/// <summary>
/// Draw a character sequence.
/// </summary>
/// <param name="ctx">
/// The <see cref="GraphicsContext"/> used for drawing.
/// </param>
/// <param name="modelview">
/// The <see cref="Matrix4x4"/> the model-view-projection matrix for the first character of <paramref name="s"/>.
/// </param>
/// <param name="color">
/// The <see cref="ColorRGBAF"/> that specifies the glyph color.
/// </param>
/// <param name="s">
/// A <see cref="String"/> that specifies the characters for be drawn.
/// </param>
public override void DrawString(GraphicsContext ctx, Matrix4x4 modelview, ColorRGBAF color, string s)
{
ModelMatrix charModel = new ModelMatrix(modelview);
ctx.Bind(_FontProgram);
// Set uniforms
_FontProgram.SetUniform(ctx, "glo_UniformColor", color);
_FontProgram.SetUniform(ctx, "glo_FontGlyph", _FontTexture);
// Set instances
char[] fontChars = s.ToCharArray();
uint instances = 0;
_GlyphInstances.Map(ctx, BufferAccessARB.WriteOnly);
try {
for (int i = 0; i < fontChars.Length; i++)
{
Glyph glyph;
if (_GlyphDb.TryGetValue(fontChars[i], out glyph) == false)
{
continue;
}
// Set instance information
Matrix4x4f modelViewProjection = new Matrix4x4f(
new Vertex4f(charModel.GetColumn(0)),
new Vertex4f(charModel.GetColumn(1)),
new Vertex4f(charModel.GetColumn(2)),
new Vertex4f(charModel.GetColumn(3))
);
Vertex3f glyphVertexParams = new Vertex3f(
glyph.GlyphSize.Width, glyph.GlyphSize.Height,
glyph.Layer
);
Vertex2f glyphTexParams = new Vertex2f(
glyph.TexScale.Width, glyph.TexScale.Height
);
_GlyphInstances.SetElement(modelViewProjection, instances, 0);
_GlyphInstances.SetElement(glyphVertexParams, instances, 1);
_GlyphInstances.SetElement(glyphTexParams, instances, 2);
// Count the instance
instances++;
// Move next
charModel.Translate(glyph.GlyphSize.Width, 0.0f);
}
} finally {
_GlyphInstances.Unmap(ctx);
}
// Rasterize it
using (State.BlendState stateBlend = State.BlendState.AlphaBlending) {
stateBlend.ApplyState(ctx, _FontProgram);
_VertexArrays.DrawInstanced(ctx, _FontProgram, instances);
}
}
/// <summary>
/// Get a list of <see cref="GlyphModelType"/> for a specific string and model-view-projection matrix.
/// </summary>
/// <param name="modelview"></param>
/// <param name="s"></param>
/// <returns></returns>
private List <GlyphModelType> GetGlyphsInstances(Matrix4x4 modelview, string s)
{
ModelMatrix charModel = new ModelMatrix(modelview);
List <GlyphModelType> glyphsInstances = new List <GlyphModelType>();
char[] fontChars = s.ToCharArray();
for (int i = 0; i < fontChars.Length; i++)
{
Glyph glyph;
if (_GlyphMetadata.TryGetValue(fontChars[i], out glyph) == false)
{
continue;
}
// Set instance information
Matrix4x4f modelViewProjection = new Matrix4x4f(
new Vertex4f(charModel.GetColumn(0)),
new Vertex4f(charModel.GetColumn(1)),
new Vertex4f(charModel.GetColumn(2)),
new Vertex4f(charModel.GetColumn(3))
);
Vertex3f glyphVertexParams = new Vertex3f(
glyph.GlyphSize.Width, glyph.GlyphSize.Height,
glyph.Layer
);
Vertex2f glyphTexParams = new Vertex2f(
glyph.TexScale.Width, glyph.TexScale.Height
);
GlyphModelType glyphModel = new GlyphModelType();
glyphModel.ModelViewProjection = modelViewProjection;
glyphModel.VertexParams = glyphVertexParams;
glyphModel.TexParams = glyphTexParams;
glyphsInstances.Add(glyphModel);
// Move next
charModel.Translate(glyph.GlyphSize.Width, 0.0f);
}
return(glyphsInstances);
}