# Copyright (c) 2013-2016 Jeffrey Pfau
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from ._pylib import ffi, lib
from . import png

class Image:
	def __init__(self, width, height, stride=0):
		self.width = width
		self.height = height
		self.stride = stride
		self.constitute()

	def constitute(self):
		if self.stride <= 0:
			self.stride = self.width
		self.buffer = ffi.new("color_t[{}]".format(self.stride * self.height))

	def savePNG(self, f):
		p = png.PNG(f)
		success = p.writeHeader(self)
		success = success and p.writePixels(self)
		p.writeClose()
		return success

def u16ToU32(c):
	r = c & 0x1F
	g = (c >> 5) & 0x1F
	b = (c >> 10) & 0x1F
	a = (c >> 15) & 1
	abgr = r << 3
	abgr |= g << 11
	abgr |= b << 19
	abgr |= (a * 0xFF) << 24
	return abgr

def u32ToU16(c):
	r = (c >> 3) & 0x1F
	g = (c >> 11) & 0x1F
	b = (c >> 19) & 0x1F
	a = c >> 31
	abgr = r
	abgr |= g << 5
	abgr |= b << 10
	abgr |= a << 15
	return abgr

if ffi.sizeof("color_t") == 2:
	def colorToU16(c):
		return c

	colorToU32 = u16ToU32

	def u16ToColor(c):
		return c

	u32ToColor = u32ToU16
else:
	def colorToU32(c):
		return c

	colorToU16 = u32ToU16

	def u32ToColor(c):
		return c

	u16ToColor = u16ToU32