_from_surface(&surface).unwrap();
+        let _ = canvas.copy(&texture, None, Rect::new(0, 0, 100, 100));
+
         canvas
             .copy_ex(
                 &fruit_atlas,