From 015a32c444841ceb91e6ae6cd5bdb57720313d58 Mon Sep 17 00:00:00 2001
From: tudnai <tamas.rudnai@gmail.com>
Date: Wed, 13 May 2020 20:40:54 -0700
Subject: [PATCH] Exponential signal edges for speaker

---
 A2Mac/Base.lproj/Main.storyboard | 12 ++++++++++++
 src/cpu/6502.c                   |  6 +++---
 src/dev/audio/speaker.c          | 22 ++++++++++++++++++++++
 src/dev/audio/speaker.h          |  6 ++++--
 src/dev/mem/mmio.h               |  6 +++---
 5 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/A2Mac/Base.lproj/Main.storyboard b/A2Mac/Base.lproj/Main.storyboard
index 6a9b6df..224ddcb 100644
--- a/A2Mac/Base.lproj/Main.storyboard
+++ b/A2Mac/Base.lproj/Main.storyboard
@@ -675,6 +675,18 @@
                                                             <action selector="Disk1_Selected:" target="Voe-Tx-rLC" id="zhC-rp-mN0"/>
                                                         </connections>
                                                     </menuItem>
+                                                    <menuItem title="Wavy Navy" identifier="Wavy Navy" id="GB7-kl-zHb">
+                                                        <modifierMask key="keyEquivalentModifierMask"/>
+                                                        <connections>
+                                                            <action selector="Disk1_Selected:" target="Voe-Tx-rLC" id="lcd-GR-OVR"/>
+                                                        </connections>
+                                                    </menuItem>
+                                                    <menuItem title="Xonix" identifier="Xonix" id="242-uR-ubX">
+                                                        <modifierMask key="keyEquivalentModifierMask"/>
+                                                        <connections>
+                                                            <action selector="Disk1_Selected:" target="Voe-Tx-rLC" id="Ysg-X9-qeK"/>
+                                                        </connections>
+                                                    </menuItem>
                                                 </items>
                                             </menu>
                                         </menuItem>
diff --git a/src/cpu/6502.c b/src/cpu/6502.c
index defd951..096c75b 100644
--- a/src/cpu/6502.c
+++ b/src/cpu/6502.c
@@ -772,10 +772,9 @@ void m6502_Run() {
             clk_6502_per_frm = clk_6502_per_frm_set;
         }
     }
-    
+
+    // play the entire sound buffer for this frame
     spkr_play();
-    
-    
 
 }
 
@@ -851,6 +850,7 @@ void m6502_ColdReset( const char * bundlePath, const char * romFileName ) {
     mhz = (double)MHz_6502 / M;
     
     spkr_init();
+//    spkr_play();
     
     unsigned long long saved_frm_set = clk_6502_per_frm_set;
     clk_6502_per_frm     =
diff --git a/src/dev/audio/speaker.c b/src/dev/audio/speaker.c
index 333f6de..90fd98e 100644
--- a/src/dev/audio/speaker.c
+++ b/src/dev/audio/speaker.c
@@ -119,6 +119,8 @@ void spkr_play() {
         alSourcei(spkr_src, AL_BUFFER, spkr_buf);
         alSourcei(spkr_src, AL_LOOPING, 0);
         
+        alSourcei( spkr_src, AL_BYTE_OFFSET, 0 );
+        al_check_error();
         alSourcePlay(spkr_src);
         
         ALint secoffset = 0;
@@ -136,3 +138,23 @@ void spkr_play() {
         alSourceStop(spkr_src);
     }
 }
+
+
+void spkr_Update() {
+    if ( spkr_src && spkr_buf ) {
+        if ( spkr_src ) {
+            alSourcePause(spkr_src);
+            al_check_error();
+            alSourcei(spkr_src, AL_BUFFER, 0);
+            al_check_error();
+        }
+
+        // Download buffer to OpenAL
+        alBufferData(spkr_buf, AL_FORMAT_MONO8, spkr_samples, spkr_buf_size / spkr_fps, spkr_sample_rate);
+        al_check_error();
+        
+        alSourcei( spkr_src, AL_BYTE_OFFSET, 0 );
+        al_check_error();
+        alSourcePlay(spkr_src);
+    }
+}
diff --git a/src/dev/audio/speaker.h b/src/dev/audio/speaker.h
index 20c8c68..0839ec4 100644
--- a/src/dev/audio/speaker.h
+++ b/src/dev/audio/speaker.h
@@ -11,13 +11,15 @@
 
 #include <stdio.h>
 
-#define SPKR_LEVEL_MIN      0
-#define SPKR_LEVEL_MAX      255
+#define SPKR_LEVEL_MIN      25
+#define SPKR_LEVEL_MAX      200
 
 extern void spkr_init(void);
 extern void spkr_exit(void);
 extern void spkr_play(void);
+extern void spkr_Update(void);
 
+extern const unsigned spkr_sample_rate;
 extern const unsigned spkr_buf_size;
 extern char spkr_samples [];
 extern unsigned spkr_sample_idx;
diff --git a/src/dev/mem/mmio.h b/src/dev/mem/mmio.h
index 2befa44..de73825 100644
--- a/src/dev/mem/mmio.h
+++ b/src/dev/mem/mmio.h
@@ -406,18 +406,18 @@ INLINE void spkr_switch() {
     
     // push a click into the speaker buffer
     // (we will play the entire buffer at the end of the frame)
-    spkr_sample_idx = clkfrm / 22;
+    spkr_sample_idx = clkfrm / (default_MHz_6502 / spkr_sample_rate);
     
     if ( spkr_level > SPKR_LEVEL_MIN ) {
         // down edge
-        while( (spkr_level -= 16) > SPKR_LEVEL_MIN ) {
+        while( (spkr_level -= (spkr_level - SPKR_LEVEL_MIN) / 2 ) > SPKR_LEVEL_MIN + 1 ) {
             spkr_samples[ spkr_sample_idx++ ] = spkr_level;
         }
         spkr_level = SPKR_LEVEL_MIN;
     }
     else {
         // up edge
-        while( (spkr_level += 16) < SPKR_LEVEL_MAX ) {
+        while( (spkr_level += (SPKR_LEVEL_MAX - spkr_level) / 2 )  < SPKR_LEVEL_MAX - 1 ) {
             spkr_samples[ spkr_sample_idx++ ] = spkr_level;
         }
         spkr_level = SPKR_LEVEL_MAX;