asgardius/virtualx-engine
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Allow picking similar colours using OKHSL.

Browse source
This commit is contained in:
K. S. Ernest (iFire) Lee 2022-04-18 11:29:29 -07:00 committed by K. S. Ernest (iFire) Lee
parent 36bd26dc75
commit 1b776a6e7a
13 changed files with 1606 additions and 39 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
COPYRIGHT.txt
View file

@ -321,6 +321,12 @@ Comment: Tangent Space Normal Maps implementation
Copyright: 2011, Morten S. Mikkelsen
License: Zlib
Files: ./thirdparty/misc/ok_color.h
./thirdparty/misc/ok_color_shader.h
Comment: OK Lab color space
Copyright: 2021, Björn Ottosson
License: Expat
Files: ./thirdparty/noise/FastNoiseLite.h
Comment: FastNoise Lite
Copyright: 2020, Jordan Peck and contributors

61
core/math/color.cpp
View file

@ -35,6 +35,8 @@
#include "core/string/print_string.h"
#include "core/templates/rb_map.h"
#include "thirdparty/misc/ok_color.h"
uint32_t Color::to_argb32() const {
uint32_t c = (uint8_t)Math::round(a * 255);
c <<= 8;
@ -240,6 +242,20 @@ void Color::set_hsv(float p_h, float p_s, float p_v, float p_alpha) {
}
}
void Color::set_ok_hsl(float p_h, float p_s, float p_l, float p_alpha) {
ok_color::HSL hsl;
hsl.h = p_h;
hsl.s = p_s;
hsl.l = p_l;
ok_color new_ok_color;
ok_color::RGB rgb = new_ok_color.okhsl_to_srgb(hsl);
Color c = Color(rgb.r, rgb.g, rgb.b, p_alpha).clamp();
r = c.r;
g = c.g;
b = c.b;
a = c.a;
}
bool Color::is_equal_approx(const Color &p_color) const {
return Math::is_equal_approx(r, p_color.r) && Math::is_equal_approx(g, p_color.g) && Math::is_equal_approx(b, p_color.b) && Math::is_equal_approx(a, p_color.a);
}
@ -568,3 +584,48 @@ Color Color::operator-() const {
1.0f - b,
1.0f - a);
}
Color Color::from_ok_hsl(float p_h, float p_s, float p_l, float p_alpha) {
Color c;
c.set_ok_hsl(p_h, p_s, p_l, p_alpha);
return c;
}
float Color::get_ok_hsl_h() const {
ok_color::RGB rgb;
rgb.r = r;
rgb.g = g;
rgb.b = b;
ok_color new_ok_color;
ok_color::HSL ok_hsl = new_ok_color.srgb_to_okhsl(rgb);
if (Math::is_nan(ok_hsl.h)) {
return 0.0f;
}
return CLAMP(ok_hsl.h, 0.0f, 1.0f);
}
float Color::get_ok_hsl_s() const {
ok_color::RGB rgb;
rgb.r = r;
rgb.g = g;
rgb.b = b;
ok_color new_ok_color;
ok_color::HSL ok_hsl = new_ok_color.srgb_to_okhsl(rgb);
if (Math::is_nan(ok_hsl.s)) {
return 0.0f;
}
return CLAMP(ok_hsl.s, 0.0f, 1.0f);
}
float Color::get_ok_hsl_l() const {
ok_color::RGB rgb;
rgb.r = r;
rgb.g = g;
rgb.b = b;
ok_color new_ok_color;
ok_color::HSL ok_hsl = new_ok_color.srgb_to_okhsl(rgb);
if (Math::is_nan(ok_hsl.l)) {
return 0.0f;
}
return CLAMP(ok_hsl.l, 0.0f, 1.0f);
}

8
core/math/color.h
View file

@ -56,6 +56,10 @@ struct _NO_DISCARD_ Color {
float get_s() const;
float get_v() const;
void set_hsv(float p_h, float p_s, float p_v, float p_alpha = 1.0);
float get_ok_hsl_h() const;
float get_ok_hsl_s() const;
float get_ok_hsl_l() const;
void set_ok_hsl(float p_h, float p_s, float p_l, float p_alpha = 1.0);
_FORCE_INLINE_ float &operator[](int p_idx) {
return components[p_idx];
@ -195,6 +199,7 @@ struct _NO_DISCARD_ Color {
static Color get_named_color(int p_idx);
static Color from_string(const String &p_string, const Color &p_default);
static Color from_hsv(float p_h, float p_s, float p_v, float p_alpha = 1.0);
static Color from_ok_hsl(float p_h, float p_s, float p_l, float p_alpha = 1.0);
static Color from_rgbe9995(uint32_t p_rgbe);
_FORCE_INLINE_ bool operator<(const Color &p_color) const; //used in set keys
@ -213,6 +218,9 @@ struct _NO_DISCARD_ Color {
_FORCE_INLINE_ void set_h(float p_h) { set_hsv(p_h, get_s(), get_v()); }
_FORCE_INLINE_ void set_s(float p_s) { set_hsv(get_h(), p_s, get_v()); }
_FORCE_INLINE_ void set_v(float p_v) { set_hsv(get_h(), get_s(), p_v); }
_FORCE_INLINE_ void set_ok_hsl_h(float p_h) { set_ok_hsl(p_h, get_ok_hsl_s(), get_ok_hsl_l()); }
_FORCE_INLINE_ void set_ok_hsl_s(float p_s) { set_ok_hsl(get_ok_hsl_h(), p_s, get_ok_hsl_l()); }
_FORCE_INLINE_ void set_ok_hsl_l(float p_l) { set_ok_hsl(get_ok_hsl_h(), get_ok_hsl_s(), p_l); }
_FORCE_INLINE_ Color() {}

2
core/variant/variant_call.cpp
View file

@ -1675,6 +1675,8 @@ static void _register_variant_builtin_methods() {
bind_static_method(Color, get_named_color, sarray("idx"), varray());
bind_static_method(Color, from_string, sarray("str", "default"), varray());
bind_static_method(Color, from_hsv, sarray("h", "s", "v", "alpha"), varray(1.0));
bind_static_method(Color, from_ok_hsl, sarray("h", "s", "l", "alpha"), varray(1.0));
bind_static_method(Color, from_rgbe9995, sarray("rgbe"), varray());
/* RID */

4
core/variant/variant_setget.h
View file

@ -329,4 +329,8 @@ SETGET_NUMBER_STRUCT_FUNC(Color, double, h, set_h, get_h)
SETGET_NUMBER_STRUCT_FUNC(Color, double, s, set_s, get_s)
SETGET_NUMBER_STRUCT_FUNC(Color, double, v, set_v, get_v)
SETGET_NUMBER_STRUCT_FUNC(Color, double, ok_hsl_h, set_ok_hsl_h, get_ok_hsl_h)
SETGET_NUMBER_STRUCT_FUNC(Color, double, ok_hsl_s, set_ok_hsl_s, get_ok_hsl_s)
SETGET_NUMBER_STRUCT_FUNC(Color, double, ok_hsl_l, set_ok_hsl_l, get_ok_hsl_l)
#endif // VARIANT_SETGET_H

18
doc/classes/Color.xml
View file

@ -165,6 +165,24 @@
[/codeblocks]
</description>
</method>
<method name="from_ok_hsl" qualifiers="static">
<return type="Color" />
<argument index="0" name="h" type="float" />
<argument index="1" name="s" type="float" />
<argument index="2" name="l" type="float" />
<argument index="3" name="alpha" type="float" default="1.0" />
<description>
Constructs a color from an [url=https://bottosson.github.io/posts/colorpicker/]OK HSL profile[/url]. [code]h[/code] (hue), [code]s[/code] (saturation), and [code]v[/code] (value) are typically between 0 and 1.
[codeblocks]
[gdscript]
var c = Color.from_ok_hsl(0.58, 0.5, 0.79, 0.8)
[/gdscript]
[csharp]
var c = Color.FromOkHsl(0.58f, 0.5f, 0.79f, 0.8f);
[/csharp]
[/codeblocks]
</description>
</method>
<method name="from_rgbe9995" qualifiers="static">
<return type="Color" />
<argument index="0" name="rgbe" type="int" />

3
doc/classes/ColorPicker.xml
View file

@ -91,6 +91,9 @@
<constant name="SHAPE_VHS_CIRCLE" value="2" enum="PickerShapeType">
HSV Color Model circle color space. Use Saturation as a radius.
</constant>
<constant name="SHAPE_OKHSL_CIRCLE" value="3" enum="PickerShapeType">
HSL OK Color Model circle color space.
</constant>
</constants>
<theme_items>
<theme_item name="h_width" data_type="constant" type="int" default="30">

