working on audio buffer stuff

include/audio.h

@@ -117,6 +117,11 @@ typedef struct {
     float right_history[384];
     u32 right_index;
 
+    u8 sq1_sample_val;
+    u32 sq1_write_index;
+    u32 sq1_read_index;
+    u8 sq1_audio_buffer[4096];
+
 } audio_context;
 
 void audio_init();

lib/audio.c

@@ -5,11 +5,13 @@
 
 #include <portaudio.h>
 #include <pa_ringbuffer.h>
+#include <math.h>
 
 #define SAMPLE_RATE 44100
 #define FRAMES_PER_BUFFER 64
 #define TIME_PER_SAMPLE 1.0f / (SAMPLE_RATE/1000.0f/1000.0f)
 #define TIME_PER_AUDIO_TICK 1.0f / (1048576.0f/1000.0f/1000.0f)
+#define AUDIO_TICKS_PER_SAMPLE 1048576.0f / SAMPLE_RATE
 #define TIME_PER_WAVE_TICK 1.0f / (2097152.0f/1000.0f/1000.0f)
 #define LFSR_BASE_CLOCK 262144.0f
 
@@ -31,6 +33,7 @@ static float right_cap = 0.0f;
 static int history_timer = 0;
 const int history_interval = 5;
 static int lfsr_clocks = 0;
+static double write_index = 0;
 
 const u8 square_sample_00[8] = {
     0x0,
@@ -90,6 +93,12 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
                             void *userData ) {
     float *out = (float *)output_buffer;
     for(int i = 0; i < framesPerBuffer; i++) {
+        write_index = write_index + AUDIO_TICKS_PER_SAMPLE;
+        ctx.sq1_read_index = (int)write_index;
+        if(ctx.sq1_read_index > ctx.sq1_write_index) {
+            ctx.sq1_read_index = ctx.sq1_write_index-1;
+            write_index = ctx.sq1_read_index;
+        }
         if(ppu_get_context()->paused) {
             *out++ = 0;
             *out++ = 0;
@@ -100,13 +109,13 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
         audio_time += TIME_PER_SAMPLE;
         wave_time += TIME_PER_SAMPLE;
         for(;audio_time >= TIME_PER_AUDIO_TICK;audio_time -= TIME_PER_AUDIO_TICK) {
-            ctx.sq1_period_timer++;
+            //ctx.sq1_period_timer++;
             ctx.sq2_period_timer++;
 
-            if(ctx.sq1_period_timer >= 0x800) {
+            //if(ctx.sq1_period_timer >= 0x800) {
-                ctx.sq1_period_timer = ctx.sq1_period_reset;
+            //    ctx.sq1_period_timer = ctx.sq1_period_reset;
-                ctx.sq1_sample = (ctx.sq1_sample + 1) % 8;
+            //    ctx.sq1_sample = (ctx.sq1_sample + 1) % 8;
-            }
+            //}
             if(ctx.sq2_period_timer >= 0x800) {
                 ctx.sq2_period_timer = ctx.sq2_period_reset;
                 ctx.sq2_sample = (ctx.sq2_sample + 1) % 8;
@@ -158,7 +167,8 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
             if(ctx.ch1_dac){
                 sq1_val = -1;
                 if(ctx.sq1_enable) {
-                    sq1_val = ((float)ctx.sq1_volume/15.0f) * (((float)(square_sample[ctx.sq1_duty][ctx.sq1_sample]) - 7.5f)/7.5f);
+                    //sq1_val = ((float)ctx.sq1_volume/15.0f) * (((float)(square_sample[ctx.sq1_duty][ctx.sq1_sample]) - 7.5f)/7.5f);
+                    sq1_val = ((float)ctx.sq1_volume/15.0f) * (((float)(ctx.sq1_audio_buffer[ctx.sq1_read_index % 4096]) - 7.5f)/7.5f);
                     if(ctx.ch1_left) {
                         left += sq1_val;
                     }else {
@@ -177,7 +187,7 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
             if(ctx.ch2_dac){
                 sq2_val = -1;
                 if(ctx.sq2_enable) {
-                    sq2_val = ((float)ctx.sq2_volume/15.0f) * (((float)(square_sample[ctx.sq2_duty][ctx.sq2_sample]) - 7.5f)/7.5f);
+                    //sq2_val = ((float)ctx.sq2_volume/15.0f) * (((float)(square_sample[ctx.sq2_duty][ctx.sq2_sample]) - 7.5f)/7.5f);
                     if(ctx.ch2_left) {
                         left += sq2_val;
                     }else {
@@ -206,7 +216,7 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
                     if(ctx.ch3_volume == 0b11) {
                         shift = 2;
                     }
-                    ch3_val = (((float)(ctx.ch3_last_sample >> shift) - 7.5f)/7.5f);
+                    //ch3_val = (((float)(ctx.ch3_last_sample >> shift) - 7.5f)/7.5f);
                     if(ctx.ch3_left) {
                         left += ch3_val;
                         //printf("left: %d\n", ctx.ch3_volume);
@@ -226,7 +236,7 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
             if(ctx.ch4_dac){
                 ch4_val = -1;
                 if(ctx.ch4_enable) {
-                    ch4_val = ((ctx.ch4_lfsr & 0b1) == 0b1) ? (((float)ctx.ch4_volume - 7.5f)/7.5f) : -1.0f;
+                    //ch4_val = ((ctx.ch4_lfsr & 0b1) == 0b1) ? (((float)ctx.ch4_volume - 7.5f)/7.5f) : -1.0f;
                     if(ctx.ch4_left) {
                         left += ch4_val;
                         //printf("left: %d\n", ctx.ch3_volume);
@@ -368,6 +378,7 @@ void audio_init(){
     ctx.sq2_env_direction = false;
     ctx.sq2_env_pace = 0x0;
     ctx.sq2_env_timer = 0x0;
+    ctx.sq1_write_index = 1;
     
     err = Pa_Initialize();
     if (err != paNoError) goto error;
@@ -412,6 +423,24 @@ void sq1_sweep() {
 static int change = 1;
 static u32 ticks = 0;
 static u32 start, end = 0;
+static u32 period_tick;
+
+void audio_period_tick() {
+    period_tick++;
+    if(period_tick % 2 == 0){
+        ctx.sq1_period_timer++;
+
+        if(ctx.sq1_period_timer >= 0x800) {
+            ctx.sq1_period_timer = ctx.sq1_period_reset;
+            ctx.sq1_sample = (ctx.sq1_sample + 1) % 8;
+        }
+        if(ctx.sq1_write_index > ctx.sq1_read_index){
+            ctx.sq1_audio_buffer[(ctx.sq1_write_index++)%4096] = square_sample[ctx.sq1_duty][ctx.sq1_sample];
+        } else {
+            printf("buffer overflow\n");
+        }
+    }
+}
 
 void audio_tick(){
     u32 prev_ticks = ticks;

lib/timer.c

@@ -44,7 +44,7 @@ void timer_tick() {
     }
 
     if((prev_div & (1 << 1)) && (!(ctx.div & (1 << 1)))){
-        //audio_period_tick();
+        audio_period_tick();
     }
 }