Implemented basic layout. Implemented VBO printer.

This commit is contained in:
the_fiddler 2007-11-06 13:29:18 +00:00
parent 9a435c6194
commit 6ac7982f27

View file

@ -1,4 +1,10 @@
using System;
#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.Drawing;
@ -6,69 +12,137 @@ using System.Text.RegularExpressions;
using OpenTK.Math;
using OpenTK.OpenGL;
using OpenTK.OpenGL.Enums;
using System.Runtime.InteropServices;
namespace OpenTK.Fonts
{
public class DefaultLayoutProvider : ILayoutProvider
/// <summary>
/// Provides methods to perform layout and print hardware accelerated text.
/// </summary>
public class TextPrinter : ITextPrinter
{
static Regex break_point = new Regex("[ .,/*-+?\\!=]", RegexOptions.Compiled | RegexOptions.IgnoreCase);
static char[] split_chars = new char[] { ' ', ',', '.', '/', '?', '!', ';', '\\', '-', '+', '*', '=' };
//static Regex break_point = new Regex("[ .,/*-+?\\!=]", RegexOptions.Compiled | RegexOptions.IgnoreCase);
//static char[] split_chars = new char[] { ' ', '\n', '\t', ',', '.', '/', '?', '!', ';', '\\', '-', '+', '*', '=' };
static bool use_vbo, use_arb_vbo, use_display_list;
static bool functionality_checked = false;
static IPrinter printer;
#region --- ILayoutProvider Members ---
#region --- Constructor ---
public void PerformLayout(string text, IFont font, RectangleF layoutRect, StringAlignment alignment, bool rightToLeft)
/// <summary>
/// Constructs a new DefaultLayoutProvider object.
/// </summary>
public TextPrinter() { }
#endregion
/// <summary>
/// Checks the machine's capabilities and selects the fastest method to print text.
/// </summary>
static void CheckNeededFunctionality()
{
Vector2[] vertices = new Vector2[2 * text.Length + 4];
float x_pos, y_pos;
int i = 0, count, last_break_point = 0;
printer =
GL.SupportsExtension("VERSION_1_5") ? new VboPrinter() :
GL.SupportsExtension("ARB_vertex_buffer_object") ? null :
GL.SupportsExtension("VERSION_1_1") ? null : null;
if (printer == null)
throw new NotSupportedException("DefaultLayoutProvider requires at least OpenGL 1.1 support.");
functionality_checked = true;
}
#region --- ITextPrinter Members ---
public void Prepare(string text, TextureFont font, out TextHandle handle)
{
this.Prepare(text, font, out handle, 0, false, StringAlignment.Near, false);
}
public void Prepare(string text, TextureFont font, out TextHandle handle, float width, bool wordWarp)
{
this.Prepare(text, font, out handle, width, wordWarp, StringAlignment.Near, false);
}
public void Prepare(string text, TextureFont font, out TextHandle handle, float width, bool wordWarp, StringAlignment alignment)
{
this.Prepare(text, font, out handle, width, wordWarp, alignment, false);
}
public void Prepare(string text, TextureFont font, out TextHandle handle, float width, bool wordWarp, StringAlignment alignment, bool rightToLeft)
{
if (!functionality_checked)
CheckNeededFunctionality();
if (text == null)
throw new ArgumentNullException("Parameter cannot be null.", "text");
if (text.Length > 4096)
throw new ArgumentOutOfRangeException("text", text.Length, "Text length must be between 1 and 4096 characters");
Vector2[] vertices = new Vector2[8 * text.Length]; // Interleaved, vertex, texcoord, vertex, etc...
ushort[] indices = new ushort[6 * text.Length];
float x_pos = 0, y_pos = 0;
ushort i = 0, index_count = 0, vertex_count = 0, last_break_point = 0;
Box2 rect = new Box2();
float char_width, char_height, measured_width, measured_height;
int texture;
// Every character comprises of 4 vertices, forming two triangles. We generate an index array which
// indexes vertices in a triangle-strip fashion. To create a single strip for the whole string, we
// need to add a degenerate triangle (0 height) to connect the last vertex of the previous line with
// the first vertex of the next line.
// This algorithm works for left-to-right scripts.
if (alignment == StringAlignment.Near && !rightToLeft || alignment == StringAlignment.Far && rightToLeft)
{
x_pos = vertices[0].X = layoutRect.Left;
y_pos = vertices[0].Y = layoutRect.Top;
vertices[1].X = x_pos;
vertices[1].Y = y_pos - font.Height;
count = 2;
foreach (char c in text)
{
// TODO: This code breaks for small widths or for words that do not fit in one width.
if (Char.IsSeparator(c))
last_break_point = i;
