/*
   Copyright (C) 2002 Free Software Foundation, Inc.

   Author:  Alexander Malmberg <alexander@malmberg.org>

   This file is part of GNUstep.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.
   
   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
Image drawing. DPSimage and helpers.
*/

#include <math.h>

#include <AppKit/NSAffineTransform.h>
#include <AppKit/NSGraphics.h>

#include "ARTGState.h"

#include "ARTWindowBuffer.h"
#include "blit.h"


static unsigned int _get_8_bits(const unsigned char *ptr, int bit_ofs,
	int num_bits)
{
/*
TODO: if we get values with more than 8 bits, we should round properly and
not just discard the extra bits
*/
  int i;
  unsigned int v;
  ptr += bit_ofs / 8;
  bit_ofs %= 8;

  v = 0;
  for (i = 0; i < 8 && i < num_bits; i++)
    {
      v <<= 1;
      if ((*ptr) & (128 >> bit_ofs))
	v |= 1;
      bit_ofs++;
      if (bit_ofs == 8)
	{
	  ptr++;
	  bit_ofs = 0;
	}
    }
  /* extend what we've got to 8 bits */
  switch (num_bits)
    {
    case 1:
      v *= 255;
      break;
    case 2:
      v *= 85;
      break;
    case 3:
      v = (v << 5) | (v << 2) | (v >> 1);
      break;
    case 4:
      v = (v << 4) | v;
      break;
    case 5:
      v = (v << 3) | (v >> 2);
      break;
    case 6:
      v = (v << 2) | (v >> 4);
      break;
    case 7:
      v = (v << 1) | (v >> 6);
      break;
    }
  return v;
}


typedef struct
{
  int width, height;
  int bits_per_sample, samples_per_pixel, bits_per_pixel, bytes_per_row;
  BOOL is_planar, has_alpha;
  const unsigned char **data;

  /*
    0  unknown, use colorspacename
    1  rgb
    2  cmyk
    3  gray
  */
  int colorspace;
  NSString *colorspacename;
} image_info_t;


static void _image_get_color_rgb_8(image_info_t *ii, render_run_t *ri,
	int x, int y)
{
  int ofs;

  if (x < 0) x = 0;
  if (y < 0) y = 0;
  if (x >= ii->width) x = ii->width - 1;
  if (x >= ii->height) y = ii->height - 1;

  ofs = ii->bytes_per_row * y + x * ii->bits_per_pixel / 8;
  if (ii->is_planar)
    {
      ri->r = ii->data[0][ofs];
      ri->g = ii->data[1][ofs];
      ri->b = ii->data[2][ofs];
      if (ii->has_alpha)
	ri->a = ii->data[3][ofs];
      else
	ri->a = 255;
    }
  else
    {
      ri->r = ii->data[0][ofs];
      ri->g = ii->data[0][ofs + 1];
      ri->b = ii->data[0][ofs + 2];
      if (ii->has_alpha)
	ri->a = ii->data[0][ofs + 3];
      else
	ri->a = 255;
    }
}

static void _image_get_color_rgb_cmyk_gray(image_info_t *ii, render_run_t *ri,
	int x, int y)
{
  int ofs, bit_ofs;
  int values[5];
  int i, j;

  if (x < 0) x = 0;
  if (y < 0) y = 0;
  if (x >= ii->width) x = ii->width - 1;
  if (x >= ii->height) y = ii->height - 1;

  ofs = y * ii->bytes_per_row;
  bit_ofs = x * ii->bits_per_pixel;

  for (i = j = 0; i < ii->samples_per_pixel; i++)
    {
      values[i] = _get_8_bits(ii->data[j] + ofs, bit_ofs, ii->bits_per_sample);
      if (ii->is_planar)
	j++;
      else
	bit_ofs += ii->bits_per_sample;
    }
  if (ii->has_alpha)
    ri->a = values[i - 1];
  else
    ri->a = 255;

  if (ii->colorspace == 1)
    {
      ri->r = values[0];
      ri->g = values[1];
      ri->b = values[2];
    }
  else if (ii->colorspace == 2)
    {
      j = 255 - values[0] - values[3];
      ri->r = j < 0?0:j;
      j = 255 - values[1] - values[3];
      ri->g = j < 0?0:j;
      j = 255 - values[2] - values[3];
      ri->b = j < 0?0:j;
    }
  else if (ii->colorspace == 3)
    {
      ri->r = ri->g = ri->b = values[0];
    }
}


