examples: enable maximization

examples/fireworks/fireworks.v

@@ -3,10 +3,12 @@ import objects
 import gg
 import gx
 import rand
+import sokol.sapp
 
 struct App {
 mut:
 	gg      &gg.Context       = 0
+	ui      &objects.UIParams = 0
 	rockets []objects.Rocket
 	frames  [][]objects.Rocket
 	// i thought about using a fixed fifo queue for the frames but the array
@@ -54,6 +56,25 @@ fn on_frame(mut app App) {
 	app.gg.end()
 }
 
+fn on_event(e &sapp.Event, mut app App) {
+	match e.typ {
+		.resized, .restored, .resumed { app.resize() }
+		else {}
+	}
+}
+
+fn (mut app App) resize() {
+	mut s := sapp.dpi_scale()
+	if s == 0.0 {
+		s = 1.0
+	}
+	w := int(sapp.width() / s)
+	h := int(sapp.height() / s)
+	app.ui.dpi_scale = s
+	app.ui.width = w
+	app.ui.height = h
+}
+
 fn main() {
 	mut font_path := os.resource_abs_path(os.join_path('../assets/fonts/', 'RobotoMono-Regular.ttf'))
 	$if android {
@@ -61,15 +82,17 @@ fn main() {
 	}
 
 	mut app := &App{}
+	app.ui = objects.get_params()
 
 	app.gg = gg.new_context(
-		width: objects.width
-		height: objects.height
+		width: app.ui.width
+		height: app.ui.height
 		window_title: 'Fireworks!'
 		bg_color: gx.black
 		use_ortho: true
 		user_data: app
 		frame_fn: on_frame
+		event_fn: on_event
 		font_path: font_path
 	)
 

examples/fireworks/modules/objects/constants.v

@@ -1,12 +1,20 @@
 module objects
 
-const (
-	width           = 800
-	height          = 800
-	gravity         = Vector{0, -0.03}
-	age_rate        = 1
-	offspring_count = 100
-	rocket_radius   = 5
-	particle_radius = 2.5
-	drag            = 0.98
-)
+pub struct UIParams {
+pub mut:
+	dpi_scale       f32    = 1.0
+	width           int    = 800
+	height          int    = 800
+	gravity         Vector = Vector{0, -0.03}
+	age_rate        int    = 1
+	offspring_count int    = 100
+	rocket_radius   int    = 5
+	particle_radius f32    = 2.5
+	drag            f32    = 0.98
+}
+
+const params = &UIParams{}
+
+pub fn get_params() &UIParams {
+	return objects.params
+}

examples/fireworks/modules/objects/particle.v

@@ -13,11 +13,12 @@ pub mut:
 }
 
 pub fn (particle Particle) draw(mut ctx gg.Context) {
-	ctx.draw_circle(particle.pos.x, height - particle.pos.y, particle_radius, particle.color)
+	ctx.draw_circle(particle.pos.x, get_params().height - particle.pos.y, get_params().particle_radius,
+		particle.color)
 }
 
 pub fn (mut particle Particle) tick(mut rocket Rocket, mut ctx gg.Context) {
-	particle.lifespan -= age_rate
+	particle.lifespan -= get_params().age_rate
 	particle.color.a = byte(particle.lifespan)
 
 	if particle.lifespan <= 0 {
@@ -25,9 +26,9 @@ pub fn (mut particle Particle) tick(mut rocket Rocket, mut ctx gg.Context) {
 		return
 	}
 
-	particle.accel += gravity
+	particle.accel += get_params().gravity
 	particle.vel += particle.accel
-	particle.vel = particle.vel.mult(drag)
+	particle.vel = particle.vel.mult(get_params().drag)
 	particle.pos += particle.vel
 	particle.draw(mut ctx)
 

examples/fireworks/modules/objects/rocket.v

@@ -16,13 +16,14 @@ pub mut:
 }
 
 pub fn (rocket Rocket) draw(mut ctx gg.Context) {
-	ctx.draw_circle(rocket.pos.x, height - rocket.pos.y, rocket_radius, rocket.color)
+	ctx.draw_circle(rocket.pos.x, get_params().height - rocket.pos.y, get_params().rocket_radius,
+		rocket.color)
 }
 
 pub fn (mut rocket Rocket) explode() {
 	rocket.exploded = true
 
-	for _ in 0 .. offspring_count {
+	for _ in 0 .. get_params().offspring_count {
 		rocket.spawn_particle()
 	}
 }
@@ -33,7 +34,7 @@ pub fn (mut rocket Rocket) tick(mut ctx gg.Context) {
 			rocket.explode()
 		}
 
-		rocket.accel += gravity
+		rocket.accel += get_params().gravity
 		rocket.vel += rocket.accel
 		rocket.pos += rocket.vel
 		rocket.draw(mut ctx)
@@ -50,7 +51,7 @@ pub fn new_rocket() Rocket {
 	return Rocket{
 		color: random_color()
 		pos: {
-			x: rand.f32_in_range(50, width - 50)
+			x: rand.f32_in_range(50, get_params().width - 50)
 		}
 		vel: {
 			x: rand.f32_in_range(-1.5, 1.5)