public override void UploadDataToGPU()
{
Vao.ChangeData(BufferTarget.ArrayBuffer, Verticies.ToArray());
this.ChangeAttribute(BufferTarget.ArrayBuffer, "position", 2,
VertexAttribPointerType.Float, false, 6 * sizeof(float), 0);
this.ChangeAttribute(BufferTarget.ArrayBuffer, "vertexColor", 4,
VertexAttribPointerType.Float, false, 6 * sizeof(float), 2 * sizeof(float));
}
/// <summary>
/// Uploads the data to GPU.
/// </summary>
public override void UploadDataToGPU()
{
Vao.ChangeData(BufferTarget.ArrayBuffer, Verticies.ToArray());
ChangeAttribute(BufferTarget.ArrayBuffer, "position", 2,
VertexAttribPointerType.Float, true, 4 * sizeof(float), 0);
ChangeAttribute(BufferTarget.ArrayBuffer, "texcoord", 2,
VertexAttribPointerType.Float, true, 4 * sizeof(float), 2 * sizeof(float));
}
public static int BufferShaderGeometry(Verticies geometry, out int vbo_interleaved, out int NumVerticies)
{
Vertex[] _interleaved = geometry.ToArray();
Console.WriteLine("Buffering Verticies..");
vbo_interleaved = GL.GenBuffer();
//GL.GenBuffers(1, out vbo_interleaved);
GL.BindBuffer(BufferTarget.ArrayBuffer, vbo_interleaved); // InterleavedArrayFormat.T2fC4fN3fV3f
GL.BufferData <Vertex>(BufferTarget.ArrayBuffer,
(IntPtr)(_interleaved.Length * Vertex.SizeInBytes),
_interleaved, BufferUsageHint.StaticDraw);
Console.WriteLine("[done]");
// Each vertex in the interleaved structure is defined as follows..
//
// In x3d-finely-sharpened, each field 'f' is a floating point value.
// The size of a float is 4 bytes, the size of a vertex structure is calculated as follows:
//
// 'p' position field is 12 bytes (3 fields * 4 bytes = 12 bytes)
// 'n' normal field is 12 bytes (3 fields * 4 bytes = 12 bytes)
// 'c' color field is 16 bytes (4 fields * 4 bytes = 16 bytes)
// 'tc' texture coordinate field is 8 bytes (2 fields * 4 bytes = 8 bytes)
// The STRIDE is the number of bytes between each interleaved structure
// stride = Pf + Nf + Cf + TCf
// stride = 12 + 12 + 16 + 8
// stride = 48 bytes
//
// Luckily this new implementation doesnt require calculation of stride
// however it is important to keep to this structure.
// Floating point values must used uniformally for each field.
// 'c' color field must be composed of 4 floating point values
// otherwise if there is no alpha channel OpenGL pads the color to 16 bytes
// automatically. This creates uneven structures and results in undesired operation.
//
// If any new fields need to be added to the Vertex structure,
// this model needs updating to reflect the changes
// new fields must be floating point values,
// finally Vertex.SizeInBytes should be checked to see
// if it returns the same value as the calculation above.
//
// P N C TC
// [f f f] [f f f] [f f f f] [f f]
// 12 13 24 25 40 41 50
NumVerticies = _interleaved.Length;
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
return(vbo_interleaved);
}
