#region File Description
#endregion
#region Using Statements
using System;
#endregion
namespace Microsoft.Xna.Framework.Graphics
{
/// <summary>
/// Built-in effect that supports environment mapping.
/// </summary>
public class EnvironmentMapEffect : Effect, IEffectMatrices, IEffectLights, IEffectFog
{
#region Effect Parameters
EffectParameter textureParam;
EffectParameter environmentMapParam;
EffectParameter environmentMapAmountParam;
EffectParameter environmentMapSpecularParam;
EffectParameter fresnelFactorParam;
EffectParameter diffuseColorParam;
EffectParameter emissiveColorParam;
EffectParameter eyePositionParam;
EffectParameter fogColorParam;
EffectParameter fogVectorParam;
EffectParameter worldParam;
EffectParameter worldInverseTransposeParam;
EffectParameter worldViewProjParam;
EffectParameter shaderIndexParam;
#endregion
#region Fields
bool oneLight;
bool fogEnabled;
bool fresnelEnabled;
bool specularEnabled;
Matrix world = Matrix.Identity;
Matrix view = Matrix.Identity;
Matrix projection = Matrix.Identity;
Matrix worldView;
Vector3 diffuseColor = Vector3.One;
Vector3 emissiveColor = Vector3.Zero;
Vector3 ambientLightColor = Vector3.Zero;
float alpha = 1;
DirectionalLight light0;
DirectionalLight light1;
DirectionalLight light2;
float fogStart = 0;
float fogEnd = 1;
EffectDirtyFlags dirtyFlags = EffectDirtyFlags.All;
#endregion
#region Public Properties
/// <summary>
/// Gets or sets the world matrix.
/// </summary>
public Matrix World
{
get { return world; }
set
{
world = value;
dirtyFlags |= EffectDirtyFlags.World | EffectDirtyFlags.WorldViewProj | EffectDirtyFlags.Fog;
}
}
/// <summary>
/// Gets or sets the view matrix.
/// </summary>
public Matrix View
{
get { return view; }
set
{
view = value;
dirtyFlags |= EffectDirtyFlags.WorldViewProj | EffectDirtyFlags.EyePosition | EffectDirtyFlags.Fog;
}
}
/// <summary>
/// Gets or sets the projection matrix.
/// </summary>
public Matrix Projection
{
get { return projection; }
set
{
projection = value;
dirtyFlags |= EffectDirtyFlags.WorldViewProj;
}
}
/// <summary>
/// Gets or sets the material diffuse color (range 0 to 1).
/// </summary>
public Vector3 DiffuseColor
{
get { return diffuseColor; }
set
{
diffuseColor = value;
dirtyFlags |= EffectDirtyFlags.MaterialColor;
}
}
/// <summary>
/// Gets or sets the material emissive color (range 0 to 1).
/// </summary>
public Vector3 EmissiveColor
{
get { return emissiveColor; }
set
{
emissiveColor = value;
dirtyFlags |= EffectDirtyFlags.MaterialColor;
}
}
/// <summary>
/// Gets or sets the material alpha.
/// </summary>
public float Alpha
{
get { return alpha; }
set
{
alpha = value;
dirtyFlags |= EffectDirtyFlags.MaterialColor;
}
}
/// <summary>
/// Gets or sets the ambient light color (range 0 to 1).
/// </summary>
public Vector3 AmbientLightColor
{
get { return ambientLightColor; }
set
{
ambientLightColor = value;
dirtyFlags |= EffectDirtyFlags.MaterialColor;
}
}
/// <summary>
/// Gets the first directional light.
/// </summary>
public DirectionalLight DirectionalLight0 { get { return light0; } }
/// <summary>
/// Gets the second directional light.
/// </summary>
public DirectionalLight DirectionalLight1 { get { return light1; } }
/// <summary>
/// Gets the third directional light.
/// </summary>
public DirectionalLight DirectionalLight2 { get { return light2; } }
/// <summary>
/// Gets or sets the fog enable flag.
/// </summary>
public bool FogEnabled
{
get { return fogEnabled; }
set
{
if (fogEnabled != value)
{
fogEnabled = value;
dirtyFlags |= EffectDirtyFlags.ShaderIndex | EffectDirtyFlags.FogEnable;
}
}
}
/// <summary>
/// Gets or sets the fog start distance.
