// Process a RGB image with alpha and 555 bit fields.
private static void RgbAlpha555(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn, value;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride +
offsetX * 2;
posn = 0;
scanline = reader.Read();
for(x = 0; x < width; ++x)
{
value = ((scanline[posn] & 0xF8) << 7) |
((scanline[posn + 1] & 0xF8) << 2) |
((scanline[posn + 2] & 0xF8) >> 3) |
((scanline[posn + 3] & 0x80) << 8);
data[offset] = (byte)value;
data[offset + 1] = (byte)(value >> 8);
offset += multX * 2;
posn += 4;
}
}
}
// Process a 16-bit RGB image with alpha.
private static void RgbAlpha16bpp(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride +
offsetX * 8;
posn = 0;
scanline = reader.Read();
for(x = 0; x < width; ++x)
{
// Flip the RGB PNG data into BGR form.
data[offset] = scanline[posn + 5];
data[offset + 1] = scanline[posn + 4];
data[offset + 2] = scanline[posn + 3];
data[offset + 3] = scanline[posn + 2];
data[offset + 4] = scanline[posn + 1];
data[offset + 5] = scanline[posn];
data[offset + 6] = scanline[posn + 7];
data[offset + 7] = scanline[posn + 6];
offset += multX * 8;
posn += 8;
}
}
}
// Process a 8-bit indexed image.
private static void Indexed8bpp(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride + offsetX;
scanline = reader.Read();
if(multX == 1)
{
Array.Copy(scanline, 0, data, offset, width);
}
else
{
posn = 0;
for(x = 0; x < width; ++x)
{
data[offset] = scanline[posn];
offset += multX;
++posn;
}
}
}
}
// Process a 16-bit gray scale image with alpha.
private static void GrayScaleAlpha16bpp(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn;
byte value;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride +
offsetX * 4;
posn = 0;
scanline = reader.Read();
for(x = 0; x < width; ++x)
{
value = scanline[posn];
data[offset] = value;
data[offset + 1] = value;
data[offset + 2] = value;
data[offset + 3] = scanline[posn + 2];
offset += multX * 4;
posn += 4;
}
}
}
// Process a 4-bit gray scale image.
private static void GrayScale4bpp(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn, bit;
byte value;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride +
offsetX * 3;
posn = 0;
bit = 4;
scanline = reader.Read();
for(x = 0; x < width; ++x)
{
value = (byte)(((scanline[posn] >> bit) & 0x0F) * 0x11);
data[offset] = value;
data[offset + 1] = value;
data[offset + 2] = value;
offset += multX * 3;
bit -= 4;
if(bit < 0)
{
++posn;
bit = 4;
}
}
}
}
// Process a 1-bit gray scale image.
private static void GrayScale1bpp(Frame frame, ScanlineReader reader,
int width, int height,
int offsetX, int offsetY,
int multX, int multY)
{
int x, y, offset, posn, bit;
byte value;
byte[] scanline;
byte[] data = frame.Data;
for(y = 0; y < height; ++y)
{
offset = ((y * multY) + offsetY) * frame.Stride +
offsetX * 3;
posn = 0;
bit = 0x80;
scanline = reader.Read();
for(x = 0; x < width; ++x)
{
if((scanline[posn] & bit) != 0)
{
value = 0xFF;
}
else
{
value = 0x00;
}
data[offset] = value;
data[offset + 1] = value;
data[offset + 2] = value;
offset += multX * 3;
bit >>= 1;
if(bit == 0)
{
++posn;
bit = 0x80;
}
}
}
}
