mirror of https://github.com/fltk/fltk
Fix and improve fl_contrast() calculations
- src/fl_contrast.cxx: - FL_CONTRAST_LEGACY: reset black/white threshold from 55 to 50 - FL_CONTRAST_CIELAB: change default contrast level from 55 to 39 - test/contrast.cxx: - set default contrast mode to CIELAB - add "random color" button to test random foreground colors (text) - slightly increase terminal size - make the Fl_Terminal widget the resizable() of the window
This commit is contained in:
Albrecht Schlosser
parent
9df6dc2aeb
commit
9820d9f555
|
|
@ -24,6 +24,10 @@
|
|||
#include <FL/Fl.H>
|
||||
#include <math.h>
|
||||
|
||||
#ifndef DEBUG_CONTRAST_LEGACY
|
||||
#define DEBUG_CONTRAST_LEGACY 0
|
||||
#endif // DEBUG_CONTRAST_LEGACY
|
||||
|
||||
// Initial values of global/static variables defined by fl_contrast_* functions.
|
||||
|
||||
// This defines the default contrast mode since FLTK 1.4.0
|
||||
|
|
@ -31,7 +35,11 @@ static int fl_contrast_mode_ = FL_CONTRAST_CIELAB;
|
|||
|
||||
// This defines the default contrast level per contrast mode
|
||||
static int fl_contrast_level_[10] = {
|
||||
0, 50, 55, 0, 0, 0, 0, 0, 0, 0
|
||||
0, // 0 = FL_CONTRAST_NONE
|
||||
50, // 1 = FL_CONTRAST_LEGACY
|
||||
39, // 2 = FL_CONTRAST_CIELAB
|
||||
0, // 3 = FL_CONTRAST_CUSTOM
|
||||
0 // 4-9 = not yet defined
|
||||
};
|
||||
|
||||
// There is no default custom contrast function
|
||||
|
|
@ -338,6 +346,18 @@ static Fl_Color fl_contrast_legacy(Fl_Color fg, Fl_Color bg, Fl_Fontsize fs, int
|
|||
|
||||
int lc = lfg - lbg; // calculated contrast (-255 .. 255)
|
||||
|
||||
#if DEBUG_CONTRAST_LEGACY
|
||||
|
||||
const char *rv = "?"; // return value as text (init)
|
||||
if (lc > tc || lc < -tc) rv = "fg"; // sufficient contrast
|
||||
else if (lbg > tbw) rv = "BLACK"; // light background
|
||||
else rv = "WHITE"; // dark background
|
||||
|
||||
printf("fl_contrast_legacy: lfg %4d (%7.2f) lbg %4d (%7.2f) lc %4d (%7.2f) => %s\n",
|
||||
lfg, lfg/255.*100, lbg, lbg/255.*100, lc, lc/255.*100, rv);
|
||||
|
||||
#endif // DEBUG_CONTRAST_LEGACY
|
||||
|
||||
// Compare and return the contrasting color...
|
||||
|
||||
if (lc > tc || lc < -tc) return fg; // sufficient contrast
|
||||
|
|
@ -364,7 +384,7 @@ static Fl_Color fl_contrast_cielab(Fl_Color fg, Fl_Color bg, Fl_Fontsize fs, int
|
|||
(void) context; // currently ignored
|
||||
|
||||
double tc = (double)fl_contrast_level(); // sufficient contrast threshold
|
||||
double tbw = 55.; // black/white threshold
|
||||
double tbw = 50.; // black/white threshold
|
||||
|
||||
// Compute the perceived lightness L* (Lstar) and the contrast
|
||||
|
||||
|
|
|
|||
|
|
@ -1,7 +1,7 @@
|
|||
//
|
||||
// Contrast function test program for the Fast Light Tool Kit (FLTK).
|
||||
//
|
||||
// Copyright 2022 by Bill Spitzak and others.
|
||||
// Copyright 2022-2024 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
|
||||
|
|
@ -35,7 +35,7 @@
|
|||
|
||||
// program version
|
||||
|
||||
const char *version = "0.9.0";
|
||||
const char *version = "0.9.1";
|
||||
|
||||
// prototypes and forward declarations
|
||||
|
||||
|
|
@ -103,8 +103,8 @@ int g_selected = -1; // selected button: -1 = none, 0 - 255 = valid b
|
|||
Fl_Fontsize g_fs = 15; // fontsize for button labels
|
||||
int g_level = 0; // *init* fl_contrast_level (sensitivity)
|
||||
|
||||
int g_algo = FL_CONTRAST_LEGACY;// contrast algorithm: 0 = none, 1 = legacy (1.3.x), 2 = CIELAB, 3 = custom
|
||||
const char *alch = ""; // algorithm as char: "LEGACY", "CIELAB" , or "CUSTOM"
|
||||
int g_algo = FL_CONTRAST_CIELAB; // contrast algorithm: 0 = none, 1 = legacy (1.3.x), 2 = CIELAB, 3 = custom
|
||||
const char *alch = ""; // algorithm as char: "LEGACY", "CIELAB" , or "CUSTOM"
|
||||
|
||||
Fl_Color lcolor = FL_BLACK; // label color, set by slider callback
|
||||
Button *buttons[256]; // array of color buttons
|
||||
|
|
@ -224,6 +224,38 @@ void slider_cb(Fl_Widget *w, void *v) {
|
|||
w->window()->redraw();
|
||||
}
|
||||
|
||||
|
||||
// callback for the "random color" button
|
||||
|
||||
void rc_cb(Fl_Widget *w, void *v) {
|
||||
static bool first = true;
|
||||
unsigned int r, g, b;
|
||||
|
||||
if (first) {
|
||||
// Seed the random number generator...