/// </summary>
public float FogStart
{
get { return fogStart; }
set
{
fogStart = value;
dirtyFlags |= EffectDirtyFlags.Fog;
}
}
/// <summary>
/// Gets or sets the fog end distance.
/// </summary>
public float FogEnd
{
get { return fogEnd; }
set
{
fogEnd = value;
dirtyFlags |= EffectDirtyFlags.Fog;
}
}
/// <summary>
/// Gets or sets the fog color.
/// </summary>
public Vector3 FogColor
{
get { return fogColorParam.GetValueVector3(); }
set { fogColorParam.SetValue(value); }
}
/// <summary>
/// Gets or sets the current texture.
/// </summary>
public Texture2D Texture
{
get { return textureParam.GetValueTexture2D(); }
set { textureParam.SetValue(value); }
}
/// <summary>
/// Gets or sets the current environment map texture.
/// </summary>
public TextureCube EnvironmentMap
{
get { return environmentMapParam.GetValueTextureCube(); }
set { environmentMapParam.SetValue(value); }
}
/// <summary>
/// Gets or sets the amount of the environment map RGB that will be blended over
/// the base texture. Range 0 to 1, default 1. If set to zero, the RGB channels
/// of the environment map will completely ignored (but the environment map alpha
/// may still be visible if EnvironmentMapSpecular is greater than zero).
/// </summary>
public float EnvironmentMapAmount
{
get { return environmentMapAmountParam.GetValueSingle(); }
set { environmentMapAmountParam.SetValue(value); }
}
/// <summary>
/// Gets or sets the amount of the environment map alpha channel that will
/// be added to the base texture. Range 0 to 1, default 0. This can be used
/// to implement cheap specular lighting, by encoding one or more specular
/// highlight patterns into the environment map alpha channel, then setting
/// EnvironmentMapSpecular to the desired specular light color.
/// </summary>
public Vector3 EnvironmentMapSpecular
{
get { return environmentMapSpecularParam.GetValueVector3(); }
set
{
environmentMapSpecularParam.SetValue(value);
bool enabled = (value != Vector3.Zero);
if (specularEnabled != enabled)
{
specularEnabled = enabled;
dirtyFlags |= EffectDirtyFlags.ShaderIndex;
}
}
}
/// <summary>
/// Gets or sets the Fresnel factor used for the environment map blending.
/// Higher values make the environment map only visible around the silhouette
/// edges of the object, while lower values make it visible everywhere.
/// Setting this property to 0 disables Fresnel entirely, making the
/// environment map equally visible regardless of view angle. The default is
/// 1. Fresnel only affects the environment map RGB (the intensity of which is
/// controlled by EnvironmentMapAmount). The alpha contribution (controlled by
/// EnvironmentMapSpecular) is not affected by the Fresnel setting.
/// </summary>
public float FresnelFactor
{
get { return fresnelFactorParam.GetValueSingle(); }
set
{
fresnelFactorParam.SetValue(value);
bool enabled = (value != 0);
if (fresnelEnabled != enabled)
{
fresnelEnabled = enabled;
dirtyFlags |= EffectDirtyFlags.ShaderIndex;
}
}
}
/// <summary>
/// This effect requires lighting, so we explicitly implement
/// IEffectLights.LightingEnabled, and do not allow turning it off.
/// </summary>
bool IEffectLights.LightingEnabled
{
get { return true; }
set { if (!value) throw new NotSupportedException("EnvironmentMapEffect does not support setting LightingEnabled to false."); }
}
#endregion
#region Methods
/// <summary>
/// Creates a new EnvironmentMapEffect with default parameter settings.
/// </summary>
public EnvironmentMapEffect(GraphicsDevice device)
: base(device, Resources.EnvironmentMapEffect)
{
CacheEffectParameters(null);
DirectionalLight0.Enabled = true;
EnvironmentMapAmount = 1;
EnvironmentMapSpecular = Vector3.Zero;
FresnelFactor = 1;
}
/// <summary>
/// Creates a new EnvironmentMapEffect by cloning parameter settings from an existing instance.