@implementation ARTGState (image)

-(void) _image_do_rgb_transform: (image_info_t *)ii
	: (NSAffineTransform *)matrix
	: (void (*)(image_info_t *ii, render_run_t *ri, int x, int y))ifunc
{
/*
TODO:
seems to have problems with rotations. 0, 90, 180, 270 work fine, but others
seem to cause edges to be off by a pixel
*/
  int x[4], y[4];
  int tx[4], ty[4];
  float fx[4], fy[4];

  int cy, ey;
  int left_delta, next;
  int lx, lx_frac, ldx, ldx_frac, l_de, le;
  int rx, rx_frac, rdx, rdx_frac, r_de, re;
  int ltx, lty, ltx_frac, lty_frac, ldtx, ldty, ldtx_frac, ldty_frac;
  int rtx, rty, rtx_frac, rty_frac, rdtx, rdty, rdtx_frac, rdty_frac;

  NSPoint p;


  p = [matrix transformPoint: NSMakePoint(0, 0)];
  fx[0] = p.x; fy[0] = p.y;
  p = [matrix transformPoint: NSMakePoint(ii->width, 0)];
  fx[1] = p.x; fy[1] = p.y;
  p = [matrix transformPoint: NSMakePoint(ii->width, ii->height)];
  fx[2] = p.x; fy[2] = p.y;
  p = [matrix transformPoint: NSMakePoint(0, ii->height)];
  fx[3] = p.x; fy[3] = p.y;

  if (fabs(fx[0] - floor(fx[0] + .5)) < 0.001) fx[0] = floor(fx[0] + .5);
  if (fabs(fx[1] - floor(fx[1] + .5)) < 0.001) fx[1] = floor(fx[1] + .5);
  if (fabs(fx[2] - floor(fx[2] + .5)) < 0.001) fx[2] = floor(fx[2] + .5);
  if (fabs(fx[3] - floor(fx[3] + .5)) < 0.001) fx[3] = floor(fx[3] + .5);
  if (fabs(fy[0] - floor(fy[0] + .5)) < 0.001) fy[0] = floor(fy[0] + .5);
  if (fabs(fy[1] - floor(fy[1] + .5)) < 0.001) fy[1] = floor(fy[1] + .5);
  if (fabs(fy[2] - floor(fy[2] + .5)) < 0.001) fy[2] = floor(fy[2] + .5);
  if (fabs(fy[3] - floor(fy[3] + .5)) < 0.001) fy[3] = floor(fy[3] + .5);

  x[0] = floor(fx[0]); y[0] = wi->sy - floor(fy[0]);
  x[1] = floor(fx[1]); y[1] = wi->sy - floor(fy[1]);
  x[2] = floor(fx[2]); y[2] = wi->sy - floor(fy[2]);
  x[3] = floor(fx[3]); y[3] = wi->sy - floor(fy[3]);

  tx[0] = 0;         ty[0] = ii->height;
  tx[1] = ii->width; ty[1] = ii->height;
  tx[2] = ii->width; ty[2] = 0;
  tx[3] = 0;         ty[3] = 0;

  cy = y[le = 0];
  if (y[1] < cy) cy = y[le = 1];
  if (y[2] < cy) cy = y[le = 2];
  if (y[3] < cy) cy = y[le = 3];
  re = le;

  ey = y[0];
  if (y[1] > ey) ey = y[1];
  if (y[2] > ey) ey = y[2];
  if (y[3] > ey) ey = y[3];

  if (x[(le + 1) & 3] < x[(le - 1) & 3])
    left_delta = 1;
  else
    left_delta = -1;

