From e7f06cc6abb6018f730942529dbc81096e444528 Mon Sep 17 00:00:00 2001
From: 0xFEEDC0DE64 <daniel@brunner.ninja>
Date: Tue, 30 Nov 2021 20:46:03 +0100
Subject: [PATCH] Added drawSunkenRect() and made color565() constexpr

---
 TFT_eSPI.cpp | 29 +++++++++++++++++++----------
 TFT_eSPI.h   | 10 ++++++++--
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/TFT_eSPI.cpp b/TFT_eSPI.cpp
index 5ec4ace..311739f 100644
--- a/TFT_eSPI.cpp
+++ b/TFT_eSPI.cpp
@@ -2489,6 +2489,25 @@ void TFT_eSPI::fillRoundRect(int32_t x, int32_t y, int32_t w, int32_t h, int32_t
   end_tft_write();              // Does nothing if Sprite class uses this function
 }
 
+void TFT_eSPI::drawSunkenRect(int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color0, uint32_t color1, uint32_t color2)
+{
+    //begin_tft_write();          // Sprite class can use this function, avoiding begin_tft_write()
+    inTransaction = true;
+
+    drawFastHLine(x, y, w, color0);
+    drawFastHLine(x, y + h - 1, w, color1);
+    // Avoid drawing corner pixels twice
+    drawFastVLine(x, y+1, h-2, color0);
+    drawFastVLine(x + w - 1, y+1, h-2, color1);
+
+    setWindow(x + 1, y + 1, x + w - 2, y + h - 2);
+
+    pushBlock(color2, (w - 2) * (h - 2));
+
+    inTransaction = false;
+    end_tft_write();              // Does nothing if Sprite class uses this function
+}
+
 
 /***************************************************************************************
 ** Function name:           drawTriangle
@@ -4173,16 +4192,6 @@ uint16_t TFT_eSPI::color565(uint8_t r, uint8_t g, uint8_t b)
 }
 
 
-/***************************************************************************************
-** Function name:           color16to8
-** Description:             convert 16 bit colour to an 8 bit 332 RGB colour value
-***************************************************************************************/
-uint8_t TFT_eSPI::color16to8(uint16_t c)
-{
-  return ((c & 0xE000)>>8) | ((c & 0x0700)>>6) | ((c & 0x0018)>>3);
-}
-
-
 /***************************************************************************************
 ** Function name:           color8to16
 ** Description:             convert 8 bit colour to a 16 bit 565 colour value
diff --git a/TFT_eSPI.h b/TFT_eSPI.h
index 7eebefb..a54c858 100644
--- a/TFT_eSPI.h
+++ b/TFT_eSPI.h
@@ -498,6 +498,9 @@ class TFT_eSPI { friend class TFT_eSprite; // Sprite class has access to protect
            // If bg_color is not included the background pixel colour will be read from TFT or sprite
   void     drawWedgeLine(float ax, float ay, float bx, float by, float aw, float bw, uint32_t fg_color, uint32_t bg_color = 0x00FFFFFF);
 
+  void     drawSunkenRect(int32_t x, int32_t y, int32_t w, int32_t h, uint32_t color0, uint32_t color1, uint32_t color2);
+
+
   void     drawCircle(int32_t x, int32_t y, int32_t r, uint32_t color),
            drawCircleHelper(int32_t x, int32_t y, int32_t r, uint8_t cornername, uint32_t color),
            fillCircle(int32_t x, int32_t y, int32_t r, uint32_t color),
@@ -624,8 +627,11 @@ class TFT_eSPI { friend class TFT_eSprite; // Sprite class has access to protect
 
 
   // Colour conversion
-           // Convert 8 bit red, green and blue to 16 bits
-  uint16_t color565(uint8_t red, uint8_t green, uint8_t blue);
+  // Convert 8 bit red, green and blue to 16 bits
+  static constexpr uint16_t color565(uint8_t red, uint8_t green, uint8_t blue) noexcept
+  {
+      return ((red & 0xF8) << 8) | ((green & 0xFC) << 3) | (blue >> 3);
+  }
 
            // Convert 8 bit colour to 16 bits
   uint16_t color8to16(uint8_t color332);