fltk/src/Fl_Image.cxx

//
// "$Id$"
//
// Image drawing code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2009 by Bill Spitzak and others.
//
// 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//

#include <FL/Fl.H>
#include <FL/fl_draw.H>
#include <FL/x.H>
#include <FL/Fl_Widget.H>
#include <FL/Fl_Menu_Item.H>
#include <FL/Fl_Image.H>
#include "flstring.h"

#ifdef WIN32
void fl_release_dc(HWND, HDC); // from Fl_win32.cxx
#endif

void fl_restore_clip(); // from fl_rect.cxx

//
// Base image class...
//

/**
  The destructor is a virtual method that frees all memory used
  by the image.
*/
Fl_Image::~Fl_Image() {
}

/**
  If the image has been cached for display, delete the cache
  data. This allows you to change the data used for the image and
  then redraw it without recreating an image object.
*/
void Fl_Image::uncache() {
}

void Fl_Image::draw(int XP, int YP, int, int, int, int) {
  draw_empty(XP, YP);
}

/**
  The protected method draw_empty() draws a box with
  an X in it. It can be used to draw any image that lacks image
  data.
*/
void Fl_Image::draw_empty(int X, int Y) {
  if (w() > 0 && h() > 0) {
    fl_color(FL_FOREGROUND_COLOR);
    fl_rect(X, Y, w(), h());
    fl_line(X, Y, X + w() - 1, Y + h() - 1);
    fl_line(X, Y + h() - 1, X + w() - 1, Y);
  }
}

/**
  The copy() method creates a copy of the specified
  image. If the width and height are provided, the image is
  resized to the specified size. The image should be deleted (or in
  the case of Fl_Shared_Image, released) when you are done
  with it.
*/
Fl_Image *Fl_Image::copy(int W, int H) {
  return new Fl_Image(W, H, d());
}

/**
  The color_average() method averages the colors in
  the image with the FLTK color value c. The i
  argument specifies the amount of the original image to combine
  with the color, so a value of 1.0 results in no color blend, and
  a value of 0.0 results in a constant image of the specified
  color. <I>The original image data is not altered by this
  method.</I>
*/
void Fl_Image::color_average(Fl_Color, float) {
}

/**
  The desaturate() method converts an image to
  grayscale. If the image contains an alpha channel (depth = 4),
  the alpha channel is preserved. <I>This method does not alter
  the original image data.</I>
*/
void Fl_Image::desaturate() {
}

/**
  The label() methods are an obsolete way to set the
  image attribute of a widget or menu item. Use the
  image() or deimage() methods of the
  Fl_Widget and Fl_Menu_Item classes
  instead.
*/
void Fl_Image::label(Fl_Widget* widget) {
  widget->image(this);
}

/**
  The label() methods are an obsolete way to set the
  image attribute of a widget or menu item. Use the
  image() or deimage() methods of the
  Fl_Widget and Fl_Menu_Item classes
  instead.
*/
void Fl_Image::label(Fl_Menu_Item* m) {
  Fl::set_labeltype(_FL_IMAGE_LABEL, labeltype, measure);
  m->label(_FL_IMAGE_LABEL, (const char*)this);
}

void
Fl_Image::labeltype(const Fl_Label *lo,		// I - Label
                    int            lx,		// I - X position
		    int            ly,		// I - Y position
		    int            lw,		// I - Width of label
		    int            lh,		// I - Height of label
		    Fl_Align       la) {	// I - Alignment
  Fl_Image	*img;				// Image pointer
  int		cx, cy;				// Image position

  img = (Fl_Image *)(lo->value);

  if (la & FL_ALIGN_LEFT) cx = 0;
  else if (la & FL_ALIGN_RIGHT) cx = img->w() - lw;
  else cx = (img->w() - lw) / 2;

  if (la & FL_ALIGN_TOP) cy = 0;
  else if (la & FL_ALIGN_BOTTOM) cy = img->h() - lh;
  else cy = (img->h() - lh) / 2;

  fl_color((Fl_Color)lo->color);

  img->draw(lx, ly, lw, lh, cx, cy);
}

void
Fl_Image::measure(const Fl_Label *lo,		// I - Label
                  int            &lw,		// O - Width of image
		  int            &lh) {		// O - Height of image
  Fl_Image *img;				// Image pointer

  img = (Fl_Image *)(lo->value);

  lw = img->w();
  lh = img->h();
}


//
// RGB image class...
//
/**  The destructor free all memory and server resources that are used by  the image. */
Fl_RGB_Image::~Fl_RGB_Image() {
  uncache();
  if (alloc_array) delete[] (uchar *)array;
}

void Fl_RGB_Image::uncache() {
#ifdef __APPLE_QUARTZ__
  if (id) {
    CGImageRelease((CGImageRef)id);
    id = 0;
  }
#else
  if (id) {
    fl_delete_offscreen((Fl_Offscreen)id);
    id = 0;
  }

  if (mask) {
    fl_delete_bitmask((Fl_Bitmask)mask);
    mask = 0;
  }
#endif
}

Fl_Image *Fl_RGB_Image::copy(int W, int H) {
  Fl_RGB_Image	*new_image;	// New RGB image
  uchar		*new_array;	// New array for image data

