/*
 Copyright 2013 Michael Pavone
 This file is part of BlastEm.
 BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "render.h"
#include "blastem.h"
#include "genesis.h"
#include "io.h"
#include "util.h"
#include "ppm.h"

#ifndef DISABLE_OPENGL
#include <GL/glew.h>
#endif

#define MAX_EVENT_POLL_PER_FRAME 2

static SDL_Window *main_window;
static SDL_Renderer *main_renderer;
static SDL_Texture  **sdl_textures;
static uint8_t num_textures;
static SDL_Rect      main_clip;
static SDL_GLContext *main_context;

static int main_width, main_height, windowed_width, windowed_height, is_fullscreen;

static uint8_t render_gl = 1;
static uint8_t scanlines = 0;

static uint32_t last_frame = 0;

static int16_t * current_psg = NULL;
static int16_t * current_ym = NULL;

static uint32_t buffer_samples, sample_rate;
static uint32_t missing_count;

static SDL_mutex * audio_mutex;
static SDL_cond * audio_ready;
static SDL_cond * psg_cond;
static SDL_cond * ym_cond;
static uint8_t quitting = 0;
static uint8_t ym_enabled = 1;

static void audio_callback(void * userdata, uint8_t *byte_stream, int len)
{
	//puts("audio_callback");
	int16_t * stream = (int16_t *)byte_stream;
	int samples = len/(sizeof(int16_t)*2);
	int16_t * psg_buf, * ym_buf;
	uint8_t local_quit;
	SDL_LockMutex(audio_mutex);
		psg_buf = NULL;
		ym_buf = NULL;
		do {
			if (!psg_buf) {
				psg_buf = current_psg;
				current_psg = NULL;
				SDL_CondSignal(psg_cond);
			}
			if (ym_enabled && !ym_buf) {
				ym_buf = current_ym;
				current_ym = NULL;
				SDL_CondSignal(ym_cond);
			}
			if (!quitting && (!psg_buf || (ym_enabled && !ym_buf))) {
				SDL_CondWait(audio_ready, audio_mutex);
			}
		} while(!quitting && (!psg_buf || (ym_enabled && !ym_buf)));

		local_quit = quitting;
	SDL_UnlockMutex(audio_mutex);
	if (!local_quit) {
		if (ym_enabled) {
			for (int i = 0; i < samples; i++)
			{
				*(stream++) = psg_buf[i] + *(ym_buf++);
				*(stream++) = psg_buf[i] + *(ym_buf++);
			}
		} else {
			for (int i = 0; i < samples; i++)
			{
				*(stream++) = psg_buf[i];
				*(stream++) = psg_buf[i];
			}
		}
	}
}

void render_disable_ym()
{
	ym_enabled = 0;
}

void render_enable_ym()
{
	ym_enabled = 1;
}

static void render_close_audio()
{
	SDL_LockMutex(audio_mutex);
		quitting = 1;
		SDL_CondSignal(audio_ready);
	SDL_UnlockMutex(audio_mutex);
	SDL_CloseAudio();
}

static SDL_Joystick * joysticks[MAX_JOYSTICKS];
static int joystick_sdl_index[MAX_JOYSTICKS];

int render_width()
{
	return main_width;
}

int render_height()
{
	return main_height;
}

int render_fullscreen()
{
	return is_fullscreen;
}

uint32_t render_map_color(uint8_t r, uint8_t g, uint8_t b)
{
	return 255 << 24 | r << 16 | g << 8 | b;
}

#ifndef DISABLE_OPENGL
static GLuint textures[3], buffers[2], vshader, fshader, program, un_textures[2], un_width, un_height, at_pos;

static GLfloat vertex_data_default[] = {
	-1.0f, -1.0f,
	 1.0f, -1.0f,
	-1.0f,  1.0f,
	 1.0f,  1.0f
};

static GLfloat vertex_data[8];

static const GLushort element_data[] = {0, 1, 2, 3};

static GLuint load_shader(char * fname, GLenum shader_type)
{
	char const * parts[] = {get_home_dir(), "/.config/blastem/shaders/", fname};
	char * shader_path = alloc_concat_m(3, parts);
	FILE * f = fopen(shader_path, "rb");
	free(shader_path);
	if (!f) {
		parts[0] = get_exe_dir();
		parts[1] = "/shaders/";
		shader_path = alloc_concat_m(3, parts);
		f = fopen(shader_path, "rb");
		free(shader_path);
		if (!f) {
			warning("Failed to open shader file %s for reading\n", fname);
			return 0;
		}
	}
	long fsize = file_size(f);
	GLchar * text = malloc(fsize);
	if (fread(text, 1, fsize, f) != fsize) {
		warning("Error reading from shader file %s\n", fname);
		free(text);
		return 0;
	}
	GLuint ret = glCreateShader(shader_type);
	glShaderSource(ret, 1, (const GLchar **)&text, (const GLint *)&fsize);
	free(text);
	glCompileShader(ret);
	GLint compile_status, loglen;
	glGetShaderiv(ret, GL_COMPILE_STATUS, &compile_status);
	if (!compile_status) {
		glGetShaderiv(ret, GL_INFO_LOG_LENGTH, &loglen);
		text = malloc(loglen);
		glGetShaderInfoLog(ret, loglen, NULL, text);
		warning("Shader %s failed to compile:\n%s\n", fname, text);
		free(text);
		glDeleteShader(ret);
		return 0;
	}
	return ret;
}
#endif

