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+//
+// "$Id: fl_read_image.cxx,v 1.1.2.1 2002/05/30 15:09:03 easysw Exp $"
+//
+// X11 image reading routines for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2002 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 to "fltk-bugs@fltk.org".
+//
+
+#include <FL/x.H>
+#include <FL/fl_draw.H>
+#include "flstring.h"
+
+#ifdef DEBUG
+# include <stdio.h>
+#endif // DEBUG
+
+#ifdef WIN32
+# include "fl_read_image_win32.cxx"
+#elif defined(__APPLE__)
+# include "fl_read_image_mac.cxx"
+#else
+# include <X11/Xutil.h>
+# ifdef __sgi
+# include <X11/extensions/readdisplay.h>
+# endif // __sgi
+
+//
+// 'fl_read_image()' - Read an image from the current window.
+//
+
+uchar * // O - Pixel buffer or NULL if failed
+fl_read_image(uchar *p, // I - Pixel buffer or NULL to allocate
+ int X, // I - Left position
+ int Y, // I - Top position
+ int w, // I - Width of area to read
+ int h, // I - Height of area to read
+ int alpha) { // I - Alpha value for image (0 for none)
+ 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...
+ //
+
+# 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) {
+ image = XGetImage(fl_display, fl_window, X, Y, w, h, AllPlanes, ZPixmap);
+ }
+
+ 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);
+#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 if we have colormap image...
+ if (image->red_mask == 0) {
+ // 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;
+}
+
+#endif
+
+//
+// End of "$Id: fl_read_image.cxx,v 1.1.2.1 2002/05/30 15:09:03 easysw Exp $".
+//
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