Add screen fade-in and card deal-in animations

Cards slide in one after another when a game starts and can't be picked
until they have landed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

main.odin

@@ -13,6 +13,8 @@ import screens "src/screens"
 import themes "src/themes"
 import ui "src/ui"
 
+TRANSITION_SPEED :: 4 // screen fade-ins per second
+
 // Where Escape takes you from each screen (nil = quit)
 parent_screen :: proc(screen: themes.Screen) -> Maybe(themes.Screen) {
     switch screen {
@@ -53,6 +55,7 @@ main :: proc() {
     if saved, ok := reflect.enum_from_name(memory.Difficulty, profile.data.difficulty); ok {
         difficulty = saved
     }
+    transition_t: f32 = 1 // fades the screen in from the background color
     running := true
     for running && !raylib.WindowShouldClose() {
         dt := raylib.GetFrameTime()
@@ -60,6 +63,7 @@ main :: proc() {
         if raylib.IsKeyPressed(.ESCAPE) {
             if parent, ok := parent_screen(screen).?; ok {
                 screen = parent
+                transition_t = 1
             } else {
                 running = false
             }
@@ -90,6 +94,11 @@ main :: proc() {
         case .MEMORY:
             next = memory.draw()
         }
+        if transition_t > 0 {
+            alpha := transition_t * transition_t
+            raylib.DrawRectangle(0, 0, themes.SCREEN_WIDTH, themes.SCREEN_HEIGHT, raylib.Fade(themes.MENU_BACKGROUND, alpha))
+            transition_t = max(transition_t - dt * TRANSITION_SPEED, 0)
+        }
         ui.end_frame()
         raylib.EndDrawing()
         free_all(context.temp_allocator)
@@ -99,6 +108,7 @@ main :: proc() {
         if deck, ok := start_deck.?; ok {
             memory.start(deck, difficulty)
         }
+        if next != screen { transition_t = 1 }
         screen = next
     }
 }

src/card/card.odin

@@ -15,6 +15,8 @@ ROUNDNESS  :: 0.16
 SEGMENTS   :: 16
 
 FLIP_SPEED     :: 2.6  // flips per second
+DEAL_SPEED     :: 3.5  // how fast a dealt card settles
+DEAL_STAGGER   :: 0.12 // delay between consecutive cards, in deal_t units
 PULSE_DURATION :: 0.35 // seconds
 HOVER_LIFT     :: 4
 
@@ -28,6 +30,7 @@ Card :: struct {
     matched:  bool,
     flip_t:   f32,  // 0 = back showing, 1 = face showing
     pulse_t:  f32,  // counts down after a match
+    deal_t:   f32,  // > 0 while being dealt onto the table (0 = resting)
     face_art: raylib.RenderTexture2D,
 }
 
@@ -214,6 +217,14 @@ update :: proc(card: ^Card, dt: f32) {
     if card.pulse_t > 0 {
         card.pulse_t = max(card.pulse_t - dt, 0)
     }
+    if card.deal_t > 0 {
+        card.deal_t = max(card.deal_t - dt * DEAL_SPEED, 0)
+    }
+}
+
+// Starts the deal-in animation; later cards in the deal arrive later
+start_deal :: proc(card: ^Card, order: int) {
+    card.deal_t = 1 + f32(order) * DEAL_STAGGER
 }
 
 start_pulse :: proc(card: ^Card) {
@@ -241,7 +252,12 @@ draw :: proc(card: ^Card, theme: themes.Theme, clickable: bool, focused := false
     hovered := mouse_over || (clickable && focused)
     if hovered { lift += HOVER_LIFT }
 
