From b5fbe0b1451ac6f709c2aced14918977d284f584 Mon Sep 17 00:00:00 2001
From: unhold <c.unhold@gmail.com>
Date: Wed, 12 Apr 2023 23:19:52 +0200
Subject: [PATCH] Fix cut-off on 2.13" waveshare/ttgo epaper displays (#4255)
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The controller of the 2.13" waveshare/ttgo epaper displays operates with a 128x250 buffer,
while only 122x250 pixels are shown. While this can be ignored for rotations 0/270°,
with roations 90/180°, 6 pixels are cut-off from the top or left edge.
This change introduces a distinction between object width and controller width,
resulting in pixel-perfect rotations.
---
 .../waveshare_epaper/waveshare_epaper.cpp     | 22 ++++++++++++++++---
 .../waveshare_epaper/waveshare_epaper.h       |  4 ++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/esphome/components/waveshare_epaper/waveshare_epaper.cpp b/esphome/components/waveshare_epaper/waveshare_epaper.cpp
index 8fd5c2e1f3..8c4b137514 100644
--- a/esphome/components/waveshare_epaper/waveshare_epaper.cpp
+++ b/esphome/components/waveshare_epaper/waveshare_epaper.cpp
@@ -137,7 +137,7 @@ void HOT WaveshareEPaper::draw_absolute_pixel_internal(int x, int y, Color color
   if (x >= this->get_width_internal() || y >= this->get_height_internal() || x < 0 || y < 0)
     return;
 
-  const uint32_t pos = (x + y * this->get_width_internal()) / 8u;
+  const uint32_t pos = (x + y * this->get_width_controller()) / 8u;
   const uint8_t subpos = x & 0x07;
   // flip logic
   if (!color.is_on()) {
@@ -146,7 +146,9 @@ void HOT WaveshareEPaper::draw_absolute_pixel_internal(int x, int y, Color color
     this->buffer_[pos] &= ~(0x80 >> subpos);
   }
 }
-uint32_t WaveshareEPaper::get_buffer_length_() { return this->get_width_internal() * this->get_height_internal() / 8u; }
+uint32_t WaveshareEPaper::get_buffer_length_() {
+  return this->get_width_controller() * this->get_height_internal() / 8u;
+}
 void WaveshareEPaper::start_command_() {
   this->dc_pin_->digital_write(false);
   this->enable();
@@ -291,7 +293,7 @@ void HOT WaveshareEPaperTypeA::display() {
       // COMMAND SET RAM X ADDRESS START END POSITION
       this->command(0x44);
       this->data(0x00);
-      this->data((this->get_width_internal() - 1) >> 3);
+      this->data((this->get_width_controller() - 1) >> 3);
       // COMMAND SET RAM Y ADDRESS START END POSITION
       this->command(0x45);
       this->data(this->get_height_internal() - 1);
@@ -392,12 +394,26 @@ int WaveshareEPaperTypeA::get_width_internal() {
     case TTGO_EPAPER_2_13_IN_B73:
     case TTGO_EPAPER_2_13_IN_B74:
     case TTGO_EPAPER_2_13_IN_B1:
+      return 122;
     case WAVESHARE_EPAPER_2_9_IN:
     case WAVESHARE_EPAPER_2_9_IN_V2:
       return 128;
   }
   return 0;
 }
+// The controller of the 2.13" displays has a buffer larger than screen size
+int WaveshareEPaperTypeA::get_width_controller() {
+  switch (this->model_) {
+    case WAVESHARE_EPAPER_2_13_IN:
+    case TTGO_EPAPER_2_13_IN:
+    case TTGO_EPAPER_2_13_IN_B73:
+    case TTGO_EPAPER_2_13_IN_B74:
+    case TTGO_EPAPER_2_13_IN_B1:
+      return 128;
+    default:
+      return this->get_width_internal();
+  }
+}
 int WaveshareEPaperTypeA::get_height_internal() {
   switch (this->model_) {
     case WAVESHARE_EPAPER_1_54_IN:
diff --git a/esphome/components/waveshare_epaper/waveshare_epaper.h b/esphome/components/waveshare_epaper/waveshare_epaper.h
index 848b293c45..a674d3af0c 100644
--- a/esphome/components/waveshare_epaper/waveshare_epaper.h
+++ b/esphome/components/waveshare_epaper/waveshare_epaper.h
@@ -54,6 +54,8 @@ class WaveshareEPaper : public PollingComponent,
     }
   }
 
+  virtual int get_width_controller() { return this->get_width_internal(); };
+
   uint32_t get_buffer_length_();
   uint32_t reset_duration_{200};
 
@@ -111,6 +113,8 @@ class WaveshareEPaperTypeA : public WaveshareEPaper {
 
   int get_height_internal() override;
 
+  int get_width_controller() override;
+
   uint32_t full_update_every_{30};
   uint32_t at_update_{0};
   WaveshareEPaperTypeAModel model_;