4
editor/editor_node.cpp
View file

@ -6109,8 +6109,8 @@ EditorNode::EditorNode() {
EDITOR_DEF("interface/inspector/resources_to_open_in_new_inspector", "Script,MeshLibrary");
EDITOR_DEF("interface/inspector/default_color_picker_mode", 0);
EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::INT, "interface/inspector/default_color_picker_mode", PROPERTY_HINT_ENUM, "RGB,HSV,RAW", PROPERTY_USAGE_DEFAULT));
EDITOR_DEF("interface/inspector/default_color_picker_shape", (int32_t)ColorPicker::SHAPE_VHS_CIRCLE);
EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::INT, "interface/inspector/default_color_picker_shape", PROPERTY_HINT_ENUM, "HSV Rectangle,HSV Rectangle Wheel,VHS Circle", PROPERTY_USAGE_DEFAULT));
EDITOR_DEF("interface/inspector/default_color_picker_shape", (int32_t)ColorPicker::SHAPE_OKHSL_CIRCLE);
EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::INT, "interface/inspector/default_color_picker_shape", PROPERTY_HINT_ENUM, "HSV Rectangle,HSV Rectangle Wheel,VHS Circle,OKHSL Circle", PROPERTY_USAGE_DEFAULT));
ED_SHORTCUT("canvas_item_editor/pan_view", TTR("Pan View"), Key::SPACE);