static uint32_t texture_buf[512 * 513];
#ifndef DISABLE_OPENGL
static void gl_setup()
{
	glGenTextures(3, textures);
	for (int i = 0; i < 3; i++)
	{
		glBindTexture(GL_TEXTURE_2D, textures[i]);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		if (i < 2) {
			//TODO: Fixme for PAL + invalid display mode
			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 512, 512, 0, GL_BGRA, GL_UNSIGNED_BYTE, texture_buf);
		} else {
			uint32_t blank = 255 << 24;
			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 1, 1, 0, GL_BGRA, GL_UNSIGNED_BYTE, &blank);
		}
	}
	glGenBuffers(2, buffers);
	glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data, GL_STATIC_DRAW);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[1]);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(element_data), element_data, GL_STATIC_DRAW);
	tern_val def = {.ptrval = "default.v.glsl"};
	vshader = load_shader(tern_find_path_default(config, "video\0vertex_shader\0", def, TVAL_PTR).ptrval, GL_VERTEX_SHADER);
	def.ptrval = "default.f.glsl";
	fshader = load_shader(tern_find_path_default(config, "video\0fragment_shader\0", def, TVAL_PTR).ptrval, GL_FRAGMENT_SHADER);
	program = glCreateProgram();
	glAttachShader(program, vshader);
	glAttachShader(program, fshader);
	glLinkProgram(program);
	GLint link_status;
	glGetProgramiv(program, GL_LINK_STATUS, &link_status);
	if (!link_status) {
		fputs("Failed to link shader program\n", stderr);
		exit(1);
	}
	un_textures[0] = glGetUniformLocation(program, "textures[0]");
	un_textures[1] = glGetUniformLocation(program, "textures[1]");
	un_width = glGetUniformLocation(program, "width");
	un_height = glGetUniformLocation(program, "height");
	at_pos = glGetAttribLocation(program, "pos");
}
#endif

static void render_alloc_surfaces()
{
	static uint8_t texture_init;

	if (texture_init) {
		return;
	}
	sdl_textures= malloc(sizeof(SDL_Texture *) * 2);
	num_textures = 2;
	texture_init = 1;
#ifndef DISABLE_OPENGL
	if (render_gl) {
		sdl_textures[0] = sdl_textures[1] = NULL;
		gl_setup();
	} else {
#endif
		
		//TODO: Fixme for invalid display mode
		sdl_textures[0] = sdl_textures[1] = SDL_CreateTexture(main_renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, LINEBUF_SIZE, 588);
#ifndef DISABLE_OPENGL
	}
#endif
}

static char * caption = NULL;
static char * fps_caption = NULL;

static void render_quit()
{
	render_close_audio();
	for (int i = 0; i < num_textures; i++)
	{
		if (sdl_textures[i]) {
			SDL_DestroyTexture(sdl_textures[i]);
		}
	}
}

static void update_aspect()
{
	//reset default values
	memcpy(vertex_data, vertex_data_default, sizeof(vertex_data));
	main_clip.w = main_width;
	main_clip.h = main_height;
	main_clip.x = main_clip.y = 0;
	//calculate configured aspect ratio
	char *config_aspect = tern_find_path_default(config, "video\0aspect\0", (tern_val){.ptrval = "4:3"}, TVAL_PTR).ptrval;
	if (strcmp("stretch", config_aspect)) {
		float src_aspect = 4.0f/3.0f;
		char *end;
		float aspect_numerator = strtof(config_aspect, &end);
		if (aspect_numerator > 0.0f && *end == ':') {
			float aspect_denominator = strtof(end+1, &end);
			if (aspect_denominator > 0.0f && !*end) {
				src_aspect = aspect_numerator / aspect_denominator;
			}
		}
		float aspect = (float)main_width / main_height;
		if (fabs(aspect - src_aspect) < 0.01f) {
			//close enough for government work
			return;
		}
#ifndef DISABLE_OPENGL
		if (render_gl) {
			for (int i = 0; i < 4; i++)
			{
				if (aspect > src_aspect) {
					vertex_data[i*2] *= src_aspect/aspect;
				} else {
					vertex_data[i*2+1] *= aspect/src_aspect;
				}
			}
		} else {
#endif
			main_clip.w = aspect > src_aspect ? src_aspect * (float)main_height : main_width;
			main_clip.h = aspect > src_aspect ? main_height : main_width / src_aspect;
			main_clip.x = (main_width  - main_clip.w) / 2;
			main_clip.y = (main_height - main_clip.h) / 2;
#ifndef DISABLE_OPENGL
		}
#endif
	}
}

