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image.cxx
image.cxx 3.94 KiB
//
// Fl_Image test program for the Fast Light Tool Kit (FLTK).
//
// Notice that Fl_Image is for a static, multiple-reuse image, such
// as an icon or postage stamp. Use fl_draw_image to go directly
// from an buffered image that changes often.
//
// Copyright 1998-2021 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/Fl_Double_Window.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Image.H>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int width = 100;
int height = 100;
uchar *image;
void make_image() {
image = new uchar[4*width*height];
uchar *p = image;
for (int y = 0; y < height; y++) {
double Y = double(y)/(height-1);
for (int x = 0; x < width; x++) {
double X = double(x)/(width-1);
*p++ = uchar(255*((1-X)*(1-Y))); // red in upper-left
*p++ = uchar(255*((1-X)*Y)); // green in lower-left
*p++ = uchar(255*(X*Y)); // blue in lower-right
X -= 0.5;
Y -= 0.5;
int alpha = (int)(255 * sqrt(X * X + Y * Y));
if (alpha < 255) *p++ = uchar(alpha); // alpha transparency
else *p++ = 255;
Y += 0.5;
}
}
}
#include <FL/Fl_Toggle_Button.H>
Fl_Toggle_Button *leftb,*rightb,*topb,*bottomb,*insideb,*overb,*inactb;
Fl_Button *b;
Fl_Double_Window *w;
void button_cb(Fl_Widget *,void *) {
int i = 0;
if (leftb->value()) i |= FL_ALIGN_LEFT;
if (rightb->value()) i |= FL_ALIGN_RIGHT;
if (topb->value()) i |= FL_ALIGN_TOP;
if (bottomb->value()) i |= FL_ALIGN_BOTTOM;
if (insideb->value()) i |= FL_ALIGN_INSIDE;
if (overb->value()) i |= FL_ALIGN_TEXT_OVER_IMAGE;
b->align(i);
if (inactb->value()) b->deactivate();
else b->activate();
w->redraw();