173
scene/gui/color_picker.cpp
View file

@ -31,6 +31,7 @@
#include "color_picker.h"
#include "core/input/input.h"
#include "core/math/color.h"
#include "core/os/keyboard.h"
#include "core/os/os.h"
#include "scene/main/window.h"
@ -39,6 +40,9 @@
#include "editor/editor_settings.h"
#endif
#include "thirdparty/misc/ok_color.h"
#include "thirdparty/misc/ok_color_shader.h"
List<Color> ColorPicker::preset_cache;
void ColorPicker::_notification(int p_what) {
@ -102,6 +106,7 @@ void ColorPicker::_notification(int p_what) {
Ref<Shader> ColorPicker::wheel_shader;
Ref<Shader> ColorPicker::circle_shader;
Ref<Shader> ColorPicker::circle_ok_color_shader;
void ColorPicker::init_shaders() {
wheel_shader.instantiate();
@ -152,11 +157,36 @@ void fragment() {
COLOR = vec4(mix(vec3(1.0), clamp(abs(fract(vec3((a - TAU) / TAU) + vec3(1.0, 2.0 / 3.0, 1.0 / 3.0)) * 6.0 - vec3(3.0)) - vec3(1.0), 0.0, 1.0), ((float(sqrt(x * x + y * y)) * 2.0)) / 1.0) * vec3(v), (b + b2 + b3 + b4) / 4.00);
})");
circle_ok_color_shader.instantiate();
circle_ok_color_shader->set_code(OK_COLOR_SHADER + R"(
// ColorPicker ok color hsv circle shader.
uniform float v = 1.0;
void fragment() {
float x = UV.x - 0.5;
float y = UV.y - 0.5;
x += 0.001;
y += 0.001;
float b = float(sqrt(x * x + y * y) < 0.5);
x -= 0.002;
float b2 = float(sqrt(x * x + y * y) < 0.5);
y -= 0.002;
float b3 = float(sqrt(x * x + y * y) < 0.5);
x += 0.002;
float b4 = float(sqrt(x * x + y * y) < 0.5);
float s = sqrt(x * x + y * y);
float h = atan(y, x) / (2.0*M_PI);
vec3 col = okhsl_to_srgb(vec3(h, s, v));
COLOR = vec4(col, (b + b2 + b3 + b4) / 4.00);
})");
}
void ColorPicker::finish_shaders() {
wheel_shader.unref();
circle_shader.unref();
circle_ok_color_shader.unref();
}
void ColorPicker::set_focus_on_line_edit() {
@ -166,8 +196,12 @@ void ColorPicker::set_focus_on_line_edit() {
void ColorPicker::_update_controls() {
const char *rgb[3] = { "R", "G", "B" };
const char *hsv[3] = { "H", "S", "V" };
if (hsv_mode_enabled) {
const char *hsl[3] = { "H", "S", "L" };
if (hsv_mode_enabled && picker_type == SHAPE_OKHSL_CIRCLE) {
for (int i = 0; i < 3; i++) {
labels[i]->set_text(hsl[i]);
}
} else if (hsv_mode_enabled && picker_type != SHAPE_OKHSL_CIRCLE) {
for (int i = 0; i < 3; i++) {
labels[i]->set_text(hsv[i]);
}
@ -176,14 +210,23 @@ void ColorPicker::_update_controls() {
labels[i]->set_text(rgb[i]);
}
}
if (picker_type == SHAPE_OKHSL_CIRCLE) {
btn_hsv->set_text(RTR("OKHSL"));
} else {
btn_hsv->set_text(RTR("HSV"));
}
if (hsv_mode_enabled) {
set_raw_mode(false);
set_hsv_mode(true);
btn_raw->set_disabled(true);
} else if (raw_mode_enabled) {
set_raw_mode(true);
set_hsv_mode(false);
btn_raw->set_disabled(false);
btn_hsv->set_disabled(true);
} else {
set_raw_mode(false);
set_hsv_mode(false);
btn_raw->set_disabled(false);
btn_hsv->set_disabled(false);
}
@ -236,8 +279,15 @@ void ColorPicker::_update_controls() {
wheel_edit->show();
w_edit->show();
uv_edit->hide();
wheel->set_material(circle_mat);
circle_mat->set_shader(circle_shader);
break;
case SHAPE_OKHSL_CIRCLE:
wheel_edit->show();
w_edit->show();
uv_edit->hide();
wheel->set_material(circle_mat);
circle_mat->set_shader(circle_ok_color_shader);
break;
default: {
}
@ -246,11 +296,17 @@ void ColorPicker::_update_controls() {
void ColorPicker::_set_pick_color(const Color &p_color, bool p_update_sliders) {
color = p_color;
if (color != last_hsv) {
h = color.get_h();
s = color.get_s();
v = color.get_v();
last_hsv = color;
if (color != last_color) {
if (picker_type == SHAPE_OKHSL_CIRCLE) {
h = color.get_ok_hsl_h();
s = color.get_ok_hsl_s();
v = color.get_ok_hsl_l();
} else {
h = color.get_h();
s = color.get_s();
v = color.get_v();
}
last_color = color;
}
if (!is_inside_tree()) {
@ -301,10 +357,13 @@ void ColorPicker::_value_changed(double) {
h = scroll[0]->get_value() / 360.0;
s = scroll[1]->get_value() / 100.0;
v = scroll[2]->get_value() / 100.0;
color.set_hsv(h, s, v, scroll[3]->get_value() / 255.0);
last_hsv = color;
if (picker_type == SHAPE_OKHSL_CIRCLE) {
color.set_ok_hsl(h, s, v, Math::round(scroll[3]->get_value() / 255.0));
} else {
color.set_hsv(h, s, v, Math::round(scroll[3]->get_value() / 255.0));
}
last_color = color;
} else {
for (int i = 0; i < 4; i++) {
color.components[i] = scroll[i]->get_value() / (raw_mode_enabled ? 1.0 : 255.0);
@ -342,7 +401,6 @@ void ColorPicker::_update_color(bool p_update_sliders) {
for (int i = 0; i < 4; i++) {
scroll[i]->set_step(1.0);
}
scroll[0]->set_max(359);
scroll[0]->set_value(h * 360.0);
scroll[1]->set_max(100);
@ -350,7 +408,7 @@ void ColorPicker::_update_color(bool p_update_sliders) {
scroll[2]->set_max(100);
scroll[2]->set_value(v * 100.0);
scroll[3]->set_max(255);
scroll[3]->set_value(color.components[3] * 255.0);
scroll[3]->set_value(Math::round(color.components[3] * 255.0));
} else {
for (int i = 0; i < 4; i++) {
if (raw_mode_enabled) {
@ -362,7 +420,7 @@ void ColorPicker::_update_color(bool p_update_sliders) {
scroll[i]->set_value(color.components[i]);
} else {
scroll[i]->set_step(1);
const float byte_value = color.components[i] * 255.0;
const float byte_value = Math::round(color.components[i] * 255.0);
scroll[i]->set_max(next_power_of_2(MAX(255, byte_value)) - 1);
scroll[i]->set_value(byte_value);
}
@ -426,7 +484,6 @@ Color ColorPicker::get_pick_color() const {
void ColorPicker::set_picker_shape(PickerShapeType p_picker_type) {
ERR_FAIL_INDEX(p_picker_type, SHAPE_MAX);
picker_type = p_picker_type;
_update_controls();
_update_color();
}
@ -702,7 +759,7 @@ void ColorPicker::_hsv_draw(int p_which, Control *c) {
Ref<Texture2D> cursor = get_theme_icon(SNAME("picker_cursor"), SNAME("ColorPicker"));
int x;
int y;
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
x = center.x + (center.x * Math::cos(h * Math_TAU) * s) - (cursor->get_width() / 2);
y = center.y + (center.y * Math::sin(h * Math_TAU) * s) - (cursor->get_height() / 2);
} else {
@ -735,6 +792,25 @@ void ColorPicker::_hsv_draw(int p_which, Control *c) {
Color col;
col.set_hsv(h, 1, 1);
c->draw_line(Point2(0, y), Point2(c->get_size().x, y), col.inverted());
} else if (picker_type == SHAPE_OKHSL_CIRCLE) {
Vector<Point2> points;
Vector<Color> colors;
Color col;
col.set_ok_hsl(h, s, 1);
points.resize(4);
colors.resize(4);
points.set(0, Vector2());
points.set(1, Vector2(c->get_size().x, 0));
points.set(2, c->get_size());
points.set(3, Vector2(0, c->get_size().y));
colors.set(0, col);