  /* silence the compiler */
  lx = lx_frac = ldx = ldx_frac = l_de = 0;
  rx = rx_frac = rdx = rdx_frac = r_de = 0;
  ltx = lty = ltx_frac = lty_frac = ldtx = ldty = ldtx_frac = ldty_frac = 0;
  rtx = rty = rtx_frac = rty_frac = rdtx = rdty = rdtx_frac = rdty_frac = 0;

  while (cy <= ey && cy < clip_y1)
    {
      if (cy == y[le])
	{
	  next = (le + left_delta) & 3;
	  while (y[le] == y[next])
	    {
	      le = next;
	      next = (le + left_delta) & 3;
	    }
	  l_de = y[next] - y[le];
	  lx = x[le];
	  lx_frac = 0;
	  ldx = (x[next] - x[le]) / l_de;
	  ldx_frac = (x[next] - x[le]) % l_de;

	  ltx = tx[le];
	  lty = ty[le];
	  ltx_frac = 0;
	  lty_frac = 0;
	  ldtx = (tx[next] - tx[le]) / l_de;
	  ldty = (ty[next] - ty[le]) / l_de;
	  ldtx_frac = (tx[next] - tx[le]) % l_de;
	  ldty_frac = (ty[next] - ty[le]) % l_de;

	  le = next;
	}
      else
	{
	  lx += ldx;
	  lx_frac += ldx_frac;
	  if (lx_frac < 0)
	    lx--, lx_frac += l_de;
	  if (lx_frac > l_de)
	    lx++, lx_frac -= l_de;

	  ltx += ldtx;
	  ltx_frac += ldtx_frac;
	  if (ltx_frac < 0)
	    ltx--, ltx_frac += l_de;
	  if (ltx_frac > l_de)
	    ltx++, ltx_frac -= l_de;

	  lty += ldty;
	  lty_frac += ldty_frac;
	  if (lty_frac < 0)
	    lty--, lty_frac += l_de;
	  if (lty_frac > l_de)
	    lty++, lty_frac -= l_de;
	}

      if (cy == y[re])
	{
	  next = (re - left_delta) & 3;
	  while (y[re] == y[next])
	    {
	      re = next;
	      next = (re - left_delta) & 3;
	    }
	  r_de = y[next] - y[re];
	  rx = x[re];
	  rx_frac = r_de - 1; /* TODO? */
	  rdx = (x[next] - x[re]) / r_de;
	  rdx_frac = (x[next] - x[re]) % r_de;

	  rtx = tx[re];
	  rty = ty[re];
	  rtx_frac = 0;
	  rty_frac = 0;
	  rdtx = (tx[next] - tx[re]) / r_de;
	  rdty = (ty[next] - ty[re]) / r_de;
	  rdtx_frac = (tx[next] - tx[re]) % r_de;
	  rdty_frac = (ty[next] - ty[re]) % r_de;

	  re = next;
	}
      else
	{
	  rx += rdx;
	  rx_frac += rdx_frac;
	  if (rx_frac < 0)
	    rx--, rx_frac += r_de;
	  if (rx_frac > r_de)
	    rx++, rx_frac -= r_de;

	  rtx += rdtx;
	  rtx_frac += rdtx_frac;
	  if (rtx_frac < 0)
	    rtx--, rtx_frac += r_de;
	  if (rtx_frac > r_de)
	    rtx++, rtx_frac -= r_de;

	  rty += rdty;
	  rty_frac += rdty_frac;
	  if (rty_frac < 0)
	    rty--, rty_frac += r_de;
	  if (rty_frac > r_de)
	    rty++, rty_frac -= r_de;
	}

      if (cy >= clip_y0 && rx > lx)
	{
	  render_run_t ri;
	  int x0, x1, de;
	  int tx, ty, tx_frac, ty_frac, dtx, dty, dtx_frac, dty_frac;
	  int delta;

	  x0 = lx;
	  x1 = rx;
	  de = x1 - x0;

	  tx = ltx;
	  ty = lty;
	  tx_frac = ltx_frac * de * r_de;
	  ty_frac = lty_frac * de * r_de;
	  de *= r_de * l_de;

	  delta = (rtx * r_de + rtx_frac) * l_de
	          - (ltx * l_de + ltx_frac) * r_de;
	  dtx = delta / de;
	  dtx_frac = delta % de;

	  delta = (rty * r_de + rty_frac) * l_de
	          - (lty * l_de + lty_frac) * r_de;
	  dty = delta / de;
	  dty_frac = delta % de;

