Working on apu

include/emu.h

@@ -7,6 +7,7 @@ typedef struct {
     bool running;
     bool die;
     u64 ticks;
+    const char *app_path;
 } emu_context;
 
 int emu_run(int, char**);

include/ppu.h

@@ -80,6 +80,8 @@ typedef struct {
 
     bool rendering_window;
     u32 target_frame_time;
+    bool paused;
+    bool frame;
 } ppu_context;
 
 void ppu_init();

lib/audio.c

@@ -1,6 +1,7 @@
 #include <audio.h>
 
 #include <emu.h>
+#include <ppu.h>
 
 #include <portaudio.h>
 #include <pa_ringbuffer.h>
@@ -22,12 +23,14 @@ static float audio_time = 0;
 static float wave_time = 0;
 static float lfsr_timer = 0;
 static float lfsr_clock = LFSR_BASE_CLOCK;
+static float lfsr_clock_buffer = LFSR_BASE_CLOCK;
 
 static float left_cap = 0.0f;
 static float right_cap = 0.0f;
 
 static int history_timer = 0;
 const int history_interval = 5;
+static int lfsr_clocks = 0;
 
 const u8 square_sample_00[8] = {
     0x0,
@@ -87,6 +90,11 @@ 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++) {
+        if(ppu_get_context()->paused) {
+            *out++ = 0;
+            *out++ = 0;
+            continue;
+        }
         float left = 0;
         float right = 0;
         audio_time += TIME_PER_SAMPLE;
@@ -118,17 +126,29 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
         }
         lfsr_timer += TIME_PER_SAMPLE;
         for(;lfsr_timer >= lfsr_clock;lfsr_timer -= lfsr_clock) {
-            if(ctx.ch4_enable) {
+            //if(ctx.ch4_enable) {
-                lfsr_timer = 0;
+                lfsr_clocks++;
-                u8 new = !((ctx.ch4_lfsr & 0b1) ^ ((ctx.ch4_lfsr >> 1) & 0b1)) & 0b1;
+                lfsr_clock = lfsr_clock_buffer;
-                ctx.ch4_lfsr |= (new << 15);
+                //lfsr_timer = 0;
-                if(ctx.ch4_lfsr_width) {
+                //u16 new = ~((ctx.ch4_lfsr & 0b1) ^ ((ctx.ch4_lfsr & 0b10) >> 1)) & 0b1;
-                    ctx.ch4_lfsr &= ~(1 << 7);
+                //ctx.ch4_lfsr &= ~(1 << 15);
-                    ctx.ch4_lfsr |= (new << 7);
+                //ctx.ch4_lfsr |= ((new << 15) & 0x8000);
-                }
+                //printf("new bit: %02X\n", (new << 15));
-                ctx.ch4_lfsr = ctx.ch4_lfsr >> 1;
+                //if(ctx.ch4_lfsr_width) {
+                //    ctx.ch4_lfsr &= ~(1 << 7);
+                //    ctx.ch4_lfsr |= (new << 7);
+                //}
+                //ctx.ch4_lfsr = ctx.ch4_lfsr >> 1;
                 //printf("lfsr: %02X, bit: %d\n", ctx.ch4_lfsr, new);
+                unsigned bit_mask = ctx.ch4_lfsr_width ? 0x4040 : 0x4000;
+                bool new_bit = (ctx.ch4_lfsr ^ (ctx.ch4_lfsr >> 1) ^ 1) & 1;
+                ctx.ch4_lfsr >>= 1;
+                if(new_bit) {
+                    ctx.ch4_lfsr |= bit_mask;
+                } else {
+                    ctx.ch4_lfsr &= ~bit_mask;
                 }
+            //}
         }
         float sq1_val = 0;
         float sq2_val = 0;
@@ -206,7 +226,7 @@ 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) ? (((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);
@@ -248,7 +268,16 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
         right_out /= 4;
 
