add brightness and contrast (#396)

* Imlib2 supports modifying gamma, brightness and contrast directly
  while sxiv only supports gamma. Makes sense to extend it to brightness
  and contrast as well.

* Since color corrections need to be aware of each other, they have been
  refactored into one centralized function.

* This also makes the code more hackable as it makes it easier to add
  more color correction functions without them interfering with each
  other.

Co-authored-by: 0ion9 <finticemo@gmail.com>
Co-authored-by: NRK <nrk@disroot.org>
Reviewed-on: https://codeberg.org/nsxiv/nsxiv/pulls/396
Reviewed-by: NRK <nrk@disroot.org>
Reviewed-by: TAAPArthur <taaparthur@noreply.codeberg.org>
Co-authored-by: Berke Kocaoğlu <kberke@metu.edu.tr>
Co-committed-by: Berke Kocaoğlu <kberke@metu.edu.tr>
This commit is contained in:
Berke Kocaoğlu 2022-12-22 11:21:40 +00:00 committed by NRK
parent 9cb9a54944
commit 95bc9b463b
7 changed files with 92 additions and 35 deletions

View File

@ -222,15 +222,28 @@ bool cg_navigate_marked(arg_t n)
return navigate_to(new);
}
bool cg_change_gamma(arg_t d)
static bool change_color_modifier(arg_t d, int *target)
{
if (img_change_gamma(&img, d * (prefix > 0 ? prefix : 1))) {
if (!img_change_color_modifier(&img, d * (prefix > 0 ? prefix : 1), target))
return false;
if (mode == MODE_THUMB)
tns.dirty = true;
return true;
} else {
return false;
}
bool cg_change_gamma(arg_t d)
{
return change_color_modifier(d, &img.gamma);
}
bool cg_change_brightness(arg_t d)
{
return change_color_modifier(d, &img.brightness);
}
bool cg_change_contrast(arg_t d)
{
return change_color_modifier(d, &img.contrast);
}
bool ci_navigate(arg_t n)

View File

@ -4,6 +4,8 @@
/* global */
bool cg_change_gamma(arg_t);
bool cg_change_brightness(arg_t);
bool cg_change_contrast(arg_t);
bool cg_first(arg_t);
bool cg_mark_range(arg_t);
bool cg_n_or_last(arg_t);
@ -47,6 +49,8 @@ bool ct_select(arg_t);
#ifdef INCLUDE_MAPPINGS_CONFIG
/* global */
#define g_change_gamma { cg_change_gamma, MODE_ALL }
#define g_change_brightness { cg_change_brightness, MODE_ALL }
#define g_change_contrast { cg_change_contrast, MODE_ALL }
#define g_first { cg_first, MODE_ALL }
#define g_mark_range { cg_mark_range, MODE_ALL }
#define g_n_or_last { cg_n_or_last, MODE_ALL }

View File

@ -33,11 +33,14 @@ static const float zoom_levels[] = {
/* default slideshow delay (in sec, overwritten via -S option): */
static const int SLIDESHOW_DELAY = 5;
/* gamma correction: the user-visible ranges [-GAMMA_RANGE, 0] and
* (0, GAMMA_RANGE] are mapped to the ranges [0, 1], and (1, GAMMA_MAX].
/* color correction: the user-visible ranges [-CC_STEPS, 0] and
* (0, CC_STEPS] are mapped to the ranges [0, 1], and (1, *_MAX].
* Higher step count will have higher granulairy.
*/
static const int CC_STEPS = 32;
static const double GAMMA_MAX = 10.0;
static const int GAMMA_RANGE = 32;
static const double BRIGHTNESS_MAX = 2.0;
static const double CONTRAST_MAX = 4.0;
/* command i_scroll pans image 1/PAN_FRACTION of screen width/height */
static const int PAN_FRACTION = 5;
@ -118,6 +121,10 @@ static const keymap_t keys[] = {
{ 0, XK_braceleft, g_change_gamma, -1 },
{ 0, XK_braceright, g_change_gamma, +1 },
{ ControlMask, XK_g, g_change_gamma, 0 },
{ ControlMask, XK_bracketright, g_change_brightness, +1 },
{ ControlMask, XK_bracketleft, g_change_brightness, -1 },
{ 0, XK_parenleft, g_change_contrast, -1 },
{ 0, XK_parenright, g_change_contrast, +1 },
{ 0, XK_h, t_move_sel, DIR_LEFT },
{ 0, XK_Left, t_move_sel, DIR_LEFT },

