Rewrite fl_read_image.cxx under the driver model.

Files fl_read_image_mac.cxx and fl_read_image_win32.cxx are no longer used;
their content is now in Fl_XXX_Screen_Driver.cxx

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11516 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

2 files changed, 457 insertions, 0 deletions

diff --git a/src/drivers/X11/Fl_X11_Screen_Driver.H b/src/drivers/X11/Fl_X11_Screen_Driver.H
index 2f89eaabf..f639fd6cb 100644
--- a/src/drivers/X11/Fl_X11_Screen_Driver.H
+++ b/src/drivers/X11/Fl_X11_Screen_Driver.H
@@ -77,6 +77,7 @@ public:
   virtual int compose(int &del);
   virtual void compose_reset();
   virtual int text_display_can_leak();
+  virtual uchar *read_win_rectangle(uchar *p, int X, int Y, int w, int h, int alpha);
 };
 
 
diff --git a/src/drivers/X11/Fl_X11_Screen_Driver.cxx b/src/drivers/X11/Fl_X11_Screen_Driver.cxx
index 50623664e..9e7c68af4 100644
--- a/src/drivers/X11/Fl_X11_Screen_Driver.cxx
+++ b/src/drivers/X11/Fl_X11_Screen_Driver.cxx
@@ -34,6 +34,17 @@
 #include <X11/extensions/Xdbe.h>
 #endif
 
+#  include <X11/Xutil.h>
+#  ifdef __sgi
+#    include <X11/extensions/readdisplay.h>
+#  else
+#    include <stdlib.h>
+#  endif // __sgi
+
+#ifdef DEBUG
+#  include <stdio.h>
+#endif // DEBUG
+
 extern Atom fl_NET_WORKAREA;
 extern XIC fl_xim_ic; // in Fl_x.cxx
 
@@ -666,5 +677,450 @@ void Fl_Screen_Driver::font_name(int num, const char *name) {
 }
 