         if(left_out < -1.0f) {
-            printf("Uh Oh! %f\n", left_out);
+            left_out = -1;
+        }
+        if(left_out > 1.0f) {
+            left_out = 1;
+        }
+        if(right_out < -1.0f) {
+            right_out = -1;
+        }
+        if(right_out > 1.0f) {
+            right_out = 1;
         }
         history_timer++;
         if(history_timer >= history_interval){
@@ -382,6 +411,7 @@ void sq1_sweep() {
 
 static int change = 1;
 static u32 ticks = 0;
+static u32 start, end = 0;
 
 void audio_tick(){
     u32 prev_ticks = ticks;
@@ -415,7 +445,7 @@ void audio_tick(){
 
         if(ctx.ch4_len_enable && ctx.ch4_enable) {
             ctx.ch4_len++;
-            //printf("Ch4 env: %02X\n", ctx.ch4_len);
+            //printf("Ch4 len: %02X\n", ctx.ch4_len);
             if(ctx.ch4_len >= 64) {
                 ctx.ch4_len = 0;
                 ctx.ch4_enable = false;
@@ -454,19 +484,20 @@ void audio_tick(){
             }
         }
 
-        if(ctx.ch4_env_pace != 0){
+        //if(ctx.ch4_env_pace != 0){
-            ctx.ch4_env_timer++;
+        ctx.ch4_env_timer--;
-            if(ctx.ch4_env_timer >= ctx.ch4_env_pace) {
+        if(ctx.ch4_env_timer <= 0) {
-                ctx.ch4_env_timer = 0;
+            ctx.ch4_env_timer = ctx.ch4_env_pace_buffer != 0 ? ctx.ch4_env_pace_buffer : 8;
-                if((ctx.ch4_env_direction && ctx.ch4_volume != 15) || (!ctx.ch4_env_direction && ctx.ch4_volume != 0)){
+            if(ctx.ch4_env_pace != 0 && ((ctx.ch4_env_direction && ctx.ch4_volume != 15) || (!ctx.ch4_env_direction && ctx.ch4_volume != 0))){
                 ctx.ch4_volume += ctx.ch4_env_direction ? 1 : -1;
+                //printf("Noise Vol: %02X\n", ctx.ch4_volume);
                 if(ctx.ch4_volume < 0)
                     ctx.ch4_volume = 0;
                 if(ctx.ch4_volume > 15)
                     ctx.ch4_volume = 15;
             }
         }
-        }
+        //}
 
     }
 
@@ -528,12 +559,15 @@ void enable_noise() {
     if(!ctx.ch4_dac){
         return;
     }
+    start = get_ticks();
     ctx.ch4_enable = true;
-    ctx.ch4_env_timer = 0;
+    ctx.ch4_env_timer = ctx.ch4_env_pace_buffer != 0 ? ctx.ch4_env_pace_buffer : 8;
     ctx.ch4_env_direction = ctx.ch4_env_direction_buffer;
     ctx.ch4_env_pace = ctx.ch4_env_pace_buffer;
     ctx.ch4_volume = ctx.ch4_initial_volume;
     ctx.ch4_lfsr = 0;
+    lfsr_clock = lfsr_clock_buffer;
+    lfsr_timer = 0;
 }
 
 u8 audio_read(u16 address) {
@@ -928,6 +962,7 @@ void audio_write(u16 address, u8 value){
         ctx.ch4_len = ctx.ch4_initial_len;
         ctx.ch4_len_fz = false;
         //printf("ch4 len: %02X\n", ctx.ch4_len);
+        printf("Write Ch4 Len: %02X\n", value);
     }
 
     if(address == 0xFF21) {
@@ -940,15 +975,18 @@ void audio_write(u16 address, u8 value){
         } else {
             ctx.ch4_dac = true;
         }
+        printf("Write Ch4 env: %02X\n", value);
     }
 
