basic version of saving current screen buffer #18

src/display.cpp

@@ -15,6 +15,12 @@
 
 GxEPD2_BW<GxEPD2_750, GxEPD2_750::HEIGHT> display(GxEPD2_750(/*CS=*/5, /*DC=*/17, /*RST=*/16, /*BUSY=*/4));
 
+void printScreen();
+void writeBitmap(const char filename[], const uint8_t bitmap[], int16_t w, int16_t h, uint16_t depth = 1);
+uint8_t filldata[] = {0x0, 0x23, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xFF, 0xFF, 0xFF, 0x0};
+void write16(File &f, uint16_t v);
+void write32(File &f, uint32_t v);
+
 void setupDisplay()
 {
 	Serial.println("setupDisplay");
@@ -45,6 +51,10 @@ void displayWriteFramebuffer(uint8_t bitmap[])
 void displayFlush()
 {
 	display.nextPage();
+
+	unsigned long startMills = millis();
+	writeBitmap("/screen.bmp", display.getBuffer(), 640, 384);
+	Serial.println(millis() - startMills);
 }
 
 void printSplash()
@@ -69,3 +79,91 @@ void printSplash()
 		display.print(Hello);
 	} while (display.nextPage());
 }
+
+void printScreen()
+{
+}
+
+void writeBitmap(const char filename[], const uint8_t bitmap[], int16_t w, int16_t h, uint16_t depth)
+{
+	File bitmapFile;
+	uint32_t rowSizeCode = (w + 8 - depth) * depth / 8;
+
+	// BMP rows are padded (if needed) to 4-byte boundary
+	uint32_t rowSizeBMP = (w * depth / 8 + 3) & ~3;
+	Serial.print("writeBitmap(\"");
+	Serial.print(filename);
+	Serial.println("\")");
+	//Serial.print("rowSizeCode ");
+	//Serial.println(rowSizeCode);
+	//Serial.print("rowSizeBMP  ");
+	//Serial.println(rowSizeBMP);
+	uint32_t headerSize = 40;
+	uint32_t imageOffset = 62;
+	uint32_t fileSize = imageOffset + h * rowSizeBMP;
+
+	String tmpFile = filename;
+	tmpFile += ".tmp";
+
+	bitmapFile = SPIFFS.open(tmpFile, FILE_WRITE);
+	if (bitmapFile)
+	{
+		bitmapFile.seek(0);
+		write16(bitmapFile, 0x4D42);	  // BMP signature
+		write32(bitmapFile, fileSize);	// fileSize
+		write32(bitmapFile, 0);			  // creator bytes
+		write32(bitmapFile, imageOffset); // image offset
+		write32(bitmapFile, headerSize);  // Header size
+		write32(bitmapFile, w);			  // image width
+		write32(bitmapFile, h);			  // image height
+		write16(bitmapFile, 1);			  // # planes
+		write16(bitmapFile, depth);		  // // bits per pixel
+		write32(bitmapFile, 0);			  // format uncompressed
+
+		uint32_t j = 0;
+		for (uint32_t i = bitmapFile.position(); i < imageOffset; i++)
+		{
+			bitmapFile.write(filldata[j++]); // remaining header bytes
+		}
+
+		uint32_t rowidx = 0;
+		for (uint16_t row = 0; row < h; row++) // for each line
+		{
+			uint32_t colidx;
+			for (colidx = 0; colidx < rowSizeCode; colidx++)
+			{
+				uint8_t data = pgm_read_byte(&bitmap[rowidx + colidx]);
+				bitmapFile.write(data);
+			}
+			rowidx += rowSizeCode;
+			while (colidx++ < rowSizeBMP)
+			{
+				bitmapFile.write(uint8_t(0)); // padding
+			}
+		}
+		bitmapFile.close();
+
+		SPIFFS.remove(filename);
+		SPIFFS.rename(tmpFile, filename);
+
+		Serial.println("done");
+	}
+	else
+	{
+		Serial.print("open file for write failed!");
+	}
+}
+
+void write16(File &f, uint16_t v)
+{
+	f.write(uint8_t(v));
+	f.write(uint8_t(v >> 8));
+}
+
+void write32(File &f, uint32_t v)
+{
+	f.write(uint8_t(v));
+	f.write(uint8_t(v >> 8));
+	f.write(uint8_t(v >> 16));
+	f.write(uint8_t(v >> 24));
+}

src/faceWeather.cpp

@@ -35,7 +35,7 @@ void loopFaceWeather()
 	render_current();
 	render_forecast();
 
-	display.nextPage();
+	displayFlush();
 }
 
 void render_current()
@@ -176,7 +176,6 @@ bool downloadWeatherData()
 
 void readWeatherData()
 {
-	SPIFFS.begin();
 	File file;
 	DeserializationError error;
 
@@ -212,6 +211,4 @@ void readWeatherData()
 	// TODO get values
 
 	file.close();
-
-	SPIFFS.end();
 }