 //
+// 'fl_subimage_offsets()' - Calculate subimage offsets for an axis
+static inline int
+fl_subimage_offsets(int a, int aw, int b, int bw, int &obw)
+{
+  int off;
+  int ob;
+  
+  if (b >= a) {
+    ob = b;
+    off = 0;
+  } else {
+    ob = a;
+    off = a - b;
+  }
+  
+  bw -= off;
+  
+  if (ob + bw <= a + aw) {
+    obw = bw;
+  } else {
+    obw = (a + aw) - ob;
+  }
+  
+  return off;
+}
+
+// this handler will catch and ignore exceptions during XGetImage
+// to avoid an application crash
+extern "C" {
+  static int xgetimageerrhandler(Display *display, XErrorEvent *error) {
+    return 0;
+  }
+}
+
+uchar *Fl_X11_Screen_Driver::read_win_rectangle(uchar *p, int X, int Y, int w, int h, int alpha)
+{
+  XImage	*image;		// Captured image
+  int		i, maxindex;	// Looping vars
+  int           x, y;		// Current X & Y in image
+  int		d;		// Depth of image
+  unsigned char *line,		// Array to hold image row
+		*line_ptr;	// Pointer to current line image
+  unsigned char	*pixel;		// Current color value
+  XColor	colors[4096];	// Colors from the colormap...
+  unsigned char	cvals[4096][3];	// Color values from the colormap...
+  unsigned	index_mask,
+		index_shift,
+		red_mask,
+		red_shift,
+		green_mask,
+		green_shift,
+		blue_mask,
+		blue_shift;
+  //
+  // Under X11 we have the option of the XGetImage() interface or SGI's
+  // ReadDisplay extension which does all of the really hard work for
+  // us...
+  //
+  int allow_outside = w < 0;    // negative w allows negative X or Y, that is, window frame
+  if (w < 0) w = - w;
+  
+#  ifdef __sgi
+  if (XReadDisplayQueryExtension(fl_display, &i, &i)) {
+    image = XReadDisplay(fl_display, fl_window, X, Y, w, h, 0, NULL);
+  } else
+#  else
+    image = 0;
+#  endif // __sgi
+  
+  if (!image) {
+    // fetch absolute coordinates
+    int dx, dy, sx, sy, sw, sh;
+    Window child_win;
+    
+    Fl_Window *win;
+    if (allow_outside) win = (Fl_Window*)1;
+    else win = fl_find(fl_window);
+    if (win) {
+      XTranslateCoordinates(fl_display, fl_window,
+                            RootWindow(fl_display, fl_screen), X, Y, &dx, &dy, &child_win);
+      // screen dimensions
+      Fl::screen_xywh(sx, sy, sw, sh, fl_screen);
+    }
+    if (!win || (dx >= sx && dy >= sy && dx + w <= sx+sw && dy + h <= sy+sh)) {
+      // the image is fully contained, we can use the traditional method
+      // however, if the window is obscured etc. the function will still fail. Make sure we
+      // catch the error and continue, otherwise an exception will be thrown.
+      XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler);
+      image = XGetImage(fl_display, fl_window, X, Y, w, h, AllPlanes, ZPixmap);
+      XSetErrorHandler(old_handler);
+    } else {
+      // image is crossing borders, determine visible region
+      int nw, nh, noffx, noffy;
+      noffx = fl_subimage_offsets(sx, sw, dx, w, nw);
+      noffy = fl_subimage_offsets(sy, sh, dy, h, nh);
+      if (nw <= 0 || nh <= 0) return 0;
+      
+      // allocate the image
+      int bpp = fl_visual->depth + ((fl_visual->depth / 8) % 2) * 8;
+      char* buf = (char*)malloc(bpp / 8 * w * h);
+      image = XCreateImage(fl_display, fl_visual->visual,
+                           fl_visual->depth, ZPixmap, 0, buf, w, h, bpp, 0);
+      if (!image) {
+        if (buf) free(buf);
+        return 0;
+      }
+      
+      XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler);
+      XImage *subimg = XGetSubImage(fl_display, fl_window, X + noffx, Y + noffy,
+                                    nw, nh, AllPlanes, ZPixmap, image, noffx, noffy);
+      XSetErrorHandler(old_handler);
+      if (!subimg) {
+        XDestroyImage(image);
+        return 0;
+      }
+    }
+  }
+  
+  if (!image) return 0;
+  
+#ifdef DEBUG
+  printf("width            = %d\n", image->width);
+  printf("height           = %d\n", image->height);
+  printf("xoffset          = %d\n", image->xoffset);
+  printf("format           = %d\n", image->format);
+  printf("data             = %p\n", image->data);
+  printf("byte_order       = %d\n", image->byte_order);
+  printf("bitmap_unit      = %d\n", image->bitmap_unit);
+  printf("bitmap_bit_order = %d\n", image->bitmap_bit_order);
+  printf("bitmap_pad       = %d\n", image->bitmap_pad);
+  printf("depth            = %d\n", image->depth);
+  printf("bytes_per_line   = %d\n", image->bytes_per_line);
+  printf("bits_per_pixel   = %d\n", image->bits_per_pixel);
+  printf("red_mask         = %08x\n", image->red_mask);
+  printf("green_mask       = %08x\n", image->green_mask);
