Add comments literally everywhere.

main/include/main.h

@@ -1,20 +1,30 @@
 
 #pragma once
 
+// For pin mappings.
 #include "hardware.h"
+// For graphics.
 #include "pax_gfx.h"
+// For PNG images.
 #include "pax_codecs.h"
+// The screen driver.
 #include "ili9341.h"
+// For all system settings and alike.
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "freertos/queue.h"
 #include "esp_system.h"
 #include "nvs.h"
 #include "nvs_flash.h"
+// For WiFi connectivity.
 #include "wifi_connect.h"
 #include "wifi_connection.h"
+// For exiting to the launcher.
 #include "soc/rtc.h"
 #include "soc/rtc_cntl_reg.h"
 
+// Updates the screen with the last drawing.
 void disp_flush();
+
+// Exits the app, returning to the launcher.
 void exit_to_launcher();

main/main.c

@@ -8,22 +8,26 @@ xQueueHandle buttonQueue;
 
 static const char *TAG = "mch2022-demo-app";
 
+// Updates the screen with the last drawing.
 void disp_flush() {
     ili9341_write(get_ili9341(), buf.buf);
 }
 
+// Exits the app, returning to the launcher.
 void exit_to_launcher() {
     REG_WRITE(RTC_CNTL_STORE0_REG, 0);
     esp_restart();
 }
 
 void app_main() {
-    // Init HW.
+    // Init the screen, the I2C and the SPI busses.
     bsp_init();
+    // Init the RP2040 (responsible for buttons among other important things).
     bsp_rp2040_init();
+    // This queue is used to await button presses.
     buttonQueue = get_rp2040()->queue;
     
-    // Init GFX.
+    // Init graphics for the screen.
     pax_buf_init(&buf, NULL, 320, 240, PAX_BUF_16_565RGB);
     
     // Init NVS.
@@ -38,22 +42,36 @@ void app_main() {
         pax_col_t col = pax_col_hsv(hue, 255 /*saturation*/, 255 /*brighness*/);
         
         // Show some random color hello world.
+        // Draw the background with aforementioned random color.
         pax_background(&buf, col);
+        // This text is shown on screen.
         char             *text = "Hello, World!";
+        // Pick the font to draw in (this is the only one that looks nice this big).
         const pax_font_t *font = pax_get_font("saira condensed");
+        // Determine how large the text is so it can be centered.
         pax_vec1_t        dims = pax_text_size(font, font->default_size, text);
+        // Use info to draw the centered text.
         pax_draw_text(
-            &buf, 0xff000000, font, font->default_size,
+            // Buffer to draw to.
+            &buf, 0xff000000,
+            // Font and size to use.
+            font, font->default_size,
+            // Position (top left corner) of the app.
             (buf.width  - dims.x) / 2.0,
             (buf.height - dims.y) / 2.0,
+            // The text to be shown.
             text
         );
+        // Draws the entire graphics buffer to the screen.
         disp_flush();
         
         // Await any button press and do another cycle.
+        // Structure used to receive data.
         rp2040_input_message_t message;
+        // Await forever (because of portMAX_DELAY), a button press.
         xQueueReceive(buttonQueue, &message, portMAX_DELAY);
         
+        // Is the home button currently pressed?
         if (message.input == RP2040_INPUT_BUTTON_HOME && message.state) {
             // If home is pressed, exit to launcher.
             exit_to_launcher();