v1.3: Screenshot, double-tap zoom, statistics screen, flight trail

src/screenshot.cpp

@@ -0,0 +1,78 @@
+#include "screenshot.h"
+#include "config.h"
+#include <SD.h>
+#include <time.h>
+
+namespace Screenshot {
+
+namespace {
+    void putU32(uint8_t* buf, uint32_t v) {
+        buf[0] = v & 0xFF;
+        buf[1] = (v >> 8) & 0xFF;
+        buf[2] = (v >> 16) & 0xFF;
+        buf[3] = (v >> 24) & 0xFF;
+    }
+}
+
+String save(TFT_eSPI& tft) {
+    if (!SD.exists(Config::SD_SCREENSHOT_DIR)) {
+        SD.mkdir(Config::SD_SCREENSHOT_DIR);
+    }
+
+    time_t now = time(nullptr);
+    struct tm tmNow;
+    localtime_r(&now, &tmNow);
+    char filename[32];
+    snprintf(filename, sizeof(filename), "%04d%02d%02d_%02d%02d%02d.bmp",
+             tmNow.tm_year + 1900, tmNow.tm_mon + 1, tmNow.tm_mday,
+             tmNow.tm_hour, tmNow.tm_min, tmNow.tm_sec);
+
+    char fullPath[64];
+    snprintf(fullPath, sizeof(fullPath), "%s/%s", Config::SD_SCREENSHOT_DIR, filename);
+
+    File f = SD.open(fullPath, FILE_WRITE);
+    if (!f) return String();
+
+    int32_t w = tft.width();
+    int32_t h = tft.height();
+
+    uint32_t rowSize = ((uint32_t)w * 3 + 3) & ~3u;
+    uint32_t dataSize = rowSize * (uint32_t)h;
+    uint32_t fileSize = 54 + dataSize;
+
+    uint8_t header[54] = {0};
+    header[0] = 'B'; header[1] = 'M';
+    putU32(&header[2], fileSize);
+    putU32(&header[10], 54);
+    putU32(&header[14], 40);
+    putU32(&header[18], (uint32_t)w);
+    putU32(&header[22], (uint32_t)h);
+    header[26] = 1;
+    header[28] = 24;
+    putU32(&header[34], dataSize);
+
+    f.write(header, 54);
+
+    uint16_t rowPixels[Config::SCREEN_WIDTH];
+    uint8_t rowBuf[Config::SCREEN_WIDTH * 3 + 3];
+
+    for (int32_t y = h - 1; y >= 0; y--) {
+        tft.readRect(0, y, w, 1, rowPixels);
+        for (int32_t x = 0; x < w; x++) {
+            uint16_t px = rowPixels[x];
+            uint8_t r5 = (px >> 11) & 0x1F;
+            uint8_t g6 = (px >> 5) & 0x3F;
+            uint8_t b5 = px & 0x1F;
+            rowBuf[x * 3 + 0] = (b5 * 255) / 31;
+            rowBuf[x * 3 + 1] = (g6 * 255) / 63;
+            rowBuf[x * 3 + 2] = (r5 * 255) / 31;
+        }
+        for (uint32_t p = (uint32_t)w * 3; p < rowSize; p++) rowBuf[p] = 0;
+        f.write(rowBuf, rowSize);
+    }
+
+    f.close();
+    return String(filename);
+}
+
+}