+  printf("blue_mask        = %08x\n", image->blue_mask);
+  printf("map_entries      = %d\n", fl_visual->visual->map_entries);
+#endif // DEBUG
+  
+  d = alpha ? 4 : 3;
+  
+  // Allocate the image data array as needed...
+  if (!p) p = new uchar[w * h * d];
+  
+  // Initialize the default colors/alpha in the whole image...
+  memset(p, alpha, w * h * d);
+  
+  // Check that we have valid mask/shift values...
+  if (!image->red_mask && image->bits_per_pixel > 12) {
+    // Greater than 12 bits must be TrueColor...
+    image->red_mask   = fl_visual->visual->red_mask;
+    image->green_mask = fl_visual->visual->green_mask;
+    image->blue_mask  = fl_visual->visual->blue_mask;
+    
+#ifdef DEBUG
+    // Defined in Fl_Xlib_Graphics_Driver_color.cxx
+    extern uchar fl_redmask, fl_greenmask, fl_bluemask;
+    extern int fl_redshift, fl_greenshift, fl_blueshift;
+    puts("\n---- UPDATED ----");
+    printf("fl_redmask       = %08x\n", fl_redmask);
+    printf("fl_redshift      = %d\n", fl_redshift);
+    printf("fl_greenmask     = %08x\n", fl_greenmask);
+    printf("fl_greenshift    = %d\n", fl_greenshift);
+    printf("fl_bluemask      = %08x\n", fl_bluemask);
+    printf("fl_blueshift     = %d\n", fl_blueshift);
+    printf("red_mask         = %08x\n", image->red_mask);
+    printf("green_mask       = %08x\n", image->green_mask);
+    printf("blue_mask        = %08x\n", image->blue_mask);
+#endif // DEBUG
+  }
+  
+  // Check if we have colormap image...
+  if (!image->red_mask) {
+    // Get the colormap entries for this window...
+    maxindex = fl_visual->visual->map_entries;
+    
+    for (i = 0; i < maxindex; i ++) colors[i].pixel = i;
+    
+    XQueryColors(fl_display, fl_colormap, colors, maxindex);
+    
+    for (i = 0; i < maxindex; i ++) {
+      cvals[i][0] = colors[i].red >> 8;
+      cvals[i][1] = colors[i].green >> 8;
+      cvals[i][2] = colors[i].blue >> 8;
+    }
+    
+    // Read the pixels and output an RGB image...
+    for (y = 0; y < image->height; y ++) {
+      pixel = (unsigned char *)(image->data + y * image->bytes_per_line);
+      line  = p + y * w * d;
+      
+      switch (image->bits_per_pixel) {
+        case 1 :
+          for (x = image->width, line_ptr = line, index_mask = 128;
+               x > 0;
+               x --, line_ptr += d) {
+            if (*pixel & index_mask) {
+              line_ptr[0] = cvals[1][0];
+              line_ptr[1] = cvals[1][1];
+              line_ptr[2] = cvals[1][2];
+            } else {
+              line_ptr[0] = cvals[0][0];
+              line_ptr[1] = cvals[0][1];
+              line_ptr[2] = cvals[0][2];
+            }
+            
+            if (index_mask > 1) {
+              index_mask >>= 1;
+            } else {
+              index_mask = 128;
+              pixel ++;
+            }
+          }
+          break;
+          
+        case 2 :
+          for (x = image->width, line_ptr = line, index_shift = 6;
+               x > 0;
+               x --, line_ptr += d) {
+            i = (*pixel >> index_shift) & 3;
+            
+            line_ptr[0] = cvals[i][0];
+            line_ptr[1] = cvals[i][1];
+            line_ptr[2] = cvals[i][2];
+            
+            if (index_shift > 0) {
+              index_mask >>= 2;
+              index_shift -= 2;
+            } else {
+              index_mask  = 192;
+              index_shift = 6;
+              pixel ++;
+            }
+          }
+          break;
+          
+        case 4 :
+          for (x = image->width, line_ptr = line, index_shift = 4;
+               x > 0;
+               x --, line_ptr += d) {
+            if (index_shift == 4) i = (*pixel >> 4) & 15;
+            else i = *pixel & 15;
+            
+            line_ptr[0] = cvals[i][0];
+            line_ptr[1] = cvals[i][1];
+            line_ptr[2] = cvals[i][2];
+            
+            if (index_shift > 0) {
+              index_shift = 0;
+            } else {
+              index_shift = 4;
+              pixel ++;
+            }
+          }
+          break;
+          
+        case 8 :
+          for (x = image->width, line_ptr = line;
+               x > 0;
+               x --, line_ptr += d, pixel ++) {
+            line_ptr[0] = cvals[*pixel][0];
+            line_ptr[1] = cvals[*pixel][1];
+            line_ptr[2] = cvals[*pixel][2];
+          }
+          break;
+          
+        case 12 :
+          for (x = image->width, line_ptr = line, index_shift = 0;
+               x > 0;
+               x --, line_ptr += d) {
