183 lines
6.1 KiB
C++
183 lines
6.1 KiB
C++
/*************************************************************************/
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/* gradient.h */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* https://godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
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/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#ifndef GRADIENT_H
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#define GRADIENT_H
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#include "core/io/resource.h"
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class Gradient : public Resource {
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GDCLASS(Gradient, Resource);
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OBJ_SAVE_TYPE(Gradient);
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public:
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enum InterpolationMode {
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GRADIENT_INTERPOLATE_LINEAR,
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GRADIENT_INTERPOLATE_CONSTANT,
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GRADIENT_INTERPOLATE_CUBIC,
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};
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struct Point {
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float offset = 0.0;
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Color color;
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bool operator<(const Point &p_ponit) const {
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return offset < p_ponit.offset;
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}
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};
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private:
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Vector<Point> points;
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bool is_sorted = true;
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InterpolationMode interpolation_mode = GRADIENT_INTERPOLATE_LINEAR;
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_FORCE_INLINE_ void _update_sorting() {
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if (!is_sorted) {
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points.sort();
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is_sorted = true;
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}
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}
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protected:
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static void _bind_methods();
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public:
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Gradient();
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virtual ~Gradient();
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void add_point(float p_offset, const Color &p_color);
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void remove_point(int p_index);
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void set_points(Vector<Point> &p_points);
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Vector<Point> &get_points();
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void reverse();
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void set_offset(int pos, const float offset);
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float get_offset(int pos);
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void set_color(int pos, const Color &color);
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Color get_color(int pos);
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void set_offsets(const Vector<float> &p_offsets);
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Vector<float> get_offsets() const;
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void set_colors(const Vector<Color> &p_colors);
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Vector<Color> get_colors() const;
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void set_interpolation_mode(InterpolationMode p_interp_mode);
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InterpolationMode get_interpolation_mode();
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_FORCE_INLINE_ float cubic_interpolate(float p0, float p1, float p2, float p3, float x) {
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return p1 + 0.5 * x * (p2 - p0 + x * (2.0 * p0 - 5.0 * p1 + 4.0 * p2 - p3 + x * (3.0 * (p1 - p2) + p3 - p0)));
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}
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_FORCE_INLINE_ Color get_color_at_offset(float p_offset) {
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if (points.is_empty()) {
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return Color(0, 0, 0, 1);
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}
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_update_sorting();
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// Binary search.
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int low = 0;
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int high = points.size() - 1;
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int middle = 0;
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#ifdef DEBUG_ENABLED
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if (low > high) {
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ERR_PRINT("low > high, this may be a bug");
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}
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#endif
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while (low <= high) {
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middle = (low + high) / 2;
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const Point &point = points[middle];
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if (point.offset > p_offset) {
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high = middle - 1; //search low end of array
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} else if (point.offset < p_offset) {
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low = middle + 1; //search high end of array
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} else {
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return point.color;
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}
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}
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// Return interpolated value.
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if (points[middle].offset > p_offset) {
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middle--;
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}
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int first = middle;
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int second = middle + 1;
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if (second >= points.size()) {
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return points[points.size() - 1].color;
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}
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if (first < 0) {
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return points[0].color;
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}
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const Point &pointFirst = points[first];
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const Point &pointSecond = points[second];
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switch (interpolation_mode) {
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case GRADIENT_INTERPOLATE_LINEAR: {
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return pointFirst.color.lerp(pointSecond.color, (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset));
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} break;
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case GRADIENT_INTERPOLATE_CONSTANT: {
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return pointFirst.color;
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} break;
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case GRADIENT_INTERPOLATE_CUBIC: {
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int p0 = first - 1;
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int p3 = second + 1;
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if (p3 >= points.size()) {
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p3 = second;
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}
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if (p0 < 0) {
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p0 = first;
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}
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const Point &pointP0 = points[p0];
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const Point &pointP3 = points[p3];
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float x = (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset);
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float r = cubic_interpolate(pointP0.color.r, pointFirst.color.r, pointSecond.color.r, pointP3.color.r, x);
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float g = cubic_interpolate(pointP0.color.g, pointFirst.color.g, pointSecond.color.g, pointP3.color.g, x);
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float b = cubic_interpolate(pointP0.color.b, pointFirst.color.b, pointSecond.color.b, pointP3.color.b, x);
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float a = cubic_interpolate(pointP0.color.a, pointFirst.color.a, pointSecond.color.a, pointP3.color.a, x);
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return Color(r, g, b, a);
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} break;
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default: {
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// Fallback to linear interpolation.
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return pointFirst.color.lerp(pointSecond.color, (p_offset - pointFirst.offset) / (pointSecond.offset - pointFirst.offset));
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}
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}
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}
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int get_points_count() const;
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};
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VARIANT_ENUM_CAST(Gradient::InterpolationMode);
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#endif // GRADIENT_H
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