minimal: embedded lhp examples

Implements a carousel rendering and displaying remote HTML + JPEG + PNGs
on a variety of display devices, including several EPDs.

README.md

@@ -26,6 +26,16 @@ sdevent, glib and uloop, as well as custom event libs.
 News
 ----
 
+## HTML + CSS + JPEG + PNG display stack in lws
+
+Want to drive your EPD or TFT / OLED display using HTML + CSS?  Only got an ESP32?
+
+Want remote JPEGs, PNGs, HTML, RGBA composition, gamma, error diffusion if needed?
+
+Realtime render into a line buffer because you don't have enough heap for a framebuffer?
+
+[Take a look here...](https://libwebsockets.org/git/libwebsockets/tree/READMEs/README.html-parser.md)
+
 ## Perl binding for lws available
 
 Thanks to Felipe Gasper, there's now a [perl binding for lws available at metacpan](https://metacpan.org/pod/Net::Libwebsockets),

minimal-examples-lowlevel/api-tests/api-test-lhp-dlo/main.c

@@ -114,6 +114,7 @@ render(lws_sorted_usec_list_t *sul)
 
 	if (!rs->line) {
 
+		lws_display_get_ids_boxes(rs);
 		lws_display_dl_dump(&rs->displaylist);
 
 		/* allocate one line of RGB output pixels to render into */

minimal-examples/embedded/esp32/esp-heltec-wb32/main/devices.c

@@ -98,7 +98,7 @@ static const lws_display_ssd1306_t disp = {
 
 static const lws_led_gpio_map_t lgm[] = {
 	{
-		.name			= "alert",
+		.name			= "red",
 		.gpio			= GPIO_NUM_25,
 		.pwm_ops		= &pwm_ops, /* managed by pwm */
 		.active_level		= 1,
@@ -205,7 +205,7 @@ init_plat_devices(struct lws_context *ctx)
 	lws_display_state_init(&lds, ctx, 10000, 20000, lls, &disp.disp);
 
 	lws_button_enable(bcs, 0, lws_button_get_bit(bcs, "user"));
-	lws_led_transition(lls, "alert", &lws_pwmseq_static_off,
+	lws_led_transition(lls, "red", &lws_pwmseq_static_off,
 					 &lws_pwmseq_static_on);
 
 	return 0;

minimal-examples/embedded/esp32/esp-heltec-wb32/main/lws-minimal-esp32.c

@@ -197,7 +197,7 @@ app_main(void)
 
 	/* put the logo on the OLED display */
 
-	lds.disp->blit(&lds, img, &box);
+	lds.disp->blit(&lds, img, &box, NULL);
 	lws_display_state_active(&lds);
 
 	/* the lws event loop */

minimal-examples/embedded/esp32/esp-wrover-kit/main/lws-minimal-esp32.c

@@ -232,7 +232,7 @@ app_main(void)
 
 	/* put the cat picture up there and enable the backlight */
 
-	lds.disp->blit(&lds, logo, &box);
+	lds.disp->blit(&lds, logo, &box, NULL);
 	lws_display_state_active(&lds);
 
 	/* the lws event loop */

minimal-examples/embedded/lhp/README.md

@@ -0,0 +1,81 @@
+# lhp (HTML renderer) embedded demos
+
+These are demos for various ESP32 + display combinations.  A lot of
+the code is common between the demos and is in the toplevel dir
+(where this README lives).
+
+Notice that although the demos are for ESP32 currently, there is no
+ESP32-specific code in the common part.  Only `main/devices.c` in the
+combination-specific directories has the platform-specific init.
+
+The demo visits some sites using h2 and renders them on the device +
+display combination, with a 10s wait between, in a carousel.
+
+ESP32 WROVER KIT, and ESP32S2 Kaluga boards and displays are
+supported, along with Waveshare ESP32 dev board and a variety of
+E-ink displays.
+
+## Setting up wifi
+
+Edit ./main/devices.c in your platform-specific subdir, enable this section
+ and set your wifi SSID and passphrase in the `xxx` strings.  This will store
+the information on flash on the device.
+
+Boot once with that and then remove your information and disable the code
+section again and rebuild.
+
+```
+#if 0
+	/*
+	 * This is a temp hack to bootstrap the settings to contain the test
+	 * AP ssid and passphrase for one time, so the settings can be stored
+	 * while there's no UI atm
+	 */
+	{
+		lws_wifi_creds_t creds;
+
+		memset(&creds, 0, sizeof(creds));
+
+		lws_strncpy(creds.ssid, "xxx", sizeof(creds.ssid));
+		lws_strncpy(creds.passphrase, "xxx", sizeof(creds.passphrase));
+		lws_dll2_add_tail(&creds.list, &netdevs->owner_creds);
+
+		if (lws_netdev_credentials_settings_set(netdevs)) {
+			lwsl_err("%s: failed to write bootstrap creds\n",
+					__func__);
+			return 1;
+		}
+	}
+#endif
+```
+
+Eventually there will be a better way to set this up.
+
+## Building
+
+Set up for esp-idf, enter the platform-specific subdir and edit
+`build.sh` to point to the correct USB device path.
+
+The first time we need to erase the whole flash and blow the whole
+image and partition table
+
+```
+ $ ./build.sh erase-flash
+ $ ./build.sh
+```
+
+Afterwards you can force-build like this which flashes both OTA
+partitions with the new imahe
+
+```
+ $ ./build.sh f
+```
+
+After you have changed `./build.sh` to your own OTA keys and upload path, and adapted the
+policy to look at your firmware server, you will typically build via uploading to that,
+which resets the board so it can find and install the update and reboot
+
+```
+ $ ./build.sh u
+```
+