static uint32_t overscan_top[NUM_VID_STD] = {2, 21};
static uint32_t overscan_bot[NUM_VID_STD] = {1, 17};
static uint32_t overscan_left[NUM_VID_STD] = {13, 13};
static uint32_t overscan_right[NUM_VID_STD] = {14, 14};
static vid_std video_standard = VID_NTSC;
static char *vid_std_names[NUM_VID_STD] = {"ntsc", "pal"};
void render_init(int width, int height, char * title, uint8_t fullscreen)
{
	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER) < 0) {
		fatal_error("Unable to init SDL: %s\n", SDL_GetError());
	}
	atexit(SDL_Quit);
	printf("width: %d, height: %d\n", width, height);
	windowed_width = width;
	windowed_height = height;
	
	uint32_t flags = SDL_WINDOW_RESIZABLE;

	if (fullscreen) {
		flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;
		SDL_DisplayMode mode;
		//TODO: Multiple monitor support
		SDL_GetCurrentDisplayMode(0, &mode);
		//the SDL2 migration guide suggests setting width and height to 0 when using SDL_WINDOW_FULLSCREEN_DESKTOP
		//but that doesn't seem to work right when using OpenGL, at least on Linux anyway
		width = mode.w;
		height = mode.h;
	}
	main_width = width;
	main_height = height;
	is_fullscreen = fullscreen;

	render_gl = 0;
	tern_val def = {.ptrval = "off"};
	char *vsync = tern_find_path_default(config, "video\0vsync\0", def, TVAL_PTR).ptrval;
	
	tern_node *video = tern_find_node(config, "video");
	if (video)
	{
		for (int i = 0; i < NUM_VID_STD; i++)
		{
			tern_node *std_settings = tern_find_node(video, vid_std_names[i]);
			if (std_settings) {
				char *val = tern_find_path_default(std_settings, "overscan\0top\0", (tern_val){.ptrval = NULL}, TVAL_PTR).ptrval;
				if (val) {
					overscan_top[i] = atoi(val);
				}
				val = tern_find_path_default(std_settings, "overscan\0bottom\0", (tern_val){.ptrval = NULL}, TVAL_PTR).ptrval;
				if (val) {
					overscan_bot[i] = atoi(val);
				}
				val = tern_find_path_default(std_settings, "overscan\0left\0", (tern_val){.ptrval = NULL}, TVAL_PTR).ptrval;
				if (val) {
					overscan_left[i] = atoi(val);
				}
				val = tern_find_path_default(std_settings, "overscan\0right\0", (tern_val){.ptrval = NULL}, TVAL_PTR).ptrval;
				if (val) {
					overscan_right[i] = atoi(val);
				}
			}
		}
	}

#ifndef DISABLE_OPENGL
	char *gl_enabled_str = tern_find_path_default(config, "video\0gl\0", def, TVAL_PTR).ptrval;
	uint8_t gl_enabled = strcmp(gl_enabled_str, "off") != 0;
	if (gl_enabled)
	{
		flags |= SDL_WINDOW_OPENGL;
		SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
		SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5);
		SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
		SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
		SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	}
#endif
	main_window = SDL_CreateWindow(title, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width, height, flags);
	if (!main_window) {
		fatal_error("Unable to create SDL window: %s\n", SDL_GetError());
	}
#ifndef DISABLE_OPENGL
	if (gl_enabled)
	{
		main_context = SDL_GL_CreateContext(main_window);
		GLenum res = glewInit();
		if (res != GLEW_OK) {
			warning("Initialization of GLEW failed with code %d\n", res);
		}

		if (res == GLEW_OK && GLEW_VERSION_2_0) {
			render_gl = 1;
			if (!strcmp("tear", vsync)) {
				if (SDL_GL_SetSwapInterval(-1) < 0) {
					warning("late tear is not available (%s), using normal vsync\n", SDL_GetError());
					vsync = "on";
				} else {
					vsync = NULL;
				}
			}
			if (vsync) {
				if (SDL_GL_SetSwapInterval(!strcmp("on", vsync)) < 0) {
					warning("Failed to set vsync to %s: %s\n", vsync, SDL_GetError());
				}
			}
		} else {
			warning("OpenGL 2.0 is unavailable, falling back to SDL2 renderer\n");
		}
	}
	if (!render_gl) {
#endif
		flags = SDL_RENDERER_ACCELERATED;
		if (!strcmp("on", vsync) || !strcmp("tear", vsync)) {
			flags |= SDL_RENDERER_PRESENTVSYNC;
		}
		main_renderer = SDL_CreateRenderer(main_window, -1, flags);

		if (!main_renderer) {
			fatal_error("unable to create SDL renderer: %s\n", SDL_GetError());
		}
		main_clip.x = main_clip.y = 0;
		main_clip.w = width;
		main_clip.h = height;
#ifndef DISABLE_OPENGL
	}
#endif

	SDL_GetWindowSize(main_window, &main_width, &main_height);
	printf("Window created with size: %d x %d\n", main_width, main_height);
	update_aspect();
	render_alloc_surfaces();
	def.ptrval = "off";
	scanlines = !strcmp(tern_find_path_default(config, "video\0scanlines\0", def, TVAL_PTR).ptrval, "on");

	caption = title;

	audio_mutex = SDL_CreateMutex();
	psg_cond = SDL_CreateCond();
	ym_cond = SDL_CreateCond();
	audio_ready = SDL_CreateCond();

