Add line_at_angle method to Display component (#6381)

esphome/components/display/display.cpp

@@ -36,6 +36,21 @@ void HOT Display::line(int x1, int y1, int x2, int y2, Color color) {
   }
 }
 
+void Display::line_at_angle(int x, int y, int angle, int length, Color color) {
+  this->line_at_angle(x, y, angle, 0, length, color);
+}
+
+void Display::line_at_angle(int x, int y, int angle, int start_radius, int stop_radius, Color color) {
+  // Calculate start and end points
+  int x1 = (start_radius * cos(angle * M_PI / 180)) + x;
+  int y1 = (start_radius * sin(angle * M_PI / 180)) + y;
+  int x2 = (stop_radius * cos(angle * M_PI / 180)) + x;
+  int y2 = (stop_radius * sin(angle * M_PI / 180)) + y;
+
+  // Draw line
+  this->line(x1, y1, x2, y2, color);
+}
+
 void Display::draw_pixels_at(int x_start, int y_start, int w, int h, const uint8_t *ptr, ColorOrder order,
                              ColorBitness bitness, bool big_endian, int x_offset, int y_offset, int x_pad) {
   size_t line_stride = x_offset + w + x_pad;  // length of each source line in pixels

esphome/components/display/display.h

@@ -258,6 +258,13 @@ class Display : public PollingComponent {
   /// Draw a straight line from the point [x1,y1] to [x2,y2] with the given color.
   void line(int x1, int y1, int x2, int y2, Color color = COLOR_ON);
 
+  /// Draw a straight line at the given angle based on the origin [x, y] for a specified length with the given color.
+  void line_at_angle(int x, int y, int angle, int length, Color color = COLOR_ON);
+
+  /// Draw a straight line at the given angle based on the origin [x, y] from a specified start and stop radius with the
+  /// given color.
+  void line_at_angle(int x, int y, int angle, int start_radius, int stop_radius, Color color = COLOR_ON);
+
   /// Draw a horizontal line from the point [x,y] to [x+width,y] with the given color.
   void horizontal_line(int x, int y, int width, Color color = COLOR_ON);
 

tests/components/display/test.esp32.yaml

@@ -0,0 +1,35 @@
+spi:
+  - id: spi_main_lcd
+    clk_pin: 16
+    mosi_pin: 17
+    miso_pin: 15
+
+display:
+  - platform: ili9xxx
+    id: main_lcd
+    model: ili9342
+    cs_pin: 12
+    dc_pin: 13
+    reset_pin: 21
+    lambda: |-
+      // Draw an analog clock in the center of the screen
+      int centerX = it.get_width() / 2;
+      int centerY = it.get_height() / 2;
+      int radius = min(it.get_width(), it.get_height()) / 4;
+
+      // Draw border
+      it.circle(centerX, centerY, radius);
+
+      // Draw hour ticks
+      for(int h = 0; h < 12; h++) {
+        int hourAngle = (h * 30) - 90;
+
+        it.line_at_angle(centerX, centerY, hourAngle, radius - 10, radius);
+      }
+
+      // Draw minute ticks
+      for(int m = 0; m < 60; m++) {
+        int minuteAngle = (m * 6) - 90;
+
+        it.line_at_angle(centerX, centerY, minuteAngle, radius - 5, radius);
+      }