From f44853a87f97697ec5f827ec1ffc0191651bebd5 Mon Sep 17 00:00:00 2001
From: Larpon <Larpon@users.noreply.github.com>
Date: Tue, 17 Nov 2020 15:25:41 +0100
Subject: [PATCH] examples: term.ui - add a pong clone (#6857)

---
 examples/term.ui/pong.v | 494 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 494 insertions(+)
 create mode 100644 examples/term.ui/pong.v

diff --git a/examples/term.ui/pong.v b/examples/term.ui/pong.v
new file mode 100644
index 0000000000..af2f14c8b1
--- /dev/null
+++ b/examples/term.ui/pong.v
@@ -0,0 +1,494 @@
+import term
+import term.ui
+import time
+
+enum Mode {
+	menu
+	game
+}
+
+const (
+	player_one = 1 // Human control this racket
+	player_two = 0 // Take over this AI controller
+	white      = ui.Color{255, 255, 255}
+	orange     = ui.Color{255, 140, 0}
+)
+
+struct App {
+mut:
+	tui    &ui.Context = 0
+	mode   Mode = Mode.menu
+	width  int
+	height int
+	game   &Game = 0
+	dt     f32
+	ticks  i64
+}
+
+fn (mut a App) init() {
+	a.game = &Game{
+		app: a
+	}
+	w, h := a.tui.window_width, a.tui.window_height
+	a.width = w
+	a.height = h
+	term.erase_del_clear()
+	term.set_cursor_position({
+		x: 0
+		y: 0
+	})
+}
+
+fn (mut a App) start_game() {
+	if a.mode != .game {
+		a.mode = .game
+	}
+	a.game.init()
+}
+
+fn (mut a App) frame() {
+	ticks := time.ticks()
+	a.dt = f32(ticks - a.ticks) / 1000.0
+	a.width, a.height = a.tui.window_width, a.tui.window_height
+	if a.mode == .game {
+		a.game.update()
+	}
+	a.tui.clear()
+	a.render()
+	a.tui.flush()
+	a.ticks = ticks
+}
+
+fn (mut a App) quit() {
+	if a.mode != .menu {
+		a.game.quit()
+		return
+	}
+	term.set_cursor_position({
+		x: 0
+		y: 0
+	})
+	exit(0)
+}
+
+fn (mut a App) event(e &ui.Event) {
+	match e.typ {
+		.mouse_move {
+			if a.mode != .game {
+				return
+			}
+			// TODO mouse movement for real Pong sharks
+			// a.game.move_player(player_one, 0, -1)
+		}
+		.key_down {
+			match e.code {
+				.escape, .q {
+					a.quit()
+				}
+				.w {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_one, 0, -1)
+				}
+				.a {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_one, 0, -1)
+				}
+				.s {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_one, 0, 1)
+				}
+				.d {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_one, 0, 1)
+				}
+				.left {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_two, 0, -1)
+				}
+				.right {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_two, 0, 1)
+				}
+				.up {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_two, 0, -1)
+				}
+				.down {
+					if a.mode != .game {
+						return
+					}
+					a.game.move_player(player_two, 0, 1)
+				}
+				.enter, .space {
+					if a.mode == .menu {
+						a.start_game()
+					}
+				}
+				else {}
+			}
+		}
+		else {}
+	}
+}
+
+fn (mut a App) free() {
+	unsafe {
+		a.game.free()
+		free(a.game)
+	}
+}
+
+fn (mut a App) render() {
+	match a.mode {
+		.menu { a.draw_menu() }
+		else { a.draw_game() }
+	}
+}
+
+fn (mut a App) draw_menu() {
+	cx := int(f32(a.width) * 0.5)
+	y025 := int(f32(a.height) * 0.25)
+	y075 := int(f32(a.height) * 0.75)
+	cy := int(f32(a.height) * 0.5)
+	//
+	a.tui.set_color(white)
+	a.tui.bold()
+	a.tui.draw_text(cx - 2, y025, 'VONG')
+	a.tui.reset()
+	a.tui.draw_text(cx - 13, y025 + 1, '(A game of Pong written in V)')
+	//
+	a.tui.set_color(white)