View File

@ -209,6 +209,26 @@ steps.
.TP
.B Ctrl-g
Reset gamma correction.
.TP
.B [
Decrease brightness correction by
.I count
steps.
.TP
.B ]
Increase brightness correction by
.I count
steps.
.TP
.B (
Decrease contrast by
.I count
steps.
.TP
.B )
Increase contrast by
.I count
steps.
.SS Thumbnail mode
The following keyboard commands are only available in thumbnail mode:
.TP

50
image.c
View File

@ -90,7 +90,9 @@ void img_init(img_t *img, win_t *win)
img->cmod = imlib_create_color_modifier();
imlib_context_set_color_modifier(img->cmod);
img_change_gamma(img, options->gamma);
img->brightness = 0;
img->contrast = 0;
img_change_color_modifier(img, options->gamma, &img->gamma);
img->ss.on = options->slideshow > 0;
img->ss.delay = options->slideshow > 0 ? options->slideshow : SLIDESHOW_DELAY * 10u;
@ -840,32 +842,36 @@ void img_toggle_antialias(img_t *img)
img->dirty = true;
}
bool img_change_gamma(img_t *img, int d)
static double steps_to_range(int d, double max, double offset)
{
/* d < 0: decrease gamma
* d = 0: reset gamma
* d > 0: increase gamma
*/
int gamma;
double range;
return offset + d * ((d <= 0 ? 1.0 : (max - 1.0)) / CC_STEPS);
}
if (d == 0)
gamma = 0;
else
gamma = MIN(MAX(img->gamma + d, -GAMMA_RANGE), GAMMA_RANGE);
if (img->gamma != gamma) {
void img_update_color_modifiers(img_t *img)
{
assert(imlib_context_get_color_modifier() == img->cmod);
imlib_reset_color_modifier();
if (gamma) {
range = gamma <= 0 ? 1.0 : GAMMA_MAX - 1.0;
imlib_modify_color_modifier_gamma(1.0 + gamma * (range / GAMMA_RANGE));
}
img->gamma = gamma;
if (img->gamma != 0)
imlib_modify_color_modifier_gamma(steps_to_range(img->gamma, GAMMA_MAX, 1.0));
if (img->brightness != 0)
imlib_modify_color_modifier_brightness(steps_to_range(img->brightness, BRIGHTNESS_MAX, 0.0));
if (img->contrast != 0)
imlib_modify_color_modifier_contrast(steps_to_range(img->contrast, CONTRAST_MAX, 1.0));
img->dirty = true;
return true;
} else {
return false;
}
bool img_change_color_modifier(img_t *img, int d, int *target)
{
int value = d == 0 ? 0 : MIN(MAX(*target + d, -CC_STEPS), CC_STEPS);
if (*target == value)
return false;
*target = value;
img_update_color_modifiers(img);
return true;
}
static bool img_frame_goto(img_t *img, int n)

4
main.c
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@ -444,6 +444,10 @@ static void update_info(void)
}
if (img.gamma)
bar_put(r, "G%+d" BAR_SEP, img.gamma);
if (img.brightness)
bar_put(r, "B%+d" BAR_SEP, img.brightness);
if (img.contrast)
bar_put(r, "C%+d" BAR_SEP, img.contrast);
bar_put(r, "%3d%%" BAR_SEP, (int) (img.zoom * 100.0));
if (img.multi.cnt > 0) {
for (fn = 0, i = img.multi.cnt; i > 0; fn++, i /= 10);

View File

@ -181,6 +181,8 @@ struct img {
Imlib_Color_Modifier cmod;
int gamma;
int brightness;
int contrast;
scalemode_t scalemode;
float zoom;
@ -212,7 +214,8 @@ bool img_pan_edge(img_t*, direction_t);
void img_rotate(img_t*, degree_t);
void img_flip(img_t*, flipdir_t);
void img_toggle_antialias(img_t*);
bool img_change_gamma(img_t*, int);
void img_update_color_modifiers(img_t*);
bool img_change_color_modifier(img_t*, int, int*);
bool img_frame_navigate(img_t*, int);
bool img_frame_animate(img_t*);
Imlib_Image img_open(const fileinfo_t*);