+            if (index_shift == 0) {
+              i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095;
+            } else {
+              i = ((pixel[1] << 8) | pixel[2]) & 4095;
+            }
+            
+            line_ptr[0] = cvals[i][0];
+            line_ptr[1] = cvals[i][1];
+            line_ptr[2] = cvals[i][2];
+            
+            if (index_shift == 0) {
+              index_shift = 4;
+            } else {
+              index_shift = 0;
+              pixel += 3;
+            }
+          }
+          break;
+      }
+    }
+  } else {
+    // RGB(A) image, so figure out the shifts & masks...
+    red_mask  = image->red_mask;
+    red_shift = 0;
+    
+    while ((red_mask & 1) == 0) {
+      red_mask >>= 1;
+      red_shift ++;
+    }
+    
+    green_mask  = image->green_mask;
+    green_shift = 0;
+    
+    while ((green_mask & 1) == 0) {
+      green_mask >>= 1;
+      green_shift ++;
+    }
+    
+    blue_mask  = image->blue_mask;
+    blue_shift = 0;
+    
+    while ((blue_mask & 1) == 0) {
+      blue_mask >>= 1;
+      blue_shift ++;
+    }
+    
+    // Read the pixels and output an RGB image...
+    for (y = 0; y < image->height; y ++) {
+      pixel = (unsigned char *)(image->data + y * image->bytes_per_line);
+      line  = p + y * w * d;
+      
+      switch (image->bits_per_pixel) {
+        case 8 :
+          for (x = image->width, line_ptr = line;
+               x > 0;
+               x --, line_ptr += d, pixel ++) {
+            i = *pixel;
+            
+            line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+            line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+            line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+          }
+          break;
+          
+        case 12 :
+          for (x = image->width, line_ptr = line, index_shift = 0;
+               x > 0;
+               x --, line_ptr += d) {
+            if (index_shift == 0) {
+              i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095;
+            } else {
+              i = ((pixel[1] << 8) | pixel[2]) & 4095;
+            }
+            
+            line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+            line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+            line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            
+            if (index_shift == 0) {
+              index_shift = 4;
+            } else {
+              index_shift = 0;
+              pixel += 3;
+            }
+          }
+          break;
+          
+        case 16 :
+          if (image->byte_order == LSBFirst) {
+            // Little-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 2) {
+              i = (pixel[1] << 8) | pixel[0];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          } else {
+            // Big-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 2) {
+              i = (pixel[0] << 8) | pixel[1];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          }
+          break;
+          
+        case 24 :
+          if (image->byte_order == LSBFirst) {
+            // Little-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 3) {
+              i = (((pixel[2] << 8) | pixel[1]) << 8) | pixel[0];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          } else {
+            // Big-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 3) {
+              i = (((pixel[0] << 8) | pixel[1]) << 8) | pixel[2];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          }
+          break;
+          
+        case 32 :
+          if (image->byte_order == LSBFirst) {
+            // Little-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 4) {
+              i = (((((pixel[3] << 8) | pixel[2]) << 8) | pixel[1]) << 8) | pixel[0];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          } else {
+            // Big-endian...
+            for (x = image->width, line_ptr = line;
+                 x > 0;
+                 x --, line_ptr += d, pixel += 4) {
+              i = (((((pixel[0] << 8) | pixel[1]) << 8) | pixel[2]) << 8) | pixel[3];
+              
+              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
+              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
+              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
+            }
+          }
+          break;
+      }
+    }
+  }
+  
+  // Destroy the X image we've read and return the RGB(A) image...
+  XDestroyImage(image);
+  
+  return p;
+}
+
+//
 // End of "$Id$".
 //