//
// Draw-to-image code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2018 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

#include <FL/platform.H>
#include <FL/fl_draw.H>
#include "Fl_Quartz_Image_Surface_Driver.H"
#include "Fl_Quartz_Graphics_Driver.H"
#include "../Cocoa/Fl_Cocoa_Window_Driver.H"
#include <ApplicationServices/ApplicationServices.h>


Fl_Quartz_Image_Surface_Driver::Fl_Quartz_Image_Surface_Driver(int w, int h, int high_res, Fl_Offscreen off) : Fl_Image_Surface_Driver(w, h, high_res, off) {
  int W = w, H = h;
  float s = 1;
  if (high_res) {
    s = Fl_Graphics_Driver::default_driver().scale();
    Fl_Window *cw = Fl_Window::current();
    if (cw && Fl_Cocoa_Window_Driver::driver(cw)->mapped_to_retina()) s *= 2;
    W *= s; H *= s;
  }
  CGColorSpaceRef lut = CGColorSpaceCreateDeviceRGB();
  offscreen = off ? off : (Fl_Offscreen)CGBitmapContextCreate(calloc(W*H,4), W, H, 8, W*4, lut, kCGImageAlphaPremultipliedLast);
  CGColorSpaceRelease(lut);
  driver(new Fl_Quartz_Graphics_Driver);
  CGContextTranslateCTM((CGContextRef)offscreen, 0.5*s, -0.5*s); // as when drawing to a window
  if (high_res) {
    CGContextScaleCTM((CGContextRef)offscreen, s, s);
    driver()->scale(s);
  }
  CGContextSetShouldAntialias((CGContextRef)offscreen, false);
  CGContextTranslateCTM((CGContextRef)offscreen, 0, height);
  CGContextScaleCTM((CGContextRef)offscreen, 1.0f, -1.0f);
  CGContextSaveGState((CGContextRef)offscreen);
  CGContextSetRGBFillColor((CGContextRef)offscreen, 1, 1, 1, 0);
  CGContextFillRect((CGContextRef)offscreen, CGRectMake(0,0,w,h));
}

Fl_Quartz_Image_Surface_Driver::~Fl_Quartz_Image_Surface_Driver() {
  if (offscreen && !external_offscreen) {
    void *data = CGBitmapContextGetData((CGContextRef)offscreen);
    free(data);
    CGContextRelease((CGContextRef)offscreen);
  }
  delete driver();
}

void Fl_Quartz_Image_Surface_Driver::set_current() {
  Fl_Surface_Device::set_current();
  pre_window = fl_window;
  driver()->gc((CGContextRef)offscreen);
  fl_window = 0;
  ((Fl_Quartz_Graphics_Driver*)driver())->high_resolution( CGBitmapContextGetWidth((CGContextRef)offscreen) > (size_t)width );
}

void Fl_Quartz_Image_Surface_Driver::translate(int x, int y) {
  CGContextRestoreGState((CGContextRef)offscreen);
  CGContextSaveGState((CGContextRef)offscreen);
  CGContextTranslateCTM((CGContextRef)offscreen, x, y);
  CGContextSaveGState((CGContextRef)offscreen);
}

void Fl_Quartz_Image_Surface_Driver::untranslate() {
  CGContextRestoreGState((CGContextRef)offscreen);
}

Fl_RGB_Image* Fl_Quartz_Image_Surface_Driver::image()
{
  CGContextFlush((CGContextRef)offscreen);
  int W = (int)CGBitmapContextGetWidth((CGContextRef)offscreen);
  int H = (int)CGBitmapContextGetHeight((CGContextRef)offscreen);
  int bpr = (int)CGBitmapContextGetBytesPerRow((CGContextRef)offscreen);
  int bpp = (int)CGBitmapContextGetBitsPerPixel((CGContextRef)offscreen)/8;
  uchar *base = (uchar*)CGBitmapContextGetData((CGContextRef)offscreen);
  int idx, idy;
  uchar *pdst, *psrc;
  unsigned char *data = new uchar[W * H * 3];
  for (idy = 0, pdst = data; idy < H; idy ++) {
    for (idx = 0, psrc = base + idy * bpr; idx < W; idx ++, psrc += bpp, pdst += 3) {
      pdst[0] = psrc[0];  // R
      pdst[1] = psrc[1];  // G
      pdst[2] = psrc[2];  // B
    }
  }
  Fl_RGB_Image *image = new Fl_RGB_Image(data, W, H);
  image->alloc_array = 1;
  return image;
}

void Fl_Quartz_Image_Surface_Driver::end_current()
{
  fl_window = pre_window;
  Fl_Surface_Device::end_current();
}