//draw
function draw_surface_safe(surface, _x = 0, _y = 0) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.draw(_x, _y);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface(surface, _x, _y);
	__channel_pos(surface);
} #endregion

function draw_surface_stretched_safe(surface, _x, _y, _w, _h) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.drawStretch(_x, _y, _w, _h);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface_stretched(surface, _x, _y, _w, _h);
	__channel_pos(surface);
} #endregion

function draw_surface_ext_safe(surface, _x, _y, _xs = 1, _ys = 1, _rot = 0, _col = c_white, _alpha = 1) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.draw(_x, _y, _xs, _ys, _rot, _col, _alpha);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface_ext(surface, _x, _y, _xs, _ys, _rot, _col, _alpha);
	__channel_pos(surface);
} #endregion

function draw_surface_tiled_safe(surface, _x, _y) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.drawTile(_x, _y);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface_tiled(surface, _x, _y);
	__channel_pos(surface);
} #endregion

function draw_surface_tiled_ext_safe(surface, _x, _y, _xs = 1, _ys = 1, _col = c_white, _alpha = 1) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.drawTile(_x, _y, _xs, _ys, _col, _alpha);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface_tiled_ext(surface, _x, _y, _xs, _ys, _col, _alpha);
	__channel_pos(surface);
} #endregion

function draw_surface_part_ext_safe(surface, _l, _t, _w, _h, _x, _y, _xs = 1, _ys = 1, _rot = 0, _col = c_white, _alpha = 1) { #region
	INLINE
	
	if(is_struct(surface)) {
		if(is_instanceof(surface, dynaSurf)) {
			surface.drawPart(_l, _t, _w, _h, _x, _y, _xs, _ys, _rot, _col, _alpha);
			return;
		} else if(is_instanceof(surface, SurfaceAtlas))
			surface = surface.getSurface();
	}
	if(!surface_exists(surface)) return;
	
	__channel_pre(surface);
		draw_surface_part_ext(surface, _l, _t, _w, _h, _x, _y, _xs, _ys, _col, _alpha);
	__channel_pos(surface);
} #endregion

#macro surface_free surface_free_safe
#macro __surface_free surface_free 

function surface_free_safe(surface) { #region
	INLINE
	
	if(!is_surface(surface)) return;
	__surface_free(surface);
} #endregion

function surface_save_safe(surface, path) { #region
	if(!is_surface(surface)) return;
	var f = surface_get_format(surface);
	
	if(f == surface_rgba8unorm) {
		surface_save(surface, path);
		return;
	}
	
	var w = surface_get_width_safe(surface);
	var h = surface_get_height_safe(surface);
	var s = surface_create(w, h, surface_rgba8unorm);
	
	switch(f) {
		case surface_rgba4unorm  :
		case surface_rgba8unorm	 :
		case surface_rgba16float :
		case surface_rgba32float :
			surface_set_shader(s, sh_draw_normal);
				draw_surface(surface, 0, 0);
			surface_reset_shader();
			surface_save(s, path);
			return;
		case surface_r8unorm	 : s = surface_create(w, h, surface_rgba8unorm);	break;
		case surface_r16float	 : s = surface_create(w, h, surface_rgba16float);	break;
		case surface_r32float	 : s = surface_create(w, h, surface_rgba32float);	break;
		default: return;
	}
	
	surface_set_shader(s, sh_draw_single_channel);
		draw_surface(surface, 0, 0);
	surface_reset_shader();
	
	surface_save(s, path);
	surface_free(s);
	return;
} #endregion

function surface_cvt_8unorm(target, surface) { #region
	if(!is_surface(surface)) return target;
	
	target = surface_verify(target, surface_get_width_safe(surface), surface_get_height_safe(surface));
	var _typ = surface_get_format(surface);
	
	switch(_typ) {
		case surface_rgba4unorm  :
		case surface_rgba8unorm	 :
		case surface_rgba16float :
		case surface_rgba32float :
			surface_set_shader(target, sh_draw_normal);
			break;
		case surface_r8unorm	 :	
		case surface_r16float	 :	
		case surface_r32float	 :	
			surface_set_shader(target, sh_draw_single_channel);
			break;
	}
			
	draw_surface(surface, 0, 0);
	surface_reset_shader();
	
	return target;
} #endregion

function surface_get_width_safe(s, crop = true) { #region
	INLINE
	
	if(is_struct(s)) {
		if(is_instanceof(s, dynaSurf)) return s.getWidth();
		else if(is_instanceof(s, SurfaceAtlas)) return crop? surface_get_width(s.getSurface()) : s.oriSurf_w;
		else return 1;
	}
	
	return surface_get_width(s);
} #endregion

function surface_get_height_safe(s, crop = true) { #region
	INLINE
	
	if(is_struct(s)) {
		if(is_instanceof(s, dynaSurf)) return s.getHeight();
		else if(is_instanceof(s, SurfaceAtlas)) return crop? surface_get_height(s.getSurface()) : s.oriSurf_h;
		else return 1;
	}
	
	return surface_get_height(s);
} #endregion

function surface_get_dimension(s) { #region
	INLINE
	
	if(!is_surface(s)) return [ 1, 1 ];
	return [ surface_get_width_safe(s), surface_get_height_safe(s) ];
} #endregion