-    scale: f32 = 1
+    // Dealing: slide up from below and grow in
+    dealt := smoothstep(1 - clamp(card.deal_t, 0, 1))
+    if dealt == 0 { return }
+    deal_offset := (1 - dealt) * 60
+
+    scale: f32 = 0.85 + 0.15 * dealt
     if card.pulse_t > 0 {
         progress := 1 - card.pulse_t / PULSE_DURATION
         scale += 0.09 * math.sin(progress * math.PI)
@@ -249,20 +265,20 @@ draw :: proc(card: ^Card, theme: themes.Theme, clickable: bool, focused := false
 
     width := card.rect.width * scale
     height := card.rect.height * scale
-    center := raylib.Vector2{card.rect.x + card.rect.width / 2, card.rect.y + card.rect.height / 2 - lift}
+    center := raylib.Vector2{card.rect.x + card.rect.width / 2, card.rect.y + card.rect.height / 2 - lift + deal_offset}
 
     // Shadow stays on the table and spreads as the card lifts
     shadow := raylib.Rectangle{
         center.x - width * squash / 2 + 2,
-        card.rect.y + card.rect.height * (1 - scale) / 2 + 4 + lift * 0.15,
+        card.rect.y + card.rect.height * (1 - scale) / 2 + 4 + lift * 0.15 + deal_offset,
         max(width * squash, 2),
         height,
     }
-    raylib.DrawRectangleRounded(shadow, ROUNDNESS, SEGMENTS, raylib.Fade(themes.BLACK, 0.12 - lift * 0.004))
+    raylib.DrawRectangleRounded(shadow, ROUNDNESS, SEGMENTS, raylib.Fade(themes.BLACK, (0.12 - lift * 0.004) * dealt))
 
     // Darken the card while it is edge-on, to fake lighting
     shade := u8(255 - (1 - squash) * 70)
-    tint := raylib.Color{shade, shade, shade, 255}
+    tint := raylib.Color{shade, shade, shade, u8(255 * dealt)}
     if hovered && !showing_face {
         tint = raylib.ColorBrightness(tint, 0.08)
     }

src/memory/memory.odin

@@ -106,6 +106,7 @@ deal :: proc(deck_id: decks.Deck_Id, game_difficulty: Difficulty) {
     start_x := (themes.SCREEN_WIDTH - total_w) / 2
     start_y := themes.GRID_TOP + (themes.SCREEN_HEIGHT - 16 - themes.GRID_TOP - total_h) / 2
     for &c, i in active_cards() {
+        card.start_deal(&c, i)
         c.rect = {
             start_x + f32(i % layout.cols) * step_x,
             start_y + f32(i / layout.cols) * step_y,
@@ -134,6 +135,11 @@ unload :: proc() {
     for &c in cards { card.unload_face(&c) }
 }
 
+// Whether the player can click or press on card i right now (it must have finished being dealt)
+can_interact :: proc(i: int) -> bool {
+    return can_pick(i) && cards[i].deal_t == 0
+}
+
 can_pick :: proc(i: int) -> bool {
     if i < 0 || i >= card_count { return false }
     c := &cards[i]
@@ -190,7 +196,7 @@ handle_keyboard :: proc() {
     }
     if raylib.IsKeyPressed(.ENTER) || raylib.IsKeyPressed(.SPACE) {
         keyboard_active = true
-        select_card(focus)
+        if can_interact(focus) { select_card(focus) }
     }
 }
 
@@ -236,7 +242,7 @@ update :: proc(dt: f32) {
         elapsed += dt
         if raylib.IsMouseButtonPressed(.LEFT) {
             for &c, i in active_cards() {
-                if card.is_hovered(&c) && select_card(i) {
+                if card.is_hovered(&c) && can_interact(i) && select_card(i) {
                     break
                 }
             }
@@ -271,7 +277,7 @@ draw :: proc() -> themes.Screen {
     }
 
     for &c, i in active_cards() {
-        card.draw(&c, theme, can_pick(i), focused = keyboard_active && i == focus && state != .OVER)
+        card.draw(&c, theme, can_interact(i), focused = keyboard_active && i == focus && state != .OVER && c.deal_t == 0)
     }
 
     if state == .OVER {