	SDL_AudioSpec desired, actual;
    char * rate_str = tern_find_path(config, "audio\0rate\0", TVAL_PTR).ptrval;
   	int rate = rate_str ? atoi(rate_str) : 0;
   	if (!rate) {
   		rate = 48000;
   	}
    desired.freq = rate;
	desired.format = AUDIO_S16SYS;
	desired.channels = 2;
    char * samples_str = tern_find_path(config, "audio\0buffer\0", TVAL_PTR).ptrval;
   	int samples = samples_str ? atoi(samples_str) : 0;
   	if (!samples) {
   		samples = 512;
   	}
    printf("config says: %d\n", samples);
    desired.samples = samples*2;
	desired.callback = audio_callback;
	desired.userdata = NULL;

	if (SDL_OpenAudio(&desired, &actual) < 0) {
		fatal_error("Unable to open SDL audio: %s\n", SDL_GetError());
	}
	buffer_samples = actual.samples;
	sample_rate = actual.freq;
	printf("Initialized audio at frequency %d with a %d sample buffer\n", actual.freq, actual.samples);
	SDL_PauseAudio(0);
	SDL_JoystickEventState(SDL_ENABLE);

	atexit(render_quit);
}

void render_set_video_standard(vid_std std)
{
	video_standard = std;
}

void render_update_caption(char *title)
{
	caption = title;
	free(fps_caption);
	fps_caption = NULL;
}

static char *screenshot_path;
void render_save_screenshot(char *path)
{
	if (screenshot_path) {
		free(screenshot_path);
	}
	screenshot_path = path;
}

uint32_t *locked_pixels;
uint32_t locked_pitch;
uint32_t *render_get_framebuffer(uint8_t which, int *pitch)
{
#ifndef DISABLE_OPENGL
	if (render_gl && which <= FRAMEBUFFER_EVEN) {
		*pitch = LINEBUF_SIZE * sizeof(uint32_t);
		return texture_buf;
	} else {
#endif
		if (which >= num_textures) {
			warning("Request for invalid framebuffer number %d\n", which);
			return NULL;
		}
		void *pixels;
		if (SDL_LockTexture(sdl_textures[which], NULL, &pixels, pitch) < 0) {
			warning("Failed to lock texture: %s\n", SDL_GetError());
			return NULL;
		}
		static uint8_t last;
		if (which <= FRAMEBUFFER_EVEN) {
			locked_pixels = pixels;
			if (which == FRAMEBUFFER_EVEN) {
				pixels += *pitch;
			}
			locked_pitch = *pitch;
			if (which != last) {
				*pitch *= 2;
			}
			last = which;
		}
		return pixels;
#ifndef DISABLE_OPENGL
	}
#endif
}

uint8_t events_processed;
#ifdef __ANDROID__
#define FPS_INTERVAL 10000
#else
#define FPS_INTERVAL 1000
#endif

void render_framebuffer_updated(uint8_t which, int width)
{
	static uint8_t last;
	uint32_t height = which <= FRAMEBUFFER_EVEN 
		? (video_standard == VID_NTSC ? 243 : 294) - (overscan_top[video_standard] + overscan_bot[video_standard])
		: 240;
	FILE *screenshot_file = NULL;
	uint32_t shot_height, shot_width;
	if (screenshot_path && which == FRAMEBUFFER_ODD) {
		screenshot_file = fopen(screenshot_path, "wb");
		if (screenshot_file) {
			info_message("Saving screenshot to %s\n", screenshot_path);
		} else {
			warning("Failed to open screenshot file %s for writing\n", screenshot_path);
		}
		free(screenshot_path);
		screenshot_path = NULL;
		shot_height = video_standard == VID_NTSC ? 243 : 294;
		shot_width = width;
	}
	width -= overscan_left[video_standard] + overscan_right[video_standard];
#ifndef DISABLE_OPENGL
	if (render_gl && which <= FRAMEBUFFER_EVEN) {
		glBindTexture(GL_TEXTURE_2D, textures[which]);
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, LINEBUF_SIZE, height, GL_BGRA, GL_UNSIGNED_BYTE, texture_buf + overscan_left[video_standard] + LINEBUF_SIZE * overscan_top[video_standard]);

		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, textures[0]);
		glUniform1i(un_textures[0], 0);

		glActiveTexture(GL_TEXTURE1);
		glBindTexture(GL_TEXTURE_2D, textures[last != which ? 1 : scanlines ? 2 : 0]);
		glUniform1i(un_textures[1], 1);

		glUniform1f(un_width, width);
		glUniform1f(un_height, height);

		glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
		glVertexAttribPointer(at_pos, 2, GL_FLOAT, GL_FALSE, sizeof(GLfloat[2]), (void *)0);
		glEnableVertexAttribArray(at_pos);

		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[1]);
		glDrawElements(GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_SHORT, (void *)0);

		glDisableVertexAttribArray(at_pos);