last_break_point = index_count;
x_pos += font.MeasureString(text.Substring(i, 1)).Width;
if (x_pos > layoutRect.Width)
if (c == '\n' || c == '\r')
{
// Move the last word to the next line. If there is not enough vertical space
// for a new line, finish layout.
//x_pos = layoutRect.Left;
x_pos = 0;
y_pos += font.Height;
if (y_pos > layoutRect.Bottom)
break;
x_pos = layoutRect.Left;
for (int j = last_break_point; j < i; j++)
{
int current_vertex = 2 * (j + 1);
vertices[current_vertex].X = x_pos;
vertices[current_vertex].Y += font.Height;
current_vertex++;
vertices[current_vertex].X = x_pos;
vertices[current_vertex].Y += font.Height;
x_pos += font.MeasureString(text.Substring(j, 1)).Width;
}
x_pos += font.MeasureString(text.Substring(i, 1)).Width;
}
vertices[count].X = x_pos;
vertices[count].Y = y_pos;
++count;
vertices[count].X = x_pos;
vertices[count].Y = y_pos - font.Height;
++count;
else
{
font.GlyphData(c, out char_width, out char_height, out rect, out texture);
vertices[vertex_count].X = x_pos; // Vertex
vertices[vertex_count++].Y = y_pos;
vertices[vertex_count].X = rect.Left; // Texcoord
vertices[vertex_count++].Y = rect.Top;
vertices[vertex_count].X = x_pos; // Vertex
vertices[vertex_count++].Y = y_pos + char_height;
vertices[vertex_count].X = rect.Left; // Texcoord
vertices[vertex_count++].Y = rect.Bottom;
vertices[vertex_count].X = x_pos + char_width; // Vertex
vertices[vertex_count++].Y = y_pos + char_height;
vertices[vertex_count].X = rect.Right; // Texcoord
vertices[vertex_count++].Y = rect.Bottom;
vertices[vertex_count].X = x_pos + char_width; // Vertex
vertices[vertex_count++].Y = y_pos;
vertices[vertex_count].X = rect.Right; // Texcoord
vertices[vertex_count++].Y = rect.Top;
indices[index_count++] = (ushort)(vertex_count - 8);
indices[index_count++] = (ushort)(vertex_count - 6);
indices[index_count++] = (ushort)(vertex_count - 4);
indices[index_count++] = (ushort)(vertex_count - 4);
indices[index_count++] = (ushort)(vertex_count - 2);
indices[index_count++] = (ushort)(vertex_count - 8);
font.MeasureString(text.Substring(i, 1), out measured_width, out measured_height);
x_pos += measured_width;
}
++i;
}
}
@ -81,9 +155,100 @@ namespace OpenTK.Fonts
throw new NotImplementedException("This feature is not yet implemented. Sorry for the inconvenience.");
}
int buf;
GL.GenBuffers(1, out buf);
handle = printer.Load(vertices, indices);
handle.font = font;
}
public void Draw(TextHandle handle)
{
GL.PushAttrib(AttribMask.TextureBit);
GL.PushAttrib(AttribMask.EnableBit);
GL.Enable(EnableCap.Texture2d);
GL.Enable(EnableCap.Blend);
GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
GL.Enable(EnableCap.Blend);
GL.BindTexture(TextureTarget.Texture2d, handle.font.Texture);
printer.Draw(handle);
GL.PopAttrib();
GL.PopAttrib();
}
#endregion
}
public class TextHandle
{
internal TextHandle(int handle)
{
Handle = handle;
}
public readonly int Handle;
internal TextureFont font;
}
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.
}
interface IPrinter
{
TextHandle Load(Vector2[] vertices, ushort[] indices);
void Draw(TextHandle handle);
}
class VboPrinter : IPrinter
{
static int allocated_handles;
static int vector2_size = Marshal.SizeOf(new Vector2());
#region --- IPrinter Members ---
public TextHandle Load(Vector2[] vertices, ushort[] indices)
{
VboTextHandle handle = new VboTextHandle(++allocated_handles);
GL.GenBuffers(1, out handle.vbo_id);
GL.GenBuffers(1, out handle.ebo_id);
GL.BindBuffer(Version15.ArrayBuffer, handle.vbo_id);
GL.BufferData(Version15.ArrayBuffer, (IntPtr)(vertices.Length * vector2_size), vertices,
Version15.StaticDraw);
GL.BindBuffer(Version15.ElementArrayBuffer, handle.ebo_id);
GL.BufferData(Version15.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(ushort)), indices,
Version15.StaticDraw);
handle.element_count = indices.Length;
return handle;
}
public void Draw(TextHandle handle)
{
VboTextHandle vbo = (VboTextHandle)handle;
GL.PushClientAttrib(ClientAttribMask.ClientVertexArrayBit);
GL.BindBuffer(Version15.StaticDraw, vbo.vbo_id);
GL.BindBuffer(Version15.ElementArrayBuffer, vbo.ebo_id);
GL.EnableClientState(EnableCap.VertexArray);
GL.EnableClientState(EnableCap.TextureCoordArray);
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, All.UnsignedShort, IntPtr.Zero);
GL.PopClientAttrib();
}
#endregion