エプソンのLCDコントローラーS1D13781評価ボードをラズパイで動かす(2)

private void MemWriteByte(uint memAddress, byte memValue)
{
    CsPin.Write(GpioPinValue.Low);

    SPI.Write(new byte[] {
        (byte)SPIBIT.SPIWRITE_8BIT, //command
        (byte)(memAddress >> 16), //address bits 18:16
        (byte)((memAddress & 0x0000FF00) >> 8), //address bits 15:8
        (byte)(memAddress & 0x000000FF), //address bits 7:0
        memValue, //data bits 7:0
    });

    CsPin.Write(GpioPinValue.High);
}

public void DrawPixel(int x, int y, Color color)
{
    if (x < 0 || y < 0 || x >= width || y >= height) return;

    uint offset = (uint)(vramAddress + (y * stride) + (x * bytesPerPixel));

    switch (imageFormat) {
    case ImageDataFormat.RGB_888:
    case ImageDataFormat.RGB_888LUT:
        //write the color components
        MemWriteByte(offset, color.B);
        MemWriteByte(offset + 1, color.G);
        MemWriteByte(offset + 2, color.R);
        break;
    }
}

//setup the BitBLT registers
RegWrite(RegIndex.REG82_BLT_CTRL_1, (ushort)(dataType << 2));
RegWrite(RegIndex.REG86_BLT_CMD, 0x0002);  //Solid Fill BitBLT
RegWrite(RegIndex.REG8C_BLT_DSADDR_0, (ushort)(vadd & 0xFFFF));
RegWrite(RegIndex.REG8E_BLT_DSADDR_1, (ushort)((vadd >> 16) & 0x0007));
RegWrite(RegIndex.REG90_BLT_RECTOFFSET, (ushort)(stride / bytesPerPixel)); // 781 requires stride in pixels (not bytes)
RegWrite(RegIndex.REG92_BLT_WIDTH, width);
RegWrite(RegIndex.REG94_BLT_HEIGHT, height);

// "c" is converted color bytes from Color class
RegWrite(RegIndex.REG9A_BLT_FGCOLOR_0, (ushort)(c & 0xFFFF));
RegWrite(RegIndex.REG9C_BLT_FGCOLOR_1, (ushort)((c >> 16) & 0x00FF));

// Start the BitBLT
RegWrite(RegIndex.REG80_BLT_CTRL_0, 0x0001);

// Wait for completion.
PollWhileRegBitsHigh(RegIndex.REG84_BLT_STATUS, 0x0001, 0, 1000);

CanvasTextFormat ctf = new CanvasTextFormat();
ctf.FontFamily = font.Source;
ctf.FontSize = (float)fontsize;
ctf.HorizontalAlignment = CanvasHorizontalAlignment.Left;
ctf.VerticalAlignment = CanvasVerticalAlignment.Top;
ctf.WordWrapping = CanvasWordWrapping.NoWrap;

var device = CanvasDevice.GetSharedDevice();
CanvasBitmap cb = CanvasBitmap.CreateFromBytes(device,
    new byte[w * h * 4], w, h, Windows.Graphics.DirectX.DirectXPixelFormat.B8G8R8A8UIntNormalized);

var offscreen = new CanvasRenderTarget(device, w, h, 96);
using (var ds = offscreen.CreateDrawingSession()) {
    ds.TextAntialiasing = Microsoft.Graphics.Canvas.Text.CanvasTextAntialiasing.Aliased;
    ds.DrawText(text, new Rect(0, 0, w, h), Colors.White, ctf);
}

byte[] buffer = offscreen.GetPixelBytes();
for (int yy = 0; yy < h; yy++) {
    if (y + yy >= height) break;

    int p = yy * w * 4;
    for (int xx = 0; xx < w; xx++) {
        if (x + xx >= width) break;
        if (buffer[p] != 0x00) DrawPixel(x + xx, y + yy, color);
        p += 4;
    }
}