		SDL_GL_SwapWindow(main_window);
		
		if (screenshot_file) {
			//properly supporting interlaced modes here is non-trivial, so only save the odd field for now
			save_ppm(screenshot_file, texture_buf, shot_width, shot_height, LINEBUF_SIZE*sizeof(uint32_t));
		}
	} else {
#endif
		if (which <= FRAMEBUFFER_EVEN && last != which) {
			uint8_t *cur_dst = (uint8_t *)locked_pixels;
			uint8_t *cur_saved = (uint8_t *)texture_buf;
			uint32_t dst_off = which == FRAMEBUFFER_EVEN ? 0 : locked_pitch;
			uint32_t src_off = which == FRAMEBUFFER_EVEN ? locked_pitch : 0;
			for (int i = 0; i < height; ++i)
			{
				//copy saved line from other field
				memcpy(cur_dst + dst_off, cur_saved, locked_pitch);
				//save line from this field to buffer for next frame
				memcpy(cur_saved, cur_dst + src_off, locked_pitch);
				cur_dst += locked_pitch * 2;
				cur_saved += locked_pitch;
			}
			height = 480;
		}
		if (screenshot_file) {
			uint32_t shot_pitch = locked_pitch;
			if (which == FRAMEBUFFER_EVEN) {
				shot_height *= 2;
			} else {
				shot_pitch *= 2;
			}
			save_ppm(screenshot_file, locked_pixels, shot_width, shot_height, shot_pitch);
		}
		SDL_UnlockTexture(sdl_textures[which]);
		SDL_Rect src_clip = {
			.x = overscan_left[video_standard],
			.y = overscan_top[video_standard],
			.w = width,
			.h = height
		};
		SDL_RenderCopy(main_renderer, sdl_textures[which], &src_clip, &main_clip);
		SDL_RenderPresent(main_renderer);
#ifndef DISABLE_OPENGL
	}
#endif
	if (screenshot_file) {
		fclose(screenshot_file);
	}
	if (which <= FRAMEBUFFER_EVEN) {
		last = which;
		static uint32_t frame_counter, start;
		frame_counter++;
		last_frame= SDL_GetTicks();
		if ((last_frame - start) > FPS_INTERVAL) {
			if (start && (last_frame-start)) {
	#ifdef __ANDROID__
				info_message("%s - %.1f fps", caption, ((float)frame_counter) / (((float)(last_frame-start)) / 1000.0));
	#else
				if (!fps_caption) {
					fps_caption = malloc(strlen(caption) + strlen(" - 100000000.1 fps") + 1);
				}
				sprintf(fps_caption, "%s - %.1f fps", caption, ((float)frame_counter) / (((float)(last_frame-start)) / 1000.0));
				SDL_SetWindowTitle(main_window, fps_caption);
	#endif
			}
			start = last_frame;
			frame_counter = 0;
		}
	}
	if (!events_processed) {
		process_events();
	}
	events_processed = 0;
}

void render_wait_quit(vdp_context * context)
{
	SDL_Event event;
	while(SDL_WaitEvent(&event)) {
		switch (event.type) {
		case SDL_QUIT:
			return;
		}
	}
}

static int find_joystick_index(SDL_JoystickID instanceID)
{
	for (int i = 0; i < MAX_JOYSTICKS; i++) {
		if (joysticks[i] && SDL_JoystickInstanceID(joysticks[i]) == instanceID) {
			return i;
		}
	}
	return -1;
}

static int lowest_unused_joystick_index()
{
	for (int i = 0; i < MAX_JOYSTICKS; i++) {
		if (!joysticks[i]) {
			return i;
		}
	}
	return -1;
}

int32_t render_translate_input_name(int32_t controller, char *name, uint8_t is_axis)
{
	static tern_node *button_lookup, *axis_lookup;
	if (controller > MAX_JOYSTICKS || !joysticks[controller]) {
		return RENDER_NOT_PLUGGED_IN;
	}
	
	if (!SDL_IsGameController(joystick_sdl_index[controller])) {
		return RENDER_NOT_MAPPED;
	}
	SDL_GameController *control = SDL_GameControllerOpen(joystick_sdl_index[controller]);
	if (!control) {
		warning("Failed to open game controller %d: %s\n", controller, SDL_GetError());
		return RENDER_NOT_PLUGGED_IN;
	}
	
