Add LVGL emulator for UI regression testing with enhanced build support

.github/workflows/config.yml

@@ -54,6 +54,25 @@ jobs:
       - name: Run Unit Tests
         run: platformio test -e native-test
 
+  screenshot-tests:
+    name: Screenshot Regression Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          token: ${{ github.token }}
+          show-progress: false
+      - name: Install Dependencies
+        run: sudo apt-get update && sudo apt-get install -y cmake g++
+      - name: Build & Run Screenshot Tests
+        run: ./test/test_screenshots/build_and_run.sh
+      - name: Upload Screenshots on Failure
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: screenshot-regression-output
+          path: test/test_screenshots/output/
+
   pio-build:
     name: PlatformIO Build
     runs-on: ubuntu-latest

.gitignore

@@ -3,3 +3,6 @@
 eppg-controller.ino.cpp
 src/sp140/sp140.ino.cpp
 diagnostics-logs/
+build-screenshot/
+test/test_screenshots/output/*.bmp
+test/test_screenshots/output/png/

inc/sp140/lvgl/lv_conf.h

@@ -134,7 +134,7 @@
  *  WIDGET USAGE
  *=================*/
 
-#define LV_USE_ANIMIMAGE    0
+#define LV_USE_ANIMIMG      0
 
 #define LV_USE_ARC        1
 

platformio.ini

@@ -84,7 +84,29 @@ build_flags =
   -I .pio/libdeps/native-test/CircularBuffer
   -D ARDUINO=1
 build_src_filter = -<*>
-test_ignore = neopixel*
+test_ignore = neopixel*, test_screenshots
 lib_deps =
   ArduinoJson@7.4.3
   rlogiacco/CircularBuffer@^1.4.0
+
+[env:native-screenshot]
+platform = native
+test_framework = googletest
+build_type = debug
+build_flags =
+  -I test/screenshot_stubs
+  -I inc
+  -I inc/sp140/lvgl
+  -D LV_CONF_INCLUDE_SIMPLE
+  -D LV_LVGL_H_INCLUDE_SIMPLE
+  -D ARDUINO=1
+  -D NATIVE_SCREENSHOT_TEST=1
+  -std=c++17
+build_src_filter =
+  -<*>
+  +<sp140/lvgl/lvgl_main_screen.cpp>
+  +<sp140/lvgl/lvgl_updates.cpp>
+  +<sp140/lvgl/lvgl_alerts.cpp>
+test_filter = test_screenshots
+lib_deps =
+  lvgl/lvgl@^9.5.0

test/screenshot_stubs/Adafruit_ST7735.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stdint.h>
+#include "SPI.h"
+
+#define INITR_BLACKTAB 0
+#define ST77XX_BLACK 0x0000
+
+class Adafruit_ST7735 {
+ public:
+  Adafruit_ST7735(SPIClass* spi, int8_t cs, int8_t dc, int8_t rst) {
+    (void)spi; (void)cs; (void)dc; (void)rst;
+  }
+  void initR(uint8_t) {}
+  void setRotation(uint8_t) {}
+  void fillScreen(uint16_t) {}
+  void setAddrWindow(uint16_t, uint16_t, uint16_t, uint16_t) {}
+  void writePixels(uint16_t*, uint32_t) {}
+  void startWrite() {}
+  void endWrite() {}
+};

test/screenshot_stubs/Arduino.h

@@ -0,0 +1,129 @@
+#pragma once
+#include <stdint.h>
+#include <chrono>
+#include <cstring>
+#include <cstdio>
+#include <cmath>
+#include <string>
+#include <thread>
+
+// Basic Arduino types and helpers for native screenshot tests
+using std::chrono::steady_clock;
+using std::chrono::milliseconds;
+
+class String {
+ public:
+  String() = default;
+  String(const char* s) : data_(s ? s : "") {}
+  bool concat(char c) { data_ += c; return true; }
+  bool concat(const char* s) { data_ += s ? s : ""; return true; }
+  const char* c_str() const { return data_.c_str(); }
+  size_t length() const { return data_.size(); }
+ private:
+  std::string data_;
+};
+
+struct __FlashStringHelper;
+
+class Print {
+ public:
+  virtual ~Print() = default;
+  virtual size_t write(uint8_t) { return 1; }
+  virtual size_t write(const uint8_t* buffer, size_t size) { (void)buffer; return size; }
+  size_t write(const char* s) { return write(reinterpret_cast<const uint8_t*>(s), s ? strlen(s) : 0); }
+  template <typename... Args> void printf(const char*, Args...) {}
+  template <typename T> void print(const T&) {}
+  template <typename T> void println(const T&) {}
+  void println() {}
+};
+
+class Printable {
+ public:
+  virtual ~Printable() = default;
+  virtual size_t printTo(Print&) const { return 0; }
+};
+
+class Stream : public Print {
+ public:
+  virtual int available() { return 0; }
+  virtual int read() { return -1; }
+  virtual size_t readBytes(char* buffer, size_t length) { (void)buffer; (void)length; return 0; }
+};
+
+struct DummySerial : public Stream {
+  inline void begin(unsigned long) {}
+};
+
+static DummySerial USBSerial;
+static DummySerial Serial;
+
+#ifndef PROGMEM
+#define PROGMEM
+#endif
+
+#ifndef pgm_read_byte
+inline uint8_t pgm_read_byte(const void* p) { return *reinterpret_cast<const uint8_t*>(p); }
+#endif
+
+inline unsigned long millis() {
+  static auto start = steady_clock::now();
+  return (unsigned long)std::chrono::duration_cast<milliseconds>(steady_clock::now() - start).count();
+}
+
+inline void delay(unsigned long ms) {
+  std::this_thread::sleep_for(std::chrono::milliseconds(ms));
+}
+
+typedef uint16_t word;
+
+// FreeRTOS type stubs
+typedef void* QueueHandle_t;
+typedef void* TaskHandle_t;
+
+// GPIO stubs
+#ifndef INPUT
+#define INPUT 0
+#endif
+#ifndef OUTPUT
+#define OUTPUT 1
+#endif
+#ifndef LOW
+#define LOW 0
+#endif
+#ifndef HIGH
+#define HIGH 1
+#endif
+#ifndef F
+#define F(x) x
+#endif
+
+inline void pinMode(int, int) {}
+inline void digitalWrite(int, int) {}
+inline int digitalRead(int) { return 0; }
+inline int analogRead(int) { return 0; }
+inline void analogReadResolution(int) {}
+
+// Math helpers
+#ifndef constrain
+template <typename T>
+inline T constrain(T x, T a, T b) { return x < a ? a : (x > b ? b : x); }
+#endif
+
+#ifndef min
+template <typename T>
+inline T min(T a, T b) { return a < b ? a : b; }
+#endif
+
+#ifndef max
+template <typename T>
+inline T max(T a, T b) { return a > b ? a : b; }
+#endif
+
+inline long map(long x, long in_min, long in_max, long out_min, long out_max) {
+  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+}
+
+// LEDC stubs (ESP32)
+inline void ledcAttach(int, int, int) {}
+inline void ledcWrite(int, int) {}
+inline void ledcDetach(int) {}

