From d20c4200dbf42116b7601eb8a6290ba302a51ae6 Mon Sep 17 00:00:00 2001 From: Aaron Franke Date: Sun, 18 Sep 2022 17:33:59 -0500 Subject: [PATCH] Update cubic interpolation methods to match core https://github.com/godotengine/godot/pull/64924 https://github.com/godotengine/godot/pull/63602 https://github.com/godotengine/godot/pull/62458 --- include/godot_cpp/core/math.hpp | 125 ++++++++++++++++++++++++++++++-- 1 file changed, 117 insertions(+), 8 deletions(-) diff --git a/include/godot_cpp/core/math.hpp b/include/godot_cpp/core/math.hpp index e25926d1..78eee8aa 100644 --- a/include/godot_cpp/core/math.hpp +++ b/include/godot_cpp/core/math.hpp @@ -280,17 +280,126 @@ inline float lerp_angle(float p_from, float p_to, float p_weight) { inline double cubic_interpolate(double p_from, double p_to, double p_pre, double p_post, double p_weight) { return 0.5 * - ((p_from * 2.0) + - (-p_pre + p_to) * p_weight + - (2.0 * p_pre - 5.0 * p_from + 4.0 * p_to - p_post) * (p_weight * p_weight) + - (-p_pre + 3.0 * p_from - 3.0 * p_to + p_post) * (p_weight * p_weight * p_weight)); + ((p_from * 2.0) + + (-p_pre + p_to) * p_weight + + (2.0 * p_pre - 5.0 * p_from + 4.0 * p_to - p_post) * (p_weight * p_weight) + + (-p_pre + 3.0 * p_from - 3.0 * p_to + p_post) * (p_weight * p_weight * p_weight)); } + inline float cubic_interpolate(float p_from, float p_to, float p_pre, float p_post, float p_weight) { return 0.5f * - ((p_from * 2.0f) + - (-p_pre + p_to) * p_weight + - (2.0f * p_pre - 5.0f * p_from + 4.0f * p_to - p_post) * (p_weight * p_weight) + - (-p_pre + 3.0f * p_from - 3.0f * p_to + p_post) * (p_weight * p_weight * p_weight)); + ((p_from * 2.0f) + + (-p_pre + p_to) * p_weight + + (2.0f * p_pre - 5.0f * p_from + 4.0f * p_to - p_post) * (p_weight * p_weight) + + (-p_pre + 3.0f * p_from - 3.0f * p_to + p_post) * (p_weight * p_weight * p_weight)); +} + +inline double cubic_interpolate_angle(double p_from, double p_to, double p_pre, double p_post, double p_weight) { + double from_rot = fmod(p_from, Math_TAU); + + double pre_diff = fmod(p_pre - from_rot, Math_TAU); + double pre_rot = from_rot + fmod(2.0 * pre_diff, Math_TAU) - pre_diff; + + double to_diff = fmod(p_to - from_rot, Math_TAU); + double to_rot = from_rot + fmod(2.0 * to_diff, Math_TAU) - to_diff; + + double post_diff = fmod(p_post - to_rot, Math_TAU); + double post_rot = to_rot + fmod(2.0 * post_diff, Math_TAU) - post_diff; + + return cubic_interpolate(from_rot, to_rot, pre_rot, post_rot, p_weight); +} + +inline float cubic_interpolate_angle(float p_from, float p_to, float p_pre, float p_post, float p_weight) { + float from_rot = fmod(p_from, (float)Math_TAU); + + float pre_diff = fmod(p_pre - from_rot, (float)Math_TAU); + float pre_rot = from_rot + fmod(2.0f * pre_diff, (float)Math_TAU) - pre_diff; + + float to_diff = fmod(p_to - from_rot, (float)Math_TAU); + float to_rot = from_rot + fmod(2.0f * to_diff, (float)Math_TAU) - to_diff; + + float post_diff = fmod(p_post - to_rot, (float)Math_TAU); + float post_rot = to_rot + fmod(2.0f * post_diff, (float)Math_TAU) - post_diff; + + return cubic_interpolate(from_rot, to_rot, pre_rot, post_rot, p_weight); +} + +inline double cubic_interpolate_in_time(double p_from, double p_to, double p_pre, double p_post, double p_weight, + double p_to_t, double p_pre_t, double p_post_t) { + /* Barry-Goldman method */ + double t = Math::lerp(0.0, p_to_t, p_weight); + double a1 = Math::lerp(p_pre, p_from, p_pre_t == 0 ? 