	SDL_GameControllerButtonBind cbind;
	if (is_axis) {
		if (!axis_lookup) {
			for (int i = SDL_CONTROLLER_AXIS_LEFTX; i < SDL_CONTROLLER_AXIS_MAX; i++)
			{
				axis_lookup = tern_insert_int(axis_lookup, SDL_GameControllerGetStringForAxis(i), i);
			}
			//alternative Playstation-style names
			axis_lookup = tern_insert_int(axis_lookup, "l2", SDL_CONTROLLER_AXIS_TRIGGERLEFT);
			axis_lookup = tern_insert_int(axis_lookup, "r2", SDL_CONTROLLER_AXIS_TRIGGERRIGHT);
		}
		intptr_t sdl_axis = tern_find_int(axis_lookup, name, SDL_CONTROLLER_AXIS_INVALID);
		if (sdl_axis == SDL_CONTROLLER_AXIS_INVALID) {
			SDL_GameControllerClose(control);
			return RENDER_INVALID_NAME;
		}
		cbind = SDL_GameControllerGetBindForAxis(control, sdl_axis);
	} else {
		if (!button_lookup) {
			for (int i = SDL_CONTROLLER_BUTTON_A; i < SDL_CONTROLLER_BUTTON_MAX; i++)
			{
				button_lookup = tern_insert_int(button_lookup, SDL_GameControllerGetStringForButton(i), i);
			}
			//alternative Playstation-style names
			button_lookup = tern_insert_int(button_lookup, "cross", SDL_CONTROLLER_BUTTON_A);
			button_lookup = tern_insert_int(button_lookup, "circle", SDL_CONTROLLER_BUTTON_B);
			button_lookup = tern_insert_int(button_lookup, "square", SDL_CONTROLLER_BUTTON_X);
			button_lookup = tern_insert_int(button_lookup, "triangle", SDL_CONTROLLER_BUTTON_Y);
			button_lookup = tern_insert_int(button_lookup, "share", SDL_CONTROLLER_BUTTON_BACK);
			button_lookup = tern_insert_int(button_lookup, "select", SDL_CONTROLLER_BUTTON_BACK);
			button_lookup = tern_insert_int(button_lookup, "options", SDL_CONTROLLER_BUTTON_START);
			button_lookup = tern_insert_int(button_lookup, "l1", SDL_CONTROLLER_BUTTON_LEFTSHOULDER);
			button_lookup = tern_insert_int(button_lookup, "r1", SDL_CONTROLLER_BUTTON_RIGHTSHOULDER);
			button_lookup = tern_insert_int(button_lookup, "l3", SDL_CONTROLLER_BUTTON_LEFTSTICK);
			button_lookup = tern_insert_int(button_lookup, "r3", SDL_CONTROLLER_BUTTON_RIGHTSTICK);
		}
		intptr_t sdl_button = tern_find_int(button_lookup, name, SDL_CONTROLLER_BUTTON_INVALID);
		if (sdl_button == SDL_CONTROLLER_BUTTON_INVALID) {
			SDL_GameControllerClose(control);
			return RENDER_INVALID_NAME;
		}
		cbind = SDL_GameControllerGetBindForButton(control, sdl_button);
	}
	SDL_GameControllerClose(control);
	switch (cbind.bindType)
	{
	case SDL_CONTROLLER_BINDTYPE_BUTTON:
		return cbind.value.button;
	case SDL_CONTROLLER_BINDTYPE_AXIS:
		return RENDER_AXIS_BIT | cbind.value.axis;
	case SDL_CONTROLLER_BINDTYPE_HAT:
		return RENDER_DPAD_BIT | (cbind.value.hat.hat << 4) | cbind.value.hat.hat_mask;
	}
	return RENDER_NOT_MAPPED;
}