+	a.tui.bold()
+	a.tui.draw_text(cx - 3, cy + 1, 'START')
+	a.tui.reset()
+	//
+	a.tui.draw_text(cx - 9, y075 + 1, 'Press SPACE to start')
+	a.tui.reset()
+	a.tui.draw_text(cx - 5, y075 + 3, 'ESC to Quit')
+	a.tui.reset()
+}
+
+fn (mut a App) draw_game() {
+	a.game.draw()
+}
+
+struct Player {
+mut:
+	game        &Game
+	pos         Vec
+	racket_size int = 4
+	score       int
+	ai          bool
+}
+
+fn (mut p Player) move(x f32, y f32) {
+	p.pos.x += x
+	p.pos.y += y
+}
+
+fn (mut p Player) update() {
+	if !p.ai {
+		return
+	}
+	if isnil(p.game) {
+		return
+	}
+	// dt := p.game.app.dt
+	ball := &p.game.ball
+	// Evil AI that eventually will take over the world
+	p.pos.y = ball.pos.y - int(f32(p.racket_size) * 0.5)
+}
+
+struct Vec {
+mut:
+	x f32
+	y f32
+}
+
+fn (mut v Vec) set(x f32, y f32) {
+	v.x = x
+	v.y = y
+}
+
+struct Ball {
+mut:
+	pos Vec
+	vel Vec
+	acc Vec
+}
+
+fn (mut b Ball) update(dt f32) {
+	b.pos.x += b.vel.x * b.acc.x * dt
+	b.pos.y += b.vel.y * b.acc.y * dt
+}
+
+struct Game {
+mut:
+	app     &App = 0
+	players []Player
+	ball    Ball
+}
+
+fn (mut g Game) move_player(id int, x int, y int) {
+	mut p := &g.players[id]
+	if p.ai { // disable AI when moved
+		p.ai = false
+	}
+	p.move(x, y)
+}
+
+fn (mut g Game) init() {
+	if g.players.len == 0 {
+		g.players = []Player{len: 2, init: Player{ // <- BUG omitting the init will result in smaller racket sizes???
+			game: g
+		}}
+	}
+	g.reset()
+}
+
+fn (mut g Game) reset() {
+	mut i := 0
+	for mut p in g.players {
+		p.score = 0
+		if i != player_one {
+			p.ai = true
+		}
+		i++
+	}
+	g.new_round()
+}
+
+fn (mut g Game) new_round() {
+	mut i := 0
+	for mut p in g.players {
+		p.pos.x = if i == 0 { 3 } else { g.app.width - 2 }
+		p.pos.y = f32(g.app.height) * 0.5 - f32(p.racket_size) * 0.5
+		i++
+	}
+	g.ball.pos.set(f32(g.app.width) * 0.5, f32(g.app.height) * 0.5)
+	g.ball.vel.set(-8, -15)
+	g.ball.acc.set(2.0, 1.0)
+}
+
+fn (mut g Game) update() {
+	dt := g.app.dt
+	mut b := &g.ball
+	for mut p in g.players {
+		p.update()
+		// Keep rackets within the game area
+		if p.pos.y <= 0 {
+			p.pos.y = 1
+		}
+		if p.pos.y + p.racket_size >= g.app.height {
+			p.pos.y = g.app.height - p.racket_size - 1
+		}
+		// Check ball collision
+		// Player left side
+		if p.pos.x < f32(g.app.width) * 0.5 {
+			// Racket collision
+			if b.pos.x <= p.pos.x + 1 {
+				if b.pos.y >= p.pos.y && b.pos.y <= p.pos.y + p.racket_size {
+					b.vel.x *= -1
+				}
+			}
+			// Behind racket
+			if b.pos.x < p.pos.x {
+				g.players[1].score++
+				g.new_round()
+			}
+		} else {
+			// Player right side
+			if b.pos.x >= p.pos.x - 1 {
+				if b.pos.y >= p.pos.y && b.pos.y <= p.pos.y + p.racket_size {
+					b.vel.x *= -1
+				}
+			}
+			if b.pos.x > p.pos.x {
+				g.players[0].score++
+				g.new_round()
+			}
+		}
+	}
+	if b.pos.x <= 1 || b.pos.x >= g.app.width {
+		b.vel.x *= -1
+	}
+	if b.pos.y <= 2 || b.pos.y >= g.app.height {
+		b.vel.y *= -1
+	}
+	b.update(dt)
+}
+
+fn (mut g Game) quit() {
+	if g.app.mode != .game {
+		return
+	}
+	g.app.mode = .menu
+}
+
+fn (mut g Game) draw_big_digit(px f32, py f32, digit int) {
+	// TODO use draw_line or draw_point to fix tearing with non-monospaced terminal fonts
+	mut gfx := g.app.tui
+	x, y := int(px), int(py)
+	match digit {
+		0 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '█   █')