//check
function is_surface(s) { #region
	INLINE
	
	if(is_instanceof(s, dynaSurf) || is_instanceof(s, SurfaceAtlas)) return true;
	if(is_numeric(s) && s > 0 && surface_exists(s))   return true;
	return false;
} #endregion

function surface_verify(surf, w, h, format = surface_rgba8unorm) { #region
	INLINE
	
	if(!is_surface(surf)) return surface_create_valid(w, h, format);
	return surface_size_to(surf, w, h, format, true);
} #endregion

function surface_valid(surf, w, h, format = surface_rgba8unorm) { #region
	INLINE
	
	if(!is_surface(surf)) return false;
	var _sw = surface_get_width(surf);
	var _sh = surface_get_height(surf);
	var _f  = surface_get_format(surf);
	
	return _sw == w && _sh == h && _f == format;
} #endregion

//get
function surface_get_pixel(surface, _x, _y) { #region
	INLINE
	
	if(!is_surface(surface)) return;
	var f  = surface_get_format(surface);
	var fx = floor(_x);
	var fy = floor(_y);
	var rx = frac(_x);
	var ry = frac(_y);
	var px = surface_getpixel(surface, fx, fy);
	
	if(rx == 0 && ry == 0) {
		if(is_numeric(px)) return px;
		return make_color_rgb(px[0] * 256, px[1] * 256, px[2] * 256);
	}
	
	var p1 = surface_getpixel(surface, fx + 1, fy + 0);
	var p2 = surface_getpixel(surface, fx + 0, fy + 1);
	var p3 = surface_getpixel(surface, fx + 1, fy + 1);
	
	return merge_color(
			   merge_color(px, p1, rx),
			   merge_color(p2, p3, rx),
	       ry);
	
} #endregion

function surface_get_pixel_ext(surface, _x, _y) { #region
	INLINE
	
	if(!is_surface(surface)) return;
	var px = surface_getpixel_ext(surface, _x, _y);
	
	if(is_numeric(px)) return px;
	return round(px[0] * (255 * power(256, 0))) + round(px[1] * (255 * power(256, 1))) + round(px[2] * (255 * power(256, 2))) + round(px[3] * (255 * power(256, 3)));
} #endregion

//create
function surface_create_empty(w, h, format = surface_rgba8unorm) { #region
	INLINE
	
	var s = surface_create(w, h, format);
	surface_clear(s);
	return s;
} #endregion

function surface_create_size(surface, format = surface_rgba8unorm) { #region
	INLINE
	
	return surface_create_valid(surface_get_width_safe(surface), surface_get_height_safe(surface), format);
} #endregion

function surface_create_valid(w, h, format = surface_rgba8unorm) { #region
	INLINE
	
	return surface_create_empty(surface_valid_size(w), surface_valid_size(h), format);
} #endregion

function surface_create_from_buffer(w, h, buff, format = surface_rgba8unorm) { #region
	INLINE
	
	if(buff < 0) return;
	var s = surface_create_valid(surface_valid_size(w), surface_valid_size(h), format);
	buffer_set_surface(buff, s, 0);
	return s;
} #endregion

function surface_from_buffer(buff) { #region
	static header_length = 24;
	
	if(!buffer_exists(buff))					return noone;
	if(buffer_get_size(buff) < header_length)	return noone;
	
	buffer_seek(buff, buffer_seek_start, 0);
	var text = "";
	repeat(4) text += chr(buffer_read(buff, buffer_u8));
	if(text != "PXCS") return noone;
	
	var w = buffer_read(buff, buffer_u16);
	var h = buffer_read(buff, buffer_u16);
	var format = buffer_read(buff, buffer_u8);
	if(w < 1 || h < 1) return noone;
	
	var s = surface_create(w, h, format);
	buffer_set_surface(buff, s, header_length);
	return s;
} #endregion

function surface_create_from_sprite(spr) { #region
	if(!sprite_exists(spr)) return noone;
	
