[display] Trim the per pixel cost of draw_pixel_at (#19360)

esphome/components/display/display.cpp

@@ -3,6 +3,7 @@
 #include <utility>
 #include <numbers>
 #include "display_color_utils.h"
+#include "esphome/core/application.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
@@ -770,10 +771,12 @@ Rect Display::get_clipping() const {
 
 void Display::clear_clipping_() { this->clipping_rectangle_.clear(); }
 
+void Display::feed_wdt_pixel_slow_() { App.feed_wdt(); }
+
 bool Display::clip(int x, int y) {
   if (x < 0 || x >= this->get_width() || y < 0 || y >= this->get_height())
     return false;
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return false;
   return true;
 }

esphome/components/display/display.h

@@ -758,6 +758,13 @@ class Display : public PollingComponent {
 
   bool is_clipping() const { return !this->clipping_rectangle_.empty(); }
 
+  /// Whether (x, y) falls outside the active clipping rectangle. Tests the
+  /// stack top in place: get_clipping() is out of line and returns the Rect
+  /// by value, which per pixel drawing cannot afford.
+  bool ESPHOME_ALWAYS_INLINE is_point_clipped(int x, int y) const {
+    return this->is_clipping() && !this->clipping_rectangle_.back().inside(x, y);
+  }
+
   /** Check if pixel is within region of display.
    */
   bool clip(int x, int y);
@@ -774,6 +781,17 @@ class Display : public PollingComponent {
   void do_update_();
   void clear_clipping_();
 
+  /// Watchdog feed for per pixel loops. App.feed_wdt() is already rate
+  /// limited, but every call reads the clock; only every 256th pixel makes
+  /// that call, so the real feeds are unchanged and a pixel costs a counter.
+  /// At 20 us per pixel on the slowest e-paper path that is about 5 ms
+  /// between clock reads.
+  void ESPHOME_ALWAYS_INLINE feed_wdt_per_pixel_() {
+    if (++this->wdt_pixel_counter_ == 0)
+      this->feed_wdt_pixel_slow_();
+  }
+  void feed_wdt_pixel_slow_();
+
   virtual int get_height_internal() = 0;
   virtual int get_width_internal() = 0;
 
@@ -793,6 +811,7 @@ class Display : public PollingComponent {
   std::vector<DisplayOnPageChangeTrigger *> on_page_change_triggers_;
   bool auto_clear_enabled_{true};
   std::vector<Rect> clipping_rectangle_;
+  uint8_t wdt_pixel_counter_{0};
   bool show_test_card_{false};
 };
 

esphome/components/display/display_buffer.cpp

@@ -2,7 +2,6 @@
 
 #include <utility>
 
-#include "esphome/core/application.h"
 #include "esphome/core/log.h"
 
 namespace esphome::display {
@@ -44,7 +43,7 @@ int DisplayBuffer::get_height() {
 }
 
 void HOT DisplayBuffer::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;  // NOLINT
 
   switch (this->rotation_) {
@@ -64,7 +63,7 @@ void HOT DisplayBuffer::draw_pixel_at(int x, int y, Color color) {
       break;
   }
   this->draw_absolute_pixel_internal(x, y, color);
-  App.feed_wdt();
+  this->feed_wdt_per_pixel_();
 }
 
 }  // namespace esphome::display

esphome/components/display/rect.cpp

@@ -63,16 +63,6 @@ bool Rect::equal(Rect rect) const {
   return (rect.x == this->x) && (rect.w == this->w) && (rect.y == this->y) && (rect.h == this->h);
 }
 
-bool Rect::inside(int16_t test_x, int16_t test_y, bool absolute) const {  // NOLINT
-  if (!this->is_set()) {
-    return true;
-  }
-  if (absolute) {
-    return test_x >= this->x && test_x < this->x2() && test_y >= this->y && test_y < this->y2();
-  }
-  return test_x >= 0 && test_x < this->w && test_y >= 0 && test_y < this->h;
-}
-
 bool Rect::inside(Rect rect) const {
   if (!this->is_set() || !rect.is_set()) {
     return true;

esphome/components/display/rect.h

@@ -26,7 +26,15 @@ class Rect {
   void shrink(Rect rect);
 
   bool inside(Rect rect) const;
-  bool inside(int16_t test_x, int16_t test_y, bool absolute = true) const;
+  bool ESPHOME_ALWAYS_INLINE inside(int16_t test_x, int16_t test_y, bool absolute = true) const {
+    if (!this->is_set()) {
+      return true;
+    }
+    if (absolute) {
+      return test_x >= this->x && test_x < this->x2() && test_y >= this->y && test_y < this->y2();
+    }
+    return test_x >= 0 && test_x < this->w && test_y >= 0 && test_y < this->h;
+  }
   bool equal(Rect rect) const;
   void info(const std::string &prefix = "rect info:");
 };

esphome/components/epaper_spi/epaper_spi.cpp

@@ -299,7 +299,7 @@ bool EPaperBase::initialise(bool partial) {
  * @return false if the coordinates are out of bounds
  */
 bool EPaperBase::rotate_coordinates_(int &x, int &y) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return false;
   if (this->effective_transform_ & SWAP_XY)
     std::swap(x, y);

esphome/components/hub75/hub75.cpp

@@ -1,5 +1,4 @@
 #include "hub75_component.h"
-#include "esphome/core/application.h"
 