	  /*
	    x0 x1 / x2 -> y0 y1 / y2  z
	    ((y0 * y2 + y1) * x2 - (x0 * x2 + x1) * y2) / (x2 * y2 * z)
	  */

	  if (x0 < clip_x0)
	    {
	      tx += dtx * (clip_x0 - x0);
	      ty += dty * (clip_x0 - x0);
	      tx_frac += dtx_frac * (clip_x0 - x0);
	      while (tx_frac < 0)
		tx--, tx_frac += de;
	      while (tx_frac >= de)
		tx++, tx_frac -= de;
	      ty_frac += dty_frac * (clip_x0 - x0);
	      while (ty_frac < 0)
		ty--, ty_frac += de;
	      while (ty_frac >= de)
		ty++, ty_frac -= de;
	      x0 = clip_x0;
	    }
	  if (x1 >= clip_x1) x1 = clip_x1 - 1;

	  ri.dst = wi->data + x0 * DI.bytes_per_pixel
	           + cy * wi->bytes_per_line;
	  ri.dsta = wi->alpha + x0 + cy * wi->sx;

	  if (wi->has_alpha)
	    {
	      for (; x0 < x1; x0++, ri.dst += DI.bytes_per_pixel, ri.dsta++)
		{
		  ifunc(ii, &ri, tx, ty);
		  RENDER_RUN_ALPHA_A(&ri, 1);

		  tx += dtx;
		  ty += dty;
		  tx_frac += dtx_frac;
		  if (tx_frac < 0)
		    tx--, tx_frac += de;
		  if (tx_frac >= de)
		    tx++, tx_frac -= de;
		  ty_frac += dty_frac;
		  if (ty_frac < 0)
		    ty--, ty_frac += de;
		  if (ty_frac >= de)
		    ty++, ty_frac -= de;
		}
	    }
	  else
	    {
	      for (; x0 < x1; x0++, ri.dst += DI.bytes_per_pixel)
		{
		  ifunc(ii, &ri, tx, ty);
		  RENDER_RUN_ALPHA(&ri, 1);

		  tx += dtx;
		  ty += dty;
		  tx_frac += dtx_frac;
		  if (tx_frac < 0)
		    tx--, tx_frac += de;
		  if (tx_frac >= de)
		    tx++, tx_frac -= de;
		  ty_frac += dty_frac;
		  if (ty_frac < 0)
		    ty--, ty_frac += de;
		  if (ty_frac >= de)
		    ty++, ty_frac -= de;
		}
	    }
	}

      cy++;
    }
}


- (void)DPSimage: (NSAffineTransform * ) matrix
		: (int) pixelsWide : (int) pixelsHigh
		: (int) bitsPerSample : (int) samplesPerPixel 
		: (int) bitsPerPixel : (int) bytesPerRow : (BOOL) isPlanar
		: (BOOL) hasAlpha : (NSString *) colorSpaceName
		: (const unsigned char *const [5]) data
{
  BOOL identity_transform, is_rgb;
  image_info_t ii;

  if (!wi || !wi->data) return;
  if (all_clipped) return;

  [matrix prependTransform: ctm];
  if (fabs(matrix->matrix.m11 - 1.0) < 0.001 &&
      fabs(matrix->matrix.m12) < 0.001 &&
      fabs(matrix->matrix.m22 - 1.0) < 0.001 &&
      fabs(matrix->matrix.m21) < 0.001)
    identity_transform = YES;
  else
    identity_transform = NO;

  if (colorSpaceName == NSDeviceRGBColorSpace ||
      colorSpaceName == NSCalibratedRGBColorSpace)
    is_rgb = YES;
  else
    is_rgb = NO;

