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fltk/src/fl_read_image.cxx
Manolo Gouy bd1446a6eb Fix for STR#3142 where fl_read_image() correctly reads GL data under X11, but ignores them under MSWindows and Mac OS X. 
Moreover, fl_read_image() behaves differently with and without OS virtualization for X11 and MSWindows.
The patched function reads whatever is in the rectangle transmitted in arguments, with and without GL data, with and without subwindows,
on ‘true’ OS or on virtualized OS.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10436 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2014-11-06 16:48:57 +00:00

636 lines
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//
// "$Id$"
//
// X11 image reading routines for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2014 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:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
#include <FL/x.H>
#include <FL/Fl.H>
#include <FL/fl_draw.H>
#include "flstring.h"
#ifdef DEBUG
# include <stdio.h>
#endif // DEBUG
#if defined(__APPLE__)
# include "fl_read_image_mac.cxx"
#else
# include <FL/Fl_RGB_Image.H>
# include <FL/Fl_Window.H>
# include <FL/Fl_Plugin.H>
# include <FL/Fl_Device.H>
static uchar *read_win_rectangle(uchar *p, int X, int Y, int w, int h, int alpha);
static void write_image_inside(Fl_RGB_Image *to, Fl_RGB_Image *from, int to_x, int to_y)
/* Copy the image "from" inside image "to" with its top-left angle at coordinates to_x, to_y.
Also, exchange top and bottom of "from". Image depth can differ between "to" and "from".
*/
{
int to_ld = (to->ld() == 0? to->w() * to->d() : to->ld());
int from_ld = (from->ld() == 0? from->w() * from->d() : from->ld());
uchar *tobytes = (uchar*)to->array + to_y * to_ld + to_x * to->d();
const uchar *frombytes = from->array + (from->h() - 1) * from_ld;
for (int i = from->h() - 1; i >= 0; i--) {
if (from->d() == to->d()) memcpy(tobytes, frombytes, from->w() * from->d());
else {
for (int j = 0; j < from->w(); j++) {
memcpy(tobytes + j * to->d(), frombytes + j * from->d(), from->d());
}
}
tobytes += to_ld;
frombytes -= from_ld;
}
}
/* Captures rectangle x,y,w,h from a mapped window or GL window.
All sub-GL-windows that intersect x,y,w,h, and their subwindows, are also captured.
Arguments when this function is initially called:
g: a window or GL window
p: as in fl_read_image()
x,y,w,h: a rectangle in window g's coordinates
alpha: as in fl_read_image()
full_img: NULL
Arguments when this function recursively calls itself:
g: an Fl_Group
p: as above
x,y,w,h: a rectangle in g's coordinates if g is a window, or in g's parent window coords if g is a group
alpha: as above
full_img: NULL, or a previously captured image that encompasses the x,y,w,h rectangle and that
will be partially overwritten with the new capture
Return value:
An Fl_RGB_Image* of depth 4 if alpha>0 or 3 if alpha = 0 containing the captured pixels.
*/
static Fl_RGB_Image *traverse_to_gl_subwindows(Fl_Group *g, uchar *p, int x, int y, int w, int h, int alpha,
Fl_RGB_Image *full_img)
{
if ( g->as_gl_window() ) {
Fl_Plugin_Manager pm("fltk:device");
Fl_Device_Plugin *pi = (Fl_Device_Plugin*)pm.plugin("opengl.device.fltk.org");
if (!pi) return full_img;
Fl_RGB_Image *img = pi->rectangle_capture(g, x, y, w, h); // bottom to top image
if (full_img) full_img = img; // top and bottom will be exchanged later
else { // exchange top and bottom to get a proper FLTK image
uchar *data = ( p ? p : new uchar[img->w() * img->h() * (alpha?4:3)] );
full_img = new Fl_RGB_Image(data, img->w(), img->h(), alpha?4:3);
if (!p) full_img->alloc_array = 1;
if (alpha) memset(data, alpha, img->w() * img->h() * 4);
write_image_inside(full_img, img, 0, 0);
delete img;
}
}
else if ( g->as_window() && (!full_img || (g->window() && g->window()->as_gl_window())) ) {
// the starting window or one inside a GL window
if (full_img) g->as_window()->make_current();
uchar *image_data;
int alloc_img = (full_img != NULL || p == NULL); // false means use p, don't alloc new memory for image
#ifdef __APPLE_CC__
// on Darwin + X11, read_win_rectangle() sometimes returns NULL when there are subwindows
do image_data = read_win_rectangle( (alloc_img ? NULL : p), x, y, w, h, alpha); while (!image_data);
#else
image_data = read_win_rectangle( (alloc_img ? NULL : p), x, y, w, h, alpha);
#endif
full_img = new Fl_RGB_Image(image_data, w, h, alpha?4:3);
if (alloc_img) full_img->alloc_array = 1;
}
int n = g->children();
for (int i = 0; i < n; i++) {
Fl_Widget *c = g->child(i);
if ( !c->visible() || !c->as_group()) continue;
if ( c->as_window() ) {
int origin_x = x; // compute intersection of x,y,w,h and the c window
if (x < c->x()) origin_x = c->x();
int origin_y = y;
if (y < c->y()) origin_y = c->y();
int width = c->w();
if (origin_x + width > c->x() + c->w()) width = c->x() + c->w() - origin_x;
if (origin_x + width > x + w) width = x + w - origin_x;
int height = c->w();
if (origin_y + height > c->y() + c->h()) height = c->y() + c->h() - origin_y;
if (origin_y + height > y + h) height = y + h - origin_y;
if (width > 0 && height > 0) {
Fl_RGB_Image *img = traverse_to_gl_subwindows(c->as_window(), p, origin_x - c->x(),
origin_y - c->y(), width, height, alpha, full_img);
if (img == full_img) continue;
int top;
if (c->as_gl_window()) {
top = origin_y - y;
} else {
top = full_img->h() - (origin_y - y + img->h());
}
write_image_inside(full_img, img, origin_x - x, top);
delete img;
}
}
else traverse_to_gl_subwindows(c->as_group(), p, x, y, w, h, alpha, full_img);
}
return full_img;
}
//
// 'fl_read_image()' - Read an image from the current window or off-screen buffer
// this is the version for X11 and WIN32. The mac version is in fl_read_image_mac.cxx
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
// negative allows capture of window title bar and frame (X11 only)
int h, // I - Height of area to read
int alpha)// I - Alpha value for image (0 for none)
{
if (w < 0 || fl_find(fl_window) == 0) { // read from off_screen buffer or title bar and frame
return read_win_rectangle(p, X, Y, w, h, alpha); // this function has an X11 and a WIN32 version
}
Fl_RGB_Image *img = traverse_to_gl_subwindows(Fl_Window::current(), p, X, Y, w, h, alpha, NULL);
uchar *image_data = (uchar*)img->array;
img->alloc_array = 0;
delete img;
return image_data;
}
#ifdef WIN32
# include "fl_read_image_win32.cxx" // gives the WIN32 version of read_win_rectangle()
#else
# include <X11/Xutil.h>
# ifdef __sgi
# include <X11/extensions/readdisplay.h>
# else
# include <stdlib.h>
# endif // __sgi
// Defined in fl_color.cxx
extern uchar fl_redmask, fl_greenmask, fl_bluemask;
extern int fl_redshift, fl_greenshift, fl_blueshift, fl_extrashift;
//
// '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;
}
}
static uchar *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
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;
}
#endif // !WIN32
#endif // !__APPLE__
//
// End of "$Id$".
//
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