C++ Adafruit_ST7735::setAddrWindow方法代码示例

void bmpDraw(Adafruit_ST7735 tft, String fileName, uint8_t x, uint8_t y) {

	file_t handle;

	int bmpWidth, bmpHeight;   		// W+H in pixels
	uint8_t bmpDepth;              	// Bit depth (currently must be 24)
	uint32_t bmpImageoffset;        // Start of image data in file
	uint32_t rowSize;               // Not always = bmpWidth; may have padding
	uint8_t sdbuffer[3 * BUFFPIXEL]; // pixel buffer (R+G+B per pixel)
	uint8_t buffidx = sizeof(sdbuffer); // Current position in sdbuffer
	boolean goodBmp = false;       	// Set to true on valid header parse
	boolean flip = true;        	// BMP is stored bottom-to-top
	int w, h, row, col;
	uint8_t r, g, b;
	uint32_t pos = 0, startTime = millis();

	if ((x >= tft.width()) || (y >= tft.height()))
		return;

	Serial.println();
	Serial.print("Loading image '");
	Serial.print(fileName);
	Serial.println('\'');

	handle = fileOpen(fileName.c_str(), eFO_ReadOnly);
	if (handle == -1)
	{
		debugf("File wasn't found: %s", fileName.c_str());
		fileClose(handle);
		return;
	}

	// Parse BMP header
	if (read16(handle) == 0x4D42) { 				// BMP signature
		debugf("File size: %d\n", read32(handle));	// get File Size
	    (void)read32(handle); 						// Read & ignore creator bytes
	    bmpImageoffset = read32(handle); 			// Start of image data
	    debugf("Image Offset: %d\n", bmpImageoffset);
	    debugf("Header size: %d\n", read32(handle));	// Read DIB header
	    bmpWidth  = read32(handle);
	    bmpHeight = read32(handle);
	    if(read16(handle) == 1) { 					// # planes -- must be '1'
	    	bmpDepth = read16(handle); 				// bits per pixel
	    	debugf("Bit Depth: %d\n", bmpDepth);
	    	if((bmpDepth == 24) && (read32(handle) == 0)) { // 0 = uncompressed
	    		goodBmp = true; 					// Supported BMP format -- proceed!

	    		debugf("Image size: %d x %d\n", bmpWidth, bmpHeight);

	            // BMP rows are padded (if needed) to 4-byte boundary
	            rowSize = (bmpWidth * 3 + 3) & ~3;

	            // If bmpHeight is negative, image is in top-down order.
	            // This is not canon but has been observed in the wild.
	            if(bmpHeight < 0) {
	              bmpHeight = -bmpHeight;
	              flip      = false;
	            }

	            // Crop area to be loaded
	            w = bmpWidth;
	            h = bmpHeight;
	            if((x+w-1) >= tft.width())  w = tft.width()  - x;
	            if((y+h-1) >= tft.height()) h = tft.height() - y;

	            // Set TFT address window to clipped image bounds
	            tft.setAddrWindow(x, y, x+w-1, y+h-1);

	            for (row=0; row<h; row++) { // For each scanline...

	              // Seek to start of scan line.  It might seem labor-
	              // intensive to be doing this on every line, but this
	              // method covers a lot of gritty details like cropping
	              // and scanline padding.  Also, the seek only takes
	              // place if the file position actually needs to change
	              // (avoids a lot of cluster math in SD library).
	              if(flip) // Bitmap is stored bottom-to-top order (normal BMP)
	                pos = bmpImageoffset + (bmpHeight - 1 - row) * rowSize;
	              else     // Bitmap is stored top-to-bottom
	                pos = bmpImageoffset + row * rowSize;
	              if (fileTell(handle) != pos) {
	            	  fileSeek(handle, pos, eSO_FileStart);
		              buffidx = sizeof(sdbuffer); // Force buffer reload
	              }
	              for (col=0; col<w; col++) { // For each pixel...
	                // Time to read more pixel data?
	                if (buffidx >= sizeof(sdbuffer)) { // Indeed
	                  fileRead(handle, sdbuffer, sizeof(sdbuffer));
	                  buffidx = 0; // Set index to beginning
	                }

	                // Convert pixel from BMP to TFT format, push to display
	                b = sdbuffer[buffidx++];
	                g = sdbuffer[buffidx++];
	                r = sdbuffer[buffidx++];
	                tft.pushColor(tft.Color565(r,g,b));
	              } // end pixel
	            } // end scanline
	            Serial.printf("Loaded in %d ms\n", millis() - startTime);
	          } // end goodBmp
//.........这里部分代码省略.........