godot/scene/resources/gradient.h
Hugo Locurcio ae18928748
Rename Curve/Curve2D/Curve3D/Gradient interpolate() to sample()
"sampling" is a more accurate term than "interpolating" for what's
happening when using that function.
2022-08-30 22:08:38 +02:00

180 lines
5.9 KiB
C++

/*************************************************************************/
/* gradient.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* 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 GRADIENT_H
#define GRADIENT_H
#include "core/io/resource.h"
class Gradient : public Resource {
GDCLASS(Gradient, Resource);
OBJ_SAVE_TYPE(Gradient);
public:
enum InterpolationMode {
GRADIENT_INTERPOLATE_LINEAR,
GRADIENT_INTERPOLATE_CONSTANT,
GRADIENT_INTERPOLATE_CUBIC,
};
struct Point {
float offset = 0.0;
Color color;
bool operator<(const Point &p_ponit) const {
return offset < p_ponit.offset;
}
};
private:
Vector<Point> points;
bool is_sorted = true;
InterpolationMode interpolation_mode = GRADIENT_INTERPOLATE_LINEAR;
_FORCE_INLINE_ void _update_sorting() {
if (!is_sorted) {
points.sort();
is_sorted = true;
}
}
protected:
static void _bind_methods();
public:
Gradient();
virtual ~Gradient();
void add_point(float p_offset, const Color &p_color);
void remove_point(int p_index);
void set_points(const Vector<Point> &p_points);
Vector<Point> &get_points();
void reverse();
void set_offset(int pos, const float offset);
float get_offset(int pos);
void set_color(int pos, const Color &color);
Color get_color(int pos);
void set_offsets(const Vector<float> &p_offsets);
Vector<float> get_offsets() const;
void set_colors(const Vector<Color> &p_colors);
Vector<Color> get_colors() const;
void set_interpolation_mode(InterpolationMode p_interp_mode);
InterpolationMode get_interpolation_mode();
_FORCE_INLINE_ Color get_color_at_offset(float p_offset) {
if (points.is_empty()) {
return Color(0, 0, 0, 1);
}
_update_sorting();
// Binary search.
int low = 0;
int high = points.size() - 1;
int middle = 0;
#ifdef DEBUG_ENABLED
if (low > high) {
ERR_PRINT("low > high, this may be a bug");
}
#endif
while (low <= high) {
middle = (low + high) / 2;
const Point &point = points[middle];
if (point.offset > p_offset) {
high = middle - 1; //search low end of array
} else if (point.offset < p_offset) {
low = middle + 1; //search high end of array
} else {
return point.color;
}
}
// Return sampled value.
if (points[middle].offset > p_offset) {
middle--;
}
int first = middle;
int second = middle + 1;
if (second >= points.size()) {
return points[points.size() - 1].color;
}
if (first < 0) {
return points[0].color;
}
const Point &pointFirst = points[first];
const Point &pointSecond = points[second];
switch (interpolation_mode) {
case GRADIENT_INTERPOLATE_LINEAR: {
return pointFirst.color.lerp(pointSecond.color, (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset));
} break;
case GRADIENT_INTERPOLATE_CONSTANT: {
return pointFirst.color;
} break;
case GRADIENT_INTERPOLATE_CUBIC: {
int p0 = first - 1;
int p3 = second + 1;
if (p3 >= points.size()) {
p3 = second;
}
if (p0 < 0) {
p0 = first;
}
const Point &pointP0 = points[p0];
const Point &pointP3 = points[p3];
float x = (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset);
float r = Math::cubic_interpolate(pointFirst.color.r, pointSecond.color.r, pointP0.color.r, pointP3.color.r, x);
float g = Math::cubic_interpolate(pointFirst.color.g, pointSecond.color.g, pointP0.color.g, pointP3.color.g, x);
float b = Math::cubic_interpolate(pointFirst.color.b, pointSecond.color.b, pointP0.color.b, pointP3.color.b, x);
float a = Math::cubic_interpolate(pointFirst.color.a, pointSecond.color.a, pointP0.color.a, pointP3.color.a, x);
return Color(r, g, b, a);
} break;
default: {
// Fallback to linear interpolation.
return pointFirst.color.lerp(pointSecond.color, (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset));
}
}
}
int get_points_count() const;
};
VARIANT_ENUM_CAST(Gradient::InterpolationMode);
#endif // GRADIENT_H