From da63ac18860a95f6ec6aad7bac7a365ca39377fd Mon Sep 17 00:00:00 2001
From: bQUARKz <bquarkz@gmail.com>
Date: Tue, 13 Jan 2026 08:30:15 +0000
Subject: [PATCH] add FADE

---
 crates/core/src/machine.rs         | 11 ++++++++
 crates/core/src/peripherals/gfx.rs | 40 ++++++++++++++++++++++++++++--
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/crates/core/src/machine.rs b/crates/core/src/machine.rs
index 82decf6a..d14c0e97 100644
--- a/crates/core/src/machine.rs
+++ b/crates/core/src/machine.rs
@@ -136,6 +136,17 @@ impl Machine {
         self.gfx.layers[3].map.set_tile(11, 4, crate::model::Tile { id: 1, ..Default::default() });
         self.gfx.layers[3].map.set_tile(11, 5, crate::model::Tile { id: 1, ..Default::default() });
 
+        // Faz a cena pulsar entre claro e escuro a cada 2 segundos
+        // Usamos uma conta matemática simples para gerar um valor de 0 a 31
+        let pulse = (self.frame_index / 4) % 64;
+        let level = if pulse > 31 { 63 - pulse } else { pulse };
+
+        self.gfx.scene_fade_level = level as u8;
+        self.gfx.scene_fade_color = Color::BLACK;
+
+        // O HUD continuará 100% visível enquanto o resto escurece!
+        self.gfx.hud_fade_level = 31;
+
         for i in 0..512 {
             let s = &mut self.gfx.sprites[i];
             s.active = true;
diff --git a/crates/core/src/peripherals/gfx.rs b/crates/core/src/peripherals/gfx.rs
index e102f619..8fb6c61d 100644
--- a/crates/core/src/peripherals/gfx.rs
+++ b/crates/core/src/peripherals/gfx.rs
@@ -24,7 +24,12 @@ pub struct Gfx {
     pub layers: [ScrollableTileLayer; 4],
     pub hud: HudTileLayer,
     pub banks: [Option<TileBank>; 16],
-    pub sprites: [Sprite; 512], // Nossa "OAM"
+    pub sprites: [Sprite; 512],
+
+    pub scene_fade_level: u8, // 0..31
+    pub scene_fade_color: Color,
+    pub hud_fade_level: u8, // 0..31
+    pub hud_fade_color: Color,
 }
 
 impl Gfx {
@@ -56,6 +61,10 @@ impl Gfx {
             hud: HudTileLayer::new(64, 32),
             banks: [EMPTY_BANK; 16],
             sprites: [EMPTY_SPRITE; 512],
+            scene_fade_level: 31,
+            scene_fade_color: Color::BLACK,
+            hud_fade_level: 31,
+            hud_fade_color: Color::BLACK,
         }
     }
 
@@ -129,8 +138,14 @@ impl Gfx {
             self.render_sprites_by_priority((i + 1) as u8);
         }
 
-        // 3. HUD (Sempre por cima)
+        // 4. Aplica Scene Fade (Afeta tudo desenhado até agora)
+        Self::apply_fade_to_buffer(&mut self.back, self.scene_fade_level, self.scene_fade_color);
+
+        // 5. HUD (Sempre por cima)
         self.render_hud();
+
+        // 6. Aplica HUD Fade (Opcional, apenas para o HUD)
+        Self::apply_fade_to_buffer(&mut self.back, self.hud_fade_level, self.hud_fade_color);
     }
 
     pub fn render_layer(&mut self, layer_idx: usize) {
@@ -261,6 +276,27 @@ impl Gfx {
         }
     }
 
+    /// Aplica o efeito de fade em todo o back buffer.
+    /// level: 0 (cor total) até 31 (visível)
+    fn apply_fade_to_buffer(back: &mut [u16], level: u8, fade_color: Color) {
+        if level >= 31 { return; } // Totalmente visível, pula processamento
+
+        let weight = level as u16;
+        let inv_weight = 31 - weight;
+        let (fr, fg, fb) = Color::unpack_to_native(fade_color.0);
+
+        for px in back.iter_mut() {
+            let (sr, sg, sb) = Color::unpack_to_native(*px);
+
+            // Fórmula: (src * weight + fade * inv_weight) / 31
+            let r = ((sr as u16 * weight + fr as u16 * inv_weight) / 31) as u8;
+            let g = ((sg as u16 * weight + fg as u16 * inv_weight) / 31) as u8;
+            let b = ((sb as u16 * weight + fb as u16 * inv_weight) / 31) as u8;
+
+            *px = Color::pack_from_native(r, g, b);
+        }
+    }
+
     /// Retorna o uso estimado de memória das estruturas gráficas em bytes.
     /// Isso ajuda a monitorar o "custo" do hardware simulado.
     pub fn memory_usage_bytes(&self) -> usize {