 #include <cinttypes>
 
@@ -124,11 +123,11 @@ void HOT HUB75Display::draw_pixel_at(int x, int y, Color color) {
   if (x >= this->get_width_internal() || x < 0 || y >= this->get_height_internal() || y < 0) [[unlikely]]
     return;
 
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;
 
   driver_->set_pixel(x, y, color.r, color.g, color.b);
-  App.feed_wdt();
+  this->feed_wdt_per_pixel_();
 }
 
 void HOT HUB75Display::draw_pixels_at(int x_start, int y_start, int w, int h, const uint8_t *ptr, ColorOrder order,

esphome/components/it8951/it8951.cpp

@@ -855,7 +855,7 @@ void IT8951Display::apply_transform_(int &x, int &y) const {
 }
 
 bool IT8951Display::rotate_coordinates_(int &x, int &y) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return false;
   this->apply_transform_(x, y);
   if (x >= this->width_ || y >= this->height_ || x < 0 || y < 0)
@@ -929,7 +929,7 @@ void IT8951Display::fill(Color color) {
 void HOT IT8951Display::draw_pixel_at(int x, int y, Color color) {
   if (this->buffer_ == nullptr)
     return;
-  App.feed_wdt();
+  this->feed_wdt_per_pixel_();
   if (!this->rotate_coordinates_(x, y))
     return;
   this->write_pixel_native_(static_cast<uint16_t>(x), static_cast<uint16_t>(y), color);

esphome/components/mipi_dsi/mipi_dsi.cpp

@@ -259,7 +259,7 @@ bool MipiDsi::check_buffer_() {
 }
 
 void MipiDsi::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;
 
   switch (this->rotation_) {

esphome/components/mipi_rgb/mipi_rgb.cpp

@@ -259,7 +259,7 @@ bool MipiRgb::check_buffer_() {
 }
 
 void MipiRgb::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y) || this->is_failed())
+  if (this->is_point_clipped(x, y) || this->is_failed())
     return;
 
   switch (this->rotation_) {

esphome/components/mipi_spi/mipi_spi.h

@@ -604,7 +604,7 @@ class MipiSpiBuffer
 
   // Draw a pixel at the given coordinates.
   void draw_pixel_at(int x, int y, Color color) override {
-    if (!this->get_clipping().inside(x, y))
+    if (this->is_point_clipped(x, y))
       return;
     if constexpr (not HAS_HARDWARE_ROTATION) {
       if (this->rotation_ == display::DISPLAY_ROTATION_180_DEGREES) {

esphome/components/pixoo/pixoo.cpp

@@ -120,7 +120,7 @@ void Pixoo::set_pixel_(uint32_t index, Color color) {
 }
 
 void HOT Pixoo::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;
   const int side = static_cast<int>(this->model_);
   switch (this->rotation_) {

esphome/components/rpi_dpi_rgb/rpi_dpi_rgb.cpp

@@ -101,7 +101,7 @@ int RpiDpiRgb::get_height() {
 }
 
 void RpiDpiRgb::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;  // NOLINT
 
   switch (this->rotation_) {
@@ -124,7 +124,7 @@ void RpiDpiRgb::draw_pixel_at(int x, int y, Color color) {
 
   this->draw_pixels_at(x, y, 1, 1, (const uint8_t *) &pixel, display::COLOR_ORDER_RGB, display::COLOR_BITNESS_565, true,
                        0, 0, 0);
-  App.feed_wdt();
+  this->feed_wdt_per_pixel_();
 }
 
 void RpiDpiRgb::dump_config() {

esphome/components/sdl/sdl_esphome.cpp

@@ -164,7 +164,7 @@ void Sdl::draw_pixels_at(int x_start, int y_start, int w, int h, const uint8_t *
 }
 
 void Sdl::draw_pixel_at(int x, int y, Color color) {
-  if (this->texture_ == nullptr || !this->get_clipping().inside(x, y))
+  if (this->texture_ == nullptr || this->is_point_clipped(x, y))
     return;
 
   if (this->rotation_ == display::DISPLAY_ROTATION_180_DEGREES) {

esphome/components/st7701s/st7701s.cpp

@@ -84,7 +84,7 @@ void ST7701S::draw_pixels_at(int x_start, int y_start, int w, int h, const uint8
 }
 
 void ST7701S::draw_pixel_at(int x, int y, Color color) {
-  if (!this->get_clipping().inside(x, y))
+  if (this->is_point_clipped(x, y))
     return;  // NOLINT
 
   switch (this->rotation_) {
@@ -107,7 +107,7 @@ void ST7701S::draw_pixel_at(int x, int y, Color color) {
 
   this->draw_pixels_at(x, y, 1, 1, (const uint8_t *) &pixel, display::COLOR_ORDER_RGB, display::COLOR_BITNESS_565, true,
                        0, 0, 0);
-  App.feed_wdt();
+  this->feed_wdt_per_pixel_();
 }
 
 void ST7701S::write_command_(uint8_t value) {