Add example audio raw stream

examples/audio/audio_raw_stream.py

@@ -0,0 +1,104 @@
+from cffi import FFI
+from pyray import *
+from math import sin, pi, floor
+
+MAX_SAMPLES = 512
+MAX_SAMPLES_PER_UPDATE = 4096
+
+
+frequency = 440.0
+audio_frequency = 440.0
+old_frequency = 1.0
+sine_idx = 0.0
+
+# Need to wrap audio callback fucntion in ffi callback
+AUDIO_CALLBACK = ffi.callback("void(void *, unsigned int)")
+
+
+def audio_input_callback(buffer_ptr, frames):
+    global audio_frequency, sine_idx
+    audio_frequency = frequency + (audio_frequency - frequency) * 0.95
+
+    incr = audio_frequency/44100.0
+
+    # cast the buffer_ptr to short (16 bit int)
+    d = ffi.cast("short *", buffer_ptr)
+
+    for i in range(frames):
+        d[i] =  int((32000.0*sin(2*pi*sine_idx)))
+        sine_idx += incr
+        if sine_idx > 1.0:
+            sine_idx -= 1.0
+
+screen_width = 800
+screen_height = 450
+
+init_window(screen_width, screen_height, "raylib [audio] example - raw stream")
+
+init_audio_device()
+
+set_audio_stream_buffer_size_default(MAX_SAMPLES_PER_UPDATE)
+
+stream = load_audio_stream(44100, 16, 1)
+
+# Wrapping auido_input_callback in ffi callback
+audio_cb = AUDIO_CALLBACK(audio_input_callback)
+
+set_audio_stream_callback(stream, audio_cb)
+
+data = [0 for _ in range(MAX_SAMPLES+1)]
+
+write_buf = [0 for _ in range(MAX_SAMPLES_PER_UPDATE)]
+
+play_audio_stream(stream)
+
+mouse_position = Vector2(-100.0, -100.0)
+
+wavelength = 1
+position = Vector2(0.,0.)
+
+set_target_fps(60)
+
+while not window_should_close():
+    mouse_position = get_mouse_position()
+
+    if is_mouse_button_down(MouseButton.MOUSE_BUTTON_LEFT):
+        fp = mouse_position.y
+        frequency = 40.0 + fp
+
+        pan = mouse_position.x/screen_width
+        set_audio_stream_pan(stream, pan)
+
+    if frequency != old_frequency:
+        wavelength = int(22050/frequency)
+        if wavelength > MAX_SAMPLES/2:
+            wavelength = int(MAX_SAMPLES/2)
+        if wavelength < 1:
+            wavelength = 1
+
+        for i in range(floor(wavelength*2)):
+            data[i] = int(sin(2*pi*(i/wavelength))*32000.0)
+
+        for j in range(floor(wavelength*2), MAX_SAMPLES):
+            data[j] = 0
+
+        old_frequency = frequency
+
+    begin_drawing()
+
+    clear_background(RAYWHITE)
+
+    draw_text(f"sine: frequency: {int(frequency)}", get_screen_width() - 220, 10, 20, RED)
+    draw_text("click mouse button to change frequency or pan", 10, 10, 20, DARKGRAY)
+
+    for i in range(screen_width):
+        position.x = i
+        position.y = 250 + 50 * data[int(i * MAX_SAMPLES/screen_width)]/32000.0
+
+        draw_pixel_v(position, RED)
+
+    end_drawing()
+
+close_audio_device()
+close_window()
+