	if(sprite_get_number(spr) == 1)
		return surface_create_from_sprite_ext(spr, 0);
	
	var s = [];
	for( var i = 0; i < sprite_get_number(spr); i++ ) {
		array_push(s, surface_create_from_sprite_ext(spr, i));
	}
	
	return s;
} #endregion

function surface_create_from_sprite_ext(spr, ind, format = surface_rgba8unorm) { #region
	if(!sprite_exists(spr)) return noone;
	var sw = sprite_get_width(spr);
	var sh = sprite_get_height(spr);
	
	var s = surface_create_valid(sw, sh, format);
	surface_set_target(s);
		BLEND_OVERRIDE;
		DRAW_CLEAR
		draw_sprite(spr, ind, sprite_get_xoffset(spr), sprite_get_yoffset(spr));
		BLEND_NORMAL
	surface_reset_target();
	
	return s;
} #endregion

function surface_size_lim(surface, width, height) { #region
	var sw = surface_get_width_safe(surface);
	var sh = surface_get_height_safe(surface);
	if(sw <= width && sh <= height) return surface;
	
	var ss = min(width / sw, height / sh);
	var s  = surface_create(max(1, sw * ss), max(1, sh * ss));
	surface_set_target(s);
	DRAW_CLEAR
	draw_surface_ext_safe(surface, 0, 0, ss, ss, 0, c_white, 1);
	surface_reset_target();
	return s;
} #endregion

function surface_size_to(surface, width, height, format = noone, skipCheck = false) { #region
	if(!skipCheck && !is_surface(surface))			return surface;
	if(!is_numeric(width) || !is_numeric(height))	return surface;
	if(width < 1 && height < 1)						return surface;
	
	if(format != noone && format != surface_get_format(surface)) {
		surface_free(surface);
		return surface_create(width, height, format);
	}
	
	width  = surface_valid_size(width);
	height = surface_valid_size(height);
	
	var ww = surface_get_width_safe(surface);
	var hh = surface_get_height_safe(surface);
	
	if(ww == width && hh == height) return surface;
	
	surface_resize(surface, width, height);
	surface_clear(surface);
	
	return surface;
} #endregion

function surface_clear(surface) { #region
	INLINE
	
	if(!is_surface(surface)) return;
	surface_set_target(surface);
		DRAW_CLEAR
	surface_reset_target();
} #endregion

function surface_copy_from(dst, src, format = noone) { #region
	INLINE
	
	surface_set_target(dst);
	DRAW_CLEAR
	BLEND_OVERRIDE;
		draw_surface_safe(src, 0, 0);
	BLEND_NORMAL
	surface_reset_target();
} #endregion

function surface_clone(surface, destination = noone, format = noone) { #region
	INLINE
	
	if(is_struct(surface) && is_instanceof(surface, dynaSurf)) 
		return surface.clone();
	if(!is_surface(surface)) return noone;
	
	destination = surface_verify(destination, surface_get_width_safe(surface), surface_get_height_safe(surface), format == noone? surface_get_format(surface) : format);
	
	surface_set_target(destination);
	DRAW_CLEAR
	BLEND_OVERRIDE;
		draw_surface_safe(surface, 0, 0);
	BLEND_NORMAL
	surface_reset_target();
	
	return destination;
} #endregion

//in-place modification
function surface_stretch(surf, _w, _h) { #region
	INLINE
	
	if(!is_surface(surf)) return noone;
	
	_w = surface_valid_size(_w);
	_h = surface_valid_size(_h);
	
	var _surf = surface_create(_w, _h);
	surface_set_target(_surf);
		DRAW_CLEAR
		draw_surface_stretched(surf, 0, 0, _w, _h);
	surface_reset_target();
	
	surface_free(surf);
	return _surf;
} #endregion

function surface_mirror(surf, _h, _v) { #region
	INLINE
	
	if(!is_surface(surf)) return noone;
	var _surf = surface_create_size(surf);
	
	surface_set_target(_surf);
		DRAW_CLEAR
		
		var x0 = _h * surface_get_width_safe(_surf);
		var y0 = _v * surface_get_height_safe(_surf);
		
		draw_surface_ext_safe(surf, x0, y0, _h * 2 - 1, _v * 2 - 1, 0, c_white, 1);
	surface_reset_target();
	surface_free(surf);
	
	return _surf;
} #endregion

//others
function surface_copy_size(dest, source, format = noone) { #region
	INLINE
	
	if(!is_surface(dest))   return;
	if(!is_surface(source)) return;
	
	surface_size_to(dest, surface_get_width_safe(source), surface_get_height_safe(source), format);
	surface_set_target(dest);
	DRAW_CLEAR
	surface_reset_target();
	
