/// <inheritdoc/>
public override void Attach(RenderBuffer2D buffer)
{
Contract.Require(buffer, nameof(buffer));
Contract.Ensure <ArgumentException>(
buffer.Width == width &&
buffer.Height == height, OpenGLStrings.RenderBufferIsWrongSize);
Contract.EnsureNotDisposed(this, Disposed);
Ultraviolet.ValidateResource(buffer);
var sdlBuffer = (OpenGLRenderBuffer2D)buffer;
Ultraviolet.QueueWorkItemAndWait(() =>
{
using (OpenGLState.ScopedBindFramebuffer(framebuffer))
{
AttachRenderBuffer(sdlBuffer);
framebufferStatus = gl.CheckNamedFramebufferStatus(framebuffer, gl.GL_FRAMEBUFFER);
gl.ThrowIfError();
}
});
sdlBuffer.MarkAttached();
buffers.Add(sdlBuffer);
}
/// <summary>
/// Gets the render target's data.
/// </summary>
/// <param name="data">An array to populate with the render target's data.</param>
/// <param name="region">The region of the render target from which to retrieve data.</param>
private unsafe void GetDataInternal(Color[] data, Rectangle region)
{
using (OpenGLState.ScopedBindFramebuffer(framebuffer, true))
{
fixed(Color *pData = data)
{
if (!gl.IsGLES2)
{
gl.ReadBuffer(gl.GL_COLOR_ATTACHMENT0);
gl.ThrowIfError();
}
gl.ReadPixels(region.X, region.Y, region.Width, region.Height, gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, pData);
gl.ThrowIfError();
}
}
// OpenGL texture data is stored upside down and in the wrong color format,
// so we need to convert that to what our caller expects.
var rowsToProcess = (Height % 2 == 0) ? Height / 2 : 1 + Height / 2;
for (int y = 0; y < rowsToProcess; y++)
{
var ySrc = (y);
var yDst = (Height - 1) - y;
for (int x = 0; x < Width; x++)
{
var ixSrc = (ySrc * Width) + x;
var ixDst = (yDst * Width) + x;
var colorSrc = new Color(data[ixSrc].PackedValue);
var colorDst = new Color(data[ixDst].PackedValue);
data[ixDst] = colorSrc;
data[ixSrc] = colorDst;
}
}
}