protected override void CreateShadowMap(EntityLightShadow light)
{
// create the shadow map
var shadowMap = new ShadowMap
{
LightDirection = light.Light.LightDirection,
LightPosition = light.Entity.Transformation.Translation,
ShadowMapSize = light.Light.ShadowMapMaxSize,
ShadowNearDistance = light.Light.ShadowNearDistance,
ShadowFarDistance = light.Light.ShadowFarDistance,
CascadeCount = light.Light.Type == LightType.Directional ? light.Light.ShadowMapCascadeCount : 1, // cascades are only supported for directional shadow maps
LightType = light.Light.Type,
Fov = light.Light.SpotFieldAngle,
Filter = light.Light.ShadowMapFilterType,
Layers = light.Light.Layers
};
// find or create the shadow map texture
ShadowMapTexture chosenTexture = null;
chosenTexture = AllocateOrChooseTexture(shadowMap, light.Light.ShadowMapFilterType == ShadowMapFilterType.Variance ? texturesVsm : texturesDefault);
shadowMap.Texture = chosenTexture;
InternalShadowMaps.Add(shadowMap);
light.ShadowMap = shadowMap;
}
private ShadowMapTexture AllocateOrChooseTexture(ShadowMap newShadowMap, Dictionary <ShadowMapTexture, List <ShadowMap> > shadowMapTextures)
{
ShadowMapTexture chosenTexture = null;
// find best texture
foreach (var shadowMapTexture in shadowMapTextures)
{
var shadowTexture = shadowMapTexture.Key;
var shadowMaps = shadowMapTexture.Value;
shadowTexture.GuillotinePacker.Clear(shadowTexture.ShadowMapDepthTexture.Width, shadowTexture.ShadowMapDepthTexture.Height);
var useShadowTexture = true;
for (var i = 0; i < shadowMaps.Count && useShadowTexture; ++i)
{
useShadowTexture = shadowTexture.GuillotinePacker.TryInsert(shadowMaps[i].ShadowMapSize, shadowMaps[i].ShadowMapSize, shadowMaps[i].CascadeCount);
}
useShadowTexture = useShadowTexture && shadowTexture.GuillotinePacker.TryInsert(newShadowMap.ShadowMapSize, newShadowMap.ShadowMapSize, newShadowMap.CascadeCount);
shadowTexture.GuillotinePacker.Clear();
if (useShadowTexture)
{
chosenTexture = shadowMapTexture.Key;
break;
}
}
if (chosenTexture == null)
{
// allocate a new texture
chosenTexture = new ShadowMapTexture(GraphicsDevice, newShadowMap.Filter, 2048);
chosenTexture.GuillotinePacker.Clear(chosenTexture.ShadowMapDepthTexture.Width, chosenTexture.ShadowMapDepthTexture.Height);
// TODO: choose texture size based on the shadow map. For now throw exception
if (!chosenTexture.GuillotinePacker.TryInsert(newShadowMap.ShadowMapSize, newShadowMap.ShadowMapSize, newShadowMap.CascadeCount))
{
var message = new StringBuilder();
message.AppendFormat("Unable to allocate shadow map texture. The default size (2048 x 2048) is too small for the shadow map ({0} cascade(s) with size {1}).", newShadowMap.CascadeCount, newShadowMap.ShadowMapSize);
throw new Exception(message.ToString());
}
chosenTexture.GuillotinePacker.Clear();
InternalShadowMapTextures.Add(chosenTexture);
var shadowMaps = new List <ShadowMap> {
newShadowMap
};
shadowMapTextures.Add(chosenTexture, shadowMaps);
}
else
{
shadowMapTextures[chosenTexture].Add(newShadowMap);
}
return(chosenTexture);
}
/// <summary>
/// Adds the shadow map texture to the budget of textures.
/// </summary>
/// <param name="shadowMapTexture">The shadow map texture.</param>
/// <param name="filterType">The filtering that will be applied to this shadow.</param>
protected void AddShadowMapTexture(ShadowMapTexture shadowMapTexture, ShadowMapFilterType filterType)
{
if (filterType == ShadowMapFilterType.Variance)
{
texturesVsm.Add(shadowMapTexture, shadowMapTexture.ShadowMapDepthTexture.Width * shadowMapTexture.ShadowMapDepthTexture.Height);
shadowMapVsmTextures.Add(shadowMapTexture);
}
else
{
texturesDefault.Add(shadowMapTexture, shadowMapTexture.ShadowMapDepthTexture.Width * shadowMapTexture.ShadowMapDepthTexture.Height);
shadowMapDefaultTextures.Add(shadowMapTexture);
}
InternalShadowMapTextures.Add(shadowMapTexture);
}
private int ShadowMapTextureComparerVsm(ShadowMapTexture texture0, ShadowMapTexture texture1)
{
return(texturesVsm[texture0] - texturesVsm[texture1]);
}
private int ShadowMapTextureComparerDefault(ShadowMapTexture texture0, ShadowMapTexture texture1)
{
return(texturesDefault[texture0] - texturesDefault[texture1]);
}