public static void RenderShadowMap(ref DeviceContext context, ref IWorld world, ref Camera camera)
{
PixHelper.BeginEvent(default(RawColorBGRA), "Shadow Rendering");
{
if (ShadowMapsNeedRemade)
CreateShadowMaps();
var shadowMapSize = ShadowMap.Width;
if (AreSplitsDirty || camera != _lastCamera)
ComputeSplits(ref camera);
_lastCamera = camera;
MakeGlobalShadowMatrix(ref camera, out ReceiverConstants.Data.ShadowMatrix);
context.Rasterizer.SetViewport(_viewport);
for (int cascadeIndex = 0; cascadeIndex < CascadeCount; ++cascadeIndex)
{
PixHelper.BeginEvent(default(RawColorBGRA), "Cascade");
{
ResetFrustumCorners(ref _frustumCorners);
var prevSplitDist = cascadeIndex == 0 ? MinCascadeDistance : _cascadeSplits[cascadeIndex - 1];
var splitDist = _cascadeSplits[cascadeIndex];
for (int i = 0; i < 8; i++)
DxVector3.TransformCoordinate(ref _frustumCorners[i],
ref camera.Constants.Data.InverseViewProjection, out _frustumCorners[i]);
for (int i = 0; i < 4; i++)
{
DxVector3 cornerRay;
DxVector3 nearCornerRay;
DxVector3 farCornerRay;
DxVector3.Subtract(ref _frustumCorners[i + 4], ref _frustumCorners[i], out cornerRay);
DxVector3.Multiply(ref cornerRay, prevSplitDist, out nearCornerRay);
DxVector3.Multiply(ref cornerRay, splitDist, out farCornerRay);
DxVector3.Add(ref _frustumCorners[i], ref farCornerRay, out _frustumCorners[i + 4]);
DxVector3.Add(ref _frustumCorners[i], ref nearCornerRay, out _frustumCorners[i]);
}
var frustumCenter = DxVector3.Zero;
for (int i = 0; i < 8; i++)
DxVector3.Add(ref frustumCenter, ref _frustumCorners[i], out frustumCenter);
DxVector3.Multiply(ref frustumCenter, 0.125F, out frustumCenter);
var upDir = DxVector3.Up;
float sphereRadius = 0.0f;
for (int i = 0; i < 8; ++i)
{
DxVector3 sum;
DxVector3.Subtract(ref _frustumCorners[i], ref frustumCenter, out sum);
sphereRadius = Math.Max(sphereRadius, sum.Length());
}
sphereRadius = (float)Math.Ceiling(sphereRadius * 16.0f) / 16.0f;
var maxExtents = new DxVector3(sphereRadius, sphereRadius, sphereRadius);
DxVector3 minExtents;
DxVector3.Negate(ref maxExtents, out minExtents);
DxVector3 cascadeExtents;
DxVector3.Subtract(ref maxExtents, ref minExtents, out cascadeExtents);
// TODO: optimize
var shadowCameraPos = frustumCenter + Direction * -minExtents.Z;
Matrix viewMatrix;
Matrix projectionMatrix;
Matrix viewProjMatrix;
Matrix.LookAtLH(ref shadowCameraPos, ref frustumCenter, ref upDir, out viewMatrix);
Matrix.OrthoOffCenterLH(minExtents.X, maxExtents.X, minExtents.Y,
maxExtents.Y, 0.0f, cascadeExtents.Z, out projectionMatrix);
Matrix.Multiply(ref viewMatrix, ref projectionMatrix, out viewProjMatrix);
var shadowOrigin = DxVector4.UnitW;
DxVector4.Transform(ref shadowOrigin, ref viewProjMatrix, out shadowOrigin);
DxVector4.Multiply(ref shadowOrigin, shadowMapSize / 2.0f, out shadowOrigin);
var roundedOrigin = new DxVector4(Mathf.Round(shadowOrigin.X), Mathf.Round(shadowOrigin.Y),
Mathf.Round(shadowOrigin.Z), Mathf.Round(shadowOrigin.W));
DxVector4 roundOffset;
DxVector4.Subtract(ref roundedOrigin, ref shadowOrigin, out roundOffset);
DxVector4.Multiply(ref roundOffset, 2.0f / shadowMapSize, out roundOffset);
roundOffset.Z = 0.0f;
roundOffset.W = 0.0f;
projectionMatrix.Row4 += roundOffset; // R[3]
Matrix.Multiply(ref viewMatrix, ref projectionMatrix, out viewProjMatrix);
// RenderDepthCPU
SetupRenderDepthState(ref context, ref viewProjMatrix, cascadeIndex);
world.RenderObjectProvider.Draw(ref context, ref camera, true);
var texScaleBias = new Matrix
{
Row1 = new SharpDX.Vector4(0.5f, 0.0f, 0.0f, 0.0f),
Row2 = new SharpDX.Vector4(0.0f, -0.5f, 0.0f, 0.0f),
Row3 = new SharpDX.Vector4(0.0f, 0.0f, 1.0f, 0.0f),
Row4 = new SharpDX.Vector4(0.5f, 0.5f, 0.0f, 1.0f)
};
Matrix.Multiply(ref viewProjMatrix, ref texScaleBias, out viewProjMatrix);
var clipNear = camera.ClipNear;
var clipFar = camera.ClipFar;
var clipDist = clipFar - clipNear;
ReceiverConstants.Data.CascadeSplits[cascadeIndex] = clipNear + splitDist * clipDist;
Matrix invCascadeMatrix;
Matrix.Invert(ref viewProjMatrix, out invCascadeMatrix);
var zero = DxVector3.Zero;
DxVector3 cascadeCorner;
DxVector3.TransformCoordinate(ref zero, ref invCascadeMatrix, out cascadeCorner);
DxVector3.TransformCoordinate(ref cascadeCorner, ref ReceiverConstants.Data.ShadowMatrix,
out cascadeCorner);
var one = DxVector3.One;
DxVector3 otherCorner;
DxVector3.TransformCoordinate(ref one, ref invCascadeMatrix, out otherCorner);
DxVector3.TransformCoordinate(ref otherCorner, ref ReceiverConstants.Data.ShadowMatrix, out otherCorner);
var cascadeScale = DxVector3.One / (otherCorner - cascadeCorner);
ReceiverConstants.Data.CascadeOffsets[cascadeIndex] = new DxVector4(-cascadeCorner, 0.0f);
ReceiverConstants.Data.CascadeScales[cascadeIndex] = new DxVector4(cascadeScale, 1.0f);
if (RenderSettings.UseFilterableShadows)
ConvertToVsm(ref context, cascadeIndex,
ref ReceiverConstants.Data.CascadeSplits[cascadeIndex],
ref ReceiverConstants.Data.CascadeScales[0]);
}
PixHelper.EndEvent();
}
}
PixHelper.EndEvent();
DataStream stream;
context.MapSubresource(ReceiverConstants.Buffer, MapMode.WriteDiscard, MapFlags.None, out stream);
stream.Write(ReceiverConstants.Data.ShadowMatrix);
stream.WriteRange(ReceiverConstants.Data.CascadeSplits, 0, 4);
stream.WriteRange(ReceiverConstants.Data.CascadeOffsets, 0, 4);
stream.WriteRange(ReceiverConstants.Data.CascadeScales, 0, 4);
stream.Write(ReceiverConstants.Data.ShadowDepthBias);
stream.Write(ReceiverConstants.Data.ShadowOffsetScale);
stream.Write(ReceiverConstants.Data.VisualizeCascades);
context.UnmapSubresource(ReceiverConstants.Buffer, 0);
//ReceiverConstants.Update(ref context);
}