internal void Clean()
{
if (_dirty)
{
int maximumArrayIndex = 0;
for (int i = 0; i < _attributes.Length; ++i)
{
VertexBufferAttribute attribute = _attributes[i].VertexBufferAttribute;
if (_attributes[i].Dirty)
{
if (attribute != null)
{
Attach(i);
}
else
{
Detach(i);
}
_attributes[i].Dirty = false;
}
if (attribute != null)
{
maximumArrayIndex = Math.Max(NumberOfVertices(attribute) - 1, maximumArrayIndex);
}
}
_dirty = false;
_maximumArrayIndex = maximumArrayIndex;
}
}
private void CreateVertexArray(Context context)
{
// TODO: Hint per buffer? One hint?
_positionBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, _billboards.Count * SizeInBytes <Vector3F> .Value);
_colorBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, _billboards.Count * SizeInBytes <BlittableRGBA> .Value);
_originBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, _billboards.Count);
_pixelOffsetBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, _billboards.Count * SizeInBytes <Vector2H> .Value);
_textureCoordinatesBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, _billboards.Count * SizeInBytes <Vector4H> .Value);
VertexBufferAttribute positionAttribute = new VertexBufferAttribute(
_positionBuffer, ComponentDatatype.Float, 3);
VertexBufferAttribute colorAttribute = new VertexBufferAttribute(
_colorBuffer, ComponentDatatype.UnsignedByte, 4, true, 0, 0);
VertexBufferAttribute originAttribute = new VertexBufferAttribute(
_originBuffer, ComponentDatatype.UnsignedByte, 1);
VertexBufferAttribute pixelOffsetAttribute = new VertexBufferAttribute(
_pixelOffsetBuffer, ComponentDatatype.HalfFloat, 2);
VertexBufferAttribute textureCoordinatesAttribute = new VertexBufferAttribute(
_textureCoordinatesBuffer, ComponentDatatype.HalfFloat, 4);
ShaderProgram sp = _drawState.ShaderProgram;
VertexArray va = context.CreateVertexArray();
va.Attributes[sp.VertexAttributes["position"].Location] = positionAttribute;
va.Attributes[sp.VertexAttributes["textureCoordinates"].Location] = textureCoordinatesAttribute;
va.Attributes[sp.VertexAttributes["color"].Location] = colorAttribute;
va.Attributes[sp.VertexAttributes["origin"].Location] = originAttribute;
va.Attributes[sp.VertexAttributes["pixelOffset"].Location] = pixelOffsetAttribute;
_drawState.VertexArray = va;
}
private void CreateVertexArray(Context context)
{
// TODO: Buffer hint.
_positionBuffer = Device.CreateVertexBuffer(BufferHint.StaticDraw, SizeInBytes <Vector2F> .Value);
VertexBufferAttribute positionAttribute = new VertexBufferAttribute(
_positionBuffer, ComponentDatatype.Float, 2);
_drawState.VertexArray = context.CreateVertexArray();
_drawState.VertexArray.Attributes[_drawState.ShaderProgram.VertexAttributes["position"].Location] = positionAttribute;
}
private void Attach(int index)
{
GL.EnableVertexAttribArray(index);
VertexBufferAttribute attribute = _attributes[index].VertexBufferAttribute;
VertexBufferGL3x bufferObjectGL = (VertexBufferGL3x)attribute.VertexBuffer;
bufferObjectGL.Bind();
GL.VertexAttribPointer(index,
attribute.NumberOfComponents,
TypeConverterGL3x.To(attribute.ComponentDatatype),
attribute.Normalize,
attribute.StrideInBytes,
attribute.OffsetInBytes);
}
internal void Update(Context context, ShaderProgram sp)
{
if (_va == null)
{
VertexBufferAttribute positionAttribute = new VertexBufferAttribute(
_positionBuffer, ComponentDatatype.Float, 2);
VertexBufferAttribute textureCoordinatesAttribute = new VertexBufferAttribute(
_textureCoordinatesBuffer, ComponentDatatype.HalfFloat, 2);
_va = context.CreateVertexArray();
_va.Attributes[sp.VertexAttributes["position"].Location] = positionAttribute;
_va.Attributes[sp.VertexAttributes["textureCoordinates"].Location] = textureCoordinatesAttribute;
}
if (_viewport != context.Viewport)
{
//
// Bottom and top swapped: MS -> OpenGL
//
float left = context.Viewport.Left;
float bottom = context.Viewport.Top;
float right = context.Viewport.Right;
float top = context.Viewport.Bottom;
Vector2F[] positions = new Vector2F[]
{
new Vector2F(left, bottom),
new Vector2F(right, bottom),
new Vector2F(left, top),
new Vector2F(right, top)
};
_positionBuffer.CopyFromSystemMemory(positions);
Vector2H[] textureCoordinates = new Vector2H[]
{
new Vector2H(0, 0),
new Vector2H(1, 0),
new Vector2H(0, 1),
new Vector2H(1, 1)
};
_textureCoordinatesBuffer.CopyFromSystemMemory(textureCoordinates);
_viewport = context.Viewport;
}
}
private static int NumberOfVertices(VertexBufferAttribute attribute)
{
return(attribute.VertexBuffer.SizeInBytes / attribute.StrideInBytes);
}
internal void Update(Context context, ShaderProgram sp)
{
if (_va == null)
{
VertexBufferAttribute positionAttribute = new VertexBufferAttribute(
_positionBuffer, ComponentDatatype.Float, 2);
VertexBufferAttribute textureCoordinatesAttribute = new VertexBufferAttribute(
_textureCoordinatesBuffer, ComponentDatatype.HalfFloat, 2);
_va = context.CreateVertexArray();
_va.Attributes[sp.VertexAttributes["position"].Location] = positionAttribute;
_va.Attributes[sp.VertexAttributes["textureCoordinates"].Location] = textureCoordinatesAttribute;
_va.IndexBuffer = _indexBuffer;
}
// 检测当前视口变换并重新计算视口矩形
if (_viewport != context.Viewport)
{
//
// Bottom and top swapped: MS -> OpenGL
//
float left = context.Viewport.Left;
float bottom = context.Viewport.Top;
float right = context.Viewport.Right;
float top = context.Viewport.Bottom;
Vector2F[] positions = new Vector2F[]
{
// left eye verts
new Vector2F(left, bottom), // -1, -1
new Vector2F((left + right) / 2.0f, bottom), // 0, -1
new Vector2F(left, top), // -1, 1
new Vector2F((left + right) / 2.0f, top), // 0, 1
// right eye verts
new Vector2F((left + right) / 2.0f, bottom), // 0, -1
new Vector2F(right, bottom), // 1, -1
new Vector2F((left + right) / 2.0f, top), // 0, 1
new Vector2F(right, top) // 1, 1
};
_positionBuffer.CopyFromSystemMemory(positions);
Vector2H[] textureCoordinates = new Vector2H[]
{
// left eye tex coord
new Vector2H(0, 1),
new Vector2H(1, 1),
new Vector2H(0, 0),
new Vector2H(1, 0),
// right eye tex coord
new Vector2H(0, 1),
new Vector2H(1, 1),
new Vector2H(0, 0),
new Vector2H(1, 0),
};
_textureCoordinatesBuffer.CopyFromSystemMemory(textureCoordinates);
ushort[] index = new ushort[] { 0, 1, 3, 0, 3, 2, 4, 5, 7, 4, 7, 6 };
_indexBuffer.CopyFromSystemMemory(index);
_viewport = context.Viewport;
}
}
