public void DrawInstancedPrimitives(
PrimitiveType primitiveType,
int baseVertex,
int minVertexIndex,
int numVertices,
int startIndex,
int primitiveCount,
int instanceCount
)
{
// Note that minVertexIndex and numVertices are NOT used!
// If this device doesn't have the support, just explode now before it's too late.
if (!GLDevice.SupportsHardwareInstancing)
{
throw new NoSuitableGraphicsDeviceException("Your hardware does not support hardware instancing!");
}
// Flush the GL state before moving on!
ApplyState();
// Unsigned short or unsigned int?
bool shortIndices = Indices.IndexElementSize == IndexElementSize.SixteenBits;
// Set up the vertex buffers.
for (int i = 0; i < vertexBufferCount; i += 1)
{
GLDevice.BindVertexBuffer(
vertexBufferBindings[i].VertexBuffer.Handle
);
vertexBufferBindings[i].VertexBuffer.VertexDeclaration.Apply(
VertexShader,
(IntPtr)(
vertexBufferBindings[i].VertexBuffer.VertexDeclaration.VertexStride *
(vertexBufferBindings[i].VertexOffset + baseVertex)
),
vertexBufferBindings[i].InstanceFrequency
);
}
// Enable the appropriate vertex attributes.
GLDevice.FlushGLVertexAttributes();
// Bind the index buffer
GLDevice.BindIndexBuffer(Indices.Handle);
// Draw!
GLDevice.glDrawElementsInstanced(
PrimitiveTypeGL(primitiveType),
GetElementCountArray(primitiveType, primitiveCount),
shortIndices ?
OpenGLDevice.GLenum.GL_UNSIGNED_SHORT :
OpenGLDevice.GLenum.GL_UNSIGNED_INT,
(IntPtr)(startIndex * (shortIndices ? 2 : 4)),
instanceCount
);
}
