private static ByteMatrix RenderResult(QRCode code, int width, int height) {
ByteMatrix input = code.GetMatrix();
int inputWidth = input.GetWidth();
int inputHeight = input.GetHeight();
int qrWidth = inputWidth + (QUIET_ZONE_SIZE << 1);
int qrHeight = inputHeight + (QUIET_ZONE_SIZE << 1);
int outputWidth = Math.Max(width, qrWidth);
int outputHeight = Math.Max(height, qrHeight);
int multiple = Math.Min(outputWidth / qrWidth, outputHeight / qrHeight);
// Padding includes both the quiet zone and the extra white pixels to accommodate the requested
// dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone.
// If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will
// handle all the padding from 100x100 (the actual QR) up to 200x160.
int leftPadding = (outputWidth - (inputWidth * multiple)) / 2;
int topPadding = (outputHeight - (inputHeight * multiple)) / 2;
ByteMatrix output = new ByteMatrix(outputWidth, outputHeight);
sbyte[][] outputArray = output.GetArray();
// We could be tricky and use the first row in each set of multiple as the temporary storage,
// instead of allocating this separate array.
sbyte[] row = new sbyte[outputWidth];
// 1. Write the white lines at the top
for (int y = 0; y < topPadding; y++) {
SetRowColor(outputArray[y], (sbyte)-1);
}
// 2. Expand the QR image to the multiple
sbyte[][] inputArray = input.GetArray();
for (int y = 0; y < inputHeight; y++) {
// a. Write the white pixels at the left of each row
for (int x = 0; x < leftPadding; x++) {
row[x] = (sbyte)-1;
}
// b. Write the contents of this row of the barcode
int offset = leftPadding;
for (int x = 0; x < inputWidth; x++) {
sbyte value = (inputArray[y][x] == 1) ? (sbyte)0 : (sbyte)-1;
for (int z = 0; z < multiple; z++) {
row[offset + z] = value;
}
offset += multiple;
}
// c. Write the white pixels at the right of each row
offset = leftPadding + (inputWidth * multiple);
for (int x = offset; x < outputWidth; x++) {
row[x] = (sbyte)-1;
}
// d. Write the completed row multiple times
offset = topPadding + (y * multiple);
for (int z = 0; z < multiple; z++) {
System.Array.Copy(row, 0, outputArray[offset + z], 0, outputWidth);
}
}
// 3. Write the white lines at the bottom
int offset2 = topPadding + (inputHeight * multiple);
for (int y = offset2; y < outputHeight; y++) {
SetRowColor(outputArray[y], (sbyte)-1);
}
return output;
}
