d028f0b37d
Function fl_read_image() obliges to keep a minimal use of global variable fl_window also under the Wayland platform, even if its type (Window) makes little sense for the hybrid library because it has its X11 value (given by X11/X.h) which is not meaningful for the Wayland leg of the hybrid platform. Virtual member function Fl_Surface_Device::as_image_surface() becomes useless.
113 lines
3.9 KiB
C++
113 lines
3.9 KiB
C++
//
|
|
// X11 image reading routines for the Fast Light Tool Kit (FLTK).
|
|
//
|
|
// Copyright 1998-2018 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:
|
|
//
|
|
// https://www.fltk.org/COPYING.php
|
|
//
|
|
// Please see the following page on how to report bugs and issues:
|
|
//
|
|
// https://www.fltk.org/bugs.php
|
|
//
|
|
|
|
#include <FL/Fl.H>
|
|
#include <FL/platform.H>
|
|
#include "Fl_Screen_Driver.H"
|
|
|
|
/**
|
|
Reads an RGB(A) image from the current window or off-screen buffer.
|
|
\param[in] p pixel buffer, or NULL to allocate one
|
|
\param[in] X,Y position of top-left of image to read
|
|
\param[in] w,h width and height of image to read
|
|
\param[in] alpha alpha value for image (0 for none)
|
|
\returns pointer to pixel buffer, or NULL if allocation failed.
|
|
|
|
The \p p argument points to a buffer that can hold the image and must
|
|
be at least \p w*h*3 bytes when reading RGB images, or \p w*h*4 bytes
|
|
when reading RGBA images. If NULL, fl_read_image() will create an
|
|
array of the proper size which can be freed using <tt>delete[]</tt>.
|
|
|
|
The \p alpha parameter controls whether an alpha channel is created
|
|
and the value that is placed in the alpha channel. If 0, no alpha
|
|
channel is generated.
|
|
|
|
\see fl_capture_window()
|
|
*/
|
|
uchar *fl_read_image(uchar *p, int X, int Y, int w, int h, int alpha) {
|
|
uchar *image_data = NULL;
|
|
Fl_RGB_Image *img;
|
|
// Under macOS and Wayland, fl_window == 0 when an Fl_Image_Surface is the current drawing
|
|
// surface. Otherwise, fl_window corresponds to a mapped Fl_Window.
|
|
// Under X11 and windows, fl_window is an offscreen buffer when an Fl_Image_Surface
|
|
// is the current drawing or when fl_read_image() is called inside the draw() of
|
|
// an Fl_Double_Window.
|
|
if (fl_find(fl_window) == 0) { // read from offscreen buffer or buffer of an Fl_Double_Window
|
|
img = Fl::screen_driver()->read_win_rectangle(X, Y, w, h, 0);
|
|
if (!img) {
|
|
return NULL;
|
|
}
|
|
img->alloc_array = 1;
|
|
} else {
|
|
img = Fl_Screen_Driver::traverse_to_gl_subwindows(Fl_Window::current(), X, Y, w, h, NULL);
|
|
}
|
|
int depth = alpha ? 4 : 3;
|
|
if (img && img->d() != depth) {
|
|
uchar *data = new uchar[img->w() * img->h() * depth];
|
|
if (depth == 4) memset(data, alpha, img->w() * img->h() * depth);
|
|
uchar *d = data;
|
|
const uchar *q;
|
|
int ld = img->ld() ? img->ld() : img->w() * img->d();
|
|
for (int r = 0; r < img->h(); r++) {
|
|
q = img->array + r * ld;
|
|
for (int c = 0; c < img->w(); c++) {
|
|
d[0] = q[0];
|
|
d[1] = q[1];
|
|
d[2] = q[2];
|
|
d += depth; q += img->d();
|
|
}
|
|
}
|
|
Fl_RGB_Image *img2 = new Fl_RGB_Image(data, img->w(), img->h(), depth);
|
|
img2->alloc_array = 1;
|
|
delete img;
|
|
img = img2;
|
|
}
|
|
if (img) {
|
|
if (img->w() != w || img->h() != h) {
|
|
Fl_RGB_Image *img2 = (Fl_RGB_Image*)img->copy(w, h);
|
|
delete img;
|
|
img = img2;
|
|
}
|
|
img->alloc_array = 0;
|
|
image_data = (uchar*)img->array;
|
|
delete img;
|
|
}
|
|
if (p && image_data) {
|
|
memcpy(p, image_data, w * h * depth);
|
|
delete[] image_data;
|
|
image_data = p;
|
|
}
|
|
return image_data;
|
|
}
|
|
|
|
/** Captures the content of a rectangular zone of a mapped window.
|
|
\param win a mapped Fl_Window (derived types including Fl_Gl_Window are also possible)
|
|
\param x,y,w,h window area to be captured. Intersecting sub-windows are captured too.
|
|
\return The captured pixels as an Fl_RGB_Image. The raw and
|
|
drawing sizes of the image can differ. Returns NULL when capture was not successful.
|
|
The image depth may differ between platforms.
|
|
\version 1.4
|
|
*/
|
|
Fl_RGB_Image *fl_capture_window(Fl_Window *win, int x, int y, int w, int h)
|
|
{
|
|
Fl_RGB_Image *rgb = NULL;
|
|
if (win->shown()) {
|
|
rgb = Fl_Screen_Driver::traverse_to_gl_subwindows(win, x, y, w, h, NULL);
|
|
if (rgb) rgb->scale(w, h, 0, 1);
|
|
}
|
|
return rgb;
|
|
}
|