From 4f378e8726fdcff72598aa6ed12eeaa6b3e61355 Mon Sep 17 00:00:00 2001 From: Jonathan Vander Mey Date: Sun, 11 Jul 2021 14:18:07 -0400 Subject: [PATCH] Refactor trig functions into LUT (#476) Replaced the use of the standard library trig functions with a LUT-based implementation instead. The standard library implementations produce more accurate results but the usage here doesn't need that. This ends up saving nearly 7kB of binary size. --- src/displayapp/screens/WatchFaceAnalog.cpp | 76 +++++++++++++--------- 1 file changed, 44 insertions(+), 32 deletions(-) diff --git a/src/displayapp/screens/WatchFaceAnalog.cpp b/src/displayapp/screens/WatchFaceAnalog.cpp index 0051408c..c589c320 100644 --- a/src/displayapp/screens/WatchFaceAnalog.cpp +++ b/src/displayapp/screens/WatchFaceAnalog.cpp @@ -5,27 +5,44 @@ #include "Symbols.h" #include "NotificationIcon.h" -#include - LV_IMG_DECLARE(bg_clock); using namespace Pinetime::Applications::Screens; -#define HOUR_LENGTH 70 -#define MINUTE_LENGTH 90 -#define SECOND_LENGTH 110 -#define PI 3.14159265358979323846 +namespace { -// ## -static int16_t coordinate_x_relocate(int16_t x) { - return ((x) + LV_HOR_RES / 2); +constexpr auto HOUR_LENGTH = 70; +constexpr auto MINUTE_LENGTH = 90; +constexpr auto SECOND_LENGTH = 110; + +// sin(90) = 1 so the value of _lv_trigo_sin(90) is the scaling factor +const auto LV_TRIG_SCALE = _lv_trigo_sin(90); + +int16_t cosine(int16_t angle) { + return _lv_trigo_sin(angle + 90); } -// ## -static int16_t coordinate_y_relocate(int16_t y) { - return (((y) -LV_HOR_RES / 2) < 0) ? (0 - ((y) -LV_HOR_RES / 2)) : ((y) -LV_HOR_RES / 2); +int16_t sine(int16_t angle) { + return _lv_trigo_sin(angle); } +int16_t coordinate_x_relocate(int16_t x) { + return (x + LV_HOR_RES / 2); +} + +int16_t coordinate_y_relocate(int16_t y) { + return std::abs(y - LV_HOR_RES / 2); +} + +lv_point_t coordinate_relocate(int16_t radius, int16_t angle) { + return lv_point_t{ + .x = coordinate_x_relocate(radius * static_cast(sine(angle)) / LV_TRIG_SCALE), + .y = coordinate_y_relocate(radius * static_cast(cosine(angle)) / LV_TRIG_SCALE) + }; +} + +} // namespace + WatchFaceAnalog::WatchFaceAnalog(Pinetime::Applications::DisplayApp* app, Controllers::DateTime& dateTimeController, Controllers::Battery& batteryController, @@ -123,15 +140,12 @@ void WatchFaceAnalog::UpdateClock() { second = dateTimeController.Seconds(); if (sMinute != minute) { - minute_point[0].x = coordinate_x_relocate(30 * sin(minute * 6 * PI / 180)); - minute_point[0].y = coordinate_y_relocate(30 * cos(minute * 6 * PI / 180)); - minute_point[1].x = coordinate_x_relocate(MINUTE_LENGTH * sin(minute * 6 * PI / 180)); - minute_point[1].y = coordinate_y_relocate(MINUTE_LENGTH * cos(minute * 6 * PI / 180)); + auto const angle = minute * 6; + minute_point[0] = coordinate_relocate(30, angle); + minute_point[1] = coordinate_relocate(MINUTE_LENGTH, angle); - minute_point_trace[0].x = coordinate_x_relocate(5 * sin(minute * 6 * PI / 180)); - minute_point_trace[0].y = coordinate_y_relocate(5 * cos(minute * 6 * PI / 180)); - minute_point_trace[1].x = coordinate_x_relocate(31 * sin(minute * 6 * PI / 180)); - minute_point_trace[1].y = coordinate_y_relocate(31 * cos(minute * 6 * PI / 180)); + minute_point_trace[0] = coordinate_relocate(5, angle); + minute_point_trace[1] = coordinate_relocate(31, angle); lv_line_set_points(minute_body, minute_point, 2); lv_line_set_points(minute_body_trace, minute_point_trace, 2); @@ -140,15 +154,13 @@ void WatchFaceAnalog::UpdateClock() { if (sHour != hour || sMinute != minute) { sHour = hour; sMinute = minute; - hour_point[0].x = coordinate_x_relocate(30 * sin((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point[0].y = coordinate_y_relocate(30 * cos((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point[1].x = coordinate_x_relocate(HOUR_LENGTH * sin((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point[1].y = coordinate_y_relocate(HOUR_LENGTH * cos((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); + auto const angle = (hour * 30 + minute / 2); - hour_point_trace[0].x = coordinate_x_relocate(5 * sin((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point_trace[0].y = coordinate_y_relocate(5 * cos((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point_trace[1].x = coordinate_x_relocate(31 * sin((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); - hour_point_trace[1].y = coordinate_y_relocate(31 * cos((((hour > 12 ? hour - 12 : hour) * 30) + (minute * 0.5)) * PI / 180)); + hour_point[0] = coordinate_relocate(30, angle); + hour_point[1] = coordinate_relocate(HOUR_LENGTH, angle); + + hour_point_trace[0] = coordinate_relocate(5, angle); + hour_point_trace[1] = coordinate_relocate(31, angle); lv_line_set_points(hour_body, hour_point, 2); lv_line_set_points(hour_body_trace, hour_point_trace, 2); @@ -156,10 +168,10 @@ void WatchFaceAnalog::UpdateClock() { if (sSecond != second) { sSecond = second; - second_point[0].x = coordinate_x_relocate(20 * sin((180 + second * 6) * PI / 180)); - second_point[0].y = coordinate_y_relocate(20 * cos((180 + second * 6) * PI / 180)); - second_point[1].x = coordinate_x_relocate(SECOND_LENGTH * sin(second * 6 * PI / 180)); - second_point[1].y = coordinate_y_relocate(SECOND_LENGTH * cos(second * 6 * PI / 180)); + auto const angle = second * 6; + + second_point[0] = coordinate_relocate(-20, angle); + second_point[1] = coordinate_relocate(SECOND_LENGTH, angle); lv_line_set_points(second_body, second_point, 2); } }