void DiFocusedShadowPolicy::calculateB(const DiSceneManager& sm, const DiCamera& cam,
const DiLight& light, const DiAABB& sceneBB, const DiAABB& receiverBB,
PointListBody *out_bodyB) const
{
DI_ASSERT_MESSAGE(out_bodyB != NULL, "bodyB vertex list is NULL");
/// perform convex intersection of the form B = ((V \cap S) + l) \cap S \cap L
// get V
mBodyB.define(cam);
if (light.GetType() != LIGHT_DIRECTIONAL)
{
if (mUseAggressiveRegion)
mBodyB.clip(sceneBB);
// form a convex hull of bodyB with the light position
mBodyB.extend(light.GetDerivedPosition());
// clip bodyB with sceneBB
mBodyB.clip(sceneBB);
// clip with the light frustum
// set up light camera to clip with the resulting frustum planes
if (!mLightFrustumCameraCalculated)
{
calculateShadowMappingMatrix(sm, cam, light, NULL, NULL, mLightFrustumCamera);
mLightFrustumCameraCalculated = true;
}
mBodyB.clip(*mLightFrustumCamera);
// extract bodyB vertices
out_bodyB->build(mBodyB);
}
else
{
// For directional lights, all we care about is projecting the receivers
// backwards towards the light, clipped by the camera region
mBodyB.clip(receiverBB);
// Also clip based on shadow far distance if appropriate
float farDist = sm.GetShadowFarDistance();
if (farDist)
{
DiVec3 pointOnPlane = cam.GetDerivedPosition() +
(cam.GetDerivedDirection() * farDist);
DiPlane p(cam.GetDerivedDirection(), pointOnPlane);
mBodyB.clip(p);
}
// Extrude the intersection bodyB into the inverted light direction and store
// the info in the point list.
// Maximum extrusion extent is to the shadow far distance
out_bodyB->buildAndIncludeDirection(mBodyB,
farDist ? farDist : cam.GetNearClipDistance() * 3000,
-light.GetDerivedDirection());
}
}
void DiFocusedShadowPolicy::calculateShadowMappingMatrix(const DiSceneManager& sm,
const DiCamera& cam, const DiLight& light, DiMat4 *out_view, DiMat4 *out_proj,
DiCamera *out_cam) const
{
DiVec3 lightPos = light.GetDerivedPosition();
DiVec3 lightDir = light.GetDerivedDirection();
// get the shadow frustum's far distance
float shadowDist = sm.GetShadowFarDistance();
if (!shadowDist)
{
// need a shadow distance, make one up
shadowDist = cam.GetNearClipDistance() * 3000;
}
float shadowOffset = shadowDist * sm.GetShadowDirLightTextureOffset();
if (light.GetType() == LIGHT_DIRECTIONAL)
{
// generate view matrix if requested
if (out_view != NULL)
{
DiVec3 pos;
#if 0
if (sm.getCameraRelativeRendering())
{
pos = DiVec3::ZERO;
}
else
#endif
{
pos = cam.GetDerivedPosition();
}
*out_view = buildViewMatrix(pos,
lightDir,
cam.GetDerivedUp());
}
// generate projection matrix if requested
if (out_proj != NULL)
{
*out_proj = DiMat4::getScale(1, 1, -1);
//*out_proj = DiMat4::IDENTITY;
}
// set up camera if requested
if (out_cam != NULL)
{
out_cam->SetProjectionType(PT_ORTHOGRAPHIC);
out_cam->SetDirection(lightDir);
out_cam->SetPosition(cam.GetDerivedPosition());
out_cam->SetFOVy(DiDegree(90));
out_cam->SetNearClipDistance(shadowOffset);
}
}
else if (light.GetType() == LIGHT_SPOT)
{
const DiSpotLight* spot = static_cast<const DiSpotLight*>(&light);
// generate view matrix if requested
if (out_view != NULL)
{
*out_view = buildViewMatrix(light.GetDerivedPosition(),
light.GetDerivedDirection(),
cam.GetDerivedUp());
}
// generate projection matrix if requested
if (out_proj != NULL)
{
// set FOV slightly larger than spotlight range
mTempFrustum->SetFOVy(DiMath::Clamp<DiRadian>(spot->GetOuterAngle() * 1.2, DiRadian(0), DiRadian(DiMath::PI/2.0f)));
mTempFrustum->SetNearClipDistance(light.DeriveShadowNearClipDistance(&cam));
mTempFrustum->SetFarClipDistance(light.DeriveShadowFarClipDistance(&cam));
*out_proj = mTempFrustum->GetProjectionMatrix();
}
// set up camera if requested
if (out_cam != NULL)
{
out_cam->SetProjectionType(PT_PERSPECTIVE);
out_cam->SetDirection(light.GetDerivedDirection());
out_cam->SetPosition(light.GetDerivedPosition());
out_cam->SetFOVy(DiMath::Clamp<DiRadian>(spot->GetOuterAngle() * 1.2, DiRadian(0), DiRadian(DiMath::PI/2.0f)));
out_cam->SetNearClipDistance(light.DeriveShadowNearClipDistance(&cam));
out_cam->SetFarClipDistance(light.DeriveShadowFarClipDistance(&cam));
}
}
#if 0
else if (light.GetType() == LIGHT_POINT)
{
// target analogue to the default shadow textures
// Calculate look at position
// We want to look at a spot shadowOffset away from near plane
// 0.5 is a little too close for angles
DiVec3 target = cam.GetDerivedPosition() +
(cam.GetDerivedDirection() * shadowOffset);
lightDir = target - lightPos;
lightDir.normalise();
// generate view matrix if requested
if (out_view != NULL)
{
*out_view = buildViewMatrix(lightPos,
lightDir,
cam.GetDerivedUp());
}
// generate projection matrix if requested
if (out_proj)
{
// set FOV to 120 degrees
mTempFrustum->SetFOVy(DiDegree(120));
mTempFrustum->SetNearClipDistance(light._deriveShadowNearClipDistance(&cam));
mTempFrustum->SetFarClipDistance(light._deriveShadowFarClipDistance(&cam));
*out_proj = mTempFrustum->GetProjectionMatrix();
}
// set up camera if requested
if (out_cam)
{
out_cam->SetProjectionType(PT_PERSPECTIVE);
out_cam->SetDirection(lightDir);
out_cam->SetPosition(lightPos);
out_cam->SetFOVy(DiDegree(120));
out_cam->SetNearClipDistance(light._deriveShadowNearClipDistance(&cam));
out_cam->SetFarClipDistance(light._deriveShadowFarClipDistance(&cam));
}
}
#endif
}