Graphics Reference
In-Depth Information
17. For the
TriangleRenderer
C# class, change the
DoRender
method to set the
PrimitiveTopology
enumeration to a patch list with three control points:
context.InputAssembler.PrimitiveTopology =
PrimitiveTopology.PatchListWith3ControlPoints;
18. For the
QuadRenderer
class, we do not need an index buffer. Instead, we will
use the following code in the
DoRender
method to set up the patch topology
and draw the vertices:
context.InputAssembler.PrimitiveTopology =
PrimitiveTopology.PatchListWith4ControlPoints;
context.InputAssembler.SetVertexBuffers(0, quadBinding);
context.Draw(4, 0);
19. Create an instance of our renderers within
D3DApp.Run
, and add a call to their
Render
method within the render loop.
20. Add the
TriangleRenderer
and
QuadRenderer
classes to the render loop:
// TRIANGLE
context.VertexShader.Set(tessellateVertexShader);
context.HullShader.Set(activeTriTessellator);
context.DomainShader.Set(tessellateTriDomainShader);
triangle.Render();
// QUAD
context.VertexShader.Set(tessellateVertexShader);
context.HullShader.Set(activeQuadTessellator);
context.DomainShader.Set(tessellateQuadDomainShader);
quad.Render();
...
// RESET SHADERS
context.VertexShader.Set(vertexShader);
context.HullShader.Set(null);
context.DomainShader.Set(null);
Attempting to use the wrong primitive topology type with the hull/domain
shader may result in an unexpected behavior; therefore, we clear the
shaders to ensure that they don't interfere with other renderers.
For example, on a test machine, it was possible to crash the display driver
subsystem by specifying a standard triangle list while a hull shader was set.