0.0 : (t - p_pre_t) / -p_pre_t); + double a2 = Math::lerp(p_from, p_to, p_to_t == 0 ? 0.5 : t / p_to_t); + double a3 = Math::lerp(p_to, p_post, p_post_t - p_to_t == 0 ? 1.0 : (t - p_to_t) / (p_post_t - p_to_t)); + double b1 = Math::lerp(a1, a2, p_to_t - p_pre_t == 0 ? 0.0 : (t - p_pre_t) / (p_to_t - p_pre_t)); + double b2 = Math::lerp(a2, a3, p_post_t == 0 ? 1.0 : t / p_post_t); + return Math::lerp(b1, b2, p_to_t == 0 ? 0.5 : t / p_to_t); +} + +inline float cubic_interpolate_in_time(float p_from, float p_to, float p_pre, float p_post, float p_weight, + float p_to_t, float p_pre_t, float p_post_t) { + /* Barry-Goldman method */ + float t = Math::lerp(0.0f, p_to_t, p_weight); + float a1 = Math::lerp(p_pre, p_from, p_pre_t == 0 ? 0.0f : (t - p_pre_t) / -p_pre_t); + float a2 = Math::lerp(p_from, p_to, p_to_t == 0 ? 0.5f : t / p_to_t); + float a3 = Math::lerp(p_to, p_post, p_post_t - p_to_t == 0 ? 1.0f : (t - p_to_t) / (p_post_t - p_to_t)); + float b1 = Math::lerp(a1, a2, p_to_t - p_pre_t == 0 ? 0.0f : (t - p_pre_t) / (p_to_t - p_pre_t)); + float b2 = Math::lerp(a2, a3, p_post_t == 0 ? 1.0f : t / p_post_t); + return Math::lerp(b1, b2, p_to_t == 0 ? 0.5f : t / p_to_t); +} + +inline double cubic_interpolate_angle_in_time(double p_from, double p_to, double p_pre, double p_post, double p_weight, + double p_to_t, double p_pre_t, double p_post_t) { + double from_rot = fmod(p_from, Math_TAU); + + double pre_diff = fmod(p_pre - from_rot, Math_TAU); + double pre_rot = from_rot + fmod(2.0 * pre_diff, Math_TAU) - pre_diff; + + double to_diff = fmod(p_to - from_rot, Math_TAU); + double to_rot = from_rot + fmod(2.0 * to_diff, Math_TAU) - to_diff; + + double post_diff = fmod(p_post - to_rot, Math_TAU); + double post_rot = to_rot + fmod(2.0 * post_diff, Math_TAU) - post_diff; + + return cubic_interpolate_in_time(from_rot, to_rot, pre_rot, post_rot, p_weight, p_to_t, p_pre_t, p_post_t); +} + +inline float cubic_interpolate_angle_in_time(float p_from, float p_to, float p_pre, float p_post, float p_weight, + float p_to_t, float p_pre_t, float p_post_t) { + float from_rot = fmod(p_from, (float)Math_TAU); + + float pre_diff = fmod(p_pre - from_rot, (float)Math_TAU); + float pre_rot = from_rot + fmod(2.0f * pre_diff, (float)Math_TAU) - pre_diff; + + float to_diff = fmod(p_to - from_rot, (float)Math_TAU); + float to_rot = from_rot + fmod(2.0f * to_diff, (float)Math_TAU) - to_diff; + + float post_diff = fmod(p_post - to_rot, (float)Math_TAU); + float post_rot = to_rot + fmod(2.0f * post_diff, (float)Math_TAU) - post_diff; + + return cubic_interpolate_in_time(from_rot, to_rot, pre_rot, post_rot, p_weight, p_to_t, p_pre_t, p_post_t); +} + +inline double bezier_interpolate(double p_start, double p_control_1, double p_control_2, double p_end, double p_t) { + /* Formula from Wikipedia article on Bezier curves. */ + double omt = (1.0 - p_t); + double omt2 = omt * omt; + double omt3 = omt2 * omt; + double t2 = p_t * p_t; + double t3 = t2 * p_t; + + return p_start * omt3 + p_control_1 * omt2 * p_t * 3.0 + p_control_2 * omt * t2 * 3.0 + p_end * t3; +} + +inline float bezier_interpolate(float p_start, float p_control_1, float p_control_2, float p_end, float p_t) { + /* Formula from Wikipedia article on Bezier curves. */ + float omt = (1.0f - p_t); + float omt2 = omt * omt; + float omt3 = omt2 * omt; + float t2 = p_t * p_t; + float t3 = t2 * p_t; + + return p_start * omt3 + p_control_1 * omt2 * p_t * 3.0f + p_control_2 * omt * t2 * 3.0f + p_end * t3; } template