colors.set(1, col);
colors.set(2, Color(0, 0, 0));
colors.set(3, Color(0, 0, 0));
c->draw_polygon(points, colors);
int y = c->get_size().y - c->get_size().y * CLAMP(v, 0, 1);
col.set_ok_hsl(h, 1, v);
c->draw_line(Point2(0, y), Point2(c->get_size().x, y), col.inverted());
} else if (picker_type == SHAPE_VHS_CIRCLE) {
Vector<Point2> points;
Vector<Color> colors;
@ -757,7 +833,7 @@ void ColorPicker::_hsv_draw(int p_which, Control *c) {
}
} else if (p_which == 2) {
c->draw_rect(Rect2(Point2(), c->get_size()), Color(1, 1, 1));
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
circle_mat->set_shader_param("v", v);
}
}
@ -793,10 +869,19 @@ void ColorPicker::_slider_draw(int p_which) {
}
Color s_col;
Color v_col;
s_col.set_hsv(h, 0, v);
if (picker_type == SHAPE_OKHSL_CIRCLE) {
s_col.set_ok_hsl(h, 0, v);
} else {
s_col.set_hsv(h, 0, v);
}
left_color = (p_which == 1) ? s_col : Color(0, 0, 0);
s_col.set_hsv(h, 1, v);
v_col.set_hsv(h, s, 1);
if (picker_type == SHAPE_OKHSL_CIRCLE) {
s_col.set_ok_hsl(h, 1, v);
v_col.set_ok_hsl(h, s, 1);
} else {
s_col.set_hsv(h, 1, v);
v_col.set_hsv(h, s, 1);
}
right_color = (p_which == 1) ? s_col : v_col;
} else {
left_color = Color(
@ -828,9 +913,8 @@ void ColorPicker::_uv_input(const Ref<InputEvent> &p_event, Control *c) {
if (bev.is_valid()) {
if (bev->is_pressed() && bev->get_button_index() == MouseButton::LEFT) {
Vector2 center = c->get_size() / 2.0;
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
real_t dist = center.distance_to(bev->get_position());
if (dist <= center.x) {
real_t rad = center.angle_to_point(bev->get_position());
h = ((rad >= 0) ? rad : (Math_TAU + rad)) / Math_TAU;
@ -867,8 +951,13 @@ void ColorPicker::_uv_input(const Ref<InputEvent> &p_event, Control *c) {
}
}
changing_color = true;
color.set_hsv(h, s, v, color.a);
last_hsv = color;
if (picker_type == SHAPE_OKHSL_CIRCLE) {
color.set_ok_hsl(h, s, v, color.a);
} else if (picker_type != SHAPE_OKHSL_CIRCLE) {
color.set_hsv(h, s, v, color.a);
}
last_color = color;
set_pick_color(color);
_update_color();
if (!deferred_mode_enabled) {
@ -892,7 +981,7 @@ void ColorPicker::_uv_input(const Ref<InputEvent> &p_event, Control *c) {
}
Vector2 center = c->get_size() / 2.0;
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
real_t dist = center.distance_to(mev->get_position());
real_t rad = center.angle_to_point(mev->get_position());
h = ((rad >= 0) ? rad : (Math_TAU + rad)) / Math_TAU;
@ -913,9 +1002,12 @@ void ColorPicker::_uv_input(const Ref<InputEvent> &p_event, Control *c) {
v = 1.0 - (y - corner_y) / real_size.y;
}
}
color.set_hsv(h, s, v, color.a);
last_hsv = color;
if (picker_type != SHAPE_OKHSL_CIRCLE) {
color.set_hsv(h, s, v, color.a);
} else if (picker_type == SHAPE_OKHSL_CIRCLE) {
color.set_ok_hsl(h, s, v, color.a);
}
last_color = color;
set_pick_color(color);
_update_color();
if (!deferred_mode_enabled) {
@ -931,7 +1023,7 @@ void ColorPicker::_w_input(const Ref<InputEvent> &p_event) {
if (bev->is_pressed() && bev->get_button_index() == MouseButton::LEFT) {
changing_color = true;
float y = CLAMP((float)bev->get_position().y, 0, w_edit->get_size().height);
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
v = 1.0 - (y / w_edit->get_size().height);
} else {
h = y / w_edit->get_size().height;
@ -939,8 +1031,12 @@ void ColorPicker::_w_input(const Ref<InputEvent> &p_event) {
} else {
changing_color = false;
}
color.set_hsv(h, s, v, color.a);
last_hsv = color;
if (picker_type != SHAPE_OKHSL_CIRCLE) {
color.set_hsv(h, s, v, color.a);
} else if (picker_type == SHAPE_OKHSL_CIRCLE) {
color.set_ok_hsl(h, s, v, color.a);
}
last_color = color;
set_pick_color(color);
_update_color();
if (!deferred_mode_enabled) {
@ -957,13 +1053,17 @@ void ColorPicker::_w_input(const Ref<InputEvent> &p_event) {
return;
}
float y = CLAMP((float)mev->get_position().y, 0, w_edit->get_size().height);
if (picker_type == SHAPE_VHS_CIRCLE) {
if (picker_type == SHAPE_VHS_CIRCLE || picker_type == SHAPE_OKHSL_CIRCLE) {
v = 1.0 - (y / w_edit->get_size().height);
} else {
h = y / w_edit->get_size().height;
}
color.set_hsv(h, s, v, color.a);
last_hsv = color;
if (hsv_mode_enabled && picker_type != SHAPE_OKHSL_CIRCLE) {
color.set_hsv(h, s, v, color.a);
} else if (hsv_mode_enabled && picker_type == SHAPE_OKHSL_CIRCLE) {
color.set_ok_hsl(h, s, v, color.a);
}
last_color = color;
set_pick_color(color);
_update_color();
if (!deferred_mode_enabled) {
@ -1128,7 +1228,7 @@ void ColorPicker::_bind_methods() {
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "hsv_mode"), "set_hsv_mode", "is_hsv_mode");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "raw_mode"), "set_raw_mode", "is_raw_mode");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "deferred_mode"), "set_deferred_mode", "is_deferred_mode");
ADD_PROPERTY(PropertyInfo(Variant::INT, "picker_shape", PROPERTY_HINT_ENUM, "HSV Rectangle,HSV Rectangle Wheel,VHS Circle"), "set_picker_shape", "get_picker_shape");
ADD_PROPERTY(PropertyInfo(Variant::INT, "picker_shape", PROPERTY_HINT_ENUM, "HSV Rectangle,HSV Rectangle Wheel,VHS Circle,OKHSL Circle"), "set_picker_shape", "get_picker_shape");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "presets_enabled"), "set_presets_enabled", "are_presets_enabled");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "presets_visible"), "set_presets_visible", "are_presets_visible");
@ -1139,6 +1239,7 @@ void ColorPicker::_bind_methods() {
BIND_ENUM_CONSTANT(SHAPE_HSV_RECTANGLE);
BIND_ENUM_CONSTANT(SHAPE_HSV_WHEEL);
BIND_ENUM_CONSTANT(SHAPE_VHS_CIRCLE);
BIND_ENUM_CONSTANT(SHAPE_OKHSL_CIRCLE);
}
ColorPicker::ColorPicker() :

6
scene/gui/color_picker.h
View file

@ -68,6 +68,7 @@ public:
SHAPE_HSV_RECTANGLE,
SHAPE_HSV_WHEEL,
SHAPE_VHS_CIRCLE,
SHAPE_OKHSL_CIRCLE,
SHAPE_MAX
};
@ -75,6 +76,7 @@ public:
private:
static Ref<Shader> wheel_shader;
static Ref<Shader> circle_shader;
static Ref<Shader> circle_ok_color_shader;
static List<Color> preset_cache;
Control *screen = nullptr;
@ -124,7 +126,7 @@ private:
float h = 0.0;
float s = 0.0;
float v = 0.0;
Color last_hsv;
Color last_color;
void _html_submitted(const String &p_html);
void _value_changed(double);
@ -161,6 +163,8 @@ public:
void set_edit_alpha(bool p_show);
bool is_editing_alpha() const;
int get_preset_size();
void _set_pick_color(const Color &p_color, bool p_update_sliders);
void set_pick_color(const Color &p_color);
Color get_pick_color() const;

