basic audio stream.

.gitmodules

@@ -8,3 +8,6 @@
 [submodule "deps/SDL_ttf"]
 	path = deps/SDL_ttf
 	url = https://github.com/libsdl-org/SDL_ttf.git
+[submodule "deps/portaudio"]
+	path = deps/portaudio
+	url = https://github.com/PortAudio/portaudio.git

CMakeLists.txt

@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 set(BUILD_SHARED_LIBS OFF)
 add_subdirectory(deps/SDL)
 add_subdirectory(deps/SDL_ttf)
+add_subdirectory(deps/portaudio)
 add_subdirectory(lib/)
 add_subdirectory(gbemu/)
 add_subdirectory(deps/check/)

deps/portaudio

@@ -0,0 +1 @@
+Subproject commit aa1cfb046f93b18db4d12986ddbff84cbaa952cb

include/audio.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <common.h>
+
+typedef struct {
+    float sq1_freq;
+    float sq1_duty;
+    float sq1_amp;
+    float sq2_freq;
+    float sq2_duty;
+    float sq2_amp;
+} audio_context;
+
+void audio_init();

lib/CMakeLists.txt

@@ -2,5 +2,5 @@ cmake_minimum_required(VERSION 3.10)
 project(Lib)
 file(GLOB SRCS *.c)
 add_library(Lib STATIC ${SRCS})
-target_include_directories(Lib PUBLIC ../include ../deps/SDL/include ../deps/SDL_ttf)
-target_link_libraries(Lib SDL2-static SDL2_ttf::SDL2_ttf-static)
+target_include_directories(Lib PUBLIC ../include ../deps/SDL/include ../deps/SDL_ttf ../deps/portaudio/include)
+target_link_libraries(Lib SDL2-static SDL2_ttf::SDL2_ttf-static portaudio)

lib/audio.c

@@ -0,0 +1,119 @@
+#include <audio.h>
+#include <math.h>
+
+#include <portaudio.h>
+
+#define SAMPLE_RATE 44100
+#define FRAMES_PER_BUFFER 64
+#define TABLE_SIZE 44100
+
+#define M_PI 3.14159265
+
+static float sine[TABLE_SIZE];
+static unsigned long ind = 0;
+static unsigned long ind2 = 0;
+
+static int sq1_on_time;
+static int sq1_off_time;
+static float sq1 = 1;
+static int sq1_timer = 0;
+
+static int sq2_on_time;
+static int sq2_off_time;
+static float sq2 = 1;
+static int sq2_timer = 0;
+
+static audio_context ctx;
+
+static int audio_callback(const void* input_uffer, void *output_buffer,
+                            unsigned long framesPerBuffer,
+                            const PaStreamCallbackTimeInfo *time_info,
+                            PaStreamCallbackFlags status_flags,
+                            void *userData ) {
+    //printf("Audio Callback!\n");
+    audio_context *ctx = (audio_context *) userData;
+    float *out = (float *)output_buffer;
+    PaTime time = time_info->currentTime;
+    sq1_on_time = 1/(ctx->sq1_freq/(float)SAMPLE_RATE) * ctx->sq1_duty;
+    sq1_off_time = 1/(ctx->sq1_freq/(float)SAMPLE_RATE) * (1 - ctx->sq1_duty);
+
+    sq2_on_time = 1/(ctx->sq2_freq/(float)SAMPLE_RATE) * ctx->sq2_duty;
+    sq2_off_time = 1/(ctx->sq2_freq/(float)SAMPLE_RATE) * (1 - ctx->sq2_duty);
+    for(int i = 0; i < framesPerBuffer; i++) {
+        float val = 0;
+        //handle audio channels
+        //val += 0.2 * sine[ind];
+        //ind += 500;
+        if((sq1_timer >= sq1_on_time && sq1 == 1)) {
+            sq1 = 0;
+            sq1_timer = 0;
+        } else if((sq1_timer >= sq1_off_time && sq1 == 0)){
+            sq1 = 1;
+            sq1_timer = 0;
+        }
+        sq1_timer++;
+        val += ctx->sq1_amp * sq1;
+
+        if((sq2_timer >= sq2_on_time && sq2 == 1)) {
+            sq2 = 0;
+            sq2_timer = 0;
+        } else if((sq2_timer >= sq2_off_time && sq2 == 0)){
+            sq2 = 1;
+            sq2_timer = 0;
+        }
+        sq2_timer++;
+        val += ctx->sq2_amp * sq2;
+        //val += 0.2 * sine[ind2];
+        //ind2 += 200;
+        if(ind >= TABLE_SIZE) ind -= TABLE_SIZE;
+        if(ind2 >= TABLE_SIZE) ind2 -= TABLE_SIZE;
+        *out++ = val;
+    }
+    return paContinue;
+}
+
+void audio_init(){
+    PaStreamParameters output_parameters;
+    PaStream *stream;
+    PaError err;
+
+    ctx.sq1_amp = 0;
+    ctx.sq1_duty = 0;
+    ctx.sq1_freq = 0;
+
+    ctx.sq2_amp = 0;
+    ctx.sq2_duty = 0;
+    ctx.sq2_freq = 0;
+
+    for(int i = 0; i < TABLE_SIZE; i++) {
+        sine[i] = (float) sin(((double)i/(double)TABLE_SIZE) * M_PI * 2.);
+    }
+    
+    err = Pa_Initialize();
+    if (err != paNoError) goto error;
+    output_parameters.device = Pa_GetDefaultOutputDevice();
+    if(output_parameters.device == paNoDevice) {
+        fprintf(stderr, "No default audio device!\n");
+        goto error;
+    }
+    output_parameters.channelCount = 1;
+    output_parameters.sampleFormat = paFloat32;
+    output_parameters.suggestedLatency = Pa_GetDeviceInfo(output_parameters.device)->defaultLowOutputLatency;
+    output_parameters.hostApiSpecificStreamInfo = NULL;
+
+    err = Pa_OpenStream(&stream,
+                        NULL,
+                        &output_parameters,
+                        SAMPLE_RATE,
+                        FRAMES_PER_BUFFER,
+                        NULL,
+                        audio_callback,
+                        &ctx);
+    if(err != paNoError) goto error;
+    err = Pa_StartStream(stream);
+    if(err != paNoError) goto error;
+    return;
+error:
+    Pa_Terminate();
+    fprintf(stderr, "portaudio stream error\n\tError Number: %d\n\tError Message: %s\n", err, Pa_GetErrorText(err));
+}

lib/emu.c

@@ -6,6 +6,7 @@
 #include <timer.h>
 #include <dma.h>
 #include <ppu.h>
+#include <audio.h>
 
 #ifdef _WIN32
 #include <windows.h>
@@ -25,6 +26,7 @@ DWORD WINAPI cpu_run(void *p) {
     ppu_init();
     timer_init();
     cpu_init();
+    audio_init();
 
     ctx.running = true;
     ctx.paused = false;

lib/ppu_pipeline.c

@@ -260,7 +260,6 @@ void pipeline_push_pixel() {
             ppu_get_context()->rendering_window = true;
             pipeline_fifo_reset();
             ppu_get_context()->pfc.cur_fetch_state = FS_TILE;
-            printf("Window X: %d\n", lcd_get_context()->win_x);
             ppu_get_context()->pfc.fetch_x = 0;
             ppu_get_context()->pfc.fifo_x = 0;
             return;