/// </summary>
protected EnvironmentMapEffect(EnvironmentMapEffect cloneSource)
: base(cloneSource)
{
CacheEffectParameters(cloneSource);
fogEnabled = cloneSource.fogEnabled;
fresnelEnabled = cloneSource.fresnelEnabled;
specularEnabled = cloneSource.specularEnabled;
world = cloneSource.world;
view = cloneSource.view;
projection = cloneSource.projection;
diffuseColor = cloneSource.diffuseColor;
emissiveColor = cloneSource.emissiveColor;
ambientLightColor = cloneSource.ambientLightColor;
alpha = cloneSource.alpha;
fogStart = cloneSource.fogStart;
fogEnd = cloneSource.fogEnd;
}
/// <summary>
/// Creates a clone of the current EnvironmentMapEffect instance.
/// </summary>
public override Effect Clone()
{
return new EnvironmentMapEffect(this);
}
/// <summary>
/// Sets up the standard key/fill/back lighting rig.
/// </summary>
public void EnableDefaultLighting()
{
AmbientLightColor = EffectHelpers.EnableDefaultLighting(light0, light1, light2);
}
/// <summary>
/// Looks up shortcut references to our effect parameters.
/// </summary>
void CacheEffectParameters(EnvironmentMapEffect cloneSource)
{
textureParam = Parameters["Texture"];
environmentMapParam = Parameters["EnvironmentMap"];
environmentMapAmountParam = Parameters["EnvironmentMapAmount"];
environmentMapSpecularParam = Parameters["EnvironmentMapSpecular"];
fresnelFactorParam = Parameters["FresnelFactor"];
diffuseColorParam = Parameters["DiffuseColor"];
emissiveColorParam = Parameters["EmissiveColor"];
eyePositionParam = Parameters["EyePosition"];
fogColorParam = Parameters["FogColor"];
fogVectorParam = Parameters["FogVector"];
worldParam = Parameters["World"];
worldInverseTransposeParam = Parameters["WorldInverseTranspose"];
worldViewProjParam = Parameters["WorldViewProj"];
shaderIndexParam = Parameters["ShaderIndex"];
light0 = new DirectionalLight(Parameters["DirLight0Direction"],
Parameters["DirLight0DiffuseColor"],
null,
(cloneSource != null) ? cloneSource.light0 : null);
light1 = new DirectionalLight(Parameters["DirLight1Direction"],
Parameters["DirLight1DiffuseColor"],
null,
(cloneSource != null) ? cloneSource.light1 : null);
light2 = new DirectionalLight(Parameters["DirLight2Direction"],
Parameters["DirLight2DiffuseColor"],
null,
(cloneSource != null) ? cloneSource.light2 : null);
}
/// <summary>
/// Lazily computes derived parameter values immediately before applying the effect.
/// </summary>
protected internal override void OnApply()
{
dirtyFlags = EffectHelpers.SetWorldViewProjAndFog(dirtyFlags, ref world, ref view, ref projection, ref worldView, fogEnabled, fogStart, fogEnd, worldViewProjParam, fogVectorParam);
dirtyFlags = EffectHelpers.SetLightingMatrices(dirtyFlags, ref world, ref view, worldParam, worldInverseTransposeParam, eyePositionParam);
if ((dirtyFlags & EffectDirtyFlags.MaterialColor) != 0)
{
EffectHelpers.SetMaterialColor(true, alpha, ref diffuseColor, ref emissiveColor, ref ambientLightColor, diffuseColorParam, emissiveColorParam);
dirtyFlags &= ~EffectDirtyFlags.MaterialColor;
}
bool newOneLight = !light1.Enabled && !light2.Enabled;
if (oneLight != newOneLight)
{
oneLight = newOneLight;
dirtyFlags |= EffectDirtyFlags.ShaderIndex;
}
if ((dirtyFlags & EffectDirtyFlags.ShaderIndex) != 0)
{
int shaderIndex = 0;
if (!fogEnabled)
shaderIndex += 1;
if (fresnelEnabled)
shaderIndex += 2;
if (specularEnabled)
shaderIndex += 4;
if (oneLight)
shaderIndex += 8;
shaderIndexParam.SetValue(shaderIndex);
dirtyFlags &= ~EffectDirtyFlags.ShaderIndex;
}
}
#endregion
}
}