     if(address == 0xFF22) {
-        ctx.ch4_clock_shift = (value >> 4);
+        ctx.ch4_clock_shift = (value >> 4) & 0xF;
         ctx.ch4_lfsr_width = (value & 0x08);
         ctx.ch4_clock_divider = value & 0b111;
-        float div = (ctx.ch4_clock_divider == 0 ? 0.5f : ctx.ch4_clock_divider);
+        float div = (ctx.ch4_clock_divider == 0 ? 0.5f : (float)ctx.ch4_clock_divider);
-        float lfsr_rate = (LFSR_BASE_CLOCK) / (div * (1 << ctx.ch4_clock_shift));
+        float lfsr_rate = (LFSR_BASE_CLOCK) / (div * (float)(1 << ctx.ch4_clock_shift));
-        lfsr_clock = 1.0f / (lfsr_rate/1000.0f/1000.0f);
+        lfsr_clock_buffer = 1.0f / (lfsr_rate/1000.0f/1000.0f);
+        //printf("Ch4 clock: Shift: %01X, Width: %d, Div: %f (%01X), Rate: %f, Clock %f\n", ctx.ch4_clock_shift, ctx.ch4_lfsr_width, div, ctx.ch4_clock_divider, lfsr_rate, lfsr_clock);
+        printf("Write Ch4 Clock: %02X\n", value);
     }
 
     if(address == 0xFF23) {
@@ -975,5 +1013,6 @@ void audio_write(u16 address, u8 value){
         if(value & 0x80) {
             enable_noise();
         }
+        printf("Write Ch4 Trigger: %02X\n", value);
     }
 }

lib/emu.c

@@ -71,6 +71,7 @@ int emu_run(int argc, char **argv) {
     }
 	
     printf("Cart loaded..\n");
+    ctx.app_path = argv[0];
 
     ui_init();
 #ifdef _WIN32

lib/ppu_sm.c

@@ -158,6 +158,14 @@ void ppu_mode_hblank() {
                 delay((ppu_get_context()->target_frame_time - frame_time));
             }
 
+            while(ppu_get_context()->paused) {
+                delay(10);
+                if(ppu_get_context()->frame){
+                    ppu_get_context()->frame = false;
+                    break;
+                }
+            }
+
             if (end - start_timer >= 1000) {
                 u32 fps = frame_count;
                 start_timer = end;

lib/timer.c

@@ -39,7 +39,7 @@ void timer_tick() {
         }
     }
 
-    if((prev_div & (1 << 13)) && (!(ctx.div & (1 << 13)))){
+    if((prev_div & (1 << 12)) && (!(ctx.div & (1 << 12)))){
         audio_tick();
     }
 

lib/ui.c

@@ -4,6 +4,7 @@
 #include <gamepad.h>
 #include <bus.h>
 #include <audio.h>
+#include <string.h>
 
 #include <SDL.h>
 #include <SDL_ttf.h>
@@ -131,7 +132,11 @@ void ui_update() {
     SDL_UpdateTexture(sdlTexture, NULL, screen->pixels, screen->pitch);
     SDL_RenderClear(sdlRenderer);
     SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, NULL);
-    TTF_Font* sans = TTF_OpenFont("Sans.ttf", 24);
+    char buffer[1024];
+    strcpy(buffer, emu_get_context()->app_path);
+    *strrchr(buffer, '\\') = 0;
+    strcat(buffer,"/Sans.ttf");
+    TTF_Font* sans = TTF_OpenFont(buffer, 24);
     if ( !sans ) {
        printf("Failed to load font: %s\n", TTF_GetError());
     }
@@ -289,6 +294,19 @@ void ui_on_key(bool down, u32 key_code) {
         }
         printf("target frame time: %d\n", ppu_get_context()->target_frame_time);
     }
+    if(ppu_get_context()->paused) {
+        if(key_code == SDLK_PERIOD && down == true){
+            ppu_get_context()->frame = true;
+        }
+    }
+    if(key_code == SDLK_p && down == true) {
+        ppu_get_context()->paused = !ppu_get_context()->paused;
+        if(ppu_get_context()->paused) {
+            printf("Paused Emulation\n");
+        } else {
+            printf("Resumed Emulation\n");
+        }
+    } 
     switch(key_code){
         case SDLK_z: gamepad_get_state()->b = down; break;
         case SDLK_x: gamepad_get_state()->a = down; break;