test/screenshot_stubs/BMS_CAN.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <stdint.h>
+
+// Stub BMS_CAN class for native builds
+class BMS_CAN {
+ public:
+  static constexpr float TEMP_PROBE_DISCONNECTED = -999.0f;
+  BMS_CAN() {}
+};

test/screenshot_stubs/NimBLEDevice.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stdint.h>
+
+// Minimal NimBLE stubs for native builds
+class NimBLECharacteristic {
+ public:
+  void setValue(const uint8_t*, size_t) {}
+  void notify() {}
+};
+
+class NimBLEServer {
+ public:
+  uint16_t getConnectedCount() { return 0; }
+};
+
+class NimBLEService {};
+class NimBLEAdvertising {};
+
+class NimBLEDevice {
+ public:
+  static void init(const char*) {}
+  static NimBLEServer* createServer() { return nullptr; }
+};

test/screenshot_stubs/NimBLEServer.h

@@ -0,0 +1,2 @@
+#pragma once
+#include "NimBLEDevice.h"

test/screenshot_stubs/NimBLEUtils.h

@@ -0,0 +1,2 @@
+#pragma once
+// Stub - no content needed

test/screenshot_stubs/SPI.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stdint.h>
+
+#define HSPI 2
+
+class SPIClass {
+ public:
+  SPIClass(int bus = 0) { (void)bus; }
+  void begin(int sck = -1, int miso = -1, int mosi = -1, int ss = -1) {
+    (void)sck; (void)miso; (void)mosi; (void)ss;
+  }
+  void end() {}
+};

test/screenshot_stubs/freertos/FreeRTOS.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <stdint.h>
+
+// FreeRTOS type stubs for native builds
+typedef void* SemaphoreHandle_t;
+typedef void* QueueHandle_t;
+typedef void* TaskHandle_t;
+typedef uint32_t TickType_t;
+typedef int32_t BaseType_t;
+typedef uint32_t UBaseType_t;
+
+#define pdTRUE 1
+#define pdFALSE 0
+#define pdPASS pdTRUE
+#define portMAX_DELAY 0xFFFFFFFF
+
+inline TickType_t pdMS_TO_TICKS(uint32_t ms) { return ms; }
+
+// Semaphore stubs
+inline SemaphoreHandle_t xSemaphoreCreateMutex() { return (void*)1; }
+inline BaseType_t xSemaphoreTake(SemaphoreHandle_t, TickType_t) { return pdTRUE; }
+inline BaseType_t xSemaphoreGive(SemaphoreHandle_t) { return pdTRUE; }
+
+// Task stubs
+inline void vTaskDelay(TickType_t) {}
+inline void vTaskDelete(TaskHandle_t) {}
+
+// Queue stubs
+inline QueueHandle_t xQueueCreate(UBaseType_t, UBaseType_t) { return (void*)1; }
+inline BaseType_t xQueueSend(QueueHandle_t, const void*, TickType_t) { return pdTRUE; }
+inline BaseType_t xQueueReceive(QueueHandle_t, void*, TickType_t) { return pdFALSE; }
+inline BaseType_t xQueueOverwrite(QueueHandle_t, const void*) { return pdTRUE; }
+inline UBaseType_t uxQueueMessagesWaiting(QueueHandle_t) { return 0; }
+inline void xQueueReset(QueueHandle_t) {}

test/screenshot_stubs/freertos/queue.h

@@ -0,0 +1,2 @@
+#pragma once
+#include "FreeRTOS.h"

test/screenshot_stubs/freertos/semphr.h

@@ -0,0 +1,2 @@
+#pragma once
+#include "FreeRTOS.h"

test/screenshot_stubs/freertos/task.h

@@ -0,0 +1,2 @@
+#pragma once
+#include "FreeRTOS.h"