  // Optimize the simple copy where the width and height are the same,
  // or when we are copying an empty image...
  if ((W == w() && H == h()) ||
      !w() || !h() || !d() || !array) {
    if (array) {
      // Make a copy of the image data and return a new Fl_RGB_Image...
      new_array = new uchar[w() * h() * d()];
      if (ld() && ld()!=w()*d()) {
        const uchar *src = array;
        uchar *dst = new_array;
        int dy, dh = h(), wd = w()*d(), wld = ld();
        for (dy=0; dy<dh; dy++) {
          memcpy(dst, src, wd);
          src += wld;
          dst += wd;
        }
      } else {
        memcpy(new_array, array, w() * h() * d());
      }
      new_image = new Fl_RGB_Image(new_array, w(), h(), d());
      new_image->alloc_array = 1;

      return new_image;
    } else return new Fl_RGB_Image(array, w(), h(), d(), ld());
  }
  if (W <= 0 || H <= 0) return 0;

  // OK, need to resize the image data; allocate memory and 
  uchar		*new_ptr;	// Pointer into new array
  const uchar	*old_ptr;	// Pointer into old array
  int		c,		// Channel number
		sy,		// Source coordinate
		dx, dy,		// Destination coordinates
		xerr, yerr,	// X & Y errors
		xmod, ymod,	// X & Y moduli
		xstep, ystep,	// X & Y step increments
    line_d; // stride from line to line


  // Figure out Bresenheim step/modulus values...
  xmod   = w() % W;
  xstep  = (w() / W) * d();
  ymod   = h() % H;
  ystep  = h() / H;
  line_d = ld() ? ld() : w() * d();

  // Allocate memory for the new image...
  new_array = new uchar [W * H * d()];
  new_image = new Fl_RGB_Image(new_array, W, H, d());
  new_image->alloc_array = 1;

  // Scale the image using a nearest-neighbor algorithm...
  for (dy = H, sy = 0, yerr = H, new_ptr = new_array; dy > 0; dy --) {
    for (dx = W, xerr = W, old_ptr = array + sy * line_d; dx > 0; dx --) {
      for (c = 0; c < d(); c ++) *new_ptr++ = old_ptr[c];

      old_ptr += xstep;
      xerr    -= xmod;

      if (xerr <= 0) {
	xerr    += W;
	old_ptr += d();
      }
    }

    sy   += ystep;
    yerr -= ymod;
    if (yerr <= 0) {
      yerr += H;
      sy ++;
    }
  }

  return new_image;
}

void Fl_RGB_Image::color_average(Fl_Color c, float i) {
  // Don't average an empty image...
  if (!w() || !h() || !d() || !array) return;

  // Delete any existing pixmap/mask objects...
  uncache();

  // Allocate memory as needed...
  uchar		*new_array,
		*new_ptr;

  if (!alloc_array) new_array = new uchar[h() * w() * d()];
  else new_array = (uchar *)array;

  // Get the color to blend with...
  uchar		r, g, b;
  unsigned	ia, ir, ig, ib;

  Fl::get_color(c, r, g, b);
  if (i < 0.0f) i = 0.0f;
  else if (i > 1.0f) i = 1.0f;

  ia = (unsigned)(256 * i);
  ir = r * (256 - ia);
  ig = g * (256 - ia);
  ib = b * (256 - ia);

  // Update the image data to do the blend...
  const uchar	*old_ptr;
  int		x, y;
  int   line_i = ld() ? ld() - (w()*d()) : 0; // increment from line end to beginning of next line

  if (d() < 3) {
    ig = (r * 31 + g * 61 + b * 8) / 100 * (256 - ia);

    for (new_ptr = new_array, old_ptr = array, y = 0; y < h(); y ++, old_ptr += line_i)
      for (x = 0; x < w(); x ++) {
	*new_ptr++ = (*old_ptr++ * ia + ig) >> 8;
	if (d() > 1) *new_ptr++ = *old_ptr++;
      }
  } else {
    for (new_ptr = new_array, old_ptr = array, y = 0; y < h(); y ++, old_ptr += line_i)
      for (x = 0; x < w(); x ++) {
	*new_ptr++ = (*old_ptr++ * ia + ir) >> 8;
	*new_ptr++ = (*old_ptr++ * ia + ig) >> 8;
	*new_ptr++ = (*old_ptr++ * ia + ib) >> 8;
	if (d() > 3) *new_ptr++ = *old_ptr++;
      }
  }

