/// <summary>
/// Use this shader for rendering.
/// </summary>
public void Use(bool setDefaultUniforms = true)
{
CurrentShader = this;
GL.UseProgram(ProgramId);
if (setDefaultUniforms)
{
SetDefaultUniforms();
}
}
/// <summary>
/// Draw a string.
/// </summary>
/// <param name="text">Text that will be drawn</param>
/// <param name="x">X-Position of the text</param>
/// <param name="y">Y-Position of the text</param>
protected void DrawString(string text, float x, float y, float size = 32f)
{
float scale = size / currentFontAtlas.Size;
ShaderBase previousShader = ShaderBase.CurrentShader;
textShader.Use();
textShader.SetVector3("textColor", new Vector3(Color.R, Color.G, Color.B));
int texcoordAttribLocation = GL.GetAttribLocation(textShader.ProgramId, "aTexcoord");
GL.ActiveTexture(TextureUnit.Texture0);
GL.BindTexture(TextureTarget.Texture2D, currentFontAtlas.TextureId);
GL.Begin(PrimitiveType.Quads);
float currentX = x;
foreach (char character in text)
{
if (!currentFontAtlas.Characters.ContainsKey(character))
{
continue;
}
CharacterData data = currentFontAtlas.Characters[character];
GL.VertexAttrib2(texcoordAttribLocation, data.uvX1, data.uvY2);
GL.Vertex2(currentX, y);
GL.VertexAttrib2(texcoordAttribLocation, data.uvX2, data.uvY2);
GL.Vertex2(currentX + data.xAdvance * scale, y);
GL.VertexAttrib2(texcoordAttribLocation, data.uvX2, data.uvY1);
GL.Vertex2(currentX + data.xAdvance * scale, y + data.height * scale);
GL.VertexAttrib2(texcoordAttribLocation, data.uvX1, data.uvY1);
GL.Vertex2(currentX, y + data.height * scale);
currentX += data.xAdvance * scale;
}
GL.End();
previousShader?.Use();
}