9
thirdparty/README.md vendored
View file

@ -432,6 +432,15 @@ Collection of single-file libraries used in Godot components.
* Upstream: https://github.com/Auburn/FastNoiseLite
* Version: git (6be3d6bf7fb408de341285f9ee8a29b67fd953f1, 2022) + custom changes
* License: MIT
- `ok_color.h`
* Upstream: https://github.com/bottosson/bottosson.github.io/blob/master/misc/ok_color.h
* Version: git (d69831edb90ffdcd08b7e64da3c5405acd48ad2c, 2022)
* License: MIT
* Modifications: License included in header.
- `ok_color_shader.h`
* https://www.shadertoy.com/view/7sK3D1
* Version: 2021-09-13
* License: MIT
- `pcg.{cpp,h}`
* Upstream: http://www.pcg-random.org
* Version: minimal C implementation, http://www.pcg-random.org/download.html

688
thirdparty/misc/ok_color.h vendored Normal file
View file

@ -0,0 +1,688 @@
// Copyright(c) 2021 Björn Ottosson
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files(the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and /or sell copies
// of the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions :
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#ifndef OK_COLOR_H
#define OK_COLOR_H
#include <cmath>
#include <cfloat>
class ok_color
{
public:
struct Lab { float L; float a; float b; };
struct RGB { float r; float g; float b; };
struct HSV { float h; float s; float v; };
struct HSL { float h; float s; float l; };
struct LC { float L; float C; };
// Alternative representation of (L_cusp, C_cusp)
// Encoded so S = C_cusp/L_cusp and T = C_cusp/(1-L_cusp)
// The maximum value for C in the triangle is then found as fmin(S*L, T*(1-L)), for a given L
struct ST { float S; float T; };
static constexpr float pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062f;
float clamp(float x, float min, float max)
{
if (x < min)
return min;
if (x > max)
return max;
return x;
}
float sgn(float x)
{
return (float)(0.f < x) - (float)(x < 0.f);
}
float srgb_transfer_function(float a)
{
return .0031308f >= a ? 12.92f * a : 1.055f * powf(a, .4166666666666667f) - .055f;
}
float srgb_transfer_function_inv(float a)
{
return .04045f < a ? powf((a + .055f) / 1.055f, 2.4f) : a / 12.92f;
}
Lab linear_srgb_to_oklab(RGB c)
{
float l = 0.4122214708f * c.r + 0.5363325363f * c.g + 0.0514459929f * c.b;
float m = 0.2119034982f * c.r + 0.6806995451f * c.g + 0.1073969566f * c.b;
float s = 0.0883024619f * c.r + 0.2817188376f * c.g + 0.6299787005f * c.b;
float l_ = cbrtf(l);
float m_ = cbrtf(m);
float s_ = cbrtf(s);
return {
0.2104542553f * l_ + 0.7936177850f * m_ - 0.0040720468f * s_,
1.9779984951f * l_ - 2.4285922050f * m_ + 0.4505937099f * s_,
0.0259040371f * l_ + 0.7827717662f * m_ - 0.8086757660f * s_,
};
}
RGB oklab_to_linear_srgb(Lab c)
{
float l_ = c.L + 0.3963377774f * c.a + 0.2158037573f * c.b;
float m_ = c.L - 0.1055613458f * c.a - 0.0638541728f * c.b;
float s_ = c.L - 0.0894841775f * c.a - 1.2914855480f * c.b;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
return {
+4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s,
-1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s,
-0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s,
};
}
// Finds the maximum saturation possible for a given hue that fits in sRGB
// Saturation here is defined as S = C/L
// a and b must be normalized so a^2 + b^2 == 1
float compute_max_saturation(float a, float b)
{
// Max saturation will be when one of r, g or b goes below zero.
// Select different coefficients depending on which component goes below zero first
float k0, k1, k2, k3, k4, wl, wm, ws;
if (-1.88170328f * a - 0.80936493f * b > 1)
{
// Red component
k0 = +1.19086277f; k1 = +1.76576728f; k2 = +0.59662641f; k3 = +0.75515197f; k4 = +0.56771245f;
wl = +4.0767416621f; wm = -3.3077115913f; ws = +0.2309699292f;
}
else if (1.81444104f * a - 1.19445276f * b > 1)
{
// Green component
k0 = +0.73956515f; k1 = -0.45954404f; k2 = +0.08285427f; k3 = +0.12541070f; k4 = +0.14503204f;
wl = -1.2684380046f; wm = +2.6097574011f; ws = -0.3413193965f;
}
else
{
// Blue component
k0 = +1.35733652f; k1 = -0.00915799f; k2 = -1.15130210f; k3 = -0.50559606f; k4 = +0.00692167f;
wl = -0.0041960863f; wm = -0.7034186147f; ws = +1.7076147010f;
}
// Approximate max saturation using a polynomial:
float S = k0 + k1 * a + k2 * b + k3 * a * a + k4 * a * b;
// Do one step Halley's method to get closer
// this gives an error less than 10e6, except for some blue hues where the dS/dh is close to infinite
// this should be sufficient for most applications, otherwise do two/three steps
float k_l = +0.3963377774f * a + 0.2158037573f * b;
float k_m = -0.1055613458f * a - 0.0638541728f * b;
float k_s = -0.0894841775f * a - 1.2914855480f * b;
{
float l_ = 1.f + S * k_l;
float m_ = 1.f + S * k_m;
float s_ = 1.f + S * k_s;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
float l_dS = 3.f * k_l * l_ * l_;
float m_dS = 3.f * k_m * m_ * m_;
float s_dS = 3.f * k_s * s_ * s_;
float l_dS2 = 6.f * k_l * k_l * l_;
float m_dS2 = 6.f * k_m * k_m * m_;
float s_dS2 = 6.f * k_s * k_s * s_;
float f = wl * l + wm * m + ws * s;
float f1 = wl * l_dS + wm * m_dS + ws * s_dS;
float f2 = wl * l_dS2 + wm * m_dS2 + ws * s_dS2;
S = S - f * f1 / (f1 * f1 - 0.5f * f * f2);
}
return S;
}
// finds L_cusp and C_cusp for a given hue
// a and b must be normalized so a^2 + b^2 == 1
LC find_cusp(float a, float b)
{
// First, find the maximum saturation (saturation S = C/L)
float S_cusp = compute_max_saturation(a, b);
// Convert to linear sRGB to find the first point where at least one of r,g or b >= 1:
RGB rgb_at_max = oklab_to_linear_srgb({ 1, S_cusp * a, S_cusp * b });
float L_cusp = cbrtf(1.f / fmax(fmax(rgb_at_max.r, rgb_at_max.g), rgb_at_max.b));
float C_cusp = L_cusp * S_cusp;
return { L_cusp , C_cusp };
}
// Finds intersection of the line defined by
// L = L0 * (1 - t) + t * L1;
// C = t * C1;
// a and b must be normalized so a^2 + b^2 == 1
float find_gamut_intersection(float a, float b, float L1, float C1, float L0, LC cusp)
{
// Find the intersection for upper and lower half seprately
float t;
if (((L1 - L0) * cusp.C - (cusp.L - L0) * C1) <= 0.f)
{
// Lower half
t = cusp.C * L0 / (C1 * cusp.L + cusp.C * (L0 - L1));
}
else
{
// Upper half
// First intersect with triangle
t = cusp.C * (L0 - 1.f) / (C1 * (cusp.L - 1.f) + cusp.C * (L0 - L1));
// Then one step Halley's method
{
float dL = L1 - L0;
float dC = C1;
float k_l = +0.3963377774f * a + 0.2158037573f * b;
float k_m = -0.1055613458f * a - 0.0638541728f * b;
float k_s = -0.0894841775f * a - 1.2914855480f * b;
float l_dt = dL + dC * k_l;
float m_dt = dL + dC * k_m;
float s_dt = dL + dC * k_s;
// If higher accuracy is required, 2 or 3 iterations of the following block can be used:
{
float L = L0 * (1.f - t) + t * L1;
float C = t * C1;
float l_ = L + C * k_l;
float m_ = L + C * k_m;
float s_ = L + C * k_s;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
float ldt = 3 * l_dt * l_ * l_;
float mdt = 3 * m_dt * m_ * m_;
float sdt = 3 * s_dt * s_ * s_;
float ldt2 = 6 * l_dt * l_dt * l_;
float mdt2 = 6 * m_dt * m_dt * m_;
float sdt2 = 6 * s_dt * s_dt * s_;
float r = 4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s - 1;
float r1 = 4.0767416621f * ldt - 3.3077115913f * mdt + 0.2309699292f * sdt;
float r2 = 4.0767416621f * ldt2 - 3.3077115913f * mdt2 + 0.2309699292f * sdt2;
float u_r = r1 / (r1 * r1 - 0.5f * r * r2);
float t_r = -r * u_r;
float g = -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s - 1;
float g1 = -1.2684380046f * ldt + 2.6097574011f * mdt - 0.3413193965f * sdt;
float g2 = -1.2684380046f * ldt2 + 2.6097574011f * mdt2 - 0.3413193965f * sdt2;
float u_g = g1 / (g1 * g1 - 0.5f * g * g2);
float t_g = -g * u_g;
b = -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s - 1;
float b1 = -0.0041960863f * ldt - 0.7034186147f * mdt + 1.7076147010f * sdt;
float b2 = -0.0041960863f * ldt2 - 0.7034186147f * mdt2 + 1.7076147010f * sdt2;
float u_b = b1 / (b1 * b1 - 0.5f * b * b2);
float t_b = -b * u_b;
t_r = u_r >= 0.f ? t_r : FLT_MAX;
t_g = u_g >= 0.f ? t_g : FLT_MAX;
t_b = u_b >= 0.f ? t_b : FLT_MAX;
t += fmin(t_r, fmin(t_g, t_b));
}
}
}
return t;
}
float find_gamut_intersection(float a, float b, float L1, float C1, float L0)
{
// Find the cusp of the gamut triangle
LC cusp = find_cusp(a, b);
return find_gamut_intersection(a, b, L1, C1, L0, cusp);
}
RGB gamut_clip_preserve_chroma(RGB rgb)
{
if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0)
return rgb;
Lab lab = linear_srgb_to_oklab(rgb);
float L = lab.L;
float eps = 0.00001f;
float C = fmax(eps, sqrtf(lab.a * lab.a + lab.b * lab.b));
float a_ = lab.a / C;
float b_ = lab.b / C;
float L0 = clamp(L, 0, 1);
float t = find_gamut_intersection(a_, b_, L, C, L0);