  // Set the new pointers/values as needed...
  if (!alloc_array) {
    array       = new_array;
    alloc_array = 1;

    ld(0);
  }
}

void Fl_RGB_Image::desaturate() {
  // Don't desaturate an empty image...
  if (!w() || !h() || !d() || !array) return;

  // Can only desaturate color images...
  if (d() < 3) return;

  // Delete any existing pixmap/mask objects...
  uncache();

  // Allocate memory for a grayscale image...
  uchar		*new_array,
		*new_ptr;
  int		new_d;

  new_d     = d() - 2;
  new_array = new uchar[h() * w() * new_d];

  // Copy the image data, converting to grayscale...
  const uchar	*old_ptr;
  int		x, y;
  int   line_i = ld() ? ld() - (w()*d()) : 0; // increment from line end to beginning of next line

  for (new_ptr = new_array, old_ptr = array, y = 0; y < h(); y ++, old_ptr += line_i)
    for (x = 0; x < w(); x ++, old_ptr += d()) {
      *new_ptr++ = (uchar)((31 * old_ptr[0] + 61 * old_ptr[1] + 8 * old_ptr[2]) / 100);
      if (d() > 3) *new_ptr++ = old_ptr[3];
    }

  // Free the old array as needed, and then set the new pointers/values...
  if (alloc_array) delete[] (uchar *)array;

  array       = new_array;
  alloc_array = 1;

  ld(0);
  d(new_d);
}

#if !defined(WIN32) && !USE_QUARTZ
// Composite an image with alpha on systems that don't have accelerated
// alpha compositing...
static void alpha_blend(Fl_RGB_Image *img, int X, int Y, int W, int H, int cx, int cy) {
  uchar *srcptr = (uchar*)img->array + img->d() * (img->w() * cy + cx);
  int srcskip = img->d() * (img->w() - W);

  uchar *dst = new uchar[W * H * 3];
  uchar *dstptr = dst;

  fl_read_image(dst, X, Y, W, H, 0);

  uchar srcr, srcg, srcb, srca;
  uchar dstr, dstg, dstb, dsta;

  if (img->d() == 2) {
    // Composite grayscale + alpha over RGB...
    // Composite RGBA over RGB...
    for (int y = H; y > 0; y--, srcptr+=srcskip)
      for (int x = W; x > 0; x--) {
	srcg = *srcptr++;
	srca = *srcptr++;

	dstr = dstptr[0];
	dstg = dstptr[1];
	dstb = dstptr[2];
	dsta = 255 - srca;

	*dstptr++ = (srcg * srca + dstr * dsta) >> 8;
	*dstptr++ = (srcg * srca + dstg * dsta) >> 8;
	*dstptr++ = (srcg * srca + dstb * dsta) >> 8;
      }
  } else {
    // Composite RGBA over RGB...
    for (int y = H; y > 0; y--, srcptr+=srcskip)
      for (int x = W; x > 0; x--) {
	srcr = *srcptr++;
	srcg = *srcptr++;
	srcb = *srcptr++;
	srca = *srcptr++;

	dstr = dstptr[0];
	dstg = dstptr[1];
	dstb = dstptr[2];
	dsta = 255 - srca;

	*dstptr++ = (srcr * srca + dstr * dsta) >> 8;
	*dstptr++ = (srcg * srca + dstg * dsta) >> 8;
	*dstptr++ = (srcb * srca + dstb * dsta) >> 8;
      }
  }

  fl_draw_image(dst, X, Y, W, H, 3, 0);

  delete[] dst;
}
#endif // !WIN32 && !USE_QUARTZ

void Fl_RGB_Image::draw(int XP, int YP, int WP, int HP, int cx, int cy) {
  // Don't draw an empty image...
  if (!d() || !array) {
    draw_empty(XP, YP);
    return;
  }