int32_t render_dpad_part(int32_t input)
{
	return input >> 4 & 0xFFFFFF;
}

uint8_t render_direction_part(int32_t input)
{
	return input & 0xF;
}

int32_t render_axis_part(int32_t input)
{
	return input & 0xFFFFFFF;
}

static uint8_t scancode_map[SDL_NUM_SCANCODES] = {
	[SDL_SCANCODE_A] = 0x1C,
	[SDL_SCANCODE_B] = 0x32,
	[SDL_SCANCODE_C] = 0x21,
	[SDL_SCANCODE_D] = 0x23,
	[SDL_SCANCODE_E] = 0x24,
	[SDL_SCANCODE_F] = 0x2B,
	[SDL_SCANCODE_G] = 0x34,
	[SDL_SCANCODE_H] = 0x33,
	[SDL_SCANCODE_I] = 0x43,
	[SDL_SCANCODE_J] = 0x3B,
	[SDL_SCANCODE_K] = 0x42,
	[SDL_SCANCODE_L] = 0x4B,
	[SDL_SCANCODE_M] = 0x3A,
	[SDL_SCANCODE_N] = 0x31,
	[SDL_SCANCODE_O] = 0x44,
	[SDL_SCANCODE_P] = 0x4D,
	[SDL_SCANCODE_Q] = 0x15,
	[SDL_SCANCODE_R] = 0x2D,
	[SDL_SCANCODE_S] = 0x1B,
	[SDL_SCANCODE_T] = 0x2C,
	[SDL_SCANCODE_U] = 0x3C,
	[SDL_SCANCODE_V] = 0x2A,
	[SDL_SCANCODE_W] = 0x1D,
	[SDL_SCANCODE_X] = 0x22,
	[SDL_SCANCODE_Y] = 0x35,
	[SDL_SCANCODE_Z] = 0x1A,
	[SDL_SCANCODE_1] = 0x16,
	[SDL_SCANCODE_2] = 0x1E,
	[SDL_SCANCODE_3] = 0x26,
	[SDL_SCANCODE_4] = 0x25,
	[SDL_SCANCODE_5] = 0x2E,
	[SDL_SCANCODE_6] = 0x36,
	[SDL_SCANCODE_7] = 0x3D,
	[SDL_SCANCODE_8] = 0x3E,
	[SDL_SCANCODE_9] = 0x46,
	[SDL_SCANCODE_0] = 0x45,
	[SDL_SCANCODE_RETURN] = 0x5A,
	[SDL_SCANCODE_ESCAPE] = 0x76,
	[SDL_SCANCODE_SPACE] = 0x29,
	[SDL_SCANCODE_TAB] = 0x0D,
	[SDL_SCANCODE_BACKSPACE] = 0x66,
	[SDL_SCANCODE_MINUS] = 0x4E,
	[SDL_SCANCODE_EQUALS] = 0x55,
	[SDL_SCANCODE_LEFTBRACKET] = 0x54,
	[SDL_SCANCODE_RIGHTBRACKET] = 0x5B,
	[SDL_SCANCODE_BACKSLASH] = 0x5D,
	[SDL_SCANCODE_SEMICOLON] = 0x4C,
	[SDL_SCANCODE_APOSTROPHE] = 0x52,
	[SDL_SCANCODE_GRAVE] = 0x0E,
	[SDL_SCANCODE_COMMA] = 0x41,
	[SDL_SCANCODE_PERIOD] = 0x49,
	[SDL_SCANCODE_SLASH] = 0x4A,
	[SDL_SCANCODE_CAPSLOCK] = 0x58,
	[SDL_SCANCODE_F1] = 0x05,
	[SDL_SCANCODE_F2] = 0x06,
	[SDL_SCANCODE_F3] = 0x04,
	[SDL_SCANCODE_F4] = 0x0C,
	[SDL_SCANCODE_F5] = 0x03,
	[SDL_SCANCODE_F6] = 0x0B,
	[SDL_SCANCODE_F7] = 0x83,
	[SDL_SCANCODE_F8] = 0x0A,
	[SDL_SCANCODE_F9] = 0x01,
	[SDL_SCANCODE_F10] = 0x09,
	[SDL_SCANCODE_F11] = 0x78,
	[SDL_SCANCODE_F12] = 0x07,
	[SDL_SCANCODE_LCTRL] = 0x14,
	[SDL_SCANCODE_LSHIFT] = 0x12,
	[SDL_SCANCODE_LALT] = 0x11,
	[SDL_SCANCODE_RCTRL] = 0x18,
	[SDL_SCANCODE_RSHIFT] = 0x59,
	[SDL_SCANCODE_RALT] = 0x17,
	[SDL_SCANCODE_INSERT] = 0x81,
	[SDL_SCANCODE_PAUSE] = 0x82,
	[SDL_SCANCODE_PRINTSCREEN] = 0x84,
	[SDL_SCANCODE_SCROLLLOCK] = 0x7E,
	[SDL_SCANCODE_DELETE] = 0x85,
	[SDL_SCANCODE_LEFT] = 0x86,
	[SDL_SCANCODE_HOME] = 0x87,
	[SDL_SCANCODE_END] = 0x88,
	[SDL_SCANCODE_UP] = 0x89,
	[SDL_SCANCODE_DOWN] = 0x8A,
	[SDL_SCANCODE_PAGEUP] = 0x8B,
	[SDL_SCANCODE_PAGEDOWN] = 0x8C,
	[SDL_SCANCODE_RIGHT] = 0x8D,
	[SDL_SCANCODE_NUMLOCKCLEAR] = 0x77,
	[SDL_SCANCODE_KP_DIVIDE] = 0x80,
	[SDL_SCANCODE_KP_MULTIPLY] = 0x7C,
	[SDL_SCANCODE_KP_MINUS] = 0x7B,
	[SDL_SCANCODE_KP_PLUS] = 0x79,
	[SDL_SCANCODE_KP_ENTER] = 0x19,
	[SDL_SCANCODE_KP_1] = 0x69,
	[SDL_SCANCODE_KP_2] = 0x72,
	[SDL_SCANCODE_KP_3] = 0x7A,
	[SDL_SCANCODE_KP_4] = 0x6B,
	[SDL_SCANCODE_KP_5] = 0x73,
	[SDL_SCANCODE_KP_6] = 0x74,
	[SDL_SCANCODE_KP_7] = 0x6C,
	[SDL_SCANCODE_KP_8] = 0x75,
	[SDL_SCANCODE_KP_9] = 0x7D,
	[SDL_SCANCODE_KP_0] = 0x70,
	[SDL_SCANCODE_KP_PERIOD] = 0x71,
};

