From 72ab1700e71305038d8f8c71f3adb53bed64c526 Mon Sep 17 00:00:00 2001 From: mathieu-mp Date: Tue, 16 Jan 2024 07:38:09 +0100 Subject: [PATCH] Add triangle shapes to display component (#6096) --- esphome/components/display/display.cpp | 116 +++++++++++++++++++++++++ esphome/components/display/display.h | 15 ++++ 2 files changed, 131 insertions(+) diff --git a/esphome/components/display/display.cpp b/esphome/components/display/display.cpp index f32fda4794..0c3631342e 100644 --- a/esphome/components/display/display.cpp +++ b/esphome/components/display/display.cpp @@ -141,6 +141,122 @@ void Display::filled_circle(int center_x, int center_y, int radius, Color color) } } while (dx <= 0); } +void HOT Display::triangle(int x1, int y1, int x2, int y2, int x3, int y3, Color color) { + this->line(x1, y1, x2, y2); + this->line(x1, y1, x3, y3); + this->line(x2, y2, x3, y3); +} +void Display::sort_triangle_points_by_y_(int *x1, int *y1, int *x2, int *y2, int *x3, int *y3) { + if (*y1 > *y2) { + int x_temp = *x1, y_temp = *y1; + *x1 = *x2, *y1 = *y2; + *x2 = x_temp, *y2 = y_temp; + } + if (*y1 > *y3) { + int x_temp = *x1, y_temp = *y1; + *x1 = *x3, *y1 = *y3; + *x3 = x_temp, *y3 = y_temp; + } + if (*y2 > *y3) { + int x_temp = *x2, y_temp = *y2; + *x2 = *x3, *y2 = *y3; + *x3 = x_temp, *y3 = y_temp; + } +} +void Display::filled_flat_side_triangle_(int x1, int y1, int x2, int y2, int x3, int y3, Color color) { + // y2 must be equal to y3 (same horizontal line) + + // Initialize Bresenham's algorithm for side 1 + int s1_current_x = x1; + int s1_current_y = y1; + bool s1_axis_swap = false; + int s1_dx = abs(x2 - x1); + int s1_dy = abs(y2 - y1); + int s1_sign_x = ((x2 - x1) >= 0) ? 1 : -1; + int s1_sign_y = ((y2 - y1) >= 0) ? 1 : -1; + if (s1_dy > s1_dx) { // swap values + int tmp = s1_dx; + s1_dx = s1_dy; + s1_dy = tmp; + s1_axis_swap = true; + } + int s1_error = 2 * s1_dy - s1_dx; + + // Initialize Bresenham's algorithm for side 2 + int s2_current_x = x1; + int s2_current_y = y1; + bool s2_axis_swap = false; + int s2_dx = abs(x3 - x1); + int s2_dy = abs(y3 - y1); + int s2_sign_x = ((x3 - x1) >= 0) ? 1 : -1; + int s2_sign_y = ((y3 - y1) >= 0) ? 1 : -1; + if (s2_dy > s2_dx) { // swap values + int tmp = s2_dx; + s2_dx = s2_dy; + s2_dy = tmp; + s2_axis_swap = true; + } + int s2_error = 2 * s2_dy - s2_dx; + + // Iterate on side 1 and allow side 2 to be processed to match the advance of the y-axis. + for (int i = 0; i <= s1_dx; i++) { + if (s1_current_x <= s2_current_x) { + this->horizontal_line(s1_current_x, s1_current_y, s2_current_x - s1_current_x + 1, color); + } else { + this->horizontal_line(s2_current_x, s2_current_y, s1_current_x - s2_current_x + 1, color); + } + + // Bresenham's #1 + // Side 1 s1_current_x and s1_current_y calculation + while (s1_error >= 0) { + if (s1_axis_swap) { + s1_current_x += s1_sign_x; + } else { + s1_current_y += s1_sign_y; + } + s1_error = s1_error - 2 * s1_dx; + } + if (s1_axis_swap) { + s1_current_y += s1_sign_y; + } else { + s1_current_x += s1_sign_x; + } + s1_error = s1_error + 2 * s1_dy; + + // Bresenham's #2 + // Side 2 s2_current_x and s2_current_y calculation + while (s2_current_y != s1_current_y) { + while (s2_error >= 0) { + if (s2_axis_swap) { + s2_current_x += s2_sign_x; + } else { + s2_current_y += s2_sign_y; + } + s2_error = s2_error - 2 * s2_dx; + } + if (s2_axis_swap) { + s2_current_y += s2_sign_y; + } else { + s2_current_x += s2_sign_x; + } + s2_error = s2_error + 2 * s2_dy; + } + } +} +void Display::filled_triangle(int x1, int y1, int x2, int y2, int x3, int y3, Color color) { + // Sort the three points by y-coordinate ascending, so [x1,y1] is the topmost point + this->sort_triangle_points_by_y_(&x1, &y1, &x2, &y2, &x3, &y3); + + if (y2 == y3) { // Check for special case of a bottom-flat triangle + this->filled_flat_side_triangle_(x1, y1, x2, y2, x3, y3, color); + } else if (y1 == y2) { // Check for special case of a top-flat triangle + this->filled_flat_side_triangle_(x3, y3, x1, y1, x2, y2, color); + } else { // General case: split the no-flat-side triangle in a top-flat triangle and bottom-flat triangle + int x_temp = (int) (x1 + ((float) (y2 - y1) / (float) (y3 - y1)) * (x3 - x1)), y_temp = y2; + this->filled_flat_side_triangle_(x1, y1, x2, y2, x_temp, y_temp, color); + this->filled_flat_side_triangle_(x3, y3, x2, y2, x_temp, y_temp, color); + } +} void Display::print(int x, int y, BaseFont *font, Color color, TextAlign align, const char *text) { int x_start, y_start; diff --git a/esphome/components/display/display.h b/esphome/components/display/display.h index 2a2a9b80c8..daa5028d6b 100644 --- a/esphome/components/display/display.h +++ b/esphome/components/display/display.h @@ -236,6 +236,12 @@ class Display : public PollingComponent { /// Fill a circle centered around [center_x,center_y] with the radius radius with the given color. void filled_circle(int center_x, int center_y, int radius, Color color = COLOR_ON); + /// Draw the outline of a triangle contained between the points [x1,y1], [x2,y2] and [x3,y3] with the given color. + void triangle(int x1, int y1, int x2, int y2, int x3, int y3, Color color = COLOR_ON); + + /// Fill a triangle contained between the points [x1,y1], [x2,y2] and [x3,y3] with the given color. + void filled_triangle(int x1, int y1, int x2, int y2, int x3, int y3, Color color = COLOR_ON); + /** Print `text` with the anchor point at [x,y] with `font`. * * @param x The x coordinate of the text alignment anchor point. @@ -532,6 +538,15 @@ class Display : public PollingComponent { void do_update_(); void clear_clipping_(); + /** + * This method fills a triangle using only integer variables by using a + * modified bresenham algorithm. + * It is mandatory that [x2,y2] and [x3,y3] lie on the same horizontal line, + * so y2 must be equal to y3. + */ + void filled_flat_side_triangle_(int x1, int y1, int x2, int y2, int x3, int y3, Color color); + void sort_triangle_points_by_y_(int *x1, int *y1, int *x2, int *y2, int *x3, int *y3); + DisplayRotation rotation_{DISPLAY_ROTATION_0_DEGREES}; optional writer_{}; DisplayPage *page_{nullptr};