New panel design

sim/CMakeLists.txt

@@ -0,0 +1,90 @@
+# Desktop simulator for the thermostat UI. Not part of the ESP-IDF build --
+# `idf.py build` never looks in here, and this never builds firmware sources
+# that touch hardware.
+#
+#   cmake -S sim -B sim/build -G Ninja && cmake --build sim/build
+#
+# See sim/README.md.
+
+cmake_minimum_required(VERSION 3.16)
+project(thermostat_sim C)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+set(FW_ROOT ${CMAKE_CURRENT_LIST_DIR}/..)
+set(LVGL_DIR ${FW_ROOT}/managed_components/lvgl__lvgl)
+
+# LVGL is pulled in by the IDF component manager, so it lives in a gitignored
+# directory that only exists after an IDF build. Using it anyway -- rather than
+# fetching a second copy -- guarantees the simulator and the firmware render
+# with the identical LVGL version. A simulator on a different version is a
+# simulator that lies.
+if(NOT EXISTS ${LVGL_DIR}/lvgl.h)
+    message(FATAL_ERROR
+        "LVGL not found at ${LVGL_DIR}\n"
+        "It is fetched by the ESP-IDF component manager. Run once:\n"
+        "    . ~/esp/esp-idf/export.sh && idf.py reconfigure")
+endif()
+
+# Nothing here uses LVGL's bundled demos or examples, and they add real build
+# time. ThorVG is a C++ vector engine we do not use either.
+set(CONFIG_LV_BUILD_DEMOS OFF CACHE BOOL "" FORCE)
+set(CONFIG_LV_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
+set(CONFIG_LV_USE_THORVG_INTERNAL OFF CACHE BOOL "" FORCE)
+
+# LVGL's desktop CMake picks up lv_conf.h from CMAKE_SOURCE_DIR, which is this
+# directory.
+add_subdirectory(${LVGL_DIR} ${CMAKE_BINARY_DIR}/lvgl)
+
+find_package(SDL2 REQUIRED)
+
+# cJSON comes from the ESP-IDF tree rather than the host's libcjson, so the
+# simulator parses Home Assistant replies with the exact same parser the
+# firmware uses. IDF_PATH is only needed for this one directory -- the rest of
+# the simulator builds with no ESP-IDF environment at all.
+if(DEFINED ENV{IDF_PATH})
+    set(IDF_ROOT $ENV{IDF_PATH})
+else()
+    set(IDF_ROOT $ENV{HOME}/esp/esp-idf)
+endif()
+set(CJSON_DIR ${IDF_ROOT}/components/json/cJSON)
+
+if(NOT EXISTS ${CJSON_DIR}/cJSON.c)
+    message(FATAL_ERROR
+        "cJSON not found at ${CJSON_DIR}\n"
+        "Set IDF_PATH, or install ESP-IDF to ~/esp/esp-idf.")
+endif()
+
+add_executable(thermostat_sim
+    sim_main.c
+    lvgl_port_sim.c
+    compat/esp_compat.c
+
+    # The point of the exercise: real firmware sources, compiled unmodified.
+    # Anything added here must stay free of hardware access -- drivers and
+    # HTTP transport stay on the device side.
+    ${FW_ROOT}/main/ui/ui_manager.c
+    ${FW_ROOT}/main/api/ha_data.c
+
+    ${CJSON_DIR}/cJSON.c
+)
+
+target_include_directories(thermostat_sim PRIVATE
+    ${CMAKE_CURRENT_LIST_DIR}
+    ${CMAKE_CURRENT_LIST_DIR}/compat   # ESP-IDF header stand-ins
+    ${FW_ROOT}/main/ui                 # ui_manager.h, lvgl_port.h
+    ${FW_ROOT}/main/api                # ha_data.h, ha_config.h, ha_template.h
+    ${CJSON_DIR}
+    ${LVGL_DIR}/src/libs/lodepng       # PNG encoder for --png mode
+    ${SDL2_INCLUDE_DIRS}
+)
+
+# SDL2_LIBRARIES can carry trailing whitespace from sdl2-config, which makes
+# the link line fail in confusing ways.
+string(STRIP "${SDL2_LIBRARIES}" SDL2_LIBRARIES)
+
+target_link_libraries(thermostat_sim PRIVATE lvgl ${SDL2_LIBRARIES} m pthread)
+
+target_compile_options(thermostat_sim PRIVATE -Wall -Wextra -Wno-unused-parameter)