static int32_t handle_event(SDL_Event *event)
{
	switch (event->type) {
	case SDL_KEYDOWN:
		handle_keydown(event->key.keysym.sym, scancode_map[event->key.keysym.scancode]);
		break;
	case SDL_KEYUP:
		handle_keyup(event->key.keysym.sym, scancode_map[event->key.keysym.scancode]);
		break;
	case SDL_JOYBUTTONDOWN:
		handle_joydown(find_joystick_index(event->jbutton.which), event->jbutton.button);
		break;
	case SDL_JOYBUTTONUP:
		handle_joyup(find_joystick_index(event->jbutton.which), event->jbutton.button);
		break;
	case SDL_JOYHATMOTION:
		handle_joy_dpad(find_joystick_index(event->jbutton.which), event->jhat.hat, event->jhat.value);
		break;
	case SDL_JOYAXISMOTION:
		handle_joy_axis(find_joystick_index(event->jaxis.which), event->jaxis.axis, event->jaxis.value);
		break;
	case SDL_JOYDEVICEADDED:
		if (event->jdevice.which < MAX_JOYSTICKS) {
			int index = lowest_unused_joystick_index();
			if (index >= 0) {
				SDL_Joystick * joy = joysticks[index] = SDL_JoystickOpen(event->jdevice.which);
				joystick_sdl_index[index] = event->jdevice.which;
				if (joy) {
					printf("Joystick %d added: %s\n", index, SDL_JoystickName(joy));
					printf("\tNum Axes: %d\n\tNum Buttons: %d\n\tNum Hats: %d\n", SDL_JoystickNumAxes(joy), SDL_JoystickNumButtons(joy), SDL_JoystickNumHats(joy));
					handle_joy_added(index);
				}
			}
		}
		break;
	case SDL_JOYDEVICEREMOVED: {
		int index = find_joystick_index(event->jdevice.which);
		if (index >= 0) {
			SDL_JoystickClose(joysticks[index]);
			joysticks[index] = NULL;
			printf("Joystick %d removed\n", index);
		} else {
			printf("Failed to find removed joystick with instance ID: %d\n", index);
		}
		break;
	}
	case SDL_MOUSEMOTION:
		handle_mouse_moved(event->motion.which, event->motion.x, event->motion.y + overscan_top[video_standard], event->motion.xrel, event->motion.yrel);
		break;
	case SDL_MOUSEBUTTONDOWN:
		handle_mousedown(event->button.which, event->button.button);
		break;
	case SDL_MOUSEBUTTONUP:
		handle_mouseup(event->button.which, event->button.button);
		break;
	case SDL_WINDOWEVENT:
		switch (event->window.event)
		{
		case SDL_WINDOWEVENT_SIZE_CHANGED:
			main_width = event->window.data1;
			main_height = event->window.data2;
			update_aspect();
#ifndef DISABLE_OPENGL
			if (render_gl) {
				SDL_GL_DeleteContext(main_context);
				main_context = SDL_GL_CreateContext(main_window);
				gl_setup();
			}
#endif
			break;
		}
		break;
	case SDL_QUIT:
		puts("");
		exit(0);
	}
	return 0;
}

static void drain_events()
{
	SDL_Event event;
	while(SDL_PollEvent(&event))
	{
		handle_event(&event);
	}
}

void process_events()
{
	if (events_processed > MAX_EVENT_POLL_PER_FRAME) {
		return;
	}
	drain_events();
	events_processed++;
}

#define TOGGLE_MIN_DELAY 250
void render_toggle_fullscreen()
{
	static int in_toggle;
	//protect against event processing causing us to attempt to toggle while still toggling
	if (in_toggle) {
		return;
	}
	in_toggle = 1;
	
	//toggling too fast seems to cause a deadlock
	static uint32_t last_toggle;
	uint32_t cur = SDL_GetTicks();
	if (last_toggle && cur - last_toggle < TOGGLE_MIN_DELAY) {
		in_toggle = 0;
		return;
	}
	last_toggle = cur;
	
	drain_events();
	is_fullscreen = !is_fullscreen;
	if (is_fullscreen) {
		SDL_DisplayMode mode;
		//TODO: Multiple monitor support
		SDL_GetCurrentDisplayMode(0, &mode);
		//In theory, the SDL2 docs suggest this is unnecessary
		//but without it the OpenGL context remains the original size
		//This needs to happen before the fullscreen transition to have any effect
		//because SDL does not apply window size changes in fullscreen
		SDL_SetWindowSize(main_window, mode.w, mode.h);
	}
	SDL_SetWindowFullscreen(main_window, is_fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
	//Since we change the window size on transition to full screen
	//we need to set it back to normal so we can also go back to windowed mode
	//normally you would think that this should only be done when actually transitioning
	//but something is screwy in the guts of SDL (at least on Linux) and setting it each time
	//is the only thing that seems to work reliably
	//when we've just switched to fullscreen mode this should be harmless though
	SDL_SetWindowSize(main_window, windowed_width, windowed_height);
	drain_events();
	in_toggle = 0;
}

void render_wait_psg(psg_context * context)
{
	SDL_LockMutex(audio_mutex);
		while (current_psg != NULL) {
			SDL_CondWait(psg_cond, audio_mutex);
		}
		current_psg = context->audio_buffer;
		SDL_CondSignal(audio_ready);

		context->audio_buffer = context->back_buffer;
		context->back_buffer = current_psg;
	SDL_UnlockMutex(audio_mutex);
	context->buffer_pos = 0;
}

void render_wait_ym(ym2612_context * context)
{
	SDL_LockMutex(audio_mutex);
		while (current_ym != NULL) {
			SDL_CondWait(ym_cond, audio_mutex);
		}
		current_ym = context->audio_buffer;
		SDL_CondSignal(audio_ready);

		context->audio_buffer = context->back_buffer;
		context->back_buffer = current_ym;
	SDL_UnlockMutex(audio_mutex);
	context->buffer_pos = 0;
}

uint32_t render_audio_buffer()
{
	return buffer_samples;
}

uint32_t render_sample_rate()
{
	return sample_rate;
}

void render_errorbox(char *title, char *message)
{
	SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title, message, NULL);
}

void render_warnbox(char *title, char *message)
{
	SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_WARNING, title, message, NULL);
}

void render_infobox(char *title, char *message)
{
	SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_INFORMATION, title, message, NULL);
}