/// <summary>
/// Draws a string to a surface.
/// </summary>
/// <param name="surface">The surface to draw to.</param>
/// <param name="shader">The shader to use for drawing.</param>
/// <param name="text">The string to draw.</param>
/// <param name="charDist">The additional distance between characters. Can be negative.</param>
/// <param name="basePos">The location of the string. (Top-left)</param>
/// <param name="color">The color to use for drawing.</param>
public void DrawString(Surface surface, Shader shader, string text, float charDist, Vector2 basePos, Vector4 color)
{
if (surface != null)
{
float xAt = -1;
float yAt = -1;
Vector2 texCoord;
Vector2 size;
Vector2 sizeQ;
char[] chars = text.ToCharArray();
GL.Enable(EnableCap.Texture2D);
GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
GL.BlendEquation(BlendEquationMode.Max);
GL.Disable(EnableCap.DepthTest);
shader.Use();
shader.SetUniform <float>("_color", color.X, color.Y, color.Z, color.W);
surface.BindFramebuffer();
texture.BindTexture();
basePos = new Vector2(basePos.X / (float)surface.Width, basePos.Y / (float)surface.Height);
GL.Begin(PrimitiveType.Quads);
foreach (var c in chars)
{
if (charLocations.ContainsKey(c))
{
Vector2 scale = new Vector2(surface.Width / (float)texture.Width, surface.Height / (float)texture.Height);
texCoord = new Vector2(charLocations[c].X / texture.Width, charLocations[c].Y / texture.Height);
size = new Vector2(charSizes[c].X / texture.Width, charSizes[c].Y / texture.Height);
sizeQ = new Vector2(size.X / scale.X, size.Y / scale.Y);
GL.TexCoord2(texCoord.X, texCoord.Y + size.Y);
GL.Vertex2(basePos.X + xAt, basePos.Y + yAt);
GL.TexCoord2(texCoord.X + size.X, texCoord.Y + size.Y);
GL.Vertex2(basePos.X + xAt + sizeQ.X, basePos.Y + yAt);
GL.TexCoord2(texCoord.X + size.X, texCoord.Y);
GL.Vertex2(basePos.X + xAt + sizeQ.X, basePos.Y + yAt + sizeQ.Y);
GL.TexCoord2(texCoord.X, texCoord.Y);
GL.Vertex2(basePos.X + xAt, basePos.Y + yAt + sizeQ.Y);
xAt += sizeQ.X * charDist;
//y += sizeQ.Y;
}
}
GL.End();
GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
GL.BindTexture(TextureTarget.Texture2D, 0);
GL.UseProgram(0);
}
}