|
||||
srand((unsigned int)time(NULL));
|
||||
first = false;
|
||||
r = g = b = 0; // initialize with black
|
||||
} else {
|
||||
r = rand() % 256;
|
||||
g = rand() % 256;
|
||||
b = rand() % 256;
|
||||
}
|
||||
|
||||
sliders[1] -> value(r);
|
||||
sliders[2] -> value(g);
|
||||
sliders[3] -> value(b);
|
||||
|
||||
// update button label colors
|
||||
lcolor = fl_rgb_color(r, g, b); // set color value
|
||||
update_labels();
|
||||
// output label color
|
||||
char color_buf[10];
|
||||
sprintf(color_buf, "%02X %02X %02X", r, g, b);
|
||||
color_out->value(color_buf);
|
||||
w->window()->redraw();
|
||||
}
|
||||
|
||||
// callback for contrast algorithm (radio buttons)
|
||||
|
||||
void algo_cb(Fl_Widget *w, void *v) {
|
||||
|
|
@ -275,7 +307,7 @@ int main(int argc, char **argv) {
|
|||
int cw = 16 * bw + 10;
|
||||
int ch = 16 * bh + 10;
|
||||
int ww = cw + 10;
|
||||
int wh = 16 * bh + 135 + 10 + 150 /* terminal */ + 10;
|
||||
int wh = 16 * bh + 135 + 10 + 170 /* terminal */ + 10;
|
||||
Fl_Double_Window window(ww, wh, "fl_contrast test");
|
||||
|
||||
int n = 0;
|
||||
|
|
@ -358,7 +390,7 @@ int main(int argc, char **argv) {
|
|||
Fl_Radio_Round_Button *aleg = new Fl_Radio_Round_Button(cgx, cgy + 25, cgw, abh, "LEGACY");
|
||||
Fl_Radio_Round_Button *acie = new Fl_Radio_Round_Button(cgx, cgy + 50, cgw, abh, "CIELAB");
|
||||
Fl_Radio_Round_Button *aapc = new Fl_Radio_Round_Button(cgx, cgy + 75, cgw, abh, "CUSTOM");
|
||||
aleg->value(1);
|
||||
acie->value(1);
|
||||
anon->callback(algo_cb, (void *)0);
|
||||
aleg->callback(algo_cb, (void *)1);
|
||||
acie->callback(algo_cb, (void *)2);
|
||||
|
|
@ -407,6 +439,12 @@ int main(int argc, char **argv) {
|
|||
lf->tooltip("Click to output a linefeed to the log.");
|
||||
lf->callback(lf_cb);
|
||||
|
||||
// random color (R) button
|
||||
|
||||
Fl_Button *rc = new Fl_Button(10 + 8 * bw + lf->w() + 2, blue->y(), bw*3/4, sh, "&RC");
|
||||
rc->tooltip("Click to select a random text color.");
|
||||
rc->callback(rc_cb);
|
||||
|
||||
// color chooser for field #255
|
||||
|
||||
int ccx = 10 + 12 * bw;
|
||||
|
|
@ -421,7 +459,13 @@ int main(int argc, char **argv) {
|
|||
color_chooser->mode(1); // byte mode
|
||||
color_chooser->align(FL_ALIGN_LEFT_BOTTOM);
|
||||
|
||||
// simple terminal for output (FLTK 1.4 only)
|
||||
// set contrast mode and level, update button label colors
|
||||
|
||||
fl_contrast_mode(g_algo);
|
||||
fl_contrast_function(custom_contrast); // dummy contrast function
|
||||
algo_cb(acie, fl_voidptr(2));
|
||||
|
||||
// Fl_Terminal for output
|
||||
|
||||
int ttx = 10;
|
||||
int tty = color_chooser->y() + cch + 10;
|
||||
|
|
@ -433,22 +477,18 @@ int main(int argc, char **argv) {
|
|||
term->textfgcolor(FL_BLACK);
|
||||
term->textsize(13);
|
||||
|
||||
term->printf("FLTK fl_contrast() test program with different contrast algorithms, version %s\n", version);
|
||||
term->printf("FLTK version %d.%d.%d\n", FL_MAJOR_VERSION, FL_MINOR_VERSION, FL_PATCH_VERSION);
|
||||
term->printf("FLTK %d.%d.%d fl_contrast() test program with different contrast algorithms, version %s\n",
|
||||
FL_MAJOR_VERSION, FL_MINOR_VERSION, FL_PATCH_VERSION, version);
|
||||
term->printf(" - Select a foreground (text) color with the gray or red/green/blue sliders (displayed inside each field).\n");
|
||||
term->printf(" - Select an arbitrary background color for field #255 with the color chooser.\n");
|
||||
term->printf(" - Select a colored field (by clicking on it) to display its attributes.\n");
|
||||
term->printf(" - Select the contrast algorithm by clicking on the radio buttons.\n");
|
||||
term->printf(" - Tune the contrast algorithm with the light blue \"level\" slider (default: 50).\n");
|
||||
term->printf(" - Tune the contrast algorithm with the light blue \"level\" slider (default: %d).\n", fl_contrast_level());
|
||||
term->printf(" - Select a random foreground (text) color by clicking the RC button\n");
|
||||
|
||||
// set contrast mode and level, update button label colors
|
||||
|
||||
fl_contrast_mode(g_algo);
|
||||
fl_contrast_function(custom_contrast); // dummy function
|
||||
algo_cb(NULL, fl_voidptr(g_algo)); // updates button labels
|
||||
|
||||
window.resizable(window);
|
||||
window.resizable(term);
|
||||
window.end();
|
||||
window.show(argc, argv);
|
||||
rc_cb(rc, 0); // update button labels - must be called after show()
|
||||
return Fl::run();
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue