From 1c0f243d0439a3e21fee20e870c14a47d1ca1132 Mon Sep 17 00:00:00 2001
From: Raimon Zamora <jaildoctor@gmail.com>
Date: Wed, 29 Jan 2025 14:03:51 +0100
Subject: [PATCH] - Treballant en el envelope sweep i el length del CH1

---
 APU.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 8 deletions(-)

diff --git a/APU.cpp b/APU.cpp
index 3e11bec..37714ab 100644
--- a/APU.cpp
+++ b/APU.cpp
@@ -33,12 +33,12 @@ namespace APU
     {
         bool enabled = false;
         uint8_t length_timer = 0;
-        bool length_timer_expired = true;
         bool length_enable = false;
         uint16_t period_divider = 0;
         uint8_t duty_cycle=0;
         uint8_t duty_step = 0;
         uint8_t volume = 0;
+        uint8_t envelope_sweep_timer=0;
     };
 
     channel_t channels[4];
@@ -113,13 +113,13 @@ namespace APU
         CH1.duty_cycle = 0;
     }
 
-    void trigger(uint8_t channel)
+    void triggerCH1()
     {
-        channels[channel].enabled = true;
-        channels[channel].length_timer_expired = false;
-        channels[channel].period_divider = NR13 | ((NR14 &0x7)<<8);
+        CH1.enabled = true;
+        CH1.length_timer=NR11&0x3f;
+        CH1.period_divider = NR13 | ((NR14 &0x7)<<8);
         // envelope timer is reset
-        channels[channel].volume = NR12>>4;
+        CH1.volume = NR12>>4;
         // sweep does several things (check documentation)
     }
 
@@ -147,10 +147,10 @@ namespace APU
         switch(address)
         {
             case 0xff10: NR10 = value; break;
-            case 0xff11: NR11 = value; CH1.duty_cycle = NR11>>6; break;
+            case 0xff11: NR11 = value; CH1.length_timer=NR11&0x3f; CH1.duty_cycle = NR11>>6; break;
             case 0xff12: NR12 = value; break;
             case 0xff13: NR13 = value; break;
-            case 0xff14: NR14 = value; if (value&0x80) trigger(0); break;
+            case 0xff14: NR14 = value; CH1.length_enable=(value&0x40); if (value&0x80) triggerCH1(); break;
 
             case 0xff24: NR50 = value; break;
             case 0xff25: NR51 = value; break;
@@ -158,9 +158,45 @@ namespace APU
         }
     }
 
+    uint8_t DIVAPU_envelope_sweep = 0;
+    uint8_t DIVAPU_length = 0;
+    uint8_t DIVAPU_CH1_freq_sweep = 0;
+
     void incDIVAPU()
     {
         DIVAPU++;
+        DIVAPU_length++;
+        if (DIVAPU_length==2) {
+            DIVAPU_length=0;
+            if (CH1.enabled && CH1.length_enable) {
+                CH1.length_timer++;
+                if (CH1.length_timer==0) {
+                    CH1.enabled = false;
+                }
+            }
+        }
+        DIVAPU_CH1_freq_sweep++;
+        if (DIVAPU_CH1_freq_sweep==4) {
+            DIVAPU_CH1_freq_sweep=0;
+            // Do the freq sweep thing
+        }
+        DIVAPU_envelope_sweep++;
+        if (DIVAPU_envelope_sweep==8) {
+            DIVAPU_envelope_sweep=0;
+            if ( NR12&0x7 ) {   // If sweep pace != 0, envelope sweep is enabled
+                CH1.envelope_sweep_timer++;
+                if ( CH1.envelope_sweep_timer == (NR12&0x07) ) {    // if timer == envelope sweep, increase or decrease volume
+                    CH1.envelope_sweep_timer=0;
+                    if (NR12&0x80) {    // bit set increases, reset decreases
+                        if (CH1.volume<0x0f) CH1.volume++;
+                    } else {
+                        if (CH1.volume>0) CH1.volume--;
+                    }
+                }
+            }
+
+            // Do the envelope sweep thing
+        }
     }
 
     uint32_t dots = 0;