Opentk/Source/OpenTK/Fonts/VboTextPrinter.cs

99 lines
3.5 KiB
C#

#region --- License ---
/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
* See license.txt for license info
*/
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using OpenTK.OpenGL;
using OpenTK.Math;
using OpenTK.OpenGL.Enums;
namespace OpenTK.Fonts
{
/// <summary>
/// Provides text printing through OpenGL 1.5 vertex buffer objects.
/// </summary>
class VboTextPrinter : ITextPrinterImplementation
{
static int allocated_handles;
static int vector2_size = Marshal.SizeOf(new Vector2());
#region --- IPrinter Members ---
public TextHandle Load(Vector2[] vertices, ushort[] indices, int index_count)
{
VboTextHandle handle = new VboTextHandle(++allocated_handles);
GL.GenBuffers(1, out handle.vbo_id);
GL.BindBuffer(BufferTarget.ArrayBuffer, handle.vbo_id);
GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * vector2_size), vertices,
BufferUsageHint.StaticDraw);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.GenBuffers(1, out handle.ebo_id);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, handle.ebo_id);
GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(ushort)), indices,
BufferUsageHint.StaticDraw);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
handle.element_count = indices.Length;
return handle;
}
public void Draw(TextHandle handle)
{
VboTextHandle vbo = (VboTextHandle)handle;
//GL.PushClientAttrib(ClientAttribMask.ClientVertexArrayBit);
//GL.EnableClientState(EnableCap.TextureCoordArray);
GL.EnableClientState(EnableCap.VertexArray);
GL.BindBuffer(BufferTarget.ArrayBuffer, vbo.vbo_id);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, vbo.ebo_id);
GL.TexCoordPointer(2, TexCoordPointerType.Float, vector2_size, (IntPtr)vector2_size);
GL.VertexPointer(2, VertexPointerType.Float, vector2_size, IntPtr.Zero);
GL.DrawElements(BeginMode.Triangles, vbo.element_count, DrawElementsType.UnsignedShort, IntPtr.Zero);
//GL.DrawArrays(BeginMode.LineLoop, 0, vbo.element_count);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
GL.DisableClientState(EnableCap.VertexArray);
//GL.DisableClientState(EnableCap.TextureCoordArray);
//GL.PopClientAttrib();
}
#endregion
}
#region class VboTextHandle : TextHandle
/// <summary>
/// Contains the necessary information to print text through the VboTextPrinter implementation.
/// </summary>
class VboTextHandle : TextHandle
{
public VboTextHandle(int handle) : base(handle) { }
internal int vbo_id; // vertex buffer object id.
internal int ebo_id; // index buffer object id.
internal int element_count; // Number of elements in the ebo.
public override string ToString()
{
return String.Format("TextHandle (vbo): {0} ({1} element(s), vbo id: {2}, ebo id: {3}",
Handle, element_count / 6, vbo_id, ebo_id);
}
}
#endregion
}