+			gfx.draw_text(x, y + 2, '█   █')
+			gfx.draw_text(x, y + 3, '█   █')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		1 {
+			gfx.draw_text(x + 3, y + 0, '█')
+			gfx.draw_text(x + 3, y + 1, '█')
+			gfx.draw_text(x + 3, y + 2, '█')
+			gfx.draw_text(x + 3, y + 3, '█')
+			gfx.draw_text(x + 3, y + 4, '█')
+		}
+		2 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '    █')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '█')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		3 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '   ██')
+			gfx.draw_text(x, y + 2, ' ████')
+			gfx.draw_text(x, y + 3, '   ██')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		4 {
+			gfx.draw_text(x, y + 0, '█   █')
+			gfx.draw_text(x, y + 1, '█   █')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '    █')
+			gfx.draw_text(x, y + 4, '    █')
+		}
+		5 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '█')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '    █')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		6 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '█')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '█   █')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		7 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '    █')
+			gfx.draw_text(x, y + 2, '    █')
+			gfx.draw_text(x, y + 3, '    █')
+			gfx.draw_text(x, y + 4, '    █')
+		}
+		8 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '█   █')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '█   █')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		9 {
+			gfx.draw_text(x, y + 0, '█████')
+			gfx.draw_text(x, y + 1, '█   █')
+			gfx.draw_text(x, y + 2, '█████')
+			gfx.draw_text(x, y + 3, '    █')
+			gfx.draw_text(x, y + 4, '█████')
+		}
+		else {}
+	}
+}
+
+fn (mut g Game) draw() {
+	mut gfx := g.app.tui
+	gfx.set_bg_color(white)
+	// Border
+	gfx.draw_empty_rect(1, 1, g.app.width, g.app.height)
+	// Center line
+	gfx.draw_dashed_line(int(f32(g.app.width) * 0.5), 0, int(f32(g.app.width) * 0.5),
+		int(g.app.height))
+	border := 1
+	mut y, mut x := 0, 0
+	for p in g.players {
+		x = int(p.pos.x)
+		y = int(p.pos.y)
+		gfx.reset_bg_color()
+		gfx.set_color(white)
+		if x < f32(g.app.width) * 0.5 {
+			g.draw_big_digit(f32(g.app.width) * 0.25, 3, p.score)
+		} else {
+			g.draw_big_digit(f32(g.app.width) * 0.75, 3, p.score)
+		}
+		gfx.reset_color()
+		gfx.set_bg_color(white)
+		// Racket
+		gfx.draw_line(x, y + border, x, y + p.racket_size)
+	}
+	// Ball
+	gfx.draw_point(int(g.ball.pos.x), int(g.ball.pos.y))
+	// gfx.draw_text(22,2,'$g.ball.pos')
+	gfx.reset_bg_color()
+}
+
+fn (mut g Game) free() {
+	g.players.clear()
+}
+
+// TODO Remove these wrapper functions when we can assign methods as callbacks
+fn init(x voidptr) {
+	mut app := &App(x)
+	app.init()
+}
+
+fn frame(x voidptr) {
+	mut app := &App(x)
+	app.frame()
+}
+
+fn cleanup(x voidptr) {
+	mut app := &App(x)
+	app.free()
+}
+
+fn fail(error string) {
+	eprintln(error)
+}
+
+fn event(e &ui.Event, x voidptr) {
+	mut app := &App(x)
+	app.event(e)
+}
+
+// main
+mut app := &App{}
+app.tui = ui.init({
+	user_data: app
+	init_fn: init
+	frame_fn: frame
+	cleanup_fn: cleanup
+	event_fn: event
+	fail_fn: fail
+	capture_events: true
+	hide_cursor: true
+	frame_rate: 60
+})
+app.tui.run()