minimal-examples/embedded/lhp/esp32-heltec-128-64/CMakeLists.txt

@@ -0,0 +1,53 @@
+cmake_minimum_required(VERSION 3.5)
+
+if (ESP_PLATFORM)
+
+	include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+	project(lws-minimal-esp32 C)
+	enable_testing()
+
+	target_link_libraries(lws-minimal-esp32.elf websockets)
+
+	option(LWS_WITH_DRIVERS "With generic drivers for gpio, i2c, display etc" ON)
+	set(LWS_WITH_DRIVERS ON)
+	option(LWS_WITH_SECURE_STREAMS "With secure streams" ON)
+	set(LWS_WITH_SECURE_STREAMS ON)
+	option(LWS_WITH_LWSAC "With lwsac" ON)
+	set(LWS_WITH_LWSAC ON)
+	option(LWS_WITH_STRUCT_JSON "With lws_struct JSON" ON)
+	set(LWS_WITH_STRUCT_JSON ON)
+	option(LWS_WITH_SYS_NTPCLIENT "With ntpclient" ON)
+        set(LWS_WITH_SYS_NTPCLIENT ON)
+	option(LWS_WITH_SECURE_STREAMS_STATIC_POLICY_ONLY "Static policy" OFF)
+	set(LWS_WITH_SECURE_STREAMS_STATIC_POLICY_ONLY OFF)
+	option(LWS_WITH_TLS_JIT_TRUST "With JIT Trust" ON)
+	set(LWS_WITH_TLS_JIT_TRUST ON)
+        option(LWS_WITH_COMPRESSED_BACKTRACES "Build with support for compressed backtraces" ON)
+        set(LWS_WITH_COMPRESSED_BACKTRACES ON)
+        set(LWS_COMPRESSED_BACKTRACES_SNIP_PRE 2 CACHE STRING "Amount of callstack to snip from top" FORCE)
+        set(LWS_COMPRESSED_BACKTRACES_SNIP_POST 2 CACHE STRING "Amount of callstack to snip from bottom" FORCE)
+
+        option(LWS_WITH_ALLOC_METADATA_LWS "Build lws_*alloc() with compressed backtraces (requires WITH_COMPRESSED_BACKTRACES)" OFF)
+        set(LWS_WITH_ALLOC_METADATA_LWS OFF)
+
+        option(LWS_WITH_OTA "Build with support for Over The Air update download and validation" ON)
+        set(LWS_WITH_OTA ON)
+
+        set(LWS_OTA_VARIANT "esp32-heltec-128-64" CACHE STRING "Build variant for OTA filtering" FORCE)
+        set(LWS_OTA_PUBLIC_JWK_FILE "$ENV{HOME}/.lws_ota/libwebsockets.org-ota-v1.public.jwk" CACHE STRING "JWK path" FORCE)
+
+	set(CMAKE_BUILD_TYPE RELEASE)
+
+	add_subdirectory(libwebsockets)
+
+	add_test(NAME flashing COMMAND idf.py flash)
+	set_tests_properties(flashing PROPERTIES
+			     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+			     TIMEOUT 120)
+
+	add_test(NAME boot COMMAND /usr/local/bin/sai-expect)
+	set_tests_properties(boot PROPERTIES
+			     DEPENDS flashing
+			     TIMEOUT 60)
+
+endif()

minimal-examples/embedded/lhp/esp32-heltec-128-64/libwebsockets

@@ -0,0 +1 @@
+../../../..

minimal-examples/embedded/lhp/esp32-heltec-128-64/main/CMakeLists.txt

@@ -0,0 +1,8 @@
+idf_component_register(SRCS
+		../../main.c
+		../../lhp-ss.c
+		devices.c
+		INCLUDE_DIRS "../libwebsockets/include;${IDF_PATH}/components/spi_flash/include;${IDF_PATH}/components/nvs_flash/include;${IDF_PATH}/components/mdns/include")
+
+target_link_libraries(${COMPONENT_LIB} websockets)
+include_directories(../build/libwebsockets)