private unsafe void ReadPixels(int x, int y, int width, int height, ReadPixelsFormat format, ReadPixelsType type, IntPtr data)
{
Framebuffer framebuffer = this.currentFramebuffer;
if (framebuffer == null)
{
throw new Exception("This should not happen!");
}
if (!Enum.IsDefined(typeof(ReadPixelsFormat), format))
{
SetLastError(ErrorCode.InvalidEnum); return;
}
if (!Enum.IsDefined(typeof(ReadPixelsType), type))
{
SetLastError(ErrorCode.InvalidEnum); return;
}
if (width < 0 || height < 0)
{
SetLastError(ErrorCode.InvalidValue); return;
}
if (format == ReadPixelsFormat.StencilIndex && framebuffer.StencilbufferAttachment == null)
{
SetLastError(ErrorCode.InvalidOperation); return;
}
if (format == ReadPixelsFormat.DepthComponent && framebuffer.DepthbufferAttachment == null)
{
SetLastError(ErrorCode.InvalidOperation); return;
}
if (format == ReadPixelsFormat.DepthStencil && (framebuffer.DepthbufferAttachment == null || framebuffer.StencilbufferAttachment == null))
{
SetLastError(ErrorCode.InvalidOperation); return;
}
if (format == ReadPixelsFormat.DepthStencil &&
(type != ReadPixelsType.UnsignedInt248 && type != ReadPixelsType.Float32UnsignedInt248Rev))
{
SetLastError(ErrorCode.InvalidEnum); return;
}
if (format != ReadPixelsFormat.RGB &&
(type == ReadPixelsType.UnsignedByte332 || type == ReadPixelsType.UnsignedByte233Rev || type == ReadPixelsType.UnsignedShort565 || type == ReadPixelsType.UnsignedShort565Rev))
{
SetLastError(ErrorCode.InvalidOperation); return;
}
if ((format != ReadPixelsFormat.RGBA && format != ReadPixelsFormat.BGRA) &&
(type == ReadPixelsType.UnsignedShort4444 || type == ReadPixelsType.UnsignedShort4444Rev || type == ReadPixelsType.UnsignedShort5551 || type == ReadPixelsType.UnsignedShort1555Rev || type == ReadPixelsType.UnsignedInt8888 || type == ReadPixelsType.UnsignedInt8888Rev || type == ReadPixelsType.UnsignedInt1010102 || type == ReadPixelsType.UnsignedInt2101010Rev))
{
SetLastError(ErrorCode.InvalidOperation); return;
}
// TODO: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object's data store is currently mapped.
// TODO: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed to the buffer object such that the memory writes required would exceed the data store size.
// TODO: GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.
// TODO: GL_INVALID_OPERATION is generated if GL_READ_FRAMEBUFFER_BINDING is non-zero, the read framebuffer is complete, and the value of GL_SAMPLE_BUFFERS for the read framebuffer is greater than zero.
IAttachable attachment = null;
if (format == ReadPixelsFormat.DepthComponent)
{
attachment = framebuffer.DepthbufferAttachment;
}
else if (format == ReadPixelsFormat.StencilIndex)
{
attachment = framebuffer.StencilbufferAttachment;
}
else if (format == ReadPixelsFormat.DepthStencil)
{
attachment = framebuffer.DepthbufferAttachment;
}
else
{
IList <uint> drawBuffers = framebuffer.DrawBuffers;
if (drawBuffers.Count > 0)
{
uint index = drawBuffers[0].ToIndex();
attachment = framebuffer.ColorbufferAttachments[index];
}
}
// copy data from attachment to "data".
if (attachment != null)
{
ReadPixels(x, y, width, height, format, type, data, attachment);
}
}
private unsafe void ReadPixels(int x, int y, int width, int height, ReadPixelsFormat format, ReadPixelsType type, IntPtr data, IAttachable attachment)
{
byte[] dataStore = attachment.DataStore;
//int srcBitSize = InternalFormatHelper.BitSize(attachment.Format);
//int srcElementByteLength = (srcBitSize % 8 == 0) ? srcBitSize / 8 : srcBitSize / 8 + 1; // TODO: any better solution?
int srcWidth = attachment.Width, srcHeight = attachment.Height;
//int dstBitSize = InternalFormatHelper.BitSize((uint)format);
//int dstElementByteLength = (dstBitSize % 8 == 0) ? dstBitSize / 8 : dstBitSize / 8 + 1; // TODO: any better solution?
var array = (byte *)data.ToPointer();
if (format == ReadPixelsFormat.BGRA && attachment.Format == GL.GL_RGBA)
{
var indexes = new int[4] {
2, 1, 0, 3
};
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
for (int t = 0; t < 4; t++)
{
int dstT = (j * width + i) * 4 + t;
int srcT = ((j + y) * srcWidth + (i + x)) * 4 + indexes[t];
array[dstT] = dataStore[srcT];
}
}
}
}
else if (format == ReadPixelsFormat.BGRA && attachment.Format == GL.GL_BGRA)
{
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
for (int t = 0; t < 4; t++)
{
int dstT = (j * width + i) * 4 + t;
int srcT = ((j + y) * srcWidth + (i + x)) * 4 + t;
array[dstT] = dataStore[srcT];
}
}
}
}
else // TODO; deal with all possibilities.
{
throw new NotImplementedException();
}
}