float L_clipped = L0 * (1 - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb({ L_clipped, C_clipped * a_, C_clipped * b_ });
}
RGB gamut_clip_project_to_0_5(RGB rgb)
{
if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0)
return rgb;
Lab lab = linear_srgb_to_oklab(rgb);
float L = lab.L;
float eps = 0.00001f;
float C = fmax(eps, sqrtf(lab.a * lab.a + lab.b * lab.b));
float a_ = lab.a / C;
float b_ = lab.b / C;
float L0 = 0.5;
float t = find_gamut_intersection(a_, b_, L, C, L0);
float L_clipped = L0 * (1 - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb({ L_clipped, C_clipped * a_, C_clipped * b_ });
}
RGB gamut_clip_project_to_L_cusp(RGB rgb)
{
if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0)
return rgb;
Lab lab = linear_srgb_to_oklab(rgb);
float L = lab.L;
float eps = 0.00001f;
float C = fmax(eps, sqrtf(lab.a * lab.a + lab.b * lab.b));
float a_ = lab.a / C;
float b_ = lab.b / C;
// The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
LC cusp = find_cusp(a_, b_);
float L0 = cusp.L;
float t = find_gamut_intersection(a_, b_, L, C, L0);
float L_clipped = L0 * (1 - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb({ L_clipped, C_clipped * a_, C_clipped * b_ });
}
RGB gamut_clip_adaptive_L0_0_5(RGB rgb, float alpha = 0.05f)
{
if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0)
return rgb;
Lab lab = linear_srgb_to_oklab(rgb);
float L = lab.L;
float eps = 0.00001f;
float C = fmax(eps, sqrtf(lab.a * lab.a + lab.b * lab.b));
float a_ = lab.a / C;
float b_ = lab.b / C;
float Ld = L - 0.5f;
float e1 = 0.5f + fabs(Ld) + alpha * C;
float L0 = 0.5f * (1.f + sgn(Ld) * (e1 - sqrtf(e1 * e1 - 2.f * fabs(Ld))));
float t = find_gamut_intersection(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb({ L_clipped, C_clipped * a_, C_clipped * b_ });
}
RGB gamut_clip_adaptive_L0_L_cusp(RGB rgb, float alpha = 0.05f)
{
if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0)
return rgb;
Lab lab = linear_srgb_to_oklab(rgb);
float L = lab.L;
float eps = 0.00001f;
float C = fmax(eps, sqrtf(lab.a * lab.a + lab.b * lab.b));
float a_ = lab.a / C;
float b_ = lab.b / C;
// The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
LC cusp = find_cusp(a_, b_);
float Ld = L - cusp.L;
float k = 2.f * (Ld > 0 ? 1.f - cusp.L : cusp.L);
float e1 = 0.5f * k + fabs(Ld) + alpha * C / k;
float L0 = cusp.L + 0.5f * (sgn(Ld) * (e1 - sqrtf(e1 * e1 - 2.f * k * fabs(Ld))));
float t = find_gamut_intersection(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb({ L_clipped, C_clipped * a_, C_clipped * b_ });
}
float toe(float x)
{
constexpr float k_1 = 0.206f;
constexpr float k_2 = 0.03f;
constexpr float k_3 = (1.f + k_1) / (1.f + k_2);
return 0.5f * (k_3 * x - k_1 + sqrtf((k_3 * x - k_1) * (k_3 * x - k_1) + 4 * k_2 * k_3 * x));
}
float toe_inv(float x)
{
constexpr float k_1 = 0.206f;
constexpr float k_2 = 0.03f;
constexpr float k_3 = (1.f + k_1) / (1.f + k_2);
return (x * x + k_1 * x) / (k_3 * (x + k_2));
}
ST to_ST(LC cusp)
{
float L = cusp.L;
float C = cusp.C;
return { C / L, C / (1 - L) };
}
// Returns a smooth approximation of the location of the cusp
// This polynomial was created by an optimization process
// It has been designed so that S_mid < S_max and T_mid < T_max
ST get_ST_mid(float a_, float b_)
{
float S = 0.11516993f + 1.f / (
+7.44778970f + 4.15901240f * b_
+ a_ * (-2.19557347f + 1.75198401f * b_
+ a_ * (-2.13704948f - 10.02301043f * b_
+ a_ * (-4.24894561f + 5.38770819f * b_ + 4.69891013f * a_
)))
);
float T = 0.11239642f + 1.f / (
+1.61320320f - 0.68124379f * b_
+ a_ * (+0.40370612f + 0.90148123f * b_
+ a_ * (-0.27087943f + 0.61223990f * b_
+ a_ * (+0.00299215f - 0.45399568f * b_ - 0.14661872f * a_
)))
);
return { S, T };
}
struct Cs { float C_0; float C_mid; float C_max; };
Cs get_Cs(float L, float a_, float b_)
{
LC cusp = find_cusp(a_, b_);
float C_max = find_gamut_intersection(a_, b_, L, 1, L, cusp);
ST ST_max = to_ST(cusp);
// Scale factor to compensate for the curved part of gamut shape:
float k = C_max / fmin((L * ST_max.S), (1 - L) * ST_max.T);
float C_mid;
{
ST ST_mid = get_ST_mid(a_, b_);
// Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
float C_a = L * ST_mid.S;
float C_b = (1.f - L) * ST_mid.T;
C_mid = 0.9f * k * sqrtf(sqrtf(1.f / (1.f / (C_a * C_a * C_a * C_a) + 1.f / (C_b * C_b * C_b * C_b))));
}
float C_0;
{
// for C_0, the shape is independent of hue, so ST are constant. Values picked to roughly be the average values of ST.
float C_a = L * 0.4f;
float C_b = (1.f - L) * 0.8f;
// Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
C_0 = sqrtf(1.f / (1.f / (C_a * C_a) + 1.f / (C_b * C_b)));
}
return { C_0, C_mid, C_max };
}
RGB okhsl_to_srgb(HSL hsl)
{
float h = hsl.h;
float s = hsl.s;
float l = hsl.l;
if (l == 1.0f)
{
return { 1.f, 1.f, 1.f };
}
else if (l == 0.f)
{
return { 0.f, 0.f, 0.f };
}
float a_ = cosf(2.f * pi * h);
float b_ = sinf(2.f * pi * h);
float L = toe_inv(l);
Cs cs = get_Cs(L, a_, b_);
float C_0 = cs.C_0;
float C_mid = cs.C_mid;
float C_max = cs.C_max;
float mid = 0.8f;
float mid_inv = 1.25f;
float C, t, k_0, k_1, k_2;
if (s < mid)
{
t = mid_inv * s;
k_1 = mid * C_0;
k_2 = (1.f - k_1 / C_mid);
C = t * k_1 / (1.f - k_2 * t);
}
else
{
t = (s - mid)/ (1 - mid);
k_0 = C_mid;
k_1 = (1.f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0;
k_2 = (1.f - (k_1) / (C_max - C_mid));
C = k_0 + t * k_1 / (1.f - k_2 * t);
}
RGB rgb = oklab_to_linear_srgb({ L, C * a_, C * b_ });
return {
srgb_transfer_function(rgb.r),
srgb_transfer_function(rgb.g),
srgb_transfer_function(rgb.b),
};
}
HSL srgb_to_okhsl(RGB rgb)
{
Lab lab = linear_srgb_to_oklab({
srgb_transfer_function_inv(rgb.r),
srgb_transfer_function_inv(rgb.g),
srgb_transfer_function_inv(rgb.b)
});
float C = sqrtf(lab.a * lab.a + lab.b * lab.b);
float a_ = lab.a / C;
float b_ = lab.b / C;
float L = lab.L;
float h = 0.5f + 0.5f * atan2f(-lab.b, -lab.a) / pi;
Cs cs = get_Cs(L, a_, b_);
float C_0 = cs.C_0;
float C_mid = cs.C_mid;
float C_max = cs.C_max;
// Inverse of the interpolation in okhsl_to_srgb:
float mid = 0.8f;
float mid_inv = 1.25f;
float s;
if (C < C_mid)
{
float k_1 = mid * C_0;
float k_2 = (1.f - k_1 / C_mid);
float t = C / (k_1 + k_2 * C);
s = t * mid;
}
else
{
float k_0 = C_mid;
float k_1 = (1.f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0;
float k_2 = (1.f - (k_1) / (C_max - C_mid));
float t = (C - k_0) / (k_1 + k_2 * (C - k_0));
s = mid + (1.f - mid) * t;
}
float l = toe(L);
return { h, s, l };
}
RGB okhsv_to_srgb(HSV hsv)
{
float h = hsv.h;
float s = hsv.s;
float v = hsv.v;
float a_ = cosf(2.f * pi * h);
float b_ = sinf(2.f * pi * h);
LC cusp = find_cusp(a_, b_);
ST ST_max = to_ST(cusp);
float S_max = ST_max.S;
float T_max = ST_max.T;
float S_0 = 0.5f;
float k = 1 - S_0 / S_max;
// first we compute L and V as if the gamut is a perfect triangle:
// L, C when v==1:
float L_v = 1 - s * S_0 / (S_0 + T_max - T_max * k * s);
float C_v = s * T_max * S_0 / (S_0 + T_max - T_max * k * s);
float L = v * L_v;
float C = v * C_v;
// then we compensate for both toe and the curved top part of the triangle:
float L_vt = toe_inv(L_v);
float C_vt = C_v * L_vt / L_v;
float L_new = toe_inv(L);
C = C * L_new / L;
L = L_new;
RGB rgb_scale = oklab_to_linear_srgb({ L_vt, a_ * C_vt, b_ * C_vt });
float scale_L = cbrtf(1.f / fmax(fmax(rgb_scale.r, rgb_scale.g), fmax(rgb_scale.b, 0.f)));
L = L * scale_L;
C = C * scale_L;
RGB rgb = oklab_to_linear_srgb({ L, C * a_, C * b_ });
return {
srgb_transfer_function(rgb.r),
srgb_transfer_function(rgb.g),
srgb_transfer_function(rgb.b),
};
}
HSV srgb_to_okhsv(RGB rgb)
{
Lab lab = linear_srgb_to_oklab({
srgb_transfer_function_inv(rgb.r),
srgb_transfer_function_inv(rgb.g),
srgb_transfer_function_inv(rgb.b)
});
float C = sqrtf(lab.a * lab.a + lab.b * lab.b);
float a_ = lab.a / C;
float b_ = lab.b / C;
float L = lab.L;
float h = 0.5f + 0.5f * atan2f(-lab.b, -lab.a) / pi;
LC cusp = find_cusp(a_, b_);
ST ST_max = to_ST(cusp);
float S_max = ST_max.S;
float T_max = ST_max.T;
float S_0 = 0.5f;
float k = 1 - S_0 / S_max;
// first we find L_v, C_v, L_vt and C_vt
float t = T_max / (C + L * T_max);
float L_v = t * L;
float C_v = t * C;
float L_vt = toe_inv(L_v);
float C_vt = C_v * L_vt / L_v;
// we can then use these to invert the step that compensates for the toe and the curved top part of the triangle:
RGB rgb_scale = oklab_to_linear_srgb({ L_vt, a_ * C_vt, b_ * C_vt });
float scale_L = cbrtf(1.f / fmax(fmax(rgb_scale.r, rgb_scale.g), fmax(rgb_scale.b, 0.f)));
L = L / scale_L;
C = C / scale_L;
C = C * toe(L) / L;
L = toe(L);
// we can now compute v and s:
float v = L / L_v;
float s = (S_0 + T_max) * C_v / ((T_max * S_0) + T_max * k * C_v);
return { h, s, v };
}
};
#endif // OK_COLOR_H