	surface_copy_from(dest, source);
} #endregion

function surface_valid_size(s) { #region
	INLINE
	
	if(!is_numeric(s))    return 1;
	if(is_infinity(s)) return 1;
	return clamp(round(s), 1, 8196);
} #endregion

function surface_array_free(arr) { #region
	INLINE
	
	if(!is_array(arr)) {
		if(is_surface(arr)) surface_free(arr);
		return;
	}
	
	for( var i = 0, n = array_length(arr); i < n; i++ ) 
		surface_array_free(arr[i]);
} #endregion

function surface_array_clone(arr) { #region
	if(!is_array(arr)) {
		if(is_surface(arr)) 
			return surface_clone(arr);
		else
			return arr;
	}
	
	var _arr = [];
	
	for( var i = 0, n = array_length(arr); i < n; i++ ) 
		_arr[i] = surface_array_clone(arr[i]);
	
	return _arr;
} #endregion

function surface_array_serialize(arr) { #region
	INLINE
	
	var _arr = __surface_array_serialize(arr);
	return json_stringify(_arr);
} #endregion

function __surface_array_serialize(arr) { #region
	if(!is_array(arr)) {
		if(is_surface(arr)) {
			var buff = buffer_create(surface_get_width_safe(arr) * surface_get_height_safe(arr) * 4, buffer_fixed, 1);
			buffer_get_surface(buff, arr, 0);
			var comp = buffer_compress(buff, 0, buffer_get_size(buff));
			var enc  = buffer_base64_encode(comp, 0, buffer_get_size(comp));
			buffer_delete(buff);
			return { width: surface_get_width_safe(arr), height: surface_get_height_safe(arr), buffer: enc };
		} else
			return arr;
	}
	
	var _arr = [];
	
	for( var i = 0, n = array_length(arr); i < n; i++ ) 
		_arr[i] = __surface_array_serialize(arr[i]);
	
	return _arr;
} #endregion

function surface_array_deserialize(arr, index = -1) { #region
	INLINE
	
	var _arr = json_try_parse(arr);
	return index == -1? __surface_array_deserialize(_arr) : __surface_array_deserialize(_arr[index]);
} #endregion
	
function __surface_array_deserialize(arr) { #region
	if(!is_array(arr)) {
		if(!is_struct(arr) || !struct_has(arr, "buffer")) 
			return noone;
			
		var buff = buffer_base64_decode(arr.buffer);
		    buff = buffer_decompress(buff);
		return surface_create_from_buffer(arr.width, arr.height, buff);
	}
	
	var _arr = [];
	
	for( var i = 0, n = array_length(arr); i < n; i++ ) 
		_arr[i] = __surface_array_deserialize(arr[i]);
	
	return _arr;
} #endregion

function surface_encode(surface) { #region
	if(!is_real(surface)) return "";
	if(!surface_exists(surface)) return "";
	
	var buff = buffer_create(surface_get_width_safe(surface) * surface_get_height_safe(surface) * 4, buffer_fixed, 1);
	buffer_get_surface(buff, surface, 0);
	var comp = buffer_compress(buff, 0, buffer_get_size(buff));
	var enc = buffer_base64_encode(comp, 0, buffer_get_size(comp));
	buffer_delete(buff);
	var str = { width: surface_get_width_safe(surface), height: surface_get_height_safe(surface), buffer: enc };
	return json_stringify(str);
} #endregion

function surface_decode(struct) { #region
	var buff = buffer_base64_decode(struct.buffer);
	var buff = buffer_decompress(buff);
	return surface_create_from_buffer(struct.width, struct.height, buff);
} #endregion

function surface_format_get_bytes(format) { #region
	switch(format) {
		case surface_rgba4unorm :  return 4 * 0.5; break;
		case surface_rgba8unorm :  return 4 * 1; break;
		case surface_rgba16float : return 4 * 2; break;
		case surface_rgba32float : return 4 * 4; break;
		
		case surface_r8unorm  : return 1 * 1; break;
		case surface_r16float : return 1 * 2; break;
		case surface_r32float : return 1 * 3; break;
	}
	return 1;
} #endregion

function surface_get_size(surface) { #region
	INLINE
	
	var sw = surface_get_width_safe(surface);
	var sh = surface_get_height_safe(surface);
	var sz = sw * sh * surface_format_get_bytes(surface_get_format(surface));
	return sz;
} #endregion

function surface_texture(surface) { #region
	INLINE
	
	if(!is_surface(surface)) return -1;
	return surface_get_texture(surface);
} #endregion