Add bounded OLED boot identity animation

src/local_boot_animation.c

@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-3.0-only */
+/* Compact monochrome derivative of images/logo.png for the 128x48 content panel. */
+
+#include "local_boot_animation.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "local_display.h"
+
+#define BOOT_ANIMATION_FRAMES 20U
+#define BOOT_ANIMATION_FRAME_MS 250U
+#define BOOT_ANIMATION_NAME_SPEED 16U
+
+static const char s_device_name[] = "ESP32 SERIAL SWISS ARMY KNIFE";
+
+static void pixel(int x, int y)
+{
+    if (x >= 0 && x < (int)LOCAL_DISPLAY_WIDTH &&
+        y >= 0 && y < (int)LOCAL_DISPLAY_CONTENT_HEIGHT) {
+        local_display_frame_set_pixel(LOCAL_DISPLAY_PANEL_CONTENT, (uint8_t)x,
+                                      (uint8_t)y, true);
+    }
+}
+
+static void line(int x0, int y0, int x1, int y1)
+{
+    int dx = x1 >= x0 ? x1 - x0 : x0 - x1;
+    int sx = x0 < x1 ? 1 : -1;
+    int dy = y1 >= y0 ? y0 - y1 : y1 - y0;
+    int sy = y0 < y1 ? 1 : -1;
+    int error = dx + dy;
+
+    for (;;) {
+        pixel(x0, y0);
+        if (x0 == x1 && y0 == y1) {
+            return;
+        }
+        int twice_error = 2 * error;
+        if (twice_error >= dy) {
+            error += dy;
+            x0 += sx;
+        }
+        if (twice_error <= dx) {
+            error += dx;
+            y0 += sy;
+        }
+    }
+}
+
+static void rectangle(int x, int y, int width, int height)
+{
+    line(x, y, x + width - 1, y);
+    line(x, y, x, y + height - 1);
+    line(x + width - 1, y, x + width - 1, y + height - 1);
+    line(x, y + height - 1, x + width - 1, y + height - 1);
+}
+
+static void draw_serial_connector(void)
+{
+    rectangle(2, 8, 16, 10);
+    rectangle(4, 10, 12, 6);
+    for (int column = 0; column < 5; ++column) {
+        pixel(6 + column * 2, 12);
+        pixel(6 + column * 2, 14);
+    }
+    line(18, 13, 30, 22);
+    line(18, 16, 28, 25);
+}
+
+static void draw_usb_connector(void)
+{
+    rectangle(2, 31, 14, 11);
+    rectangle(4, 33, 10, 7);
+    line(16, 35, 29, 30);
+    line(16, 39, 30, 34);
+    pixel(7, 35);
+    pixel(10, 38);
+}
+
+static void draw_terminal(bool cursor_on)
+{
+    rectangle(28, 21, 42, 22);
+    rectangle(30, 23, 38, 18);
+    /* Keep the prompt upright even though the source logo is reoriented. */
+    line(38, 28, 45, 33);
+    line(45, 33, 38, 38);
+    if (cursor_on) {
+        line(51, 37, 59, 37);
+    }
+    line(31, 27, 31, 39);
+    line(67, 27, 67, 39);
+    line(34, 22, 34, 20);
+    line(63, 22, 63, 20);
+}
+
+static void draw_board(void)
+{
+    rectangle(72, 7, 28, 36);
+    rectangle(78, 14, 16, 17);
+    for (int row = 0; row < 5; ++row) {
+        pixel(74, 11 + row * 6);
+        pixel(76, 11 + row * 6);
+        pixel(96, 11 + row * 6);
+        pixel(98, 11 + row * 6);
+    }
+    for (int column = 0; column < 6; ++column) {
+        pixel(79 + column * 3, 35);
+        pixel(79 + column * 3, 38);
+    }
+    line(70, 28, 72, 28);
+    line(70, 34, 72, 34);
+}
+
+static void draw_wifi(uint8_t frame)
+{
+    bool outer = (frame % 2U) == 0U;
+    if (outer) {
+        line(103, 8, 109, 3);
+        line(109, 3, 115, 8);
+    }
+    line(105, 12, 109, 8);
+    line(109, 8, 113, 12);
+    line(107, 16, 109, 14);
+    line(109, 14, 111, 16);
+    pixel(109, 19);
+}
+
+static void draw_logo(uint8_t frame)
+{
+    draw_serial_connector();
+    draw_usb_connector();
+    draw_terminal((frame % 2U) == 0U);
+    draw_board();
+    draw_wifi(frame);
+}
+
+static void draw_scrolling_name(uint8_t frame)
+{
+    int text_width = ((int)sizeof(s_device_name) - 1) * 6;
+    int x = (int)LOCAL_DISPLAY_WIDTH - (int)frame * BOOT_ANIMATION_NAME_SPEED;
+    if (x < -text_width) {
+        x += text_width + (int)LOCAL_DISPLAY_WIDTH;
+    }
+    const char *text = s_device_name;
+    while (x < 0 && *text != '\0') {
+        x += 6;
+        ++text;
+    }
+    if (x < (int)LOCAL_DISPLAY_WIDTH && *text != '\0') {
+        local_display_frame_draw_text(LOCAL_DISPLAY_PANEL_STATUS, (uint8_t)x, 4U, text);
+    }
+}
+
+esp_err_t local_boot_animation_play(void)
+{
+    for (uint8_t frame = 0U; frame < BOOT_ANIMATION_FRAMES; ++frame) {
+        esp_err_t error = local_display_frame_begin();
+        if (error != ESP_OK) {
+            return error;
+        }
+        local_display_frame_clear_all();
+        draw_scrolling_name(frame);
+        draw_logo(frame);
+        error = local_display_frame_end();
+        if (error != ESP_OK) {
+            return error;
+        }
+        vTaskDelay(pdMS_TO_TICKS(BOOT_ANIMATION_FRAME_MS));
+    }
+    return ESP_OK;
+}