663
thirdparty/misc/ok_color_shader.h vendored Normal file
View file

@ -0,0 +1,663 @@
// Copyright(c) 2021 Björn Ottosson
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files(the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and /or sell copies
// of the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions :
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#ifndef OK_COLOR_SHADER_H
#define OK_COLOR_SHADER_H
#include "core/string/ustring.h"
static String OK_COLOR_SHADER = R"(shader_type canvas_item;
const float M_PI = 3.1415926535897932384626433832795;
float cbrt( float x )
{
return sign(x)*pow(abs(x),1.0f/3.0f);
}
float srgb_transfer_function(float a)
{
return .0031308f >= a ? 12.92f * a : 1.055f * pow(a, .4166666666666667f) - .055f;
}
float srgb_transfer_function_inv(float a)
{
return .04045f < a ? pow((a + .055f) / 1.055f, 2.4f) : a / 12.92f;
}
vec3 linear_srgb_to_oklab(vec3 c)
{
float l = 0.4122214708f * c.r + 0.5363325363f * c.g + 0.0514459929f * c.b;
float m = 0.2119034982f * c.r + 0.6806995451f * c.g + 0.1073969566f * c.b;
float s = 0.0883024619f * c.r + 0.2817188376f * c.g + 0.6299787005f * c.b;
float l_ = cbrt(l);
float m_ = cbrt(m);
float s_ = cbrt(s);
return vec3(
0.2104542553f * l_ + 0.7936177850f * m_ - 0.0040720468f * s_,
1.9779984951f * l_ - 2.4285922050f * m_ + 0.4505937099f * s_,
0.0259040371f * l_ + 0.7827717662f * m_ - 0.8086757660f * s_
);
}
vec3 oklab_to_linear_srgb(vec3 c)
{
float l_ = c.x + 0.3963377774f * c.y + 0.2158037573f * c.z;
float m_ = c.x - 0.1055613458f * c.y - 0.0638541728f * c.z;
float s_ = c.x - 0.0894841775f * c.y - 1.2914855480f * c.z;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
return vec3(
+4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s,
-1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s,
-0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s
);
}
// Finds the maximum saturation possible for a given hue that fits in sRGB
// Saturation here is defined as S = C/L
// a and b must be normalized so a^2 + b^2 == 1
float compute_max_saturation(float a, float b)
{
// Max saturation will be when one of r, g or b goes below zero.
// Select different coefficients depending on which component goes below zero first
float k0, k1, k2, k3, k4, wl, wm, ws;
if (-1.88170328f * a - 0.80936493f * b > 1.f)
{
// Red component
k0 = +1.19086277f; k1 = +1.76576728f; k2 = +0.59662641f; k3 = +0.75515197f; k4 = +0.56771245f;
wl = +4.0767416621f; wm = -3.3077115913f; ws = +0.2309699292f;
}
else if (1.81444104f * a - 1.19445276f * b > 1.f)
{
// Green component
k0 = +0.73956515f; k1 = -0.45954404f; k2 = +0.08285427f; k3 = +0.12541070f; k4 = +0.14503204f;
wl = -1.2684380046f; wm = +2.6097574011f; ws = -0.3413193965f;
}
else
{
// Blue component
k0 = +1.35733652f; k1 = -0.00915799f; k2 = -1.15130210f; k3 = -0.50559606f; k4 = +0.00692167f;
wl = -0.0041960863f; wm = -0.7034186147f; ws = +1.7076147010f;
}
// Approximate max saturation using a polynomial:
float S = k0 + k1 * a + k2 * b + k3 * a * a + k4 * a * b;
// Do one step Halley's method to get closer
// this gives an error less than 10e6, except for some blue hues where the dS/dh is close to infinite
// this should be sufficient for most applications, otherwise do two/three steps
float k_l = +0.3963377774f * a + 0.2158037573f * b;
float k_m = -0.1055613458f * a - 0.0638541728f * b;
float k_s = -0.0894841775f * a - 1.2914855480f * b;
{
float l_ = 1.f + S * k_l;
float m_ = 1.f + S * k_m;
float s_ = 1.f + S * k_s;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
float l_dS = 3.f * k_l * l_ * l_;
float m_dS = 3.f * k_m * m_ * m_;
float s_dS = 3.f * k_s * s_ * s_;
float l_dS2 = 6.f * k_l * k_l * l_;
float m_dS2 = 6.f * k_m * k_m * m_;
float s_dS2 = 6.f * k_s * k_s * s_;
float f = wl * l + wm * m + ws * s;
float f1 = wl * l_dS + wm * m_dS + ws * s_dS;
float f2 = wl * l_dS2 + wm * m_dS2 + ws * s_dS2;
S = S - f * f1 / (f1 * f1 - 0.5f * f * f2);
}
return S;
}
// finds L_cusp and C_cusp for a given hue
// a and b must be normalized so a^2 + b^2 == 1
vec2 find_cusp(float a, float b)
{
// First, find the maximum saturation (saturation S = C/L)
float S_cusp = compute_max_saturation(a, b);
// Convert to linear sRGB to find the first point where at least one of r,g or b >= 1:
vec3 rgb_at_max = oklab_to_linear_srgb(vec3( 1, S_cusp * a, S_cusp * b ));
float L_cusp = cbrt(1.f / max(max(rgb_at_max.r, rgb_at_max.g), rgb_at_max.b));
float C_cusp = L_cusp * S_cusp;
return vec2( L_cusp , C_cusp );
} )"
R"(// Finds intersection of the line defined by
// L = L0 * (1 - t) + t * L1;
// C = t * C1;
// a and b must be normalized so a^2 + b^2 == 1
float find_gamut_intersection(float a, float b, float L1, float C1, float L0, vec2 cusp)
{
// Find the intersection for upper and lower half seprately
float t;
if (((L1 - L0) * cusp.y - (cusp.x - L0) * C1) <= 0.f)
{
// Lower half
t = cusp.y * L0 / (C1 * cusp.x + cusp.y * (L0 - L1));
}
else
{
// Upper half
// First intersect with triangle
t = cusp.y * (L0 - 1.f) / (C1 * (cusp.x - 1.f) + cusp.y * (L0 - L1));
// Then one step Halley's method
{
float dL = L1 - L0;
float dC = C1;
float k_l = +0.3963377774f * a + 0.2158037573f * b;
float k_m = -0.1055613458f * a - 0.0638541728f * b;
float k_s = -0.0894841775f * a - 1.2914855480f * b;
float l_dt = dL + dC * k_l;
float m_dt = dL + dC * k_m;
float s_dt = dL + dC * k_s;
// If higher accuracy is required, 2 or 3 iterations of the following block can be used:
{
float L = L0 * (1.f - t) + t * L1;
float C = t * C1;
float l_ = L + C * k_l;
float m_ = L + C * k_m;
float s_ = L + C * k_s;
float l = l_ * l_ * l_;
float m = m_ * m_ * m_;
float s = s_ * s_ * s_;
float ldt = 3.f * l_dt * l_ * l_;
float mdt = 3.f * m_dt * m_ * m_;
float sdt = 3.f * s_dt * s_ * s_;
float ldt2 = 6.f * l_dt * l_dt * l_;
float mdt2 = 6.f * m_dt * m_dt * m_;
float sdt2 = 6.f * s_dt * s_dt * s_;
float r = 4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s - 1.f;
float r1 = 4.0767416621f * ldt - 3.3077115913f * mdt + 0.2309699292f * sdt;
float r2 = 4.0767416621f * ldt2 - 3.3077115913f * mdt2 + 0.2309699292f * sdt2;
float u_r = r1 / (r1 * r1 - 0.5f * r * r2);
float t_r = -r * u_r;
float g = -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s - 1.f;
float g1 = -1.2684380046f * ldt + 2.6097574011f * mdt - 0.3413193965f * sdt;
float g2 = -1.2684380046f * ldt2 + 2.6097574011f * mdt2 - 0.3413193965f * sdt2;
float u_g = g1 / (g1 * g1 - 0.5f * g * g2);
float t_g = -g * u_g;
float b = -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s - 1.f;
float b1 = -0.0041960863f * ldt - 0.7034186147f * mdt + 1.7076147010f * sdt;
float b2 = -0.0041960863f * ldt2 - 0.7034186147f * mdt2 + 1.7076147010f * sdt2;
float u_b = b1 / (b1 * b1 - 0.5f * b * b2);
float t_b = -b * u_b;
t_r = u_r >= 0.f ? t_r : 10000.f;
t_g = u_g >= 0.f ? t_g : 10000.f;
t_b = u_b >= 0.f ? t_b : 10000.f;
t += min(t_r, min(t_g, t_b));
}
}
}
return t;
}
float find_gamut_intersection_5(float a, float b, float L1, float C1, float L0)
{
// Find the cusp of the gamut triangle
vec2 cusp = find_cusp(a, b);
return find_gamut_intersection(a, b, L1, C1, L0, cusp);
})"
R"(
vec3 gamut_clip_preserve_chroma(vec3 rgb)
{
if (rgb.r < 1.f && rgb.g < 1.f && rgb.b < 1.f && rgb.r > 0.f && rgb.g > 0.f && rgb.b > 0.f)
return rgb;
vec3 lab = linear_srgb_to_oklab(rgb);
float L = lab.x;
float eps = 0.00001f;
float C = max(eps, sqrt(lab.y * lab.y + lab.z * lab.z));
float a_ = lab.y / C;
float b_ = lab.z / C;
float L0 = clamp(L, 0.f, 1.f);
float t = find_gamut_intersection_5(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb(vec3( L_clipped, C_clipped * a_, C_clipped * b_ ));
}
vec3 gamut_clip_project_to_0_5(vec3 rgb)
{
if (rgb.r < 1.f && rgb.g < 1.f && rgb.b < 1.f && rgb.r > 0.f && rgb.g > 0.f && rgb.b > 0.f)
return rgb;
vec3 lab = linear_srgb_to_oklab(rgb);
float L = lab.x;
float eps = 0.00001f;
float C = max(eps, sqrt(lab.y * lab.y + lab.z * lab.z));
float a_ = lab.y / C;
float b_ = lab.z / C;
float L0 = 0.5;
float t = find_gamut_intersection_5(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb(vec3( L_clipped, C_clipped * a_, C_clipped * b_ ));
}
vec3 gamut_clip_project_to_L_cusp(vec3 rgb)
