Sample to check behavior of native env.

main.cpp

#include <M5Unified.h>

M5Canvas sprite;

void setup() {
  M5.begin();

  sprite.createSprite(120, 120);
  sprite.drawCircle(sprite.width() >> 1, sprite.height() >> 1, sprite.width() >> 2, RED);
  sprite.drawRect(0, 0, sprite.width() - 1, sprite.height() - 1, RED);

  const auto offset = -40;
  // xに負の値を指定すると下記2行の挙動が変わる(native時のみ)
  sprite.pushSprite(&M5.Display, offset, 0);
  sprite.pushSprite(&M5.Display, offset, 120, BLACK);
}

void loop() {
}

platformio.ini

; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html

[platformio]
default_envs = native

[env]
lib_deps = https://github.com/m5stack/M5Unified

[env:native]
platform = native
build_type = debug
build_flags = -O0 -xc++ -std=c++14 -lSDL2
  -I"/usr/local/include/SDL2"                ; for intel mac homebrew SDL2
  -L"/usr/local/lib"                         ; for intel mac homebrew SDL2
  -I"${sysenv.HOMEBREW_PREFIX}/include/SDL2" ; for arm mac homebrew SDL2
  -L"${sysenv.HOMEBREW_PREFIX}/lib"          ; for arm mac homebrew SDL2

[env:native_m5stack]
extends = native
platform = native
build_flags = ${env:native.build_flags}
  -DM5GFX_BOARD=board_M5Stack

[env:m5stack-core-esp32]
platform = espressif32
board = m5stack-core-esp32
framework = arduino
monitor_speed = 115200