playdate running AMY

Makefile

HEAP_SIZE      = 8388208
STACK_SIZE     = 61800

PRODUCT = HelloWorld.pdx

# Locate the SDK
SDK = ${PLAYDATE_SDK_PATH}
ifeq ($(SDK),)
	SDK = $(shell egrep '^\s*SDKRoot' ~/.Playdate/config | head -n 1 | cut -c9-)
endif

ifeq ($(SDK),)
$(error SDK path not found; set ENV value PLAYDATE_SDK_PATH)
endif

######
# IMPORTANT: You must add your source folders to VPATH for make to find them
# ex: VPATH += src1:src2
######

VPATH += src

# List C source files here
SRC = src/main.c 
SRC += $(addprefix /Users/bwhitman/outside/amy/src/, \
	amy.c \
	algorithms.c \
	custom.c \
	patches.c \
	delay.c \
	envelope.c \
	filters.c \
	oscillators.c \
	transfer.c \
	sequencer.c \
	partials.c \
	pcm.c \
	log2_exp2.c \
)

# List all user directories here
UINCDIR = /Users/bwhitman/outside/amy/src/

# List user asm files
UASRC = 

# List all user C define here, like -D_DEBUG=1
UDEFS = -Wno-strict-aliasing -Wextra -Wno-unused-parameter -Wpointer-arith \
-Wno-float-conversion -Wno-missing-declarations -Wno-strict-prototypes -Wno-double-promotion \
-Wno-old-style-declaration 

# Define ASM defines here
UADEFS = 

# List the user directory to look for the libraries here
ULIBDIR =

# List all user libraries here
ULIBS = --specs=nosys.specs

include $(SDK)/C_API/buildsupport/common.mk

playdate-amy.c

//
//  main.c
//  Extension
//
//  Created by Dave Hayden on 7/30/14.
//  Copyright (c) 2014 Panic, Inc. All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>

#include "pd_api.h"
#include "amy.h"
#include "examples.h"
static int update(void* userdata);
const char* fontpath = "/System/Fonts/Asheville-Sans-14-Bold.pft";
LCDFont* font = NULL;

// Context state for audio callback
typedef struct {
    PlaydateAPI *pd;
    SoundSource *source;
} AudioState;


void example_juno_note() {
    struct event e = amy_default_event();
    e.load_patch = 0;
    strcpy(e.voices, "0");
    amy_add_event(e);

    e = amy_default_event();
    strcpy(e.voices, "0");
    e.midi_note = 50;
    e.velocity = 1;
    e.time = 1000;
    amy_add_event(e);
}

// I've seen frame counts as big as 1440, I think *8 is enough room (2048)
#define OUTPUT_RING_FRAMES (AMY_BLOCK_SIZE*8)
#define OUTPUT_RING_LENGTH (OUTPUT_RING_FRAMES*AMY_NCHANS)
int16_t output_ring[OUTPUT_RING_LENGTH];

uint16_t ring_write_ptr = AMY_BLOCK_SIZE*AMY_NCHANS; // start after one AMY frame
uint16_t ring_read_ptr = 0 ;
uint16_t in_ptr = 0;
extern int16_t amy_in_block[AMY_BLOCK_SIZE*AMY_NCHANS];



// https://devforum.play.date/t/tips-and-tricks-for-processing-audio-in-c/8025/5
int amy_callback(void* context, int16_t* left, int16_t* right, int len) {
    // We lag a AMY block behind input here because our frame size is never a multiple of AMY block size
    for(uint16_t frame=0;frame<len;frame++) {
        in_ptr+=2;  // stereo

        if(in_ptr == (AMY_BLOCK_SIZE*2)) { // we have a block of input ready
            // render and copy into output ring buffer
            int16_t * buf = amy_simple_fill_buffer();
            // reset the input pointer for future input data
            in_ptr = 0;
            // copy this output to a ring buffer
            for(uint16_t amy_frame=0;amy_frame<AMY_BLOCK_SIZE;amy_frame++) {
                output_ring[ring_write_ptr++] = buf[AMY_NCHANS * amy_frame + 0];
                output_ring[ring_write_ptr++] = buf[AMY_NCHANS * amy_frame + 1];
                if(ring_write_ptr == OUTPUT_RING_LENGTH) ring_write_ptr = 0;
            }
        }
        // Per audio frame, copy (lagged by AMY_BLOCK_SIZE) output data from AMY into expected audio out buffer
        left[frame] = output_ring[ring_read_ptr++];
        right[frame] = output_ring[ring_read_ptr++];
        if(ring_read_ptr == OUTPUT_RING_LENGTH ) ring_read_ptr = 0;
    }

    return 1;
}


#ifdef _WINDLL
__declspec(dllexport)
#endif
int eventHandler(PlaydateAPI* pd, PDSystemEvent event, uint32_t arg)
{
	(void)arg; // arg is currently only used for event = kEventKeyPressed

	if ( event == kEventInit )
	{
        amy_start(1,1,1,1);
        
        example_juno_note();

        // Create a new audio source with a state context
        AudioState *state = pd->system->realloc(NULL, sizeof (AudioState));
        state->pd     = pd;
        state->source = pd->sound->addSource(&amy_callback, state, 1);


		const char* err;
		font = pd->graphics->loadFont(fontpath, &err);
		
		if ( font == NULL )
			pd->system->error("%s:%i Couldn't load font %s: %s", __FILE__, __LINE__, fontpath, err);

		// Note: If you set an update callback in the kEventInit handler, the system assumes the game is pure C and doesn't run any Lua code in the game
		pd->system->setUpdateCallback(update, pd);
	}
	
	return 0;
}


#define TEXT_WIDTH 86
#define TEXT_HEIGHT 16

int x = (400-TEXT_WIDTH)/2;
int y = (240-TEXT_HEIGHT)/2;
int dx = 1;
int dy = 2;

static int update(void* userdata)
{
	PlaydateAPI* pd = userdata;
	
	pd->graphics->clear(kColorWhite);
	pd->graphics->setFont(font);
	pd->graphics->drawText("Hello World!", strlen("Hello World!"), kASCIIEncoding, x, y);

	x += dx;
	y += dy;
	
	if ( x < 0 || x > LCD_COLUMNS - TEXT_WIDTH )
		dx = -dx;
	
	if ( y < 0 || y > LCD_ROWS - TEXT_HEIGHT )
		dy = -dy;
        
	pd->system->drawFPS(0,0);

	return 1;
}