{
if (rgb.r < 1.f && rgb.g < 1.f && rgb.b < 1.f && rgb.r > 0.f && rgb.g > 0.f && rgb.b > 0.f)
return rgb;
vec3 lab = linear_srgb_to_oklab(rgb);
float L = lab.x;
float eps = 0.00001f;
float C = max(eps, sqrt(lab.y * lab.y + lab.z * lab.z));
float a_ = lab.y / C;
float b_ = lab.z / C;
// The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
vec2 cusp = find_cusp(a_, b_);
float L0 = cusp.x;
float t = find_gamut_intersection_5(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb(vec3( L_clipped, C_clipped * a_, C_clipped * b_ ));
}
vec3 gamut_clip_adaptive_L0_0_5(vec3 rgb, float alpha)
{
if (rgb.r < 1.f && rgb.g < 1.f && rgb.b < 1.f && rgb.r > 0.f && rgb.g > 0.f && rgb.b > 0.f)
return rgb;
vec3 lab = linear_srgb_to_oklab(rgb);
float L = lab.x;
float eps = 0.00001f;
float C = max(eps, sqrt(lab.y * lab.y + lab.z * lab.z));
float a_ = lab.y / C;
float b_ = lab.z / C;
float Ld = L - 0.5f;
float e1 = 0.5f + abs(Ld) + alpha * C;
float L0 = 0.5f * (1.f + sign(Ld) * (e1 - sqrt(e1 * e1 - 2.f * abs(Ld))));
float t = find_gamut_intersection_5(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb(vec3( L_clipped, C_clipped * a_, C_clipped * b_ ));
}
vec3 gamut_clip_adaptive_L0_L_cusp(vec3 rgb, float alpha)
{
if (rgb.r < 1.f && rgb.g < 1.f && rgb.b < 1.f && rgb.r > 0.f && rgb.g > 0.f && rgb.b > 0.f)
return rgb;
vec3 lab = linear_srgb_to_oklab(rgb);
float L = lab.x;
float eps = 0.00001f;
float C = max(eps, sqrt(lab.y * lab.y + lab.z * lab.z));
float a_ = lab.y / C;
float b_ = lab.z / C;
// The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
vec2 cusp = find_cusp(a_, b_);
float Ld = L - cusp.x;
float k = 2.f * (Ld > 0.f ? 1.f - cusp.x : cusp.x);
float e1 = 0.5f * k + abs(Ld) + alpha * C / k;
float L0 = cusp.x + 0.5f * (sign(Ld) * (e1 - sqrt(e1 * e1 - 2.f * k * abs(Ld))));
float t = find_gamut_intersection_5(a_, b_, L, C, L0);
float L_clipped = L0 * (1.f - t) + t * L;
float C_clipped = t * C;
return oklab_to_linear_srgb(vec3( L_clipped, C_clipped * a_, C_clipped * b_ ));
}
float toe(float x)
{
float k_1 = 0.206f;
float k_2 = 0.03f;
float k_3 = (1.f + k_1) / (1.f + k_2);
return 0.5f * (k_3 * x - k_1 + sqrt((k_3 * x - k_1) * (k_3 * x - k_1) + 4.f * k_2 * k_3 * x));
}
float toe_inv(float x)
{
float k_1 = 0.206f;
float k_2 = 0.03f;
float k_3 = (1.f + k_1) / (1.f + k_2);
return (x * x + k_1 * x) / (k_3 * (x + k_2));
}
)"
R"(vec2 to_ST(vec2 cusp)
{
float L = cusp.x;
float C = cusp.y;
return vec2( C / L, C / (1.f - L) );
}
// Returns a smooth approximation of the location of the cusp
// This polynomial was created by an optimization process
// It has been designed so that S_mid < S_max and T_mid < T_max
vec2 get_ST_mid(float a_, float b_)
{
float S = 0.11516993f + 1.f / (
+7.44778970f + 4.15901240f * b_
+ a_ * (-2.19557347f + 1.75198401f * b_
+ a_ * (-2.13704948f - 10.02301043f * b_
+ a_ * (-4.24894561f + 5.38770819f * b_ + 4.69891013f * a_
)))
);
float T = 0.11239642f + 1.f / (
+1.61320320f - 0.68124379f * b_
+ a_ * (+0.40370612f + 0.90148123f * b_
+ a_ * (-0.27087943f + 0.61223990f * b_
+ a_ * (+0.00299215f - 0.45399568f * b_ - 0.14661872f * a_
)))
);
return vec2( S, T );
}
vec3 get_Cs(float L, float a_, float b_)
{
vec2 cusp = find_cusp(a_, b_);
float C_max = find_gamut_intersection(a_, b_, L, 1.f, L, cusp);
vec2 ST_max = to_ST(cusp);
// Scale factor to compensate for the curved part of gamut shape:
float k = C_max / min((L * ST_max.x), (1.f - L) * ST_max.y);
float C_mid;
{
vec2 ST_mid = get_ST_mid(a_, b_);
// Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
float C_a = L * ST_mid.x;
float C_b = (1.f - L) * ST_mid.y;
C_mid = 0.9f * k * sqrt(sqrt(1.f / (1.f / (C_a * C_a * C_a * C_a) + 1.f / (C_b * C_b * C_b * C_b))));
}
float C_0;
{
// for C_0, the shape is independent of hue, so vec2 are constant. Values picked to roughly be the average values of vec2.
float C_a = L * 0.4f;
float C_b = (1.f - L) * 0.8f;
// Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
C_0 = sqrt(1.f / (1.f / (C_a * C_a) + 1.f / (C_b * C_b)));
}
return vec3( C_0, C_mid, C_max );
}
vec3 okhsl_to_srgb(vec3 hsl)
{
float h = hsl.x;
float s = hsl.y;
float l = hsl.z;
if (l == 1.0f)
{
return vec3( 1.f, 1.f, 1.f );
}
else if (l == 0.f)
{
return vec3( 0.f, 0.f, 0.f );
}
float a_ = cos(2.f * M_PI * h);
float b_ = sin(2.f * M_PI * h);
float L = toe_inv(l);
vec3 cs = get_Cs(L, a_, b_);
float C_0 = cs.x;
float C_mid = cs.y;
float C_max = cs.z;
float mid = 0.8f;
float mid_inv = 1.25f;
float C, t, k_0, k_1, k_2;
if (s < mid)
{
t = mid_inv * s;
k_1 = mid * C_0;
k_2 = (1.f - k_1 / C_mid);
C = t * k_1 / (1.f - k_2 * t);
}
else
{
t = (s - mid)/ (1.f - mid);
k_0 = C_mid;
k_1 = (1.f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0;
k_2 = (1.f - (k_1) / (C_max - C_mid));
C = k_0 + t * k_1 / (1.f - k_2 * t);
}
vec3 rgb = oklab_to_linear_srgb(vec3( L, C * a_, C * b_ ));
return vec3(
srgb_transfer_function(rgb.r),
srgb_transfer_function(rgb.g),
srgb_transfer_function(rgb.b)
);
}
vec3 srgb_to_okhsl(vec3 rgb)
{
vec3 lab = linear_srgb_to_oklab(vec3(
srgb_transfer_function_inv(rgb.r),
srgb_transfer_function_inv(rgb.g),
srgb_transfer_function_inv(rgb.b)
));
float C = sqrt(lab.y * lab.y + lab.z * lab.z);
float a_ = lab.y / C;
float b_ = lab.z / C;
float L = lab.x;
float h = 0.5f + 0.5f * atan(-lab.z, -lab.y) / M_PI;
vec3 cs = get_Cs(L, a_, b_);
float C_0 = cs.x;
float C_mid = cs.y;
float C_max = cs.z;
// Inverse of the interpolation in okhsl_to_srgb:
float mid = 0.8f;
float mid_inv = 1.25f;
float s;
if (C < C_mid)
{
float k_1 = mid * C_0;
float k_2 = (1.f - k_1 / C_mid);
float t = C / (k_1 + k_2 * C);
s = t * mid;
}
else
{
float k_0 = C_mid;
float k_1 = (1.f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0;
float k_2 = (1.f - (k_1) / (C_max - C_mid));
float t = (C - k_0) / (k_1 + k_2 * (C - k_0));
s = mid + (1.f - mid) * t;
}
float l = toe(L);
return vec3( h, s, l );
}
vec3 okhsv_to_srgb(vec3 hsv)
{
float h = hsv.x;
float s = hsv.y;
float v = hsv.z;
float a_ = cos(2.f * M_PI * h);
float b_ = sin(2.f * M_PI * h);
vec2 cusp = find_cusp(a_, b_);
vec2 ST_max = to_ST(cusp);
float S_max = ST_max.x;
float T_max = ST_max.y;
float S_0 = 0.5f;
float k = 1.f- S_0 / S_max;
// first we compute L and V as if the gamut is a perfect triangle:
// L, C when v==1:
float L_v = 1.f - s * S_0 / (S_0 + T_max - T_max * k * s);
float C_v = s * T_max * S_0 / (S_0 + T_max - T_max * k * s);
float L = v * L_v;
float C = v * C_v;
// then we compensate for both toe and the curved top part of the triangle:
float L_vt = toe_inv(L_v);
float C_vt = C_v * L_vt / L_v;
float L_new = toe_inv(L);
C = C * L_new / L;
L = L_new;
vec3 rgb_scale = oklab_to_linear_srgb(vec3( L_vt, a_ * C_vt, b_ * C_vt ));
float scale_L = cbrt(1.f / max(max(rgb_scale.r, rgb_scale.g), max(rgb_scale.b, 0.f)));
L = L * scale_L;
C = C * scale_L;
vec3 rgb = oklab_to_linear_srgb(vec3( L, C * a_, C * b_ ));
return vec3(
srgb_transfer_function(rgb.r),
srgb_transfer_function(rgb.g),
srgb_transfer_function(rgb.b)
);
}
)"
R"(
vec3 srgb_to_okhsv(vec3 rgb)
{
vec3 lab = linear_srgb_to_oklab(vec3(
srgb_transfer_function_inv(rgb.r),
srgb_transfer_function_inv(rgb.g),
srgb_transfer_function_inv(rgb.b)
));
float C = sqrt(lab.y * lab.y + lab.z * lab.z);
float a_ = lab.y / C;
float b_ = lab.z / C;
float L = lab.x;
float h = 0.5f + 0.5f * atan(-lab.z, -lab.y) / M_PI;
vec2 cusp = find_cusp(a_, b_);
vec2 ST_max = to_ST(cusp);
float S_max = ST_max.x;
float T_max = ST_max.y;
float S_0 = 0.5f;
float k = 1.f - S_0 / S_max;
// first we find L_v, C_v, L_vt and C_vt
float t = T_max / (C + L * T_max);
float L_v = t * L;
float C_v = t * C;
float L_vt = toe_inv(L_v);
float C_vt = C_v * L_vt / L_v;
// we can then use these to invert the step that compensates for the toe and the curved top part of the triangle:
vec3 rgb_scale = oklab_to_linear_srgb(vec3( L_vt, a_ * C_vt, b_ * C_vt ));
float scale_L = cbrt(1.f / max(max(rgb_scale.r, rgb_scale.g), max(rgb_scale.b, 0.f)));
L = L / scale_L;
C = C / scale_L;
C = C * toe(L) / L;
L = toe(L);
// we can now compute v and s:
float v = L / L_v;
float s = (S_0 + T_max) * C_v / ((T_max * S_0) + T_max * k * C_v);
return vec3 (h, s, v );
})";
#endif