Add timer.h functions

3 files changed, 115 insertions, 44 deletions

diff --git a/cmd/demo/main.ha b/cmd/demo/main.ha
index f7ece50..43aea33 100644
--- a/cmd/demo/main.ha
+++ b/cmd/demo/main.ha
@@ -5,11 +5,21 @@ use sdl2;
 use sdl2::image;
 use strings;
 
+type texture = struct {
+	tex: *sdl2::texture,
+	w: int,
+	h: int,
+};
+
 type state = struct {
-	hare: *sdl2::texture,
-	cat: *sdl2::texture,
+	window: *sdl2::window,
+	render: *sdl2::renderer,
+	hare: texture,
+	cat: texture,
 	hare_x: int,
 	hare_y: int,
+	hare_dx: int,
+	hare_dy: int,
 	cat_x: int,
 	cat_y: int,
 };
@@ -41,67 +51,83 @@ export fn main() void = {
 	defer sdl2::destroy_renderer(render);
 
 	let state = state {
-		hare = {
-			const path = strings::to_c("mascot.jpg");
-			defer free(path);
-			yield match (image::load_texture(render, path)) {
-			case let tex: *sdl2::texture =>
-				yield tex;
-			case null =>
-				fmt::fatal("sdl2::image::load_texture failed for mascot.jpg");
-			};
-		},
-		cat = {
-			const path = strings::to_c("cat.png");
-			defer free(path);
-			yield match (image::load_texture(render, path)) {
-			case let tex: *sdl2::texture =>
-				yield tex;
-			case null =>
-				fmt::fatal("sdl2::image::load_texture failed for cat.png");
-			};
-		},
+		window = win,
+		render = render,
+		hare = load_texture(render, "mascot.jpg"),
+		cat = load_texture(render, "cat.png"),
 		hare_x = 100,
 		hare_y = 100,
+		hare_dx = 2,
+		hare_dy = 2,
 		...
 	};
-	defer sdl2::destroy_texture(state.hare);
-	defer sdl2::destroy_texture(state.cat);
-
-	draw_frame(&state, render);
+	defer sdl2::destroy_texture(state.hare.tex);
+	defer sdl2::destroy_texture(state.cat.tex);
 
 	let ev = sdl2::event { ... };
-	for (sdl2::wait_event(&ev) == 1) {
-		switch (ev.event_type) {
+	for (true) {
+		if (sdl2::poll_event(&ev) == 1) switch (ev.event_type) {
 		case event_type::QUIT =>
 			break;
 		case => void;
 		};
+
+		update(&state);
+		draw(&state);
+
+		sdl2::delay(1000 / 60);
 	};
 
 	os::exit(0); // https://todo.sr.ht/~sircmpwn/hare/525
 };
 
-fn draw_frame(state: *state, render: *sdl2::renderer) void = {
-	sdl2::set_render_draw_color(render, 50, 50, 50, 255);
-	sdl2::render_clear(render);
-	draw_tex(render, state.cat, state.cat_x, state.cat_y);
-	draw_tex(render, state.hare, state.hare_x, state.hare_y);
-	sdl2::render_present(render);
+fn load_texture(render: *sdl2::renderer, path: str) texture = {
+	const path = strings::to_c(path);
+	defer free(path);
+
+	const tex = match (image::load_texture(render, path)) {
+	case let tex: *sdl2::texture =>
+		yield tex;
+	case null =>
+		fmt::fatal("sdl2::image::load_texture failed for cat.png");
+	};
+
+	let w = 0, h = 0;
+	sdl2::query_texture(tex, null, null, &w, &h);
+	return texture {
+		tex = tex,
+		w = w,
+		h = h,
+	};
 };
 
-fn draw_tex(
-	render: *sdl2::renderer,
-	tex: *sdl2::texture,
-	x: int,
-	y: int,
-) void = {
+fn update(state: *state) void = {
 	let width = 0, height = 0;
-	sdl2::query_texture(tex, null, null, &width, &height);
-	sdl2::render_copy(render, tex, null, &sdl2::rect {
+	sdl2::get_window_size(state.window, &width, &height);
+
+	state.hare_x += state.hare_dx;
+	state.hare_y += state.hare_dy;
+	if (state.hare_x <= 0 || state.hare_x + state.hare.w >= width) {
+		state.hare_dx = -state.hare_dx;
+	};
+	if (state.hare_y <= 0 || state.hare_y + state.hare.h >= height) {
+		state.hare_dy = -state.hare_dy;
+	};
+};
+
+fn draw(state: *state) void = {
+	sdl2::set_render_draw_color(state.render, 50, 50, 50, 255);
+	sdl2::render_clear(state.render);
+	draw_tex(state, &state.hare, state.hare_x, state.hare_y);
+	draw_tex(state, &state.cat, state.cat_x, state.cat_y);
+	sdl2::render_present(state.render);
+};
+
+fn draw_tex(state: *state, tex: *texture, x: int, y: int) void = {
+	sdl2::render_copy(state.render, tex.tex, null, &sdl2::rect {
 		x = x,
 		y = y,
-		w = width,
-		h = height,
+		w = tex.w,
+		h = tex.h,
 	});
 };
diff --git a/sdl2/timer.ha b/sdl2/timer.ha
new file mode 100644
index 0000000..da958b6
--- /dev/null
+++ b/sdl2/timer.ha
@@ -0,0 +1,32 @@
+// Get the number of milliseconds since SDL library initialization.
+//
+// This value wraps if the program runs for more than ~49 days.
+//
+// Returns an unsigned 32-bit value representing the number of milliseconds
+// since the SDL library initialized.
+export @symbol("SDL_GetTicks") fn getticks() u32;
+
+// Get the current value of the high resolution counter.
+//
+// This function is typically used for profiling.
+//
+// The counter values are only meaningful relative to each other. Differences
+// between values can be converted to times by using
+// [[getperformancefrequency]].
+//
+// Returns the current counter value.
+export @symbol("SDL_GetPerformanceCounter") fn getperformancecounter() u64;
+
+// Get the count per second of the high resolution counter.
+//
+// Returns a platform-specific count per second.
+export @symbol("SDL_GetPerformanceFrequency") fn getperformancefrequency() u64;
+
+// Wait a specified number of milliseconds before returning.
+//
+// This function waits a specified number of milliseconds before returning. It
+// waits at least the specified time, but possibly longer due to OS
+// scheduling.
+export @symbol("SDL_Delay") fn delay(ms: u32) void;
+
+// TODO: Timers
diff --git a/sdl2/video.ha b/sdl2/video.ha
index e12ca12..e6dfa58 100644
--- a/sdl2/video.ha
+++ b/sdl2/video.ha
@@ -71,3 +71,16 @@ export @symbol("SDL_CreateWindow") fn create_window(title: const *char,
 
 // Destroy a window.
 export @symbol("SDL_DestroyWindow") fn destroy_window(window: *window) void;
+
+// Get the size of a window's client area.
+//
+// Null may safely be passed as the 'w' or 'h' parameter if the width or
+// height value is not desired.
+//
+// The window size in screen coordinates may differ from the size in pixels, if
+// the window was created with `ALLOW_HIGHDPI` on a platform with high-dpi
+// support (e.g. iOS or macOS). Use [[gl_getdrawablesize]],
+// [[vulkan_getdrawablesize]], or [[getrendereroutputsize]] to get the real
+// client area size in pixels.
+export @symbol("SDL_GetWindowSize") fn get_window_size(window: *window,
+	w: nullable *int, h: nullable *int) void;