  // account for current clip region (faster on Irix):
  int X,Y,W,H; fl_clip_box(XP,YP,WP,HP,X,Y,W,H);
  cx += X-XP; cy += Y-YP;
  // clip the box down to the size of image, quit if empty:
  if (cx < 0) {W += cx; X -= cx; cx = 0;}
  if (cx+W > w()) W = w()-cx;
  if (W <= 0) return;
  if (cy < 0) {H += cy; Y -= cy; cy = 0;}
  if (cy+H > h()) H = h()-cy;
  if (H <= 0) return;
  if (!id) {
#ifdef __APPLE_QUARTZ__
    CGColorSpaceRef lut = 0;
    if (d()<=2)
      lut = CGColorSpaceCreateDeviceGray();
    else
      lut = CGColorSpaceCreateDeviceRGB();
    CGDataProviderRef src = CGDataProviderCreateWithData( 0L, array, w()*h()*d(), 0L);
    id = CGImageCreate( w(), h(), 8, d()*8, ld()?ld():w()*d(),
        lut, (d()&1)?kCGImageAlphaNone:kCGImageAlphaLast,
        src, 0L, false, kCGRenderingIntentDefault);
    CGColorSpaceRelease(lut);
    CGDataProviderRelease(src);
#elif defined(WIN32)
    id = fl_create_offscreen(w(), h());
    if (d() == 2 || d() == 4 && fl_can_do_alpha_blending()) {
      fl_begin_offscreen((Fl_Offscreen)id);
      fl_draw_image(array, 0, 0, w(), h(), d()|FL_IMAGE_WITH_ALPHA, ld());
      fl_end_offscreen();
    } else {
      fl_begin_offscreen((Fl_Offscreen)id);
      fl_draw_image(array, 0, 0, w(), h(), d(), ld());
      fl_end_offscreen();
      if (d() == 2 || d() == 4) {
        mask = fl_create_alphamask(w(), h(), d(), ld(), array);
      }
    }
#else
    if (d() == 1 || d() == 3) {
      id = fl_create_offscreen(w(), h());
      fl_begin_offscreen((Fl_Offscreen)id);
      fl_draw_image(array, 0, 0, w(), h(), d(), ld());
      fl_end_offscreen();
    }
#endif
  }

#if defined(USE_X11)
  if (id) {
    if (mask) {
      // I can't figure out how to combine a mask with existing region,
      // so cut the image down to a clipped rectangle:
      int nx, ny; fl_clip_box(X,Y,W,H,nx,ny,W,H);
      cx += nx-X; X = nx;
      cy += ny-Y; Y = ny;
      // make X use the bitmap as a mask:
      XSetClipMask(fl_display, fl_gc, mask);
      int ox = X-cx; if (ox < 0) ox += w();
      int oy = Y-cy; if (oy < 0) oy += h();
      XSetClipOrigin(fl_display, fl_gc, X-cx, Y-cy);
    }

    fl_copy_offscreen(X, Y, W, H, id, cx, cy);

    if (mask) {
      // put the old clip region back
      XSetClipOrigin(fl_display, fl_gc, 0, 0);
      fl_restore_clip();
    }
  } else {
    // Composite image with alpha manually each time...
    alpha_blend(this, X, Y, W, H, cx, cy);
  }
#elif defined(WIN32)
  if (mask) {
    HDC new_gc = CreateCompatibleDC(fl_gc);
    int save = SaveDC(new_gc);
    SelectObject(new_gc, (void*)mask);
    BitBlt(fl_gc, X, Y, W, H, new_gc, cx, cy, SRCAND);
    SelectObject(new_gc, (void*)id);
    BitBlt(fl_gc, X, Y, W, H, new_gc, cx, cy, SRCPAINT);
    RestoreDC(new_gc,save);
    DeleteDC(new_gc);
  } else if (d()==2 || d()==4) {
    fl_copy_offscreen_with_alpha(X, Y, W, H, (Fl_Offscreen)id, cx, cy);
  } else {
    fl_copy_offscreen(X, Y, W, H, (Fl_Offscreen)id, cx, cy);
  }
#elif defined(__APPLE_QUARTZ__)
  if (id && fl_gc) {
    CGRect rect = { { X, Y }, { W, H } };
    Fl_X::q_begin_image(rect, cx, cy, w(), h());
    CGContextDrawImage(fl_gc, rect, (CGImageRef)id);
    Fl_X::q_end_image();
  }
#else
# error unsupported platform
#endif
}

void Fl_RGB_Image::label(Fl_Widget* widget) {
  widget->image(this);
}

void Fl_RGB_Image::label(Fl_Menu_Item* m) {
  Fl::set_labeltype(_FL_IMAGE_LABEL, labeltype, measure);
  m->label(_FL_IMAGE_LABEL, (const char*)this);
}


//
// End of "$Id$".
//