  /* optimize common case */
  if (identity_transform && is_rgb &&
      bitsPerSample == 8 && !isPlanar &&
      bytesPerRow == samplesPerPixel * pixelsWide &&
      ((samplesPerPixel == 3 && bitsPerPixel == 24 && !hasAlpha) ||
       (samplesPerPixel == 4 && bitsPerPixel == 32 && hasAlpha)))
    {
      int x, y, ox, oy;
      const unsigned char *src = data[0];
      unsigned char *alpha_dest;
      render_run_t ri;

      if (wi->has_alpha)
	{
	  if (DI.inline_alpha)
	    alpha_dest = wi->data + DI.inline_alpha_ofs;
	  else
	    alpha_dest = wi->alpha;
	}
      else
	alpha_dest = NULL;
	
      ox = [matrix transformPoint: NSMakePoint(0, 0)].x;
      oy = wi->sy - [matrix transformPoint: NSMakePoint(0, 0)].y - pixelsHigh;
	
      for (y = 0; y < pixelsHigh; y++)
	{
	  for (x = 0; x < pixelsWide; x++)
	    {
	      if (x + ox < clip_x0 || x + ox >= clip_x1 ||
	          y + oy < clip_y0 || y + oy >= clip_y1)
		{
		  if (hasAlpha)
		    src += 4;
		  else
		    src += 3;
		  continue;
		}
	      ri.dst = wi->data + (x + ox) * DI.bytes_per_pixel
	               + (y + oy) * wi->bytes_per_line;
	      ri.dsta = wi->alpha + (x + ox) + (y + oy) * wi->sx;
	      ri.r = src[0];
	      ri.g = src[1];
	      ri.b = src[2];
	      if (hasAlpha)
		{
		  ri.a = src[3];
		  /* TODO: find out if input is premultiplied or not */
/*		  if (ri.a && ri.a != 255)
		    {
		      ri.r = (255 * ri.r) / ri.a;
		      ri.g = (255 * ri.g) / ri.a;
		      ri.b = (255 * ri.b) / ri.a;
		    }*/
		  if (alpha_dest)
		    {
		      if (src[3] == 255)
			RENDER_RUN_OPAQUE_A(&ri, 1);
		      else if (src[3])
			RENDER_RUN_ALPHA_A(&ri, 1);
		    }
		  else
		    {
		      if (src[3] == 255)
			RENDER_RUN_OPAQUE(&ri, 1);
		      else if (src[3])
			RENDER_RUN_ALPHA(&ri, 1);
		    }
		  src += 4;
		}
	      else
		{
		  ri.a = 255;
		  if (alpha_dest)
		    RENDER_RUN_OPAQUE_A(&ri, 1);
		  else
		    RENDER_RUN_OPAQUE(&ri, 1);
		  src += 3;
		}
	    }
	}
      return;
    }

  ii.bits_per_sample = bitsPerSample;
  ii.bits_per_pixel = bitsPerPixel;
  ii.is_planar = isPlanar;
  ii.has_alpha = hasAlpha;
  ii.width = pixelsWide;
  ii.height = pixelsHigh;
  ii.samples_per_pixel = samplesPerPixel;
  ii.bytes_per_row = bytesPerRow;
  ii.data = (const unsigned char **)data;

  if (bitsPerSample == 8 && is_rgb &&
      ((samplesPerPixel == 3 && !hasAlpha) ||
       (samplesPerPixel == 4 && hasAlpha)))
    {
      [self _image_do_rgb_transform: &ii : matrix : _image_get_color_rgb_8];
      return;
    }

  if (is_rgb)
    ii.colorspace = 1;
  else if (colorSpaceName == NSDeviceCMYKColorSpace)
    ii.colorspace = 2;
  else if (colorSpaceName == NSDeviceWhiteColorSpace ||
	   colorSpaceName == NSDeviceBlackColorSpace ||
	   colorSpaceName == NSCalibratedWhiteColorSpace ||
	   colorSpaceName == NSCalibratedBlackColorSpace)
    ii.colorspace = 3;
  else
    ii.colorspace = 0;

  if (ii.colorspace != 0)
    {
      [self _image_do_rgb_transform: &ii : matrix :
        _image_get_color_rgb_cmyk_gray];
      return;
    }

  NSLog(@"unimplemented DPSimage  %ix%i  |%@|  bips=%i spp=%i bipp=%i bypr=%i  planar=%i alpha=%i\n",
	pixelsWide, pixelsHigh, matrix,
	bitsPerSample, samplesPerPixel, bitsPerPixel, bytesPerRow, isPlanar,
	hasAlpha);
}

@end