/// <summary>
/// OGL2 does not support VAOs, and instead must bind the VBOs to their attributes manually.
/// </summary>
private void DrawOGL2()
{
if (VertexCount == 0)
{
return;
}
BindAttributes(Program);
Gl.DrawElements(DrawMode, VertexCount, DrawElementsType.UnsignedInt, IntPtr.Zero);
}
/// <summary>
/// OGL2 does not support VAOs, and instead must bind the VBOs to their attributes manually.
/// </summary>
private void DrawOGL2()
{
if (VertexCount == 0)
{
return;
}
BindAttributes(Program);
Gl.DrawElements(DrawMode, VertexCount, elementType, offsetInBytes);
}
/// <summary>
/// Draw the elements indices.
/// </summary>
/// <param name="ctx">
/// The <see cref="GraphicsContext"/> used for drawing.
/// </param>
protected virtual void DrawElements(GraphicsContext ctx, IntPtr pointer)
{
uint count = (ElementCount == 0) ? ArrayIndices.ItemCount : ElementCount;
Debug.Assert(count - ElementOffset <= ArrayIndices.ItemCount, "element indices array out of bounds");
// Draw elements as usual
Gl.DrawElements(ElementsMode, (int)count, ArrayIndices.ElementsType, pointer);
}
/// <summary>
/// OGL3 method uses a vertex array object for quickly binding the VBOs to their attributes.
/// </summary>
private void DrawOGL3()
{
if (vaoID == 0 || VertexCount == 0)
{
return;
}
Gl.BindVertexArray(vaoID);
Gl.DrawElements(DrawMode, VertexCount, DrawElementsType.UnsignedInt, IntPtr.Zero);
Gl.BindVertexArray(0);
}
/// <summary>
/// OGL3 method uses a vertex array object for quickly binding the VBOs to their attributes.
/// </summary>
private void DrawOGL3()
{
if (ID == 0 || VertexCount == 0)
{
return;
}
Gl.BindVertexArray(ID);
Gl.DrawElements(DrawMode, VertexCount, elementType, offsetInBytes);
Gl.BindVertexArray(0);
}
/// <summary>
/// Draw the elements.
/// </summary>
/// <param name="ctx">
/// The <see cref="GraphicsContext"/> used for drawing.
/// </param>
public override void Draw(GraphicsContext ctx)
{
if (ctx == null)
{
throw new ArgumentNullException("ctx");
}
if (ctx.IsCurrent == false)
{
throw new ArgumentException("not current", "ctx");
}
ArrayBufferObjectBase.IArraySection arraySection = ArrayIndices.GetArraySection(0);
Debug.Assert(arraySection != null);
// Element array must be (re)bound
ArrayIndices.Bind(ctx);
// Enable restart primitive?
if (ArrayIndices.RestartIndexEnabled)
{
Debug.Assert(ElementCount != 0, "specified ElementCount but primitive restart enabled");
if (PrimitiveRestart.IsPrimitiveRestartSupported(ctx))
{
// Enable primitive restart
PrimitiveRestart.EnablePrimitiveRestart(ctx, ArrayIndices.ElementsType);
// Draw elements as usual
Gl.DrawElements(ElementsMode, (int)ElementCount, ArrayIndices.ElementsType, arraySection.Pointer);
// Disable primitive restart
PrimitiveRestart.DisablePrimitiveRestart(ctx);
}
else
{
// Note: uses MultiDrawElements to emulate the primitive restart feature; PrimitiveRestartOffsets and
// PrimitiveRestartCounts are computed at element buffer creation time
Gl.MultiDrawElements(ElementsMode, ArrayIndices.PrimitiveRestartOffsets, ArrayIndices.ElementsType, ArrayIndices.PrimitiveRestartCounts, ArrayIndices.PrimitiveRestartOffsets.Length);
}
}
else
{
uint count = (ElementCount == 0) ? ArrayIndices.ItemCount : ElementCount;
Debug.Assert(count - ElementOffset <= ArrayIndices.ItemCount, "element indices array out of bounds");
// Draw vertex arrays by indices
Gl.DrawElements(ElementsMode, (int)count, ArrayIndices.ElementsType, arraySection.Pointer);
}
}
/// <summary>
/// Performs the draw routine with a custom shader program.
/// </summary>
/// <param name="program"></param>
public void DrawProgram(ShaderProgram program)
{
BindAttributes(program);
Gl.DrawElements(DrawMode, VertexCount, DrawElementsType.UnsignedInt, IntPtr.Zero);
}
/// <summary>
/// OGL2 does not support VAOs, and instead must bind the VBOs to their attributes manually.
/// </summary>
private void DrawOGL2()
{
BindAttributes(this.Program);
Gl.DrawElements(DrawMode, VertexCount, DrawElementsType.UnsignedInt, IntPtr.Zero);
}
/// <summary>
/// Performs the draw routine with a custom shader program.
/// </summary>
/// <param name="program"></param>
public void DrawProgram(ShaderProgram program)
{
BindAttributes(program);
Gl.DrawElements(DrawMode, VertexCount, elementType, offsetInBytes);
}