From 26acbbedbf2626eec1232343901a01348369a8ce Mon Sep 17 00:00:00 2001
From: Samuel Sieb <samuel-github@sieb.net>
Date: Mon, 15 Jan 2024 23:44:12 -0800
Subject: [PATCH] Add continuous option to the graph (#6093)

Co-authored-by: Samuel Sieb <samuel@sieb.net>
---
 esphome/components/graph/__init__.py |  4 +++
 esphome/components/graph/graph.cpp   | 37 +++++++++++++++++++++++-----
 esphome/components/graph/graph.h     |  3 +++
 3 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/esphome/components/graph/__init__.py b/esphome/components/graph/__init__.py
index 046f59ca1a..0b83b71fe4 100644
--- a/esphome/components/graph/__init__.py
+++ b/esphome/components/graph/__init__.py
@@ -61,6 +61,7 @@ VALUE_POSITION_TYPE = {
     "BELOW": ValuePositionType.VALUE_POSITION_TYPE_BELOW,
 }
 
+CONF_CONTINUOUS = "continuous"
 
 GRAPH_TRACE_SCHEMA = cv.Schema(
     {
@@ -70,6 +71,7 @@ GRAPH_TRACE_SCHEMA = cv.Schema(
         cv.Optional(CONF_LINE_THICKNESS): cv.positive_int,
         cv.Optional(CONF_LINE_TYPE): cv.enum(LINE_TYPE, upper=True),
         cv.Optional(CONF_COLOR): cv.use_id(color.ColorStruct),
+        cv.Optional(CONF_CONTINUOUS): cv.boolean,
     }
 )
 
@@ -186,6 +188,8 @@ async def to_code(config):
         if CONF_COLOR in trace:
             c = await cg.get_variable(trace[CONF_COLOR])
             cg.add(tr.set_line_color(c))
+        if CONF_CONTINUOUS in trace:
+            cg.add(tr.set_continuous(trace[CONF_CONTINUOUS]))
         cg.add(var.add_trace(tr))
     # Add legend
     if CONF_LEGEND in config:
diff --git a/esphome/components/graph/graph.cpp b/esphome/components/graph/graph.cpp
index 294e16dbb1..0e437a3425 100644
--- a/esphome/components/graph/graph.cpp
+++ b/esphome/components/graph/graph.cpp
@@ -165,17 +165,42 @@ void Graph::draw(Display *buff, uint16_t x_offset, uint16_t y_offset, Color colo
   for (auto *trace : traces_) {
     Color c = trace->get_line_color();
     uint16_t thick = trace->get_line_thickness();
+    bool continuous = trace->get_continuous();
+    bool has_prev = false;
+    bool prev_b = false;
+    int16_t prev_y = 0;
     for (uint32_t i = 0; i < this->width_; i++) {
       float v = (trace->get_tracedata()->get_value(i) - ymin) / yrange;
       if (!std::isnan(v) && (thick > 0)) {
-        int16_t x = this->width_ - 1 - i;
-        uint8_t b = (i % (thick * LineType::PATTERN_LENGTH)) / thick;
-        if (((uint8_t) trace->get_line_type() & (1 << b)) == (1 << b)) {
-          int16_t y = (int16_t) roundf((this->height_ - 1) * (1.0 - v)) - thick / 2;
-          for (uint16_t t = 0; t < thick; t++) {
-            buff->draw_pixel_at(x_offset + x, y_offset + y + t, c);
+        int16_t x = this->width_ - 1 - i + x_offset;
+        uint8_t bit = 1 << ((i % (thick * LineType::PATTERN_LENGTH)) / thick);
+        bool b = (trace->get_line_type() & bit) == bit;
+        if (b) {
+          int16_t y = (int16_t) roundf((this->height_ - 1) * (1.0 - v)) - thick / 2 + y_offset;
+          if (!continuous || !has_prev || !prev_b || (abs(y - prev_y) <= thick)) {
+            for (uint16_t t = 0; t < thick; t++) {
+              buff->draw_pixel_at(x, y + t, c);
+            }
+          } else {
+            int16_t mid_y = (y + prev_y + thick) / 2;
+            if (y > prev_y) {
+              for (uint16_t t = prev_y + thick; t <= mid_y; t++)
+                buff->draw_pixel_at(x + 1, t, c);
+              for (uint16_t t = mid_y + 1; t < y + thick; t++)
+                buff->draw_pixel_at(x, t, c);
+            } else {
+              for (uint16_t t = prev_y - 1; t >= mid_y; t--)
+                buff->draw_pixel_at(x + 1, t, c);
+              for (uint16_t t = mid_y - 1; t >= y; t--)
+                buff->draw_pixel_at(x, t, c);
+            }
           }
+          prev_y = y;
         }
+        prev_b = b;
+        has_prev = true;
+      } else {
+        has_prev = false;
       }
     }
   }
diff --git a/esphome/components/graph/graph.h b/esphome/components/graph/graph.h
index 339a6f6d94..34accb7d3a 100644
--- a/esphome/components/graph/graph.h
+++ b/esphome/components/graph/graph.h
@@ -116,6 +116,8 @@ class GraphTrace {
   void set_line_type(enum LineType val) { this->line_type_ = val; }
   Color get_line_color() { return this->line_color_; }
   void set_line_color(Color val) { this->line_color_ = val; }
+  bool get_continuous() { return this->continuous_; }
+  void set_continuous(bool continuous) { this->continuous_ = continuous; }
   std::string get_name() { return name_; }
   const HistoryData *get_tracedata() { return &data_; }
 
@@ -125,6 +127,7 @@ class GraphTrace {
   uint8_t line_thickness_{3};
   enum LineType line_type_ { LINE_TYPE_SOLID };
   Color line_color_{COLOR_ON};
+  bool continuous_{